0 0 6 ' AO
/
PROCEEDINGS
OF THE
National Academy
of Sciences
OF THE UNITED STATES OF AMERICA
VOLUME 4, 1918
if \ A
EDITORIAL BOARD
Raymond Pearl, Chairman Edwin B. Wilson, Managing Editor
Arthur L. Day, Home Secretary
George E. Hale, Foreign Secretary
J. J. Abel
J. M. Clarke
H. H. Donaldson
E. B. Frost
R. A. Harper
J. P. Iddings
Jacques Loeb
Graham Lusk
A. G. Mayor
R. A. Millikan
E. H. Moore
A. A. No yes
Alexander Smith
E. L. Thorndike
W. M. Wheeler
Publication Office: Williams & Wilkins Company, Baltimore
Editorial Office: Massachusetts Institute of Technology, Cambridge
Home Office of the Academy : Washington, D. C.
CONTENTS
PAGE
Officers and Members of the Academy vii
Notices of Biographical Memoirs 54
Report of the Annual Meeting, April, 1918 261
Award of Medals 273
Research Grants from the Trust Funds of the Academy 273
Index 419
NATIONAL RESEARCH COUNCIL
Report of the Committee on Anthropology 52
Meetings of the Executive Committee 76
Minutes of Executive Board of War Organization 122
Executive Order Issued by the President of the United States, May 11, 1918. . 251
Minutes of the Second Meeting of the Executive Board of the War Organi-
zation in Joint Session with the Council of the National Academy of
Sciences 252
Minutes of Third Meeting of Executive Board of War Organization 256
Minutes of the Meeting of the Executive Board 397, 405
Minutes of Joint Meeting of the Executive Board and the Council of the
National Academy of Sctences 410
Minutes of the Meeting of the Executive Board 414
MATHEMATICS
Invariants which are Functions of Parameters of the Transformation
By Oliver E. Glenn 145
On the Representation of a Number as the Sum of any Number of Squares
and in Particular of Five or Seven By G. H. Hardy 189
Arithmetical Theory of Certain Hurwitzian Continued Fractions
By D. N. Lehmer 214
On Closed Curves Described by a Spherical Pendulum By Arnold Emch 218
On the ck-Holomorphisms of a Group By G. A. Miller 293
Invariants and Canonical Forms By E. J. Wilczynski 300
On Certain Projective Generalizations of Metric Theorems, and the Curves
of Darboux and Segre By Gabriel M. Green 346
On Jacobi's Extension of the Continued Fraction Algorithm. . .By D. N. Lehmer 360
A Characterization of Jordan Regions by Properties Having No Reference to
their Boundaries By Robert L. Moore 364
ASTRONOMY
The Location of the Sun's Magnetic Axis
By F. H. Seares, A. van Maanen, and F. Ellerman 4
The Rotation and Radial Velocity of the Central Part of the Andromeda
Nebula By F.G. Pease 21
A Determination of the Solar Motion and the Stream Motion Based on Radial
Velocities and Absolute Magnitudes By Gustaf Str timber g 36
Dependence of the Spectral Relation of Double Stars upon Distance
By C. D. Perrine 71
iii
iv
CONTENTS
Hypothesis to Account for the Spectral Conditions of the Stars
By C. D. Perrine 75
Some Spectral Characteristics of Cephetd Variables
By W. S. Adams and A. H. Joy 129
A Study of the Motions of Forty-eight Double Stars By Eric Doolittle 137
Studies of Magnitudes in Star Clusters, VIII. A Summary of Results Bearing
on the Structure of the Sidereal Universe By Harlow Shapley 224
The Smithsonian 'Solar Constant' Expedition to Calama, Chile. .By C. G. Abbot 313
The Absorption Spectrum of the Novae ByW.S. Adams 354
The Distances of Six Planetary Nebulae By Adriaan van Maanen 394
PHYSICS AND ENGINEERING
Resonance and Ionization Potentials for Electrons in Cadmium, Zinc, and
Potassium Vapors By John T. Tate and Paul D. Foote 9
The Validity of the Equation P = T dv/dT in Thermo-Electricity
By Edwin H. Hall 11
On the Equations of the Rectangular Interferometer By Carl Bar us 13
Thermo-Electric Diagrams on the P-V-Plane By Edwin H. Hall 29
Is a Moving Star Retarded by the Reaction of Its Own Radiation?
By Leigh Page 47
On Electromagnetic Induction and Relative Motion. II By S. J. Barnett 49
The Resolving Powers of X-Ray Spectrometers and the Tungsten X-Ray
Spectrum , By Elmer Dershem 62
Note on Methods of Observing Potential Differences Induced by the Earth's
Magnetic Field in an Insulated Moving Wire
By Carl Barus and Maxwell Barus 66
Mobilities of Ions in Air, Hydrogen, and Nitrogen By Kia-Lok Yen 91
Thermo-Electric Action with Dual Conduction of Electricity
By Edwin H. Hall 98
Terrestrial Temperature and Atmospheric Absorption By C. G. Abbot 104
Mobilities of Ions in Vapors By Kia-Lok Yen 106
Types of Achromatic Fringes By Carl Barus 132
Interference of Pencils Which Constitute the Remote Divergences from a
Slit , By Carl Barus 134
The Structure of an Electromagnetic Field By H. Bateman 140
The Crystal Structure of Ice By Ancel St. John 193
On the Correction of Optical Surfaces By A. A. Michelson 210
The Depth of the Effective Plane in X-Ray Crystal Penetration
By F. C. Blake 236
Thermo-Electric Action with Thermal Effusion in Metals: A Correction
By Edwin H. Hall 297
Types of Phosphorescence By Edward L. Nichols and H. L. Howes 305
The Interferometry of Vibrating Systems By Carl Barus 328
On the Essence of Physical Relativity By Sir Joseph Larmor 334
Gravitational Attraction in Connection with the Rectangular Interferometer
By Carl Barus 338
The General Character of Specific Heats at High Temperatures
By Walter P. White 343
The Rectangular Interferometer with Achromatic Displacement Fringes in
Connection with the Horizontal Pendulum By Carl Barus 349
CONTENTS
v
CHEMISTRY
The Heat Capacity of Electro-Positive Metals and the Thermal Energy of
Free Electrons By Gilbert N. Lewis, E. D. Eastman and W. H. Rodebush 25
Notes on Isotopic Lead By Frank Wigglesworth Clarke 181
Refractive Index and Solubilities of the Nitrates of Lead Isotopes
By Theodore W. Richards and Walter C. Schumb 386
The Purification by Sublimation and the Analysis of Gallium Chloride
By Theodore W. Richards, W. M. Craig, and J. Sameshima 387
The Purification of Gallium by Electrolysis, and the Compressibility and
Density of Gallium By Theodore W. Richards and Sylvester Boyer 388
GEOLOGY AND PALEONTOLOGY
The Study of the Sediments as an Aid to the Earth Historian
By Eliot Blackwelder 163
Fringing Reefs of the Philippine Islands By W. M. Davis 197
Glacial Depression and Post-Glacial Uplift of Northeastern America
By H. L. Fair child 229
Metalliferous Laterite in New Caledonia By W. M. Davis 21 S
The Importance of Nivation as an Erosive Factor, and of Soil Flow as a Trans-
porting Agency, in Northern Greenland ByW. Elmer Ekblaw 288
The Phylogeny of the Acorn Barnacles By Rudolf Ruedemann 382
Possible Derivation of the Lepadid Barnacles from the Phyllopods
By John M. Clarke 384
MINERALOGY AND PETROLOGY
A Contribution to the Petrography of the South Sea Islands
By J. P. Iddings and E. W. Morley 110
Tests for Fluorine and Tin in Meteorites with Notes on Maskelynite and
the Effect of Dry Heat on Meteoric Stones By George P. Merrill 176
BOTANY
Dynamical Aspects of Photosynthesis By W.J. V. Osterhout and A.R.C. Haas 85
The Taxonomic Position of the Genus Actinomyces By Charles Drechsler 221
A Bacteriological Study of the Soil of Loggerhead Key, Tortugas, Florida
By C. B. Lipman and D. D. Way nick 232
ZOOLOGY
The Reactions of the Melanophores of Amiurus to Light and to Adrenalin
By A . W. L. Bray 58
Further Experiments on the Sex of Parthenogenetic Frogs.. By Jacques Loeb 60
Possible Action of the Sex-Determining Mechanism By C.E. McClung 160
The Growth of the Alaskan Fur Seal Herd Between 1912 and 1917
By G. H. Parker 168
Autonomous Responses of the Labial Palps of Anodonta By P. H. Cobb 234
The Myodome and Trigemino-Facialis Chamber of Fishes and the Correspond-
ing Cavities in Higher Vertebrates By Edward Phelps Allis, Jr. 241
Variation and Heredity During the Vegetative Reproduction of Arcella
Dentata By R.W Hegner 283
vi
CONTENTS
The 'Homing Habits' of the Pulmonate Mollusk Onchidium
By Leslie B. Arey and W. J. Crozier 319
Growth and Duration of Life of Chiton Tuberculatus By W.J. Crozier 322
Growth of Chiton Tuberculatus in Different Environments. .By W. J. Crozier 325
On the Method of Progression in Polyclads By W. J. Crozier 379
The Growth-Rate of Samoan Coral Reefs By Alfred G. Mayor 390
GENETICS
Disease Resistance in Cabbage By L. R. Jones 42
The Effect of Artificial Selection on Bristle Number in Drosophila Ampelo-
phila and its Interpretation By Fernandus Payne 55
Hereditary Tendency to Form Nerve Tumors By C. B. Davenport 213
The Effect of Inbreeding and Crossbreeding upon Development
By D. F. Jones 246
Maroon — A Recurrent Mutation in Drosophila By Calvin B. Bridges 316
Sex and Sex Intergrades in Cladocera By Authur M. Banta 373
PHYSIOLOGY AND PATHOLOGY
The Basal Katabolism of Cattle and Other Species
By Henry Prentiss Armsby, J. August Fries and Winfred Waite Braman 1
The Brain Weight in Relation to the Body Length and also the Partition of
Non-Protein Nitrogen, in the Brain of the Gray Snapper (Neomaenis
Griseus) By Shinkishi Hatai 19
The Law Controlling the Quantity and Rate of Regeneration
By Jacques Loeb 117
Effects of a Prolonged Reduction in Diet on 25 Men. I. Influence on Basal
Metabolism and Nitrogen Excretion By Francis G. Benedict and Paul Roth 149
Effects of a Prolonged Reduction in Diet on 25 Men. II. Bearing on Neuro-
muscular Processes and Mental Condition By Walter R. Miles 152
Effects of a Prolonged Reduction in Diet on 25 Men. III. Influence on
Efficiency During Muscular Work By H. Monmouth Smith 157
The Destruction of Tetanus Antitoxin by Chemical Agents
By W. N. Berg and R. A. Kelser 174
Dilation of the Great Arteries Distal to Parttally Occluding Bands
By William S. Halsted 204
A Comparison of Growth Changes in the Nervous System of the Rat with
Corresponding Changes in the Nervous System of Man
By Henry H. Donaldson 280
A Biometric Study of Human Basal Metabolism
H By J. Arthur Harris and Francis G. Benedict 370
ANTHROPOLOGY AND PSYCHOLOGY
Measuring the Mental Strength of an Army By Major Robert M. Yerkes 295
OFFICERS AND MEMBERS OF THE ACADEMY
NOVEMBER 20, 1918
OFFICERS OF THE ACADEMY
Charles D. Walcott, President
A. A. Michelson, Vice-President George E. Hale, Foreign Secretary
Whitman Cross, Treasurer C. G. Abbot, Acting Home Secretary
Additional Members of the Council
W. H. Howell E. G. Conklin R. H. Chittenden
C. G. Abbot A. A. Noyes M. I. Pupin
MEMBERS OF THE ACADEMY
Abbot, Charles Greeley Smithsonian Institution, Washington. D. C.
Abbot, Henry L., U. S. A.. 23 Berkeley St., Cambridge, Mass.
Abel, John Jacob Johns Hopkins University, Baltimore, Md.
Adams, Walter Sydney Solar Observatory Office, Pasadena, Cat.
Aitken, Robert Grant Lick Observatory, Mount Hamilton, Cal.
Allen, J. Asaph American Museum of Natural History, New York City.
Ames, Joseph S Johns Hopkins University, Baltimore, Md.
Atkinson, George Francis Cornell University, Ithaca, N. Y.
Bailey, Liberty Hyde Cornell University, Ithaca, N. Y.
Barnard, E. E Yerkes Observatory, Williams Bay, Wis,
Barus, Carl Brown University, Providence, R. I.
Baxter, Gregory Paul T. J. Coolidge, Jr. Mem. Lab., Cambridge, Mass.
Becker, George F U. S. Geological Survey, Washington, D. C.
Bell, A. Graham 1331 Connecticut Ave., Washington, D. C.
Benedict, Francis Gano Nutrition Laboratory, Bqston., Mass.
Birkhoff, George David Harvard University, Cambridge, Mass.
Bliss, Gilbert Ames University of Chicago, Chicago, III.
Boas, Franz Columbia University, New York City.
Bogert, Marston Taylor Columbia University, New York City.
Boltwood. B. B Yale University, New Haven, Conn.
Bolza, Oskar Reichsgrafenstr .10, Freiburg, Germany.
Branner, John C Stanford University, California.
Bridgman Percy Williams Harvard University, Cambridge, Mass.
Britton, Nathaniel Lord New York Botanical Gardens, New York City.
Bumstead, Henry Andrews Yale University, New Haven, Conn.
Campbell, D. H Stanford University, California.
Campbell, William W Lick Observatory, Mount Hamilton, California.
Cannon, Walter Bradford Harvard University, Cambridge, Mass.
Carty, John J. . : Am. Telegraph and Telephone Co., N. Y. City.
Castle, William Ernest 186 Payson Road, Belmont, Mass.
Cattell, James McK Garrison, N. Y.
Chamberlin, Thomas C University of Chicago, Chicago, III.
Chandler, Charles F Columbia University, New York City.
Chittenden, Russell H Sheffield Scientific School, New Haven, Conn.
Clarke, F. W U.S. Geological Survey, Washington, D. C.
vii
viii
OFFICERS AND MEMBERS
Clarke, J. M State Hall, Albany, N. Y.
Comstock, George C W ashburn Observatory , Madison, Wis.
Conklin, E. G Princeton, N. J.
Coulter, J. M University of Chicago, Chicago, III.
Councilman, William T Harvard Medical School, Boston, Mass.
Crew, Henry Northwestern University, Evanston, III.
Cross, Whitman U. S. Geological Survey, Washington, D. C.
Cushing, Harvey Harvard University, Cambridge, Mass.
Dall, William H Smithsonian Institution, Washington, D. C.
Dana, Edward S Yale University, New Haven, Conn.
Davenport, Charles B Cold Spring Harbor, N. Y.
Davis, William Morris 31 Hawthorn St., Cambridge, Mass.
Day, Arthur L .- Geophysical Laboratory, Washington, D. C.
Dewey, John Columbia University, New York City.
Dickson, Leonard E University of Chicago, Chicago, III.
Donaldson, Henry Herbert Wistar Institute of Anatomy, Philadelphia, Pa.
Durand, William Frederick 4227 4th St. and Missouri Avenue, Washington, D. C.
Elkin, William L Yale University Observatory, New Haven, Conn.
Farlow, W. G Harvard University, Cambridge, Mass.
Fewkes, Jesse Walter Bureau of American Ethnology, Washington, D. C.
Flexner, Simon Rockefeller Institute, New York City.
Folin, Otto Harvard Medical School, Boston, Mass.
Forbes, Stephen Alfred University of Illinois, Urbana, III.
Franklin, Edward Curtis Stanford University, California.
Freeman, John Ripley Providence, R. I.
Frost, Edwin B Yerkes Observatory, Williams Bay, Wis.
Gomberg, Moses University of Michigan, Ann Arbor, Mich.
Gooch, Frank A Yale University, New Haven, Conn.
Good ale, George L Harvard University, Cambridge, Mass.
Hale, George E Solar Observatory Office, Pasadena, Cal.
Hall, Edwin H Harvard University, Cambridge, Mass.
Hall, Granville Stanley Clark University, Worcester, Mass.
Halsted, William Stewart Johns Hopkins Medical School, Baltimore, Md.
Harper, R. A Columbia University, New York City.
Harrison, Ross G Yale University, New Haven, Conn.
Hastings, Charles S Yale University, New Haven, Conn.
Hayford, John F Northwestern University, Evanston, III.
Hektoen, Ludvig University of Chicago, Chicago, III.
Herrick, Charles Judson University of Chicago, Chicago, III.
Hillebrand, William F. Bureau of Standards, Washington, D. C.
Holmes, William H U.S. National Museum, Washington, D. C.
Howard, Leland Ossian U. S. Dept. of Agriculture, Washington, D. C.
Howe, Henry Marion Broad Brook Road, Bedford Hills, N. Y.
Howell, William H Johns Hopkins University, Baltimore, Md.
Iddings, Joseph P U.S. Geological Survey, Washington, D. C.
Jackson, Charles L 6 Boylston Hall, Cambridge, Mass.
Jennings, Herbert Spencer Johns Hopkins University, Baltimore, Md.
Jewett, Frank Baldwin Western Electric Co., New York, N. Y.
Jones, Walter Johns Hopkins University, Baltimore, Md.
Kasner, Edward Columbia University, New York City.
Kemp, James F Columbia University, New York City.
Langmuir, Irving General Electric Co., Schenectady, N. Y.
OFFICERS AND MEMBERS • ix
Leuschner, Armin O U niversity of California, Berkeley, Cal.
Levene, Phcebus Aaron Theodor Rockefeller Institute, New York City.
Lewis, Gilbert N University of California, Berkeley, Cal.
Lillie, Frank Rattray University of Chicago, Chicago, III.
Lindgren, Waldemar Massachusetts Institute of Technology, Cambridge, Mass.
Loeb, Jacoues Rockefeller Institute, New York City.
Lusk, Graham Cornell University Medical College, New York City.
Lyman, Theodore Harvard University, Cambridge, Mass.
Mark, Edward L 109 Irving St., Cambridge, Mass.
Mayor, Alfred Goldsborough Carnegie Institution, Maplewood, N. J.
Meltzer, Samuel James Rockefeller Institute, New York City.
Mendel, Lafayette B 262 Canner St., New Haven, Conn.
Mendenhall, Charles Ellwood University of Wisconsin, Madison, Wis.
Mendenhall, Thomas C 329 North Chestnut St., Ravenna, Ohio.
Merriam, C. Hart 1919 16th St., Washington, D. C.
Merriam, John Campbell University of California, Berkeley, Cal.
Merritt, Ernest Cornell University, Ithaca, N. Y.
Michael, Arthur 219 Parker St., Newton Center, Mass.
Michelson, Albert A University of Chicago, Chicago, III.
Millikan, Robert Andrews University of Chicago, Chicago, III.
Moore, Eliakim H University of Chicago, Chicago, III.
Morgan, T. H Columbia University, New York City.
Morley, Edward W West Hartford, Conn.
Morse, Edward S Salem, Mass.
Morse, Harmon N Johns Hopkins University, Baltimore, Md.
Moulton, F. R University of Chicago, Chicago, III.
Nichols, Edward L Cornell University, Ithaca, N. Y.
Nichols, Ernest F Yale University, New Haven, Conn.
No yes, Arthur A Massachusetts Institute of Technology, Cambridge, Mass.
No yes, William A University of Illinois, Urbana, III.
Osborn, H. F American Museum of Natural History, New York City
Osborne, T. B Agricultural Experiment Station, New Haven, Conn.
Osgood, William Fogg Harvard University, Cambridge, Mass.
Parker, George H 16 Berkeley St., Cambridge, Mass.
Pearl, Raymond Maine Agricultural Experiment Station, Orono, Me.
Pickering, Edward C Harvard College Observatory, Cambridge, Mass.
Pjpsson, Louis V 41 Trumbull St., New Haven, Conn.
Prudden, T. Mitchell Columbia University, New York City.
Pumpelly, Raphael Gibbs Ave., Newport, R. I.
Pupin, Michael I Columbia University, New York City.
Ransome, Frederick Leslie U.S. Geological Survey, Washington, D. C.
Redd, H. Fielding Johns Hopkins University, Baltimore, Md.
Remsen, Ira Johns Hopkins University, Baltimore, Md.
Richards, Theodore W Wolcott Gibbs Memorial Laboratory, Cambridge, Mass.
Rddgway, Robert U. S. National Museum, Washington, D. C.
Rosa, Edward B Bureau of Standards, Washington, D. C.
Russell, Henry Norris Princeton University, Princeton, N.J.
Sabine, Wallace C Harvard University, Cambridge, Mass.
Sargent, Charles S Arnold Arboretum, Jamaica Plain, Mass.
Schlesinger, Frank Allegheny Observatory, Allegheny, Pa.
Schuchert, Charles Yale University, New Haven, Conn.
Scott, William B Princeton University, Princeton, N. J.
X
OFFICERS AND MEMBERS
Smith, Alexander Columbia University, New York City.
Smith, Edgar F University of Pennsylvania, Philadelphia, Pa.
Smith, Erwin F Bureau of Plant Industry, Washington, D. C.
Smith, Theobald Princeton, N. J.
Stieglitz, Julius University of Chicago, Chicago, III.
Story, William E Clark University, Worcester, Mass.
Stratton, Samuel Wesley Bureau of Standards, Washington, D. C.
Taylor, David Watson. .Bureau of Construction and Repair, U. S. Navy, Washington, D. C.
Thaxter, Roland Harvard University, Cambridge, Mass.
Thomson, Ellhu. f Swampscott, Mass.
Thorndike, Edward Lee Columbia University, New York City.
Trelease, William University of Illinois, Urbana, III.
Trowbrldge, John Harvard University, Cambridge, Mass.
Ulrich, Edward Oscar U.S. Geological Survey, Washington, D. C.
Van Vleck, E..B University of Wisconsin, Madison, Wis.
Vaughan, Victor Clarence University of Michigan, Ann Arbor, Mich.
Verrill, A. E., 53 Ralston St., Whitneyville, Conn.
Walcott, Charles D Smithsonian Institution, Washington, D. C.
Webster, Arthur G Clark University, Worcester, Mass.
Welch, William H 807 St. Paul St., Baltimore, Md.
Wells, Horace L Yale University, New Haven, Conn.
Wheeler, William M Harvard University, Cambridge, Mass.
White, David U.S. Geological Survey, Washington, D. C.
White, Henry Seely Vassar College, Poughkeepsie, N. Y.
Whitney, Willis Rodney General Electric Co., Schenectady, N. Y.
Wilson, Edmund B Columbia University, New York City.
Wood, Horatio C 4107 Chester Ave., Philadelphia, Pa.
Wood, Robert W Johns Hopkins University, Baltimore, Md.
Woodward, Robert S Carnegie Institution, Washington, D. C.
Smith, Sidney I Yale University, New Haven, Conn.
Arrhenius, S. A
Barrois, Charles
BR0GGER, W. C
Crookes, Sir William
Deslandres, Henri
Dewar, Sir James
Fischer, Emil
Forsyth, A. R
Geikie, Sir Archibald
Groth, Paul von
Helm, Albert
Hilbert, David
Kapteyn, John C
Klein, Felix
Kossel, Albrecht
Kustner, Karl Friedrich
Lankester, Sir E. Ray. . .
L armor, Sir Joseph
FOREIGN ASSOCIATES
Univtersiteit, Goltingen.
.Rijks Universiteu, Groningen.
Universitdt, Gottingen.
Heidelberg.
Bonn.
. .South Kensington, London.
St. Johns College, Cambridge..
Nobelinstitut, Stockholm.
Universite, Lille.
Universitet, Christiania.
London.
Astrophysical Observatory, Meudon.
University, Cambridge.
; .Chemisches Institut der Universitdt, Berlin.
Imperial College of Science and Technology, London.
Haslemere, Surrey.
Universitdt, Munich.
Ziirich.
OFFICERS AND MEMBERS
xi
Lorentz, Hendrik Anton Rijks Universiteit, Leiden.
Ostwald, Welhelm Grossbothen, bei Leipsig
Pavlov, Ivan Petrovitch Institute for Experimental Medicine, Petrograd.
Penck, Albrecht \ .Universiidt, Berlin.
Pfeffer, Wilhelm Botanisches Institut der Universitdt, Leipziz.
Picard, Charles Smile Univer site, Paris.
Rayleigh, Lord University, Cambridge.
Retzius, Gustav Hogskolan, Stockholm.
Rutherford, Sir Ernest ■ University, Manchester.
Schuster, Arthur Secretary of the Royal Society, London.
Seeliger, Hugo Ritter von Universitdt, Munich.
Thomson, Sir Joseph University, Cambridge.
Volterra, Vito Universitd, Rome.
Vries, Hugo de U niversiteit, Amsterdam.
Waals, Johannes D. van der Amsterdam.
Waldeyer, Wilhelm Universitdt, Berlin.
Wolf, Max F. J. C Heidelberg.
Wundt, Wilhelm Universitdt, Leipzig.
VOLUME 4
JANUARY, 1918
NUMBER 1
PROCEEDINGS
OF THE
National Academy
of Sciences
OF THE
UNITED STATES OF AMERICA
EDITORIAL BOARD
Raymond Pearl, Chairman
Arthur L. Day, Home Secretary
Edwin B. Wilson, Managing Editor
George E. Hale, Foreign Secretary
J. J. Abel
j. M. Clarke
H. H. Donaldson
E. B. Frost
R. A. Harper
J. P. Iddings
Jacques Loeb
Graham Lusk
A. G. Mayer
R. A. Millie an
E. H. Moore
A. A. Noyes
Alexander Smith
E. L. Thorndike
W. M. Wheeler
Publication Office: Williams & Wilkins Company, Baltimore
Editorial Office: Massachusetts Institute of Technology, Cambridge
Home Office of the Academy: Washington, D. C.
Entered as second-class matter at the Post Office at Baltimore, Md., under the Act of August 24, 1912
INFORMATION TO CONTRIBUTORS
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Copyright, 1918, by the National Academy of Sciences
PROCEEDINGS
OF THE
NATIONAL ACADEMY OF SCIENCES
Volume 4 JANUARY 15, 1918 Number 1
THE BASAL KATABOLISM OF CATTLE AND OTHER SPECIES
By Henry Prentiss Armsby, J. August Fries and Winfred Waite
B RAMAN
Institute of Animal Nutrition, The Pennsylvania State College
Communicated by R. Pearl, December 13, 1917
The basal katabolism of herbivora and especially of ruminants, unlike that
of man or carnivora, cannot well be measured in the fasting state on account
of the relatively large amount of feed always present in the alimentary canal
of the former species. It may, however, be determined indirectly in the
manner described by the authors3,2,3 by measuring the total metabolism
upon two different amounts of the same ration and from these data computing
the level to which the metabolism would be reduced were all feed withdrawn.
For example, a steer receiving two different amounts of the same mixed ration ,
gave the following results:
DRY MATTER EATEN
DAILY
DAILY HEAT
PRODUCTION
Period 2
kgms.
9.146
4.463
calories
16,511
10,905
Period 1
Difference
4.683
5,606
Heat increment per kilogram of dry matter
1,197
Evidently, out of the total metabolism of 10905 Calories in Period 1, 1197
X 4.463 = 5342 Calories may be regarded as the heat production caused by
the 4.463 kgm. of dry matter eaten while the remainder, 5563 Calories is the
basal katabolism.
Our investigations upon the metabolism of cattle, which have been published
elsewhere3 afford data for computing in the manner just illustrated the basal
katabolism of ten unfattened steers in twenty-seven experiments. In view of
the very striking effect of standing in increasing the metabolism of cattle the
1
2
PHYSIOLOGY: ARMSBY, FRIES AND BRAMAN
basal katabolism per 24 hours has been computed separately from the observed
rate of heat production during the intervals of lying and standing, respectively,
and also for 12 hours standing and 12 hours lying per day, assumed as repre-
senting average conditions.
As was to be expected, the basal katabolism increased with the size of the
animal but with very considerable fluctuations. The graphs of the results
indicate an equally close relation of the basal katabolism with the weight and
with the two-thirds power of the weight (computed body surface) and this
conclusion is confirmed by a comparison of the coefficients of correlation as
follows:
Coefficients of correlation
WITH LIVE WEIGHT
WITH 2/3 POWER OF
LIVE WEIGHT
0.8655 ±0.0326
0.9032 ±0.0239
0.8733 ±0.0308
0.8710 ±0.0313
0.8548 ±0.0350
0.8250 ±0.0415
Computing the basal katabolism per square meter of body surface as esti-
mated by Moul ton's formulae4 viz.,
For unfattened animals S = 0.1186 W5/8
For fattened animals S = 0.158 W5/9
the following results were obtained.
Basal katabolism of cattle per square meter of body surface
LYING 24 HOURS
STANDING 12 HOURS
STANDING 24 HOURS
Mean, Calories
964.0
1173.0
1365.0
Probable error of mean, Calories
± 24.0
± 21.4
± 25.7
Probable error of single result, Calories . . .
±124.8
±110.9
±133.6
Standard deviation, Calories
185.1 ± 17.0
164.5 ± 15.1
198.0 ± 18.2
Coefficient of variability
0.1920
0.1462
0.1451
A positive correlation of the basal katabolism per square meter body sur-
face with the live weight was also found as follows:
Coefficients of correlation with live weight
Basal katabolism per square meter
Lying 24 hours 0.5375 ± 0.0923
Standing 12 hours 0.3666 ± 0.1124
Standing 24 hours 0.2405 ± 0.1223
The results show the marked influence of standing upon the metabolism of
cattle, the mean 24 hour basal katabolism lying, standing 12 hours and stand-
ing 24 hours being in the proportion of 100 : 121 : 141, the differences largely
exceeding the probable errors. Computing, from the results per square
PHYSIOLOGY: ARMSBY, FRIES AND B RAM AN
3
meter of surface, the basal katabolism for 12 hours standing and 12 hours
lying gives as the maintenance requirement for a 1000-pound steer 5918 ± 560
Calories.
The results for the basal katabolism of man reported by Benedict, Emmes,
Roth and Smith,5 and by Means6 present much the same picture as ours upon
cattle with the exception of a much lower variability.
Coefficients of correlation
WITH BODY WEIGHT
WITH BODY SURFACE
Total basal katabolism
98 men
0.7263 ± 0.0320
0.7759 ± 0.0310
0.7747 ± 0.0272
0.7447 ±0.0347
Daily basal katabolism of men and women per square meter of surface
MEN
WOMEN
Mean Calories
830.0
± 4.3
±42.3
62.7 ±3.0
1 0.0755
768.0
± 4.9
±42.8
63.5 ±3.1
0.0827
Probable error of mean, Calories
Probable error of single result, Calories
Standard deviation, Calories
Coefficient of variability
Correcting for the error shown by D. and E. F. DuBois7 to be incident to
the use of the Meeh formula, the means for men and women are as follows:
Corrected daily basal katabolism of men and women per square meter of body surface
MEN
WOMEN
Means, Calories
935.0
886.0
Probable error of mean
± 4.8
± 5.8
Probable error of single result
±47.5
±49.4
Including the data obtained by Meissl, Strohmer, and Lorenz8 by Tangl9
and by Fingerling, Kohler and Reinhardt10 for swine and by Zuntz and Hager
mannl] for the horse, the following comparison of species may be made.
Mean daily basal katabolism per square meter of body surface
Men (complete muscular rest) 935 ± 5
Women (complete muscular rest) 886 ± 6
Cattle (lying)../ 964 ± 24
Hogs (lying) 1078 ± ?
Horse (standing quietly) 948 ± ?
Considering the nature of the results they show a rather striking degree
of uniformity and tend to confirm the conclusions of E. Voit12 that the basal
4
ASTRONOMY: SEARES, VAN MAANEN AND ELLERMAN
katabolism of different species of animals is substantially proportional to
their body surface. It may be surmised that the exceptional result with the
hog is due to the imperfect data available for computing the body surface
of this species.
1 Armsby, Washington, D. C, U. S. Dept. Agric, Bur. Anim. Indust., Bui. 142, 1912.
2 Armsby and Fries, Ibid., Bui. 128, 1911.
3 Armsby and Fries, /. Agric. Res., Washington, 3, 1915, (435); 10, 1917, (599); 11, 1917.
4 Moulton, /. Biol. Chem., New York, 24, 1916, (299).
5 Benedict, Emmes, Roth and Smith, Ibid., 18, 1914, (139).
6 Means, Ibid., 21, 1915, (263).
7 DuBois and DuBois, Arch. Inter. Med., 15, 1915, (868).
8 Meissl, Strohmer and Lorenz, Zs. Biol., Miinchen 22, 1886, (63).
9 Tangl, Biochem. Zs., 44, 1912, (252).
10 Fingerling, Kohler and Reinhardt, Landw. Versuchstat, Berlin, 84, 1914, (149).
11 Zuntz and Hageman, Landw. Jahrb., Berlin, 27, 1898, Ergzbd. Ill, (284).
12 Voit, E., Zs. Biol., Miinchen, 41, 1901, (113).
THE LOCATION OF THE SUN'S MAGNETIC AXIS
By F. H. Seares, A. van Maanen, and F. Ellerman
Mount Wilson Solar Observatory, Carnegie Institution or Washington
Communicated by G. E. Hale, November 26, 1917
The discovery by Mr. Hale in 1913 of a general magnetic field1 surrounding
the sun raised at once questions of great interest. First among these was the
character of the field and the variation of its intensity over the solar surface.
A preliminary investigation showed that approximately the sun may be re-
garded as a uniformly magnetized sphere, its axis coinciding with the axis of
rotation. The minuteness of the observed quantities and the difficulties ex-
perienced in their measurement necessitated the provisional acceptance of
this simple hypothesis; nevertheless, well-known peculiarities of the earth's
magnetic field suggested that the solar field might deviate from that of a
spherical magnet, and that its axis might be inclined to the rotation axis by an
amount susceptible of measurement by special series of observations. This
communication is concerned with the latter of these questions, namely, the
position of the magnetic axis.
Observations of the sun's field are made by placing the slit of the spectro-
graph in coincidence with the central solar meridian. A compound quarter-
wave plate and a Nicol prism just outside the slit serve as an analyzer, the ob-
served effect being a minute displacement of an appropriately chosen spectral
line. The amount of the displacement varies with the inclination of the lines
of force to the line of sight, in other words, with the position of the sun's
magnetic axis, the heliographic latitude of the point observed, and the dis-
ASTRONOMY: SEARES, VAN MA AN EN AND ELLERMAN
5
tance of the observer from the plane of the sun's equator. If the field be
that of a uniformly magnetized sphere,2
kA = { 3 sin (20 - D) + sin D) cos i
+ { 3 cos (20 - £>) + cos D) sin * cos X (1)
in which
A = displacement of spectral line;
0 = heliographic latitude of point observed;
D = angular deviation of observer from plane of sun's equator;
1 = inclination of sun's magnetic axis to axis of rotation;
X = heliographic longitude of north magnetic pole referred to central
meridian;
k = constant depending on the units and the behavior of the line in a
field of known intensity.
For i = 0, equation (1) reduces to
kA = 3 sin (20 - D) + sin D, (2)
and, if D also is zero, to
kA = 3 sin 2 0. (3)
Since the maximum value of D is about 7°, equation (2) differs but little
from (3). The displacement curves derived by Mr. Hale from preliminary
observations agreed substantially with these equations, whence it follows
that i must also be small and that the difference between equations (1) and
(2), which represents the influence of i, is a quantity of the second order.
When A is expressed in thousandths of a millimeter, k, for the lines observed,
is of the order of unity. The maximum displacement, by equation (3), is
therefore 3 or 4 ix (about 0.001 A). To determine the position of the magnetic
axis, quantities of the order of 0.5 \x must accordingly be evaluated. This in-
dicates sufficiently the nature of the problem and the degree of precision that
had to be attained. It was evident from the beginning that a long and care-
fully executed series of observations would be required for a successful attack
on the problem.
The original investigation by Mr. Hale was based on only four lines. Later
observations have increased the number known to be affected by the sun's
field to 30, for 18 of which results were communicated at the Atlanta meeting
of the American Astronomical Society in December, 1913. For the investiga-
tion here described three chromium lines, XX 5247, 5300, 5329 were selected,
which are of special suitability for measurement because of intensity (2 and
3), location in the spectrum, and magnitude of displacement. .
From June 8 to September 23, 1914, these lines were photographed daily
under the direction of Ellerman, with almost no break in the series. The cir-
cumstances were most favorable owing to the small number of sun-spots, whose
magnetic fields, many times the intensity of the underlying field of the sun,
seriously complicate the investigation. Because of advantages connected
6
ASTRONOMY: SEARES, VAN MAANEN AND ELLERMAN
with the numerical solution and the necessity of limiting what at best could
be only a very laborious undertaking, the observations were confined to the
zone 45°N-45°S. Twelve spectrograms with exposures of 10 to 30 minutes
constituted the normal observing program for each day. For 63 of the days
the photographs have been completely measured by van Maanen, who has
assumed the responsibility for this part of the undertaking. More than 2000
sets of measures were required, each involving about a hundred settings of
the micrometer.
In measures of minute displacements of spectral lines, systematic errors
are always to be suspected, as well as the influence of prejudice arising from
a knowledge of the results that will satisfy a given hypothesis. Such syste-
matic errors as may have entered in the present case probably affect only the
constant k, which varies from line to line but does not enter into the determi-
nation of the position of the magnetic axis.
To exclude the influence of prejudice, the procedure devised by Mr. Hale
has been followed here. The limited zone of heliographic latitude covered by a
single spectrogram may lie in the northern hemisphere, where the displace-
ments are positive, or in the southern hemisphere, where they are negative;
or it may extend over the equator and thus show only very small displace-
ments, some negative and some positive. The measurer has rarely known in
advance the latitudes covered by any spectrogram. Further, the above dis-
tribution of algebraic signs presupposes that the photograph has been made
with the compound quarter-wave plate in its normal position. Since the in-
version of the plate reverses the signs of the displacements, its position, as a
final precaution, has been varied at random by the observer, and the measurer
has not known the position used for a given photograph until after his settings
were finished.
The data have been treated as follows : Each displacement affords an equa-
tion of condition of the form (1) for the determination of the unknowns k, i,
and X. The longitude of the magnetic pole, X, involves an epoch, to, when the
pole was on the central meridian, and the period, P, in which the magnetic
axis revolves around the axis of rotation. For a single day we may assume
X to be constant, which leads us to discuss separately the observations for
each day and for each line, thus deriving values for two new unknowns, x and
y, which are functions of k, i, and X. The analysis of x and y for the whole
series of days then determines k, i, P, and to.
Equation (1) may be written
Ax + By = A. (4)
A and B are the bracketed expressions of (1), including only known quantities,
and
x — k~l cos i, y = k~l sin i cos X (5)
whence
Y = y/x = tan i cos X. (6)
ASTRONOMY: SEARES, VAN MAANEN AND ELLERMAN
7
About 50 values of A were available for each line on each day. Means were
found for groups of 5 or 6 adjoining displacements, thus giving 8 or 10
observation equations of the form (4) for a least-squares determination of x
and y.
The individual values of A for September 2, 1914, a series of average weight,
are plotted in Fig. 1 against the latitudes as abscissae. The close agreement
with a sine curve of the type of equation (3) appears at a glance. The calcu-
lated displacement-curves corresponding to the values of x and y derived from
these data, are also shown in the figure. Their ordinates for 0 = 0, namely,
+0.8, +1.0, and +0.5 respectively, are of the order of the small quantities
S 60° 40° 20° 0° 20° 4JT 60° N
1914 Sept. 2
X524 7.737
•
•}_-!
•
• •
• •
.• — — — •
•
•
«
•
X5 3 00.9 2 9
• 9
1 — 8 * *
* •
9— :— —
J*— • "
X5329.329
~
•
•
-•~S .
s
FIG. 1. DISPLACEMENT-CURVES FOR 1914, SEPTEMBER 2
Abscissae are heliographic latitudes. Ordinates are displacements, the scale being 1 di-
vision of diagram = 0.005 mm. The curves, which correspond to equation (1), have been
derived from the observed values of A. Their ordinates for sin i = 0.06 cm., nearly,
whereas the maximum displacement AN throughout the whole series (equiva-
lent to the telescopic field width) does not exceed AN = 5 X 10~3 cm. Hence
(AN/ANo)2/2 may here be neglected to about 1/300 and (again apart from
signs) since i = 45°,
Ae = L(AN/AN0) = 325 AN,
as it should be; i.e., the relation of Ae and AN is practically linear, if the dis-
placement AN is not excessive or goes beyond the equivalent of field width.
As the determination of ANo is inconvenient we thus come back to the
practical equation already used, or
AN /Ad = \/2A
' is halfway between G and Z>.
For the potential difference of each of the. lines A B, B C, and D C, of
figure 1, we have a corresponding representation; but these areas all combined,
the sum of the areas for A D and D C being subtracted from the sum of the
areas for A B and B C, will give, as before, ~ X A B C D, as the net e.m.f.
Ge
of the circuit.
T D
C T
FIG. 3
FIG. 4
If the diagram A B C D represented the operation of an ordinary fluid, like
air or steam, working in a cylinder under a piston, the path ABC would rep-
resent that part of the cycle in which the fluid, expanding, does work on the
piston at the expense of heat energy, while the path C B A would represent
that part of the cycle in which the returning piston does work in compressing
the fluid. In the thermo-electric case, under the conditions which we have
assumed, the path ABC represents that part of the cycle in which the ex-
panding electric fluid does work in storing up electric potential energy at the
expense of heat energy, while the path CD A represents that part of the
cycle in which electric potential energy works to compress the electric fluid.
PHYSICS: E. H. HALL
35
So far as mere expansions and contractions are concerned, we may ignore the
electrical property of the circulating fluid; for the mutual electrical self-repul-
sion of its particles is balanced by the action of the equally numerous positive
ions.
It is to be noted that no necessity has appeared in this discussion for any
'specific attraction' of either metal for electrons. Ordinary electro-static at-
traction and repulsion, together with the mechanical, expansive, heat-pressure
of the electrons, is apparently enough to account for all that is known to occur
in thermo-electric action confined to a metallic circuit. All the evidence
we have to show the existence of the so-called 'specific,' or 'essential,' attrac-
tion comes from other regions of phenomena, especially from studies of ther-
mionic emission and the Volta contact potential-difference. If such an at-
traction exists and is active within metals, we need not change the discussion
above given except in the interpretation of P. This has here been taken as
ordinary electrostatic potential. If there is an 'essential attraction' between
electrons and matter having no electric charge, P will appear in the formulas
just as it appears now, but it will be interpreted as what I have called in a
previous paper1 virtual potential, potential due to all attractions and repul-
sions acting on the progressive electrons.
It is of interest to observe that the e.m.f . along any part of the circuit does
not, under either hypothesis (A) or hypothesis (B), necessarily correspond to
the amount of heat absorbed in this part. For example, the Thomson heat
absorbed along the line A D may be positive, negative, or zero, according to
the inclination of the line, while the e.m.f. of this part, represented by the
area E A DG, remains always of the same sign.
The preceding discussion expressly assumes that the free electrons are the
only ones which move through a metal. This is a provisional assumption
only. If the associated electrons also move progressively, as I have in cer-
tain previous papers supposed them to do, the conditions of equilibrium in a
detached metal bar, having a temperature-gradient, are different from those
indicated in this paper. This matter I hope to discuss at another time.
1 Boston, Proc. Amer. Acad. Arts ScL, 50, 4 July, 1914.
2 Great steepness of this curve does not, as one might at first suppose, indicate a very
rapid increase of n with increase of T, but the contrary.
3 That is, if the moving body of electrons that constitute an electric current obeyed the
laws of a perfect manotomic gas, we should have in lead n oc T1'5, very nearly.
36
ASTRONOMY: G. STROMBERG
A DETERMINATION OF THE SOLAR MOTION AND THE STREAM
MOTION BASED ON RADIAL VELOCITIES AND
ABSOLUTE MAGNITUDES
By Gustaf Stromberg
Mount Wilson Solar Observatory, Carnegie Institution of Washington
Communicated by W. S. Adams, December 14, 1917. Read before the Academy,
November 21, 1917
In previous determinations of the motion of the sun in space and of
the star streams the stars have been divided for discussion according to spec-
tral type or apparent magnitude. The recent investigations of Adams and
Stromberg1 have shown that the intrinsically faint stars have a higher average
radial velocity than those that are intrinsically brighter, or in other words,
that radial velocity is a function of absolute magnitude. Accordingly an
investigation of the solar motion and the stream motion based upon a division
of stars into groups of nearly equal absolute magnitude is of exceptional inter-
est, since the dispersion of the radial velocities within each group is consid-
erably less than in the usual case. A brief account of such an investigation
is given in this communication.
Of the 1300 stars of the spectral types F, G and K with measured radial
velocities which have been used in the discussion, about 700 have absolute
magnitudes determined spectroscopically by Adams. For the remainder, ob-
served mainly at the Lick and Mills Observatories, mean parallaxes have
been computed by the aid of the following formula connecting proper motion
and apparent magnitude:
Log 7T = log A + log (ju + c) + m log e,
in which ir is the mean parallax, fx the proper motion, m the apparent magni-
tude, and A , c and € constants determined by means of the spectroscopic paral-
laxes. The formula differs from that of Kapteyn,2 which for later type stars
of very small proper motion gives parallaxes that are too small, in the addition
of the constant c.
Solar Motion. — The constants of the solar motion have been determined by
a least squares solution of equations of condition of the form
V = x0 cos a cos 8 + yQ sin a cos 5 + z0 sin 8 + K,
in which V is the radial velocity, — x0, —yo, and — zQ the rectangular compo-
nents of the sun's motion, and K Campbell's K-term, the quantity which must
be- subtracted from each of the radial velocities, corrected for the sun's motion,
in order to make their sum equal to zero. The results indicate that the K-
term has a small positive value in the case of the very luminous stars, and
probably a negative value in the case of the fainter stars. For K equal to
ASTRONOMY: G. STROM BERG 37
zero the constants of the solar motion have the values given in table 1. M
and m are the arithmetical means of the absolute and apparent magnitudes,
A and D the right ascension and declination of the sun's apex, V0 the sun's
velocity in space, and 6 the arithmetical mean of the radial velocities corrected
for the sun's motion, taken regardless of sign. The results given by the
groups of faintest magnitude are necessarily uncertain since the stars included
within them are almost exclusively in the northern hemisphere and the dis-
tribution is relatively unfavorable.
TABLE 1
Constants of Solar Motion (K = 0)
NO.
M
m
A
D
F and G type stars
km.
km.
211
0.31
4.68
251?4
+22?5
19.4
11.3
177
1.44
5.42
267.5
+36.3
16.6
14.6
167
2.76
5.27
272.1
+36.4
22.8
16.3
170
5.29
6.41
(279.6)
( + 10.9)
(27.1)
(23.9)
725
2.32
5.40
268.3
+26.1
20.1
17.2
K type stars
122
0.54
4.22
279?6
+33?8
24.0
13.7
245
1.41
4.86
268.1
+37.2
20.4
16.6
99
2.58
5.12
284.5
+20.1
26.0
18.6
79
7.07
7.41
(289.0)
(+26.5)
(22.1)
(26.2)
545
2.25
5.13
277.0
+ 32.5
22.2
18.5
M type giants
135
1.5
4.98
264?2
+26?1
26.8
16.9
All stars of late type
A = 270?9 ± 3?3 D = + 29?2 ± 3?4 VQ = 21.48 ^ 1.02 km
&= 17.7 km K=+ 0.36 ± 0.60 km
There appears to be a tendency toward smaller values of the declination
for the intrinsically faint stars. If real this effect may be explained on the
assumption of a variation in the proportion of stars belonging to the two star
drifts. A marked feature of the results is the increase of the average radial
velocity with decreasing brightness.
Stream Motion. — For a study of stream motion the stars with measured
radial velocities have been divided into three groups, as follows, according to
absolute magnitude:
I
38 ASTRONOMY: G. ST ROM BERG
GROUP
NO.
M
m
7T
km.
I
509
0.76
4.83
Of 015
13.11
II
513
2,08
5.09
0.025
17.13
III
260
6.05
6.82
0.070
25.88
Each group contains stars of spectral types F, G and K, the third group, com-
prising the faintest stars, also including 11 stars of the dwarf M type. The
symbol t denotes the geometrical mean of the parallaxes, which is readily
derived by the formula
5 log 7r = M — m — 5.
In accordance with the method of Charlier, the sky has been divided into
48 equal areas situated symmetrically with reference to the galactic equator.
If star streaming is studied on the basis of the ellipsoidal or the two drift theory,
opposite areas may be combined by assuming that the stream motion is the
same in all parts of the space.
Since the sun, however, is not situated at the center of the stellar system,
but at a distance from it probably comparable with the mean distance of the
later type stars used in this investigation, we might, according to the theory
of Turner3 and Eddington,4 conceive the stream-motion to be due to the gen-
eral attraction of the stellar system. It would then differ from point to
point and be related to the position of the center and the central plane of the
stellar system. Such a theory is supported by Kapteyn's5 suggestion that
there is an acceleration of the first stream; i.e., that the velocity of the first
stream is different in different parts of the space.
In order to test for the existence of such a varying stream-motion, I have
tried to express the average radial velocity as a rational integral function of
the direction-cosines of the line of sight such that the radius vector of the sur-
face thus defined equals the average radial velocity. Using only terms of
second order we can in this way determine the stream-motion, if the latter is
constant (Eddington6). If the stream motion is variable this must be marked
by the existence of asymmetrical (odd) terms in the analytical representation
of the surface.
In this investigation terms to the third order inclusive have been
determined.
If terms of the second order alone are included, opposite areas in the sky
may be combined. The resulting directions of the axes of maximum radial
velocity 0 are thus:
GROUP I
GROUP II
GROUP III
a
8
a
5
OL
8
km.
16.14
98°
+ 5°
km.
20.98
86°
+ 10°
km.
32.4
100°
+ 34'3
ASTRONOMY: G. STROM BERG
39
The position found for the axes of preferential motion is in good agree-
ment with other determinations which, according to the summary by Edding-
ton, give a = 94°, 8 = +12°.
The asymmetrical terms, or those of odd order, are next determined sepa-
rately for the three groups. If those which depend only on the galactic lati-
tude are considered, we obtain expressions for 9 from which the following
maximum values may be derived :
GROUP I
GROUP II
GROUP III
b
d
b
b
km.
13.9
-19?1
km.
19.7
-19?9
km.
28.4
-22?8
We find, accordingly, in all cases a negative latitude for the maximum fl-
it is known, however, that the sun is situated north of the real galactic plane?
the distance being about 20 parsecs,7 or a distance corresponding to a parallax
of 0".05. This indicates a maximum of motion, not in the galactic equator,
but in the real galactic plane. The form of the surface for the second group
is shown in figure 1 .
The surfaces which represent the average radial velocity for the first and
second groups are very nearly the same, the most important features being
two large terms of second and third order. These are as follows, b and /
being the galactic latitude and longitude, respectively:
SECOND ORDER
THIRD ORDER
Group I
2
59 cos'2 b cos 2 (7 —
174?3)
2
90 cos3
b cos 3 (/ —
76?0)
Group II
3
18 cos'2 b cos 2 (Z —
162?7)
3
10 cos3
b cos 3 (/ —
77?6)
The second order terms define the stream motion, and the existence of the
large third order terms shows that the axes of maximum radial velocity do not
lie in a straight line.
The two principal maxima of 6 in the two surfaces are
I
b
a
8
/
b
a
8
km.
km.
Group I
19.60
190°
+ 4°
109°
-7°
17.50
324°
- 2°
264°
-33°
Group II
24.23
179
-18
84
-7
26.33
322
-19
283
-41
We find, therefore, that the axes of largest radial mobility, which may be
assumed to correspond approximately to the direction of preferential motion
in space, form obtuse angles equal to 134° and 128°, respectively, for the two
40
ASTRONOMY: G. STROMBERG
groups, and that there is a pronounced minimum at longitude 258°. The
nearest approach to a symmetrical plane at right angles to the galacticplane
has the longitude
258?6 for Group I and 256?6 for Group II.
270*
20
KM-
AtC-
In figures 2 and 3 are shown the intersections between the radial velocity
surfaces and the galactic equator. The dotted curves indicate the intersec-
tions when only terms of even order are considered, and the arrows mark the
position of the symmetrical planes.
The properties of these surfaces may be explained on the assumption that
ASTRONOMY: G. STROM BERG
41
the motions of the stars depend upon their positions relative to the center of
the galactic system. According to Charlier3 the position of the center as
derived from 800 B-type stars is
/ = 236° b = - 14° Distance = 88 parsecs.
O. R. Walkey8 finds from 30736 stars of all types the longitude I = 246°.
These values of the galactic longitude of the center of the stellar system are
in fair agreement with the value 258° found for the position of the symmetrical
plane. We may, therefore, conclude that the variation of average radial
velocity with direction is due probably to a motion of the stars around the
center of the galactic system. Moreover, if the stars are moving around the
center of the stellar system we should expect a minimum orbital velocity near
the center and a maximum at a certain distance from the center.5 The mini-
mum in radial velocity near longitude 268° is in agreement with this
conclusion.
In the case of the stars nearest to us, we should expect the axes of prefer-
ential motion to lie nearly in a straight line, since their distance from us is
small as compared with their distance from the center.9 To test this question
I have made an analysis of the radial velocities of the stars in Group III,
which contains the nearest stars, combining all stars between galactic lati-
tudes — 66° and +66°. The axes of maximum radial velocity for the result-
ing curve have the longitudes 157° and 340°, which thus differ by 183°. The
longitude of the axis of symmetry is 254°, a value in good agreement with that
found for the more distant stars. The intersection of the surface with the
galactic plane is shown in figure 4.
The conclusion to be drawn from these results is that stream motion is prob-
ably a local effect caused by a preferential motion of the stars in both direc-
tions around the center of the stellar system. This might have been expected
from the fact that the motions of the two 'drifts' have been found to be in
the galactic plane and at right angles to the direction of the center of the
galaxy. The deviation of the axes of preferential motion from a straight line
furnishes strong evidence in support of this conclusion.
1 Adams, W. S., and Stromberg, G., Mt. Wilson Contr. No. 131, Astro ph. J., Chicago, 45,
1917, (293-305).
2 Kapteyn, J. C, Groningen, Pub. Astr. Lab., No. 8.
3 Turner, H. H., Mon. Not. R. Astr., Soc. London, 72, 1912, (387-407).
4 Eddington, A. S., Ibid., 75, 1915, (366-376).
5 Mt. Wilson Solar Observatory, Annual Report, 1916, (255).
6 Eddington, A. S., Mon. Not. R. Astr. Soc, London, F. S., 1915, (521-530).
7 Charlier, C. V. L., Medd. Lunds Obs., Upsala, Ser. 2, No. 14, 1916, (31).
8 Walkey, O. R., Ibid., 74, 1914, (649-655).
9 Stromgren, E., Astr. Nachr., Kiel, 203, 1916, (17-24).
42
AGRICULTURE: L. R. JONES
DISEASE RESISTANCE IN CABBAGE
By L. R. Jones
College of Agriculture, University of Wisconsin
Communicated by R. A. Harper, December 31, 1917
The cabbage, while ordinarily one of the most vigorous of cultivated plants,
is highly susceptible to certain parasitic diseases. The most destructive of
these, known as 'yellows,' is due to a soil inhabiting fungus (Fusarium con-
glutinans) which invades the root system. Once introduced this parasite
may persist indefinitely in the soil rendering it ' cabbage sick' so that this crop
can no longer be grown upon it. One who knows the nature of this parasite
and its manner of host invasion would have little hope of its practical con-
trol through any of the usual methods of spraying or seed or soil treatment.
Extensive experimental trials have justified this conclusion.1 On the other
hand, when we were called upon in 1910 to investigate this disease and its
control in Wisconsin, it was these very factors which encouraged the hope
that it might be possible to secure disease resistant varieties or strains. The
principle involved in such an undertaking is, of course, that of ' the survival
of the fittest.' The things essential to any satisfactory progress are that
there be among the host plants well marked variations in individual suscepti-
bility or ' resistance' to the parasitic attacks and that this character, whatever
its cause, be fixed and transmissible from generation to generation. Another
very important matter, from the practical standpoint, is that such resistant
characters be combined with those which give the plants economic value.
Examination of the worst diseased fields led to the discovery of certain indi-
vidual plants which developed apparently normally although all neighboring
plants were dying or dead from the effects of the parasite. Moreover, among
these survivors were to be found representatives of the best commercial
types. The first and last conditions were therefore met. Would these
characters persist in seed obtained from such plants?
Somewhat over 50 such resistant individuals were selected in the autumn of .
1910, seed was grown from them in 1911, and in 1912 this seed planted, each
' head strain' separately, on the ' sickest' available soil. Omitting all details the
general results may be summarized by the statement that in every case the
selected head strains transmitted in considerable degree their resistant qualities,
and certain of them did so in high degree. Thus of the control (non-selected)
varieties the majority were killed by the parasite and most of the balance
were so diseased that they failed to form heads, whereas the poorest of the
selected head strains proved decidedly superior to the best of these controls,
and of the best selected head strain 98% of the plants lived through the
season and 93% of them formed heads. The figures which may best be
cited are, however, those comparing the head strain which in the behavior
AGRICULTURE: L. R. JONES
43
of its progeny has since proved to be the best with the unselected control
strains.
Selected head strain 96% lived 80% headed
Non-selected controls 36% lived 16% headed
From the best of these heads, selected as the second generation survivors
on sick soil in 1912, seed was grown in 1913 and like trials on the same in-
fected soil made again in 1914. In order the better to show the significance
of these results the following summary includes the averages of all of the
head strains selected from the best strain in 1912 together with the results
from the best head strain. Data are also here included as to the per cent
of diseased plants in each strain at the end of the season, the average weight
of the heads, and the computed yields in tons per acre.
SECOND GENERAL TRIALS, 1914
LIVED
HEADED
DISEASED
WEIGHT
PER HEAD
YIELD
PER ACRE
per cent
per cent
Per tent
pounds
tons
99.5
94.0
5.0
4.0
12.2
100.0
98.0
1.5
5.5
18.8
46.0
24.5
81.0
2.7
2.1
A comparison of the 1914 results with each other and with those of 1912
shows clearly certain encouraging things. First, the disease resistant char-
acter, whatever may constitute it, is fixed and inheritable; second, there is a
distinct improvement in the second generation as compared with the first;
third, there is enough variation as between the selected head strains of the
second generation to furnish a basis for further possible improvement by
continued selection. Perhaps this last idea requires restatement in such a
way as to lay the emphasis upon another fact. Since there is a considerable
variation within the progeny of even the selected head strains it is necessary
to continue the method of growing the seed strains on ' sick' soil for trial and
selection in order to maintain the highest standards, and were this to be dis-
continued there would probably be a tendency toward gradual reversion.
Such selections and trials have since been continued in an intensive way
by our department with further encouraging results while the more exten-
sive work of seed growing and its distribution (under the name Wisconsin
Hollander) has passed to the hands of a committee of practical cabbage
growers organized for this purpose.
In this way our own departmental activities, including the investigations
of certain graduate students, have been freed for direction to some of the
more fundamental questions involved. Among these the following may be
defined.
1. Wherein is the difference between the susceptible and the resistant
plant? In other words, what constitutes disease resistance?
44
AGRICULTURE: L. R. JONES
FIG. I. A FUSAR1UM-SICK CABBAGE FIELD
Note that while most of the plants are diseased or dead certain appear normal. Selec-
tions of such were made from this field in 1910.
FIG. 2. A TRIAL OF RESISTANT STRAINS ON 'SICK' SOIL IN 1916
The central row, nearly all dead, is a commercial non-resistant strain planted as a con-
trol. The remainder of the field is planted with selected resistant strains, the first row at
the left being recently selected kraut varieties, Brunswick and All Seasons, the rest being
Wisconsin Hollander.
AGRICULTURE: L. R. JONES 45
2. How does this factor of disease resistance behave in inheritance? Is
it surely transmissible and does it 'Mendelize?'
3. Is the quality of resistance or susceptibility influenced by environ-
mental factors, if so, how? Related to this is the question as to whether such
resistance will persist when the strain selected in one locality, e.g., Wisconsin,
is grown in a remote locality, e.g., New Jersey.
4. Is the principle general? In other words, is there similar variation in
individual susceptibility and resistance to this parasite among other varie-
ties of cabbage than the one considered above? How general is the occur-
rence of such differences with other host plants and other plant parasites?
While wholly satisfying answers are not yet formulated for any of these
questions, such evidence as has been secured may be summarized as follows.
As bearing on the first question, W. H. Tisdale, working in our laboratory,
has sought to learn what difference there is in the relations of the parasite
to the resistant and the susceptible plants. Since the cabbage is a clumsy
plant of slow development he used for his primary investigations the flax
which is invaded by a closely similar parasitic Fusarium and which has well dif-
ferentiated resistant and susceptible strains. Secondary comparative studies
with the cabbage, while not yet complete, indicate a general likeness in be-
havior. He has learned that the difference in resistance is not due to any
superficial obstacle since the parasite, which may enter through the root
hairs, penetrates these freely in the resistant as well as the susceptible plants.
The difference is in the relations of the interior cells of the host and the para-
site. In the suceptible plants the parasite penetrates directly to the vessels
and then ramifies through them to the destruction of the host. In the re-
sistant individuals, on the other hand, the invasion advances more slowly
and before it reaches the vessels is checked and permanently walled off by the
development of a corky layer. This reaction may be interpreted in various
ways but the one we favor is that the resistant tissues have the ability to
restrain the development of the parasite to a greater degree than do the
susceptible and so give time for the protective cork formation.
With reference to the second question, Tisdale2 has also sought to follow the
behavior of resistance as an inherited character again using the flax. Biffin,
in England, working with wheat, concluded that resistance to the rust parasite
(Puccinia) was inherited as a simple Mendelian character, being recessive.
With flax the problem proves not so simple. Crossing highly susceptible
with resistant strains and testing the progeny shows that resistance is clearly
a transmissible character, but the hybrids are in general more or less inter-
mediate in this respect with a tendency for resistance to be dominant. Much
variation is found in lines originating from different parents. The indica-
tions are that resistance is not a single character but a complex, dependent
upon a number of heritable factors.
As to the third question, environmental factors do have a marked influence
in determining whether the Fusarium parasite will invade the cabbage. J. C.
46
AGRICULTURE: L. R. JONES
Gilman working at Wisconsin and later at the Missouri Botanical Garden
found that there is a 'critical soil temperature,' about 17°C., for such inva-
sion. Below this the plants are not parasitized, even in the sickest soils while
for some 10° above this the attack becomes progressively more virulent.
Correlated with this is the experience that at lower soil temperatures, e.g.,
in cool summers, there is little disease even with susceptible strains and in
hot summers there is a certain amount of infection even with our most re-
sistant strains. It is theoretically possible, therefore, that a strain which
was resistant in a relatively cool climate might prove susceptible when trans-
ferred to a warmer region. As a matter of field trial, however, these resistant
Wisconsin cabbage strains have proved similarly resistant under trials extend-
ing from New Jersey to Iowa.
Regarding the fourth question we may speak with considerable confidence
also. Our earlier work was confined, as previously suggested, to one cab-
bage variety, the Hollander. Selections which have since been made from
other varieties, both in connection with our own investigations and by others
in Ohio, Iowa and Maryland, have given encouraging results. We may be
reasonably confident, therefore, that a Fusarium-resistant strain of cabbage
may be secured from any vigorous established variety.
If we do not ask for too much in the way of practical application we may
safely go farther in the generalization as to the occurrence of disease resist-
ance in plants. Plants are always varying of course, and this includes varia-
tions in those factors which make them more or less susceptible or resistant
to the attacks of any parasite. Unquestionably constantly increasing recog-
nition of this principle will be given by plant breeders and plant pathologists
in seeking to control plant diseases. On the other hand, experience indicates
that with parasites of certain kinds including the Fusariums, it is relatively
easier in practice to secure disease-resistant strains of host plants than it is
with many other parasites, for example the common wheat rust.
1 For a more detailed consideration of these matters reference may be made to Wis.
Agric. Exp. Sta. Res. Bid., 38, The Control of Cabbage Yellows through Disease Resistance,
by L. R. Jones and J. C. Gilman, December, 1915.
2 Tisdale did his work on inheritance as a graduate student under the direction of Dr.
L. J. Cole in the department of experimental breeding, at the University of Wisconsin.
His results along these two lines have been formulated for publication in the Journal of
Agricultural Research.
PHYSICS: L. PAGE
47
IS A MOVING STAR RETARDED BY THE REACTION OF ITS
OWN RADIATION?
By Leigh Page
Sloane Physical Laboratory, Yale University
Communicated by H. A. Bumstead, January 21, 1918
A question of some interest to the astronomer is whether or not a body in
motion, such as a star, is retarded by the reaction of its own radiation. For,
on the electromagnetic theory of radiation as developed by Maxwell and his
followers, a beam of radiant energy is supposed to have a quasi-momentum,
such that if a body emits energy in a single direction it will lose momentum
and in consequence suffer a reaction tending to push it in the opposite direc-
tion. Now if a star is at rest, and in thermal equilibrium, it follows from sym-
metry that it will radiate equally in all directions, and there will be no result-
ant impulse. If, however, the star is in motion, classical electrodynamics
leads to a greater emission in the forward direction than in the backward,
and consequently it would appear at first sight as though there should be a
retardation which would ultimately bring the star to rest. The problem
has been treated in some detail by Professor Sir Joseph Larmor in the Pro-
ceedings of the Fifth International Congress of Mathematicians,1 held at Cam-
bridge in 1912, and he finds the resistance to motion due to the radiation to be
F = -vR/c2
where v is the velocity of the star, R the rate of emission of energy, and c the
velocity of light.
Apart from its intrinsic interest, Larmor's result is of importance in that it
would constitute, if correct, a contradiction between classical electrody-
namics and the Principle of Relativity (reference here is to the relativity of
constant velocity systems, not to the broader conception of general relativity
recently developed by Einstein). It is known, however, that the connection
between classical electrodynamics and the Principle of Relativity is very
close. Lorentz obtained the relativity transformations in his effort to give
the electrodynamic equations for a moving system the same form as for a
fixed system, even before Einstein advanced the relativity idea, and the
author has shown that the electrodynamic equations can be derived in their
entirety and exactly from the kinematical transformations of relativity and
the assumption that each and every element of charge is a center of uniformly
diverging tubes of strain.2
Now to calculate rigorously from the electrodynamic equations the reaction
on so complicated a mass as a star would be hopelessly involved. Fortu-
nately, however, the problem can be simplified to the extent of dealing with
48
PHYSICS: L. PAGE
a single oscillator, i.e., a single vibrating electron, and yet we can obtain a
result that will be a perfectly general test of Larmor's expression. For the
latter gives the retarding force as a function of the rate of total radiation and
the velocity of the radiating body, and of these quantities alone. Hence if
the ether exerts a reaction on a group of moving oscillators, it will exert a
similar reaction on a single oscillator; and conversely, if there is no reaction
on a single vibrating electron due to its drift velocity, there can be none on a
group of such vibrators.
A rigorous solution of the problem for this relatively simple case shows
the existence of no retarding force. Larmor's result is found to be invalid
because of a tacit assumption underlying his reasoning which was introduced
substantially in the following manner. In order not to complicate matters
by the introduction of terms in the inverse second power, the radiation reaction
is calculated by applying the electrodynamic equations to the surface "of a
moving sphere with the electron as center, whose radius is large compared to
that of the electron (though small compared to a millimeter) . In this way
only those terms in the expressions for the electric and magnetic fields which
involve the inverse first power of the distance from the electron need be
retained. But the result obtained really gives the force on the electron and
the ether inside the moving sphere, not that on the electron alone. Now,
if the motion of the electron were undamped, the field inside this moving
sphere would remain unchanged, and consequently the force found by Larmor
would be that actually exerted on the electron. But as the electron is radiat-
ing, its motion must be damped unless energy is supplied from some outside
source, and in that case it must be shown that no impulse accompanies the
transfer of energy to the electron — a matter of considerable difficulty to
treat rigorously. It is far simpler to consider the case of an oscillator left
to itself and allowed to radiate at the expense of the energy of its vibration.
For this case it is found that the force exerted on the electronic vibrator by
the ether inside the moving sphere mentioned above is exactly equal and
opposite to that due to the ether outside. Moreover, from the point of
exchange of momentum, the law of conservation of momentum demands that
Momentum lost by electron = Momentum gained by ether outside
sphere — Momentum lost by ether inside sphere.
The terms on the right hand side (the second of which is overlooked by Lar-
mor) annul one another. Therefore a single moving oscillator is not retarded
by its radiation field, and as already noted we can generalize this result and
conclude that a moving body of any size and complexity suffers no retarda-
tion as a result of its emission of radiant energy.
In the analytical reasoning leading to this conclusion it is found necessary
to develop the complete dynamical equation of the Lorentz electron through
terms of the fifth order, for the most general type of motion. Previous deri-
vations of this equation have been confined to some special case, such as
PHYSICS: S. J. BARNETT
49
quasi-stationary motion in a straight line. The general equation is here
published for the first time:
p e% Ajf. V/.
* 6«*c2(l--/32)3/2 2 xc4(l-/32)3 6«;3 (1 - /32)2
, e fxg _ g fxa
+ 97rC4(l-/32)5/2 18tt<;5(1-/32)3'
77 _ e2fy _ ft-fif, e2fy
V 6^(1 -/32)1/2 2tc*(1-(32)2 6ttC3(1-/32)
e2fya e2'fya2
2\2
where the X axis is taken in the direction of motion, the Y axis is in any
direction perpendicular to the velocity, a stands for the radius of the elec-
tron, / is its acceleration, and $ = d/c where v is the velocity of the electron
and c that of light. The charge e is expressed in Lorentz's unit. It may be
remarked that the form of this equation, in so far as it involves fi, is in exact
accord with the Principle of Relativity.
The analytical reasoning involved in obtaining these results from the
electrodynamic equations will be given in a paper which has been submitted
for publication to the Physical Review.
^Proc. Fifth Int. Cong. Math., 1, 1912, (207).
2 Relativity and the Ether, Amer. J. Sci., New Haven, 38, 1914, (169).
ON ELECTROMAGNETIC INDUCTION AND RELATIVE
MOTION. II.
By S. J. Barnett
Department of Physics, Ohio State University
Communicated by R. A. Millikan, January 19, 1918
1. If a cylindrical condenser is placed in a uniform magnetic field with
lines of induction parallel to its axis, and is short-circuited and rotated, to-
gether with the short-circuiting wire, about this axis, it becomes charged to a
potential difference equal to the motional electromotive force in the wire, or
the rate at which the wire cuts magnetic flux. If, however, the condenser
and wire are fixed and the agent producing the magnetic field rotates, the
relative motion being the same as before, the condenser does not become
charged, as was proved1 by precise experiment in 1912. This is the first
case in electromagnetic induction in which the observed effect does not depend
entirely on the relativity of the motion.
50
PHYSICS: S. J. BARNETT
Without, however, the introduction of hypotheses unproved by experiment
it does not seem possible to determine from the experiments on rotation what
would happen in the case of translatory motion, or to obtain from them any
answer to the question of the existence of the aether. The present investiga-
tion was undertaken with the hope of shedding some light upon these problems.
2. If an air condenser with horizontal parallel plates, short-circuited and
placed in a uniform magnetic field whose lines of induction are parallel to the
plates, is moved, together with the short-circuiting wire, in a direction parallel
to the plates and perpendicular to the lines of induction, it will become charged
to a potential difference equal to the motional electromotive force, which will
be denoted by E, in the wire, the charges (provided, as will be assumed, that
edge effects are negligible) being restricted to the inner or opposing faces of
the -plates.
3. If the region below the plane of the upper surface of the lower con-
denser plate were filled with a medium of zero permeability, the tubes of
magnetic induction would be confined to the region above this plane, and the
condenser would become charged exactly as before for the same motion.
4. If, with the arrangement of §3, the condenser and wire were to remain
fixed and the agent producing the magnetic field were to move, the relative
motion being the same as before, the results to be expected would be different
according to the hypothesis adopted with respect to the aether:
A. If there is no aether, and the principle of relativity is valid, the con-
denser would become charged exactly as in §2 and 3.
B. If the aether exists, the electric intensity produced by the motion of
the tubes of induction in the aether between the condenser plates would be
equal and opposite to the field intensity there due to the potential differences
produced by the electromotive force in the short-circuiting wire, and there
would thus be no charge on the lower condenser plate.
Thus we should have a method of discriminating between the two
hypotheses.
5. There being of course no medium of zero permeability in existence, I
have tried to secure an arrangement equivalent to that of §4, so far as the
effect under investigation is concerned, by using an artifice analogous to the
electric guard-ring.
Two similar electromagnets, referred to as the upper and lower magnets,
with their coils in series are used to produce the field. The four poles are all
alike, each being a rectangular parallelepiped with the largest sides horizontal
and parallel to the condenser plates. The lower magnet and condenser are
fixed to the floor. The upper magnet forms the bob of a huge pendulum
swung from the ceiling, and has translatory motion parallel to the condenser
plates when in its lowest position. When the upper magnet is in this position,
the upper and lower poles are about a centimeter apart, and the upper surface
of the lower condenser plate is symmetrically located with reference to all
PHYSICS: S. J. BARNETT
51
the poles and the other parts of the magnets. The (now) uniform field con-
taining the condenser is conceived to be divided into. two parts as follows:
an approximately fixed field beneath the plane of the upper surface of the
lower plate, and above this plane a field whose tubes of induction move ap-
proximately with the speed of the upper magnet. The induced electro-
motive forces are thus restricted to the same regions as in the imaginary
experiments of §4.
6. In the experimental arrangement the lower condenser plate is (ordi-
narily) connected by a wire with one quadrant pair of an electrometer. The
other pair and the upper plate are connected (the latter through a key at will)
to a thin metallic case forming a practically complete electric screen about the
condenser-electrometer system. The wire joining the condenser and elec-
trometer can be connected to the case by closing an electrically operated key
K, thus short-circuiting both condenser and electrometer. A suitable cali-
brating arrangement is provided.
7. The calibration experiments give the deflection D which would be
produced by charging the condenser to the potential difference E of §2 (the
upper plate being disconnected from the case for the purpose), insulating the
lower plate and electrometer by opening K, and reconnecting the upper plate
to the case.
8. The principal experiment, together with experiments for determining
extraneous effects, gives the deflection d due to any charge on the lower plate
produced when the upper magnet moves (with known speed) past the center
of the fixed system, opening the key K at the center of the motion. An ex-
tended series of experiments shows that d/D is zero within the limits of the
experimental error.
The investigation thus appears to support the hypothesis of §4, B, which
assumes the existence of the aether, and to be inconsistent with the principle
of relativity.
I am indebted to Mrs. Barnett for a great deal of help in making the exper-
iments, to Mr. Freund for mechanician's assistance, and to the Carnegie
Institution and Professor Pegram for some of the instruments used.
A detailed account of the work will be submitted for publication to the
Phvsical Review.
1 Barnett, S. J., Physic. Rev., Ithaca, N. Y., 35, 1912, (323-336)
52
NATIONAL RESEARCH COUNCIL
NATIONAL RESEARCH COUNCIL
REPORT OF THE COMMITTEE ON ANTHROPOLOGY
The Committee on Anthropology was one of the first constituted under
the National Research Council. Its personnel is limited to representatives
of Physical and Medical Anthropology which branches it was recognized
could be of direct assistance in national preparedness. Its membership com-
prises William H. Holmes, Chairman; Ales Hrdlicka, Secretary; Dr. Charles
B. Davenport, Carnegie Institution; Dr. Frederick L. Hoffman, Chief Statis-
tician, The Prudential Insurance Company; Dr. E. A. Hooton, Anthropologist
of Harvard University; Dr. George M. Kober, Dean of the Medical Depart-
ment, Georgetown University; Mr. Madison Grant, Trustee, American
Museum of Natural History; and Dr. Tom A. Williams, Psychiatrist and
Anthropologist.
Activities of the Committee. — On February 16, 1917, certain recommenda-
tions were formulated, which under the heading "A National Anthropomet-
ric Survey," were submitted to the Executive Committee of the National
Research Council by Dr. Charles D. Walcott, first vice president of the
Council.
In April additional suggestions were laid before Dr. V. C. Vaughan, repre-
senting the Council. These suggestions related to changes in the physical
requirements of the Army, the advisability of proper regulation of the instru-
ments and methods to be used in the measurement of recruits, the need of
additional anthropological observations on drafted men in the camps, and
the preservation of valuable data and specimens on post-mortem material.
Later these recommendations were formally submitted to the National Re-
search Council.
In May these suggestions were submitted in final form. In June they were
presented before the Medical Branch of the National Defense Council, and in
August were published in brief form in the Proceedings of the National Acad-
emy. In June the Committee made further definite proposals for the stand-
ardization of the instruments used in the examination of recruits and for the
regulation of methods.
Finally during August and September a proposal was made for sending a
trained anatomist to the base hospitals in Europe for the purpose of collect-
ing much needed observations as well as specimens for further study. At
the same time the Committee called attention to the probability that our
men in France would discover in their digging operations valuable archeologi-
cal and skeletal material, which should be preserved to science; and further,
the Committee offered its services in dealing with the many problems relat-
ing to race, nationality and language which are bound to be encountered
NATIONAL RESEARCH COUNCIL
53
by the Commission that will have charge for the United States of peace
negotiations.
The results of the activities of the Committee unfortunately are not wholly
encouraging. It finds on the one hand a number of simple, practical and from
every standpoint desirable steps to be taken, and on the other the great diffi-
culty of securing favorable action by the proper authorities. The only rec-
ommendation of the Committee so far adopted is that relating to the necessity
of reducing the minimum physical requirements in recruiting. Practically
nothing has been done towards the improvement of the methods and instru-
ments employed in the examination of drafted men. The blanks used for the
examination of recruits are essentially the same as of old. The Manual of
Instructions for examiners was printed but no directions were included respect-
ing the methods or instruments to be used in the measuring. The Committee
has found that a large percentage of the instruments used for the examinations
are more or less defective; that the methods of taking the measurements are
regulated by individual opinion, necessarily resulting in many errors; and that
in cases the measuring is relegated by the examining physician to enlisted men,
without adequate supervision. It is painfully evident that no improvement
has been effected in this important matter since the Civil War, and that the
millions of measurements to be taken will be entirely unreliable for scientific
purposes. Thus we lose demographic data of the greatest value; data which
would have given to science and to government for the first time reliable
information regarding the physical characteristics of the American people
in different parts of the country, in different occupations, and under different
environments.
During the latter part of August and the first part of September the Sec-
retary of the Committee took up with Major Vaughan and Major Millikan,
the Acting Head of the National Research Council, the question of sending a
trained anatomist or anthropologist to Europe, to be attached to the Ameri-
can base hospitals and to take charge of the collecting of data and objective
material relating to post-mortem cases. As many races will be represented in
the United States Army, this step is of particular importance. Both normal
and pathological specimens should in suitable instances be preserved, to be
deposited for future studies in the National and the Army Medical Museums
and possibly other institutions. It was recommended that the specialist sent
should be a man of high training and experience and that he be commissioned
in the Medical Service of the Army so that his work could be carried on in a
regular manner and not dependent on favors. It was suggested by the Com-
mittee that if necessary the salary and working expenses of this officer might
be provided for, but this suggestion met with a stumbling block in the disin-
clination of those who are concerned, to commission the specialist who might
be recommended.
The next step suggested by the Committee relates to the preservation of
54
NOTICE OF BIOGRAPHICAL MEMOIRS
any finds of ancient human material, archeological or skeletal, that may be
discovered by the American Army in their trench digging and excavations in
France. France, as is well known, was the home par excellence of man from
the haziest antiquity. Most of our knowledge relating to his evolution has
come from collections made in France, and much more material doubtless
still lies in French soil. During the extensive digging of trenches and other
excavations the men of our Army are more than likely to come across such
precious remains and steps should be taken for their preservation. The
armies on the western front have already made such discoveries.
Notwithstanding the discouragement so far encountered by the Committee
a great deal in the line of its recommendations can still be accomplished.
Many more drafted men will be examined and the opportunities for observa-
tions in the camps are multiplying. The collection of post-mortem data and
material can be initiated at any time before the actual fighting commences.
Our great problem now is how shall we proceed in order to be more success-
ful in these directions in the future than we have been in the past, and how
can our recommendations be made effective?
W. H. Holmes, Chairman.
Ales Hrdlicka, Secretary.
NOTICE OF BIOGRAPHICAL MEMOIRS
The following biographical memoir has been published by the Academy
since the last notices of such memoirs appeared in the August 1917 number
of the Proceedings.
John Shaw Billings (1838-1913). By S. Weir Mitchell, With The
Scientific Work of John Shaw Billings. By Fielding H. Garrison.
Biographical Memoirs of the National Academy, 8, pp. 375^116.
The first biographer sketches in generality, and with the sympathy of a personal friend,
the life work of John Shaw Billings in its early struggles, in the army during the Civil War,
in the Army Medical Museum, in the National Academy, and in the Astor-Tilden-Lenox
Library of New York. Dr. Garrison, though not neglecting personal characteristics, treats
primarily the achievements of Dr. Billings in the six fields of his activity, military and pub-
lic hygiene, hospital construction and sanitary engineering, vital and medical statistics,
medical bibliography and history, advancement of medical education and the condition of
medicine in the United States, and in civil administration; he also gives an account of the
scientific contributions originating with Dr. Billings either directly or through his pupils,
but attempts no formal bibliographical list of the published writings.
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CONTENTS
Pag*
Chemistry. — The Heat Capacity of Electro Positive Metals and the Thermal
Energy of Free Electrons
By Gilbert N. Lewis, E. D. Eastman and W. H. Rodebush 25
Physics. — Thermc-Electric Diagrams on the P-V-Plane . . By Edwin H. Hall 29
Astronomy. — A Determination, of the Solar Motion and the Stream Motion
Based on Radial Velocities and Absolute Magnitudes. By Gustaf Stromberg 36
Agriculture. — Disease Resistance In Cabbage By L. R. Jones 42
Physics. — Is a Moving Star Retaeded by the Reaction of Its Own Radiation?
By Leigh Page 47
Physics. — On Electromagnetic Induction and Relative Motion. II
By S. J. Barnett 49
National Research Council — Report of the Committee on Anthropology . . 52
Notice of Biographical Memoirs 54
VOLUME 4
MARCH, 1918
NUMBER 3
PROCEEDINGS
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• OF THE
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Volume 4 MARCH 15, 1918 Number 3
THE EFFECT OF ARTIFICIAL SELECTION ON BRISTLE NUMBER
IN DROSOPHILA A MPELOPHILA AND ITS INTERPRETATION
By Fernandus Payne
Zoological Laboratory, Indiana University
Communicated by H. S. Jennings, January 7, 1918
About two years ago I began an experiment to test the effect of artificial
selection in a bisexual form. Drosophila ampelophila was chosen after a
careful search through the list of material which could be bred in the lab-
oratory. There were two principal reasons for using this material. First, it
is easily bred, and second, because of the four sets of linked genes described
by Morgan and others, it is possible to better interpret how the results of
selection have been accomplished. I wish to emphasize that the interpre-
tation of the results is the important part of the problem. Practically every
one admits that selection may be, in certain cases, effective.
The present work is not a repetition of McDowell's, although the character,
bristle number, has been used. He used the bristles on the thorax, while I
have used the bristles on the scutellum. Some of our final conclusions may
agree, yet, the work is very different and I believe my own conclusions have
been carried to a more definite termination. McDowell did not attempt to
link up the factors which he believed the cause of extra bristle number with
any other genes.
The experiment was started by mating a female with one extra bristle on
the scutellum to a normal male (four bristles is the normal number). Both
flies were taken from a mass culture which had been kept in the laboratory
for about three months. Counts in this mass culture before the experiment
began gave 612 normal flies and the one female with one extra bristle. The
result of this cross (female five by normal male) was 226 normal flies and two
females with one extra bristle. These two Fi females with one extra bristle
were mated to Fi normal brothers. These two pairs gave F2 offspring as fol-
lows: 935 normal, 39 with one extra bristle, and four with two extra bristles,
a ratio of extras to normals of 1 : 21.7. From these F2 offspring, the flies with
55
56
GENETICS: F. PAYNE
extra bristles were mated. This method of selecting the high grade parent
has been continue4 for 38 generations. A rise in the per cent of extra bristled
flies and also in the mean bristle number has been produced until in the last
generations of selection no normal flies were found and the mean number of
bristles in the twenty-ninth generation was ,9.084. From the twenty-ninth
to the thirty-eighth generation the mean remained practically the same.
The highest bristle number found in any one individual fly was 15.
I cannot give details, but I think these figures are sufficient to show that
selection has been effective. How then has it been effective? Have the re-
sults been produced by selecting merely somatic variations? Have they been
produced by selecting the variations of a single gene, or have they been pro-
duced by getting rid of or by piling factors? The possibility that selection
can act upon somatic variations, I believe, can now be dismissed without
much consideration. Practically every one admits that variations must be
germinal in order to be inherited. As to the second and third possibilities,
my evidence is in favor of the third.
In the selection line the bristle number in the females is slightly higher
than in the males. This indicated that there might be a sex-linked factor
present, which when homozygous produced a different effect than when hetero-
zygous. An experiment was devised to eliminate the X-chromosome but
retain the others. This was done as follows: A male from the high selection
line was mated to a bar female (bar is a sex-linked dominant). The Fi males
will get their X-chromosome from the bar female and hence will be bar. Of
the other three pairs of chromosomes, one of each pair will come from the
high selection line and the other from the bar line. Some of these Fi males
have extra bristles. These were mated to bar females from stock. All flies
from this cross will get their X-chromosomes from the bar line. Some of
them may get one member of each of the second, third, and fourth pairs from
the high selection line. Since extra bristle number is partially dominant to
the normal, such flies might have extra bristles if there are any genes for
extra bristles in the second, third; or fourth chromosomes. Some of the flies
from this cross did have extra bristles. They were mated and the line has
been inbred to see whether the bristle number could be increased until it
reached the mean in the high selection line. If so, then the X-chromosome
could carry no gene for extra bristles. If the mean could not be raised, then
it would indicate that the X-chromosome carried such a gene. Five gen-
erations of inbreeding has failed to raise the mean above 5.2.
Further, by crossing the high selection line to eosin, miniature and to
eosin ruby forked (sex-linked characters), and mating the Fi females back to
the recessives, it comes out clearly that a gene influencing bristle number is
located in the X-chromosome, somewhere near eosin. Of the cross-overs
between eosin and miniature and between eosin ruby and forked, miniature
and forked flies have a higher bristle number than the eosin, and eosin ruby.
GENETICS: F. PAYNE
57
The high selection line was also mated to black, pink, bent stock. The
gene for black is in the second, that for pink in the third, and that for bent
in the fourth chromosome. The Fi flies were mated inter se and the Fx
males were mated back to black, pink, bent females. The normal, the black,
and the bent flies from these crosses had a much higher bristle number than
the pink flies. This fact indicated that there probably was a factor for bristle
number in the third chromosome. To test this possibility the high selection
line was mated to sepia spineless kidney sooty rough stock. The genes for
these characters are located in the third chromosome. The Fi females were
mated to sepia spineless kidney sooty rough males. If crossing-over had
occurred, this cross should have enabled me to link up the gene for extra
bristles (if one is present) with one of the other genes. Unfortunately, only
a low percentage of crossing-over occurs and hence the cross yielded no
results.
Another method of analysis was used. A female from the high selection
line was crossed to a sepia spineless kidney sooty rough male. The Fx
male from this cross was mated to a sepia spineless kidney sooty rough
female. The offspring are normal females and males, and sepia spineless
kidney sooty rough females and males. Some of the normal females and
males and some of the sepia spineless kidney sooty rough females had
extra bristles. None of the sepia spineless kidney sooty rough males had
extra bristles. When the chromosomes of these flies are analyzed, it is found
that the normal females may get one member of each of the second, third, and
fourth chromosome pairs from the selection line and must get one of the
X-chromosomes from this line. The normal males may get one chromosome
of each of the second, third, and fourth chromosome pairs from the selection
line, but they get their X-chromosome from the sepia, spineless, kidney,
sooty, rough line. The sepia spineless kidney sooty rough females get
both their third chromosomes from the sepia, spineless, kidney sooty rough
line and may get one member of each of the second and fourth pairs from the
selection line. They get one X-chromosome from the selection line and one
from the other. The sepia spineless kidney sooty rough males, however,
get their X-chromosome and both third chromosomes from the sepia spine-
less kidney sooty rough line and may get one chromosome of the second and
fourth pairs from the selection line. Since these sepia spineless kidney sooty
rough males have no extra bristles, it would seem that the X- and the third
chromosomes carry the factors for extra bristle number.
A back selection line started from the eleventh generation and carried for
twenty-five generations, changed slightly in the first few generations of se-
lection and then remained practically unchanged. -A mass culture started a
year ago has not returned to the normal.
My conclusion then is that there are, at least, two factors for extra bristle
number and that one of these is located in the first and one in the third chro-
58
ZOOLOGY: A. W. L. BRAY
mosome. I am inclined to think there are more than two. It seems prob-
able that one of these factors was present at the beginning of selection and
that the others occurred as mutations during the course of the experiment.
The complete data and analysis will be given in the final paper.
THE REACTIONS OF THE MELANOPHORES OF AMIURUS TO
LIGHT AND TO ADRENALIN
By A. W. L. Bray
Zoological Laboratory, Museum of Comparative Zoology, Harvard College*
Communicated by G. H. Parker, January 8, 1918
The following is a brief summary of results obtained in experiments to test
the reactions of the melanophores in the skin of Amiurus to light and to ad-
renalin. The fishes tested were kept under as normal conditions as possible
and no fish was used until it had become accustomed to its laboratory sur-
roundings and to handling.
The melanophores of Amiurus contract under the influence of light of ordi-
nary intensity and expand in the dark. Fish kept in white porcelain aquaria
contract the melanophores to a much greater extent than do animals kept
in black lined aquaria under similar conditions of overhead illumination.
When the eyes are removed from normal healthy animals the latter remain
dark under all light conditions. There are considerable differences in indi-
viduals with respect to the power of contraction of the melanophores. Some
fishes become extremely light owing to complete contraction of the pigment
cells; others, under similar conditions, never become so light. This cannot
be explained entirely by the relative numbers of melanophores per unit area
of body surface, as was shown by several counts. It may be due, possibly,
to differences in nervous excitability.
If some ' sensitive' individuals are raised to a high pitch of nervous irrita-
bility, the melanophores are contracted to the maximum extent, and remain
in this condition for a protracted period, even when the fishes are placed in
the dark. One such fish was kept in the dark for three weeks and no expan-
sion was observed in the melanophores. These cells appeared to be in a
condition comparable to tetanus.
When such an 'excited' animal, with melanophores contracted, is ether-
ized, the pigment cells expand and the fish becomes dark. On coming out
of the ether, the melanophores contract slightly, but if the fish is now placed
in the dark, the pigment cells gradually assume the expanded condition. If,
however, the eyes are removed whilst the fish is under ether, there is no
return to the contracted condition when the animal is subsequently kept in
the light. The fact that there was no return to the contracted condition
ZOOLOGY: A. W. L. BRAY 59
of the melanophores after the eyes were removed, both in normal and
1 excited' animals, suggests that there is an adaptive significance to be at-
tached to the reactions of the melanophores, and that these reactions are
mediated by the nervous system through the eyes.
Excised portions of the skin of Amiurus with melanophores expanded, were
immersed in solutions of adrenalin of various strengths, others in tap water
and still others in physiological salt solution, and the rates of contraction
of the melanophores observed under the microscope.
Strength of adrenalin solution Average time for maximum contraction
1 : 5000 Almost immediately
1 : 10,000 4 to 6 minutes
1 : 100,000 6 to 8 minutes
1 : 1,000,000 16 to 40 minutes
1 : 2,000,000 120 minutes
1 : 5,000,000 Partial contraction in 3 hours
If an excised portion of the skin with melanophores contracted is placed in
ether water, the melanophores expand slowly, whilst the controls, in physio-
logical salt solution or in tap water, show no change.
Intra-muscular injections of adrenalin were made, and others of physio-
logical salt solution as controls. The results on the melanophores were in
every way comparable to those found for the excised portions of the skin;
that is, the melanophores contracted after injection of adrenalin at rates
varying with the strength of the injection. The minimum dilution found
effective was 1 : 5,000,000. An injection of 1 : 10,000,000 caused local con-
traction of the melanpphores in the area around the point where the injection
was made, but not in other parts of the skin.
The effect of adrenalin disappears after a time varying with the strength
of the injection and ranging from one to several hours.
If a fish, which has been injected with 1: 1,000,000 part of adrenalin, is
etherized when it has reached a condition of maximum contraction of the
melanophores, there is a perceptible darkening, due to partial expansion of the
melanophores. On coming out of the ether the fish returns to the light con-
dition, that is, its melanophores contract. If the fish is subsequently kept
in the dark the melanophores gradually expand.
Some fish were removed for a time from the water and two pieces of filter
ptaper, one moistened with physiological salt solution and one with a 1 : 100,000
solution of adrenalin were placed on the skin. After fifteen minutes, both were
removed. The area of the skin covered by the filter paper moistened with salt
solution had become lighter, but darkened rapidly on removal of the paper.
The portion covered by the paper moistened with adrenalin solution was
quite light, and remained so for about three hours. The influence of the
adrenalin spread only slightly to adjacent parts, but a light band appeared in
some cases where a little of the solution had run down from the paper.
60
ZOOLOGY: J. LOEB
From the above results it is seen that the melanophores in the skin of
Amiurus react to direct stimulation by adrenalin. They are also subject to
nervous control, and this control is mediated through the eye. There is also
a suggestion of the secretion of a hormone under certain conditions and of
its influence on the melanophores.
* Contributions from the Zoological Laboratory of the Museum of Comparative Zoology
at Harvard College, No. 306.
FURTHER EXPERIMENTS ON THE SEX OF PARTHENOGENETIC
FROGS
By Jacques Loeb
Rockefeller Institute for Medical Research
Communicated January 23, 1918
It seemed necessary to furnish proof that by the methods of artificial
parthenogenesis not only normal larvae can be produced from unfertilized
eggs but that these larvae can also develop into full sized normal adults.
This task is difficult to accomplish in sea urchins and thus far only Delage
has reported that he has succeeded in raising one parthenogenetic larva of a
sea urchin to the sexually mature form.
The possibility of producing artificial parthenogenesis in the eggs of the
frog by the method of puncture, as demonstrated in the experiments of Guyer
and of Bataillon, seemed more promising. The writer has made use of this
method for deciding the question whether such frogs can reach the adult size,
and determining their sex. He has now raised twenty leopard frogs to an age
of from ten to eighteen months, and nine of these frogs are still alive. Some
of these male frogs have reached the full size of the adult male leopard frog.
We are, therefore, entitled to say that the frogs produced by artificial parthenogenesis
can develop into adults of full size and of an entirely normal character.
Loeb and Bancroft1 tried to ascertain the sex of a parthenogenetic frog
immediately after metamorphosis but found the gonads in the intermediate
stage, i.e., testes containing a few eggs, though it was obvious that the frog was
developing into a male. It was clear that older frogs were needed for the
decision of the problem of sex. The writer has been able to ascertain the sex
in nine frogs of the age of from ten to eighteen months, and in all of these the
ambiguity inherent in the younger frogs had disappeared. He has already
reported that the first two of these parthenogenetic frogs has normal mature
testes containing fully developed spermatozoa.2 No eggs were found in these
testes.
The next four frogs examined were also males, so that the problem seemed
settled when a year ago last summer one parthenogenetic frog, sixteen months
ZOOLOGY: J. WEB
61
old, was found whose gonads were macroscopically and microscopically well
developed ovaries. The next frog was again a male. Although the possibility
of an error in method seemed excluded the writer did not wish to publish the
fact that both sexes appear in parthenogenetic frogs without having checked
the result by a new series of experiments.
These experiments were started in February, 1917. The same precautions
as in the older experiments were used. Copulating females which had not yet
laid any eggs were separated from their males and kept separated for at least
twenty-four hours. The females were repeatedly washed with water during
the time of isolation, and directly before the experiment were submerged in
90% alcohol and left there to die. They were taken out, their abdominal
cavity was opened with sterilized instruments and the oviduct laid bare. The
eggs were taken out from the oviduct with sterilized instruments, and precau-
tions were taken that the eggs did not come in contact with the hands of the
experimenter or with the skin or outside of the frog. Alternate lots of about
50 to 100 eggs were punctured or kept untreated as controls. None of these
non-treated eggs ever developed. From the punctured, unfertilized eggs ten
developed into frogs, of which nine are still alive. The tenth was killed
December 21 and the microscopic examination of its gonads showed that it
was a female. This leaves then no doubt that both sexes can be produced
from the unfertilized eggs of the frog. We have thus far obtained seven
male frogs and two females, while the determination in two was missed by
accident.
How can we account for the production of both sexes? The diploid num-
ber of chromosomes in the frog seems to be 26, according to Swingle,3 and,
therefore, the haploid number 13. The question then arises: Do we find the
diploid or haploid number of chromosomes in the cells of the parthenogenetic
frog? Brachet4 found the diploid number in the somatic cells of a partheno-
genetic tadpole eighteen days old, but, of course, it was out of the question
to ascertain the sex of the tadpole.
The gap can be filled by counting the chromosomes in the fully developed
parthenogenetic frogs. Thus far the sections of the testes of only one of the
writer's parthenogenetic frogs have been examined cytologically. This male
was seventeen months old, had reached the full size of the adult, and had large
testes with ripe spermatozoa. Prof. R. Goldschmidt, who was good enough
to examine some of the sections, counted over 20 chromosomes, and there
can be no doubt that this parthenogenetic male frog possessed the diploid
number of chromosomes. The writer has not yet been able to ascertain
whether the nuclei of the female frogs have the haploid or diploid number.
It is not known whether the female or male is homozygous for sex in the
frog. If the female were homozygous it would mean that the haploid num-
ber of chromosomes would be 12 + x and the diploid 24 + 2 x. In this
case only a female could have the diploid number since 2 x would determine
a female. Since we find the diploid number of the male parthenogenetic
62
PHYSICS: E. DERSHEM
frog the assumption of homozygosity of the female is inadequate if not ex-
cluded. If we assume that the female is heterozygous for sex, and that it
has the chromosome constitution 2A -\- x -\- y (where y maybe missing), the
male must have the chromosome constitution 24 + 2 x. The haploid num-
ber in the egg would be5 12 '+ x, and the diploid number either 24 + 2 x or
24 + x + y. The diploid number 24 + 2 x would give rise to a male, while
a female might be produced by either the haploid number 12 + x or the dip-
loid number 24 + x + y. It is, therefore, of some interest to find out whether
or not the female has the haploid number 12 + x chromosomes. It is use-
less to enter into further speculation until this point is decided, which the
writer hopes may be possible in the near future.
Summary. — The author has raised twenty leopard frogs produced by the
methods of artificial parthenogenesis from unfertilized eggs to the age of
from ten to eighteen months. Nine of these frogs are still alive. Some
have reached the size of the full grown normal adult male. Both sexes are
represented among the parthenogenetic frogs. Seven of the nine older frogs
whose gonads were examined were males, and two were females. The
parthenogenetic males possess the diploid number of chromosomes.
1 Loeb, J., and Bancroft, F. W., /. Exp. Zool., Wistar Inst., Philadelphia, 14, 1913, (275);
15, 1913, (379).
2 Loeb, J., these Proceedings, 2, 1916, (313); The Organism as a Whole, New York,
1916.
3 Swingle, W. W., Biol. Bull., Wood's Hole, 33, 1917, (70).
4Brachet, A., Arch. Biol., Paris-Bruxelles, 26, 1911, (362).
5 The other haploid number 12 + y may be left out of consideration for the present
since it is possible that such eggs may not be able to develop.
THE RESOLVING POWERS OF X-RA Y SPECTROMETERS AND THE
TUNGSTEN X-RAY SPECTRUM
By Elmer Dershem
Department of Physics, University of Illinois
Communicated by R. A. Millikan, February 11, 1918
This work was undertaken at the University of Iowa with the purpose of
determining the wave lengths and the number of lines in the X-ray spectrum
of tungsten with greater precision than had heretofore been done.
The method adopted was the well known photographic one in which the
crystal is slowly rotated so that it will progressively pass through all the
angular positions which are required for reflection of the incident X-rays as
demanded by the formula rik = 2 d sin 6, in which n is the order of the spec-
trum, X the wave length) d the grating constant, and 6 the glancing angle of
reflection.
PHYSICS: E. DERSHEM
63
Some of the conditions affecting the resolving power of an X-ray spectrom-
eter, that is the ability of the instrument to separate two waves of nearly
the same length may be derived by the aid of the diagram (fig. 1).
Assume a source, i.e., a slit, of width s and a crystal of thickness / and
assume that the absorption in the crystal is not so great but that some of
the rays may penetrate entirely through the crystal and being reflected from
the planes on the lower side again traverse the crystal and finally reach the
photographic plate B'A'C'D'. It is easily seen that there will be an image
on the plate equal in width to the width of the source s, due to reflection
from the upper surface alone. In addition there is a widening of the line
due to the part reflected from the lower planes equal to the line DE which is
drawn from P perpendicular to AAf. Then since DF = t = the thickness of
the crystal, t = AD sin 6 and AD = DE/sin 2 0 and by substitution
t = DE/sin 0 = \ DE/cos 0. Whence DE = 2 t cos 0.
Since DE is the width of beam due to penetration into the crystal the total
width of beam is s + 2 t cos 0 and this is the width of line on the photo-
graphic plate.
Crystal
FIG. 1 FIG. 2
In order to resolve two lines of nearly the same wave length it is neces-
sary that their images on the photographic plate should not overlap, that is
the centers of their images must be further apart than the width of beam,
s + 2 t cos 0.
Assume two wave lengths, X and X + AX, then to find how small AX may
be and still have the two wave lengths clearly separated on the plate: Using
the formula n\ = 2 d sin 0 let X take on a small increment AX and 0 the
corresponding increment Ad. Then by differentiation we obtain nA\ =
d cos 6 Ad.
From figure 2 we see that the angle of the crystal must be changed by the
amount A0 in order to reflect the wave of length X + AX instead of the one
of length X and that the reflected ray being rotated through twice this amount
is rotated through the angle 2A0. If the distance from the crystal to the
plate is r then the distance the beam has moved along the plate in changing
from X to X + AX is 2rAd and this distance must be greater than the width of
beam, s -\- 2 t cos 6. Thus
2rAS > s + 2t cos 0
64
PHYSICS: E. DERSHEM
But
Whence
AA>^i-V + 2/cosfl).
nr
Denning, as usual, the resolving power to be X/AX, we have by dividing X
by each side of the inequality
X ^ nr\
AX d cos 6 (s + It cos 6)
From this it is apparent that the resolving power may be increased by in-
creasing the order of the spectrum and the distance between the crystal and
the plate and also by decreasing the width of the source and the thickness
of the crystal. To increase the resolving power by any of these means re-
sults in a loss of intensity which must be compensated for by an increased
time of exposure. To secure the best results in any given case requires a
selection by experience of the Dest relative values of these quantities which
will depend upon the kind of crystal used and the hardness of the X-rays.
It is also apparent by an inspection of figure 1 that the true position of the
line on the photographic plate is to be obtained by measuring to the outer or
most deviated side of the image and then subtracting one half of the width of
the source. This does not in general coincide with the position of the most
intense part of the image and since the point of greatest intensity is the one
obtained by an ionization chamber method the latter can never give results
of the greatest accuracy.
In the experimental work the endeavor was made to obtain as high re-
solving power and as accurate measurements as possible. A Coolidge tube
with a tungsten target was used with a rock salt crystal to obtain the results
given in the table. These results are certainly accurate to within 0.1% in the
case of the L radiations and 0.8% in the case of the K radiations.
By the use of a crystal of rock salt which was first waxed to glass and then
ground to a thickness of 0.019 cm. the widening of the K lines due to penetra-
tion into the crystal was reduced to such an extent as to cause the doublets
to be clearly separated in the spectrum of the first order and this is not pos-
sible if the thickness of the crystal is not limited.
In the case of the L group of lines the resolving power as defined by the
above formula was less than 170 but nevertheless 19 separate and distinct lines
were obtained and this very naturally suggests that if it were possible to ob-
tain such resolving powers in X-ray spectroscopy as have been obtained in
A0
2d cos 0
nrA\
d cos 6
> s + it cos e,
PHYSICS: E. DERSHEM 65
The Tungsten X-ray spectrum
GLANCING ANGLE OF
WAVE LENGTH
REMARKS
REFLECTION FROM ROCK SALT
IN ANGSTROM UNITS
Lines of the L group
lo 10. o
1 . 45Z°
Woo lr
1 CO O O'
lo y .y
1 A 702
1 .11 L*
Strong
1 A° 7A C
14 .54. o
1 Ai A3
1.410* j
Very faint
16 19.9
1 .29/'
Medium
16 16.1
1 .280°
Very faint
16 l.l
1 .27o4
otrong
lz 04.4
1 1 roc
1 .25o°
Medium
12 44.0
1 .241"
Strong
12° 31.3'
1.2202]
12° 24.8'
1.2098j>
Very faint
12° 4.5'
1.1773J
11° 34.4'
1 . 1292
Weak
11° 13.3'
1.0953
Strong
10° 57.9'
1.0705
Faint
10° 54.3'
1.0648
Medium
10° 50.5'
1.0587
Medium
10° 40.6'
1.0427
Very faint
10° 29.8'
1.0253
Medium
9° 22.0'
0.9159
Bromine absorption line
7° 12.9'
0.7068
4
Medium
4° 55.5'
0.4833
Silver absorption line
Lines of the K group
2° 9.7'
0.2124
Strong
2° 6.8'
0.2076
Strong
1°52.0'
0.1834
Strong
1°49.0'
0.1784
Medium
the case of light by the aid of the grating and echelon the number of char-
acteristic X-ray lines would be found to be as great as the number of light
spectral lines are now known to be.
Many thanks are due to Professor Stewart and the Staff of the Physics
Department of the University of Iowa where this work was performed for
assistance in this research.
66
PHYSICS: BARUS AND BARUS
NOTE ON METHODS OF OBSERVING POTENTIAL DIFFERENCES
INDUCED BY THE EARTH'S MAGNETIC FIELD IN
AN INSULATED MOVING WIRE
By Carl Barus and Maxwell Barus
Department of Physics, Brown University
Communicated January 24, 1918
In Science, 45, 1917, p. 270, it was shown that the current induced in a
rod about a meter long by the earth's vertical magnetic field, could be made
surprisingly evident by the aid of an ordinary galvanometer, synchronized
with the period of the inductor pendulum, of which the rod acts as the bob
of a bifilar metallic suspension, including the galvanometer. Thus with a
galvanometer showing but 10~6 amperes per cm. of deflection, and with a
common period of about 4 seconds, the double amplitude of the spot of light
reached over 20 cm. per average knot of speed of the rod. Similar results
must be obtainable in case of a ship, where the charges accumulating at the
ends of a long transverse rod may be tapped off into the water; or in case of
a train where the tracks are available for dissipating charge. If, however,
the rod is insulated, the determination of the potential difference in question
is quite difficult. We made many attempts, as for instance the dissipation
of charge from the ends by radium, electric incandescence, etc., the magnetic
screening of parts of a circuit, etc., all to no practical effect. It seemed
necessary therefore to carry the charge from end to end of the wire bodily;
i.e., to reverse the principle of any type of induction electric machine, pos-
sibly with the additional object of securing intensification. Here also we have
no ultimate success to record; but the secondary results are not devoid of
interest, the idea being to construct, with precision, a large intensifier to pick
up whatever electrostatic potentials may momentarily or permanently exist
in the vicinity.
Simple Apparatus. — The apparatus (fig. 1), producing current is essentially
cylindrical in shape, large and capable of revolving around an axle a with con-
siderable speed. The electrical parts are of light metal, all insulated or
screwed firmly to insulating discs attached to the axle. This frame work
will not be shown in the figures.
A, A', A", A'" are four insulated plates adjusted like the staves of a barrel,
each making up about \ of its cylindrical area. Hence if the diameter of the
barrel is D and its length L the area of each segment is A = wLD/n, if there
are n segments. The plates A, communicate by means of metallic rods
s, s', s", s"', with the commutator segments or posts c, cr , c" \ c'" , each sys-
tem, A, s, c, etc., being insulated.
When the barrel revolves, a pair of brushes b b" serve to put the two seg-
ments A A" momentarily in contact when in the horizontal position. A
PHYSICS: BARUS AND BARUS
67
similar pair of brushes b' b'" put the segments A' A'" momentarily in contact
when in the vertical position. These brushes lead to the inclosed sensitive
galvanometer G. Hence there will be two contacts for each pair of segments A
for each rotation. B, B' are auxiliary insulated armatures and here removed.
Let the earth's vertical field be H and suppose the corresponding insulated
metallic spokes 5 s" in contact through b b". Suppose the barrel to move
forward as indicated at v in the direction of its axis, i.e., out of the diagram.
Then there will be an induced electric field F in the direction A" s" s A,
due to the cutting of the earth's vertical field. The result of the momentary
contact is thus a positive charge q on A and an equal negative charge on A".
When as a result of the rotation of the drum around its axis, the segments
reach the position A' A'" electromagnetic induction ceases and the field F
from this source is zero. Hence on momentary contact the charge will pass
through the galvanometer G. With continued rotation this process is indefi-
nitely repeated, so that a nearly continuous current flows through G; but there
is no intensification.
fig. 1
Elementary Estimate. — Let the drum move in the direction of its axis with
a speed v, so that the spokes s + s'f — D cut the earth's vertical field H at
this rate. Hence if the difference of potential between the plates A and A"
is V, when c and c" are in contact
V = HDv elm. units. (1)
Again when c and c" are insulated A and A" may be considered the plate
of a condenser and so long as the field within may be considered as virtually
uniform, we may estimate by Gauss's theorem
AV
4iD
Hv
4tt 3 X 1010
electrostatic units
(2)
where q is the positive charge on the area A.
Finally if the drum rotates
68
PHYSICS: BARUS AND BARUS
around its axis a with the speed of N turns per second and if there are n
segments, A, the corresponding mean current passing through the galvanom-
eter, with inclusion of the value of A above, on reducing to practical units
will be
/ = NDLHv/3.6 X 1020 amperes (3)
Let N = 100; D = 100 cm.; L = 100 cm.; H = 0.4 dynes per unit pole;
v = 50 cm./sec. or about 1 knot. Then
r 102 X 102 X 102 X.4 X 50 cvy1„l4
1 = 3 6 X 102D = amperes, nearly.
i.e., the current traversing the galvanometer per knot of axial motion through
the earth's vertical field would scarcely be perceptible by an extremely sen-
sitive galvanometer.
In our trial of the apparatus we used a disc pattern like figure 3, putting
both a galvanometer and a telephone in series, at G. On charging auxiliary
armatures like B, B" in figure 1, with a small Wimshurst machine, a loud rattle
was immediately heard in the telephone and the galvanometer showed an
average current of 2 X 10~6 amperes at about 10 (or less) rotations per
second. This slowly dropped owing to leakage of charge from the armatures;
but at least 10~6 amperes persisted indefinitely. Discharging the armatures
was followed with immediate permanent silence in the telephone. If we es-
timate the difference of potentials of the armatures as 104 yolts, and the earth's
field H (as above) to supply 5 X 10-5 volts, the latter should produce 5 X 10-5
(2 X 10~6/104) = 10-14 amperes, which is of the order of values computed.
Charging the armatures with 25 volts from a storage battery produced no
result, as was to be expected.
Intensification. — The drum was now to be modified as suggested in figure 2,
though the experiments below were carried out with the disc form, figure 3,
which is more easily constructed. All contacts must be synchronous and
momentary.
In the disc type of machine (fig. 3) (as here constructed about 2 feet in
diameter), A, B, C, D (in front) are the segments, rotating around the axis
m, and E, F the armatures behind the diagram. The metallic posts or com-
mutators a, b, c, d stick out normally from the disc both in front and behind
it. The vertical brushes d and b touching diametrically opposite posts in
front successively, include the galvanometer, etc., G, K being an insulating
holder. The horizontal brushes, g and h, in metallic connection with E
and F, respectively, touch the other two posts successively behind the disc
and store the charges of A and C on E and F.- H shows the earth's magnetic
field and v the motion through it.
If we suppose that any charge on the armature E, for instance, induces the
same but opposite charge on the segment B, the charges successively pass-
ing through the galvanometer for each quarter turn may be scheduled in
PHYSICS: BARUS AND BARUS
69
such a way that the sum is a geometrical progression. Thus for N turns
Q =Sg = (4/5)kNq coulombs, nearly, where k is a large empiric constant
depending on the method of initial charging and on the effective capacity of
the armature-quadrant condenser.
Finally if there are N turns per second and n = 4 segments, the average
current is in the first second:
/ = kNDLHv/1.8 X 1021 amperes.
W-<§
FIGS. 2 AND 3
Thus even if N = 10 turns for 1 second, 20 turns for 2 seconds, etc., the
current would soon be appreciable.
Observations with the Intensifier. — The telephone and galvanometer may be
inserted together and their indications as to intensity are identical; but the
galvanometer additionally shows the sign of the current. The average cur-
rent of 10-7 amperes could still be easily heard in the telephone. The elec-
70
PHYSICS: BARUS AND BARUS
troscope and electrometer were also tested; but these instruments are un-
suitable as on open circuit the potential may suddenly rise to sparking values
and ruin them.
Great care was taken to secure all insulators firmly and to allow only metal
appurtenances (brushes) to touch each other.
The sounds (taps) were usually strong on starting the intensifier. As the
speed increases to about 5 or 10 rotations per second a maximum of cur-
rent was reached. This may be an average current of =±= 10-5 amperes or more,
as specified. The current frequently has an approximately regular period of
reversal; as for instance (L, low current, here about — 2.5 X 10-6 amperes;
H, high current, + 5 X 10-6 ampere, both fluctuating).
Successive currents L H L H L H L H L H L H, etc.
Period of each (seconds) 25 30 30 30 30 35 45 35 40 35 45 35 etc.
The current is zero when the armatures are metallically connected. This
shows that stray magnetic lines from the motor are without direct effect, a
conclusion which was further tested by supplying stationary looped magnetic
lines from a strong horseshoe magnet. Left to itself the machine picks up
potentials either from within itself, incidentally, or from the room or sur-
sounding walls in cold weather; and these are much higher than any which
can be produced with a moving magnetic field. The machine, thoroughly
flame-cleaned on both sides, with armatures in contact, soon* charges itself,
the maximum potentials being usually approached by successive alternations
of rapidly increasing amplitude. Finally sparks appear at the brushes. If a
bunsen flame is near, its depolarizing effect is appreciable at about a foot;
the machine ceases to function at about six inches. Only under favorable
conditions were we able to build up potentials from the induction of a small
horseshoe magnet. It is obvious therefore that before putting such an ap-
paratus to the final test it will have to be constructed with precision and ex-
periments made in an environment free from stray potentials, with elimina-
tion of voltaic potentials, etc., in the parts, as everything of this nature is
so quickly assimilated and intensified. As to the means of rating the value
of the inducing potential, the current obtained on disconnecting the armatures
for a definite small interval of time suggests itself.
The efficiency is enormously increased by diminishing the distance between
the armatures and the rotating segments (condenser) though in the above
improvised apparatus it was not possible to approach closer than an average
half inch.
ASTRONOMY: C. D. PERRINE
71
DEPENDENCE OF THE SPECTRAL RELATION OF DOUBLE STARS
UPON DISTANCE
By C. D. Perrine
Observatorio Nacional Argentino, Cordoba
Communicated by E. B. Frost, January 7, 1918
In the course of an investigation of the cause of the spectral differences
of the stars, an examination of the spectra of the components of double stars
was made. Almost at once it was seen that there was a relation other than
the well known conclusion that in contrasted pairs the fainter component is
generally of the earlier type. It was found that such stars are almost invari-
ably very distant, and that the reverse generally occurs in the near pairs.
The principal data used in this investigation were taken from the obser-
vations of the spectra of 745 double stars made at Harvard and classified by
Miss Cannon.1 Seventy-eight stars were selected of which the spectra of both
components had been determined, having a difference of brightness of at
least half a magnitude and known to be either binary or to have common
proper motion.
It was noticed that the stars in which the fainter component was of the
earlier type were, in general, closer together than those in which the com-
panion was of a later type. The effect of distance on the separations of these
stars was investigated by means of proper motion. The result indicated a
greater average absolute separation in both classes than for the stars whose
magnitudes and spectral classes are nearly the same. Incidentally, however,
it was shown that the pairs in which the fainter component is of earlier type
are distant, whereas those in which the fainter companion is of later type,
with the exception of the stars both of whose components are of classes B
and A, are much nearer.
Of the stars selected, 24 have the fainter components of the same spectral
type, 26 have the fainter components of later and 28 of earlier spectral type.
The last two groups are given in detail in the tables following.
With the exception of the pairs (12 in number) of table 1, which have
both components of classes B and A and whose proper motions are less than
0".05, the remainder show large differences of spectral type and large average
proper motion. It is to be noted that 4 of the 12 stars with small /jl in this
table, having the fainter component of later type, belong to 15 Cephei. The
consistency in the spectral relations of this group is noticeable.
The pairs of table 2, with two exceptions, show small proper motions.
The proper motions of these two stars cannot be said to be large and it is fur-
ther to be noted that their differences of spectral type are rather small. The
1 Ann. Harvard Coll. Obs., Cambridge, 56, no. 7.
72
ASTRONOMY: C. D. PERRINE
average ju of the entire 28 stars is but 0".037, or omitting the largest two, is
but 0".030. The criterion of proper motion, therefore, indicates that these
stars are at the same general distance as the class B stars.
The stars of table 2 also show a decided preference for the galaxy, half of
them being within 15° and three-quarters of them within 40° of the galactic
plane. This is significant when it is considered that the principal stars of
these pairs belong almost entirely to the middle and later types of spectra.
TABLE 1
Fainter Component op Later Type
MA GN ITUDE
A
SPECTRAL CLASS
BRIGHTER
s
COMPONENT
MA GNIT UD K
Brighter
Fainter
5.6
0.9
A6
G5
0.143
„
23.7
5.2
2.6
F5
G
.295
49.4
6.0
0.7
Ac
A2
25
16.6
3.0
3.3
B6
A0
52
117.3
4.9
0.6
B8
A0
82
7.8
1.3
6.3
B8
G
.247
176.7
5.3
1.8
T?
-T 0
rv
.289
288.1
5.4
1.4
A0p
A3
29
145.3
0.3
1.4
Go
K6
3.67
21.9
2.9
2.2
A2
F5
.131
231.0 .
4.5
2.2
F0
K0
.169
108.3
4.3
2.2
B3
A
34
41.3
4.9
2.7
A2
F
65
88.8
6.0
0.6
B8
A
38
21.7
5.8
0.8
B3
A
22
35.7
4.6
1.9
A3
G?
.230
6.9
5.8
0.7
B3
B5
18
22.4
3.6
2.5
A5
K0
.107
337.1
4.8
2.7
B6
A
10
22.8
Var.3.4
4.4
B2
B3
8
46.0
'6.7
0.9
Bo
B9
13
183.4
]
6.8
0.8
B5
B9
13
136*1
]
6.7
0.1
Bo
B5
13
236.3
6.8
1.0
B5
B9
13
192.4
4.2
1.7
B9
A0
.121
26.9
4.8
4.8
Ap
K
.138
222.8
Further evidence is found in 19 of the Harvard stars which have com-
posite spectra and in 62 stars of Campbell's Catalog of Spectroscopic Binaries,2
in which the spectra of both components have been observed or strongly
suspected.
For both spectra to appear on a photograph, the difference in brightness
of the components of close binary stars will usually be small. On account
of the tendency for components of nearly the same brightness to have similar
2 Lick. Obs. Bull, Berkeley, 6, 1910, (46).
ASTRONOMY: C. D. PERRINE
73
spectra, the evidence from these two sources is not of as great weight as the
preceding. It is, nevertheless, quite definite.
Of the 19 Harvard composite stars, two are somewhat uncertain as to the
difference of spectral class, both being of early type. Of the remainder, the
one having the largest proper motion (0".15) has the fainter component of the
later type. The remaining 16 all have very small proper motions. Of these,
5 have the fainter component of later type and 11 of earlier type. All of
TABLE 2
Fainter Component of Earlier Type
MAGNITUDE
A
SPECTRAL CLASS
BRIGHTER
s
COMPONENT
MAGNITUDE
Brighter
Fainter
6.2
1.2
Go
A
0'018
2:9
4.3
0.9
A3
A
42
2.6
2.3
2.8
K0
A
70
10.7
5.0
1.4
G5
B?
34
6.9
5.5
1.2
G
A3
29
3.0
5.9
1.1
A0
B9
27
28.9
5.8
1.2
G
A
47
0.4
5.4
3.1
K
A
7
2.3
3.9
1.9
K0
G
97
13.3
6.4
0.5
G
Ao
rv2
41
63.4
4.2
2.4
G5
A2
54
30.6
5.2
1.5
K0
A3
17
20.6
5.3
0.5
A2
A
33
21.6
2.7
2.4
K0
A
49
2.8
3.5
4.5
K0
G0
155
104.8
1.2
5.8
Ma
A
34
3.2
6.4
1.1
K
F5
48
111.2
6.1
1.7
G
A
11
45.5
5.6
1.2
F5
A
13
0.6
7.1
1.0
G
A
42
4.1
6.0
1.5
F5
A2
18
15.0
3.2
2.1
K
B9
9
34.7
5.6
3.3
K0
A
34
19.8
6.5
1.1
F
A
Small
1.2
5.7
2.2
Go
A
20
89.9
6.1
0.
G5
A2
25
23.0
3.9
3.2
K
B8
2
107.1
3.3
2.8
G0
A0
28
205.2
the most strongly marked spectral contrasts have the fainter components of
earlier type and all but one of these 11 are well marked in respect to spectral
contrasts.
Of the 62 stars of Campbell's Catalog, 30 belong to types O and B and 23
to type A. It is reasonably certain, therefore, that all of the O and B stars
are distant and the probability is strong that most of the 23 stars of type A
74
ASTRONOMY: C. D. PERRINE
are distant also. Campbell concludes,3 I understand, that the rule that
when one spectrum is considerably fainter than the other, the spectrum of
the secondary is apparently of a slightly earlier type than the spectrum of
the primary, applies to these stars, which we have just found to be distant.
Both of these pieces of evidence are confirmatory of the condition pre-
viously found.
I have also examined several well known systems whose colors have been
observed, viz., a Herculis, rj Geminorum, 7 Delphini, tj Cassiopaeiae, £ Bootis,
]8 Cephei and 7 Leonis. These stars also show in general the same relation
to distance.
Careful consideration of the data seems to show beyond doubt that the
relation is to distance coupled with low galactic latitude. It cannot well
depend upon the actual separations of the stars, for the ranges in that respect
seem to be about the same in all of the groups. It can scarcely depend upon
the differences of mass of the conponents as indicated by their differences of
brightness, for a similar reason. There is a difference of absolute magnitude
between the two groups, but there seems to be no reason for suspecting a
relation in this case, whatever may be the bearing of such differences in
others.
It is not known whether both components of double stars were originally
of the same spectral type or not. Investigators have generally assumed that
they were. It is not possible to say, therefore, just what the course of change
has been. However, we may justly conclude, I think, that the conditions
are such in these regions as to produce opposite spectral effects in the com-
ponents. There can be little doubt that the fainter components are in general
also of smaller mass. The conclusion may be stated, therefore, in the fol-
lowing form: — The conditions appear to be such that if two stars of unequal
mass were introduced into the near region the smaller body would move
more rapidly toward the later stage than the larger one, whereas in the rela-
tively distant galactic regions the tendency would be for the smaller body to
become of earlier type more rapidly than the larger one.
This investigation also shows that the greatest differences in spectral type
are in general found among the stars whose components show the greatest
differences in brightness. The differences of brightness in the pairs having
the same spectra are consistently small for all types.
The results of this investigation seem to indicate with considerable force
that some external cause is operating in more or less definite regions of our
stellar system upon the conditions which produce spectral class.
The details have been given more fully in a paper which will be published
in the Astrophysical Journal.
*IMd.} 6, 1910, (47).
ASTRONOMY: C. D. PERRINE
75
HYPOTHESIS TO ACCOUNT FOR THE SPECTRAL CONDITIONS
OF THE STARS
By C. D. Perrine
Observatorio Nacional Argentino, Cordoba
Communicated by E. B. Frost, January 7, 1918
The peculiar behavior of double stars in the near and relatively distant
regions of the galaxy, which has just been discovered (these Proceedings, 4,
1918, 71), together with the well known preference of the stars of type B
for the Milky Way and the general preference of the later types for the nearer
regions of space, suggest the conclusion that spectral class depends largely
upon external causes.
Further study of the brightnesses and spectra shows that there is a strong
similarity between the brighter stars of early type if arranged in the order
B, O, gaseous nebulae, and the changes in the novae in their early stages.
As is well known, all of these objects are confined to relatively distant re-
gions in the direction of the galaxy. There is also reason to think that the
same cause which is believed to underlie the phenomena of the outbursts
in the novae may be a vital factor in the determination of spectral class among
the ordinary stars.
As a result of these investigations the following general hypothesis has
been formulated to account for the present classes of stellar spectra.
Hypothesis. — The cause is dual, depending upon the amount of cosmic
matter and upon phenomena of radiation and condensation. Many of the
A stars, the B and O stars, the planetary and irregular gaseous nebulae, the
novae and perhaps the Cepheid variables, are confined to the galaxy because
there the matter is sufficiently plentiful to cause an increase of energy, the
energy from the matter swept up being in excess of that lost by radiation.
The direction of spectral change under such conditions in toward the nebulae.
In the regions (distant or near) where there is little or no cosmical matter,
radiation will be in excess of the energy received from external sources and the
direction of change will be toward the late types.
In a considerable portion of the system the changes of spectral class may
be due simply to retardation.
The hypothesis may be further generalized as follows —
The spectral condition of a star depends chiefly upon its size and mass
and the external conditions of density of cosmical matter and relative veloci-
ties of star and matter.
Upon this hypothesis the stars are probably all pursuing one definite course
of very slow change toward extinction, but each individual star will be pur-
suing a course which may have many whole or partial cycles due to varying
external causes.
Details of this investigation are given in a paper which has been sent to the
Astro physical Journal.
76
NATIONAL RESEARCH COUNCIL
NATIONAL RESEARCH COUNCIL
MEETINGS OF THE EXECUTIVE COMMITTEE
Thirty-fourth Meeting — December 4, 1917
The meeting convened in the offices of the Council in the Munsey Build-
ing, Washington, D. C, and was called to order at 9.15 a.m. by the
Chairman, Mr. Hale.
Messrs. Marston T. Bogart, Russell H. Chittenden, George E. Hale, Arthur
A. Noyes, Raymond Pearl, S. W. Stratton, Charles D. Walcott, and, by
invitation, W. F. Durand and Charles E. Mendenhall were present.
The minutes of the meeting of the Committee of November 10 were
approved as prepared and submitted to the members of the Committee.
The Chairman of the Council reported:
1. That Col. P. D. Lockridge, Acting President of the Army War College, and Capt.
Roger Welles, Director of Naval Intelligence, U.S.N., have been appointed members of
the Council and of its Military Committee.
2. That at a recent meeting of the Military Committee the request of the British Min-
istry of Munitions, and a later communication from the British War Mission, relative to the
organization of an experimental liaison were considered, involving the appointment of a
competent group of American scientists to secure adequate intercommunication between
English and American industrial and military projects and development. This request
was cordially received and approved, having already received the approval of the Executive
Committee. A full discussion of the subject at meetings of the Military Committee, how-
ever, led also to the approval of the organization of a more extensive program, involving
intercommunication between the entente allies on all subjects of industrial and scientific
importance. A subcommittee, consisting of the Director of the Bureau of Standards, the
Acting President of the Army War College, and the Director of Naval Intelligence, was
appointed to submit recommendations with regard to the procedure necessary to establish
this liaison, under direct authority of the War and Navy Departments of the Government.
A financial statement, showing expenditures since the last monthly meet-
ing of the Committee, was submitted and approved.
Upon recommendation of the Vice-Chairman of the Engineering Com-
mittee, the following were added to the membership of this Committee:
Comfort A. Adams, Harvard University; Jesse Coates, Consulting
Engineer.
Mr. Durand reported for the special committee, consisting of himself and
Messrs. Millikan and Stratton, which was appointed to undertake the selec-
tion of a larger committee to consider the organization and various problems
of the Patent Office. As a result of discussion the following members of
such a committee were appointed:
Leo H. Baekeland, William F. Durand, Thomas Ewing, Frederick P. Fish,
Robert A. Millikan, Edwin J. Prindle, Michael I. Pupin, S. W. Stratton.
Upon recommendation of the Chairman of the Chemistry Committee,
NATIONAL RESEARCH COUNCIL
77
Lieut. Col. Wm. H. Walker was added to the membership of this Committee
and Frederick W. Brown, of the Bureau of Soils of the U. S. Department of
Agriculture, was named a member of the Subcommittee on Chemistry of
Soils and Fertilizers.
The Chairman of the Chemistry Committee also reported that a donation
of $100 a month had been received from B. T. Bush of the Antoine Chiris
Company of New York to assist the work of this Committee. Upon motion,
the Executive Committee tendered a vote of thanks to Mr. Bush for his co-
operation and financial assistance in this connection.
The Chairman of the Council reported upon conferences which had been
held relative to the organization and work of the proposed Forestry Com-
mittee and submitted for consideration a list of persons who might be favor-
ably considered for appointment as members of the Committee. After dis-
cussion it was voted that a special committee, consisting of Irving W.
Bailey, Raymond Pearl and Karl F. Kellerman, be appointed to consider
the organization and duties of the Forestry Committee of the Council as a
correlating agency for research in this field and to submit to the Executive
Committee recommendations with regard to the personnel of the Forestry
Committee, the proposed scope and functions of this Committee, and its
status in the general organization scheme now under consideration relative to
the future activities of the Council.
Mr. Stratton, for the Subcommittee of the Military Committee, appointed
to submit recommendations with regard to procedure necessary to establish a
scientific liaison between the entente allies, submitted a report with recom-
mendations which had been adopted by the Military Committee at its meet-
ing of December 3. These recommendations were considered carefully by
the Executive Committee and, after certain minor modifications, were adopted
as follows:
In order to facilitate the securing and dissemination of scientific and technical industrial
information for military purposes, the Military Committee of the Research Council recom-
mends as follows:
1. There shall be a committee known as the Research Information Committee, to con-
sist of the Chief of the Military Intelligence Section of the Army, the Director of the Naval
Intelligence Bureau of the Navy, and a representative of the National Research Council to
be nominated by the Chairman of that body and appointed by the Council of National
Defense, who shall be Chairman of the Committee.
2. A scientific and technical industrial representative of the National Research Council
shall be attached to the offices of both the Naval and Military Intelligence in London, Paris,
and such other countries as may be considered desirable, and the said representative together
with the said military and naval attaches shall form a committee at each station acting as
a subcommittee of the Research Information Committee.
3. The duties of this Committee shall be to provide for the collection of scientific and
technical industrial information relating to military and naval affairs at home and abroad
and for the dissemination of the same to the Governmental departments interested both at
home and abroad.
4. This Committee shall be provided with a permanent secretary, and with the clerical
78
NATIONAL RESEARCH COUNCIL
and office facilities requisite for such files, indices and correspondence as the Committee
may direct.
5. In addition to the usual duties in connection with the keeping of files, indices, conduct
of correspondence, and so forth, the especial duty of the Chairman of the Committee shall
be to assist the proper officials in securing, locating, and disseminating the information
required, under such rules and regulations as the Committee may formulate from time to
time.
6. When scientific and technical industrial information is required which involves inves-
tigation to be made in cooperation with foreign civil authorities or military authorities not
at the front, the investigators selected shall be duly vouched for by this Committee and
shall be accredited by it to the Research Information Committee abroad.
Upon motion of Mr. Noyes it was voted that these recommendations be
transmitted to the Council of National Defense with such additional details
relating to the cost and organization of the proposed liaison as may be for-
mulated by the subcommittee of the Military Committee in consultation
with the Chairman of the Council.
The Chairman of the Council reported that the Committee on Organiza-
tion had tentatively considered a scheme for the organization and future
development of the Council, copies of which were laid before members of the
Executive Committee. Extended discussion took place, after which it was
decided to hold another meeting of the Executive Committee in the near
future to continue such consideration.
The Chairman of the Council was requested to appoint a special committee *
to consider the acquisition of adequate office accommodations in Washington.
The meeting adjourned at 1.30 p.m.
Thirty-fifth Meeting, December 19, 1917
The meeting convened in the offices of the Council, Munsey Building,
Washington, D. C, and was called to order at 9.15 a.m. by the Chairman of
the Council, Mr. Hale.
Marston T. Bogert, Russell H. Chittenden, Edwin G. Conklin, Gano Dunn,
George E. Hale, Van H. Manning, R. A. Millikan, Arthur A. Noyes, Ray-
mond Pearl, S. W. Stratfcon, Victor C. Vaughan, Charles D. Walcott, and, by
invitation, William F. Durand and John C. Merriam were present.
The Chairman of the Council reported:
1. That arrangements have been made to lease the building at 1023 16th Street, Wash-
ington, D. C, for the offices of the Council, at a rental of $500 a month, and that a state-
ment of estimated office expenses of the Council, aggregating $29,250.00, for the year 1918,
has been submitted to the Director of the Council of National Defense.
2. That the resignation of Mr. Mendenhall as Chairman of the Committee on Rela-
tions with State Research Councils has been accepted and that Mr. Merriam, of the Uni-
versity of California, has been appointed Chairman of this Committee.
Upon suggestion of the Chairman, Mr. Merriam reported upon the pro-
posed scope and organization of the Committee on Relations with State Re-
search Councils. Upon motion the Committee on Relations with State
NATIONAL RESEARCH COUNCIL
79
Research Councils was requested to submit a report to the Executive Com-
mittee as soon as practicable, with recommendations concerning steps to be
taken to affiliate and closely coordinate the work of State Research Councils
with that of the National Research Council.
In extension of the discussion which took place at the meeting of the Ex-
ecutive Committee on December 4 relative to the reorganization and future
development of the Council, Mr. Hale spoke of the rapid extension of its work
and particularly of the importance of its Military Committee and of its gov-
ernmental associations, as well as of the necessity of basing any future scheme
of organization on the charter of the National Academy of Sciences, as an
official advisor of the Government.
A proposed plan of organization was laid before the Committee and tenta-
tively adopted as a basis for further consideration and discussion.
Mr. Dunn explained that the Engineering Foundation had expressed its
willingness and desire to furnish financial assistance in aid of researches which
might advisedly be undertaken by the National Research Council in the field
of engineering, and upon his suggestion, as Chairman of the Engineering
Committee of the Council, it was voted that the Executive Committee re-
quest the Engineering Committee to submit suggestions to the Engineering
Foundation with regard to financial needs for problems in engineering research.
The meeting, which adjourned at 11.40 a.m., was followed by two sessions
of a joint meeting of the Executive Committee of the Research Council and
of the Council of the National Academy of Sciences, at which discussion took
place with regard to the proposed organization of the Research Council and
its relations to the National Academy of Sciences.
Thirty-sixth Meeting, January 17, 1918
A joint meeting of the Council of tne National Academy of Sciences and
of the Executive Committee of the National Research Council convened at
9.30 a.m. in the offices of the Research Council at 1023 16th Street, Wash-
ington, D. C, with President Walcott of the National Academy of Sciences
in the chair.
Present: Members of Council of National Academy of Sciences: Russell H.
Chittenden, Whitman Cross, George E. Hale, William H. Howell, Charles
D. Walcott. Members of Executive Committee of National Research Coun-
cil: Marston T. Bogert, Russell H. Chittenden, George E. Hale, Van H.
Manning, Robert A. Millikan, S. W. Stratton, Charles D. Walcott, William
H. Welch. Also present by invitation: William F. Durand, Simon Flexner,
Charles E. Mendenhall, John C. Merriam, Robert M. Yerkes, and William
H. Walker.
The Chairman of the Council reported:
1. That an allotment of $29,250 has been authorized, by the President of the United
States, from the emergency appropriation at his disposal to apply toward the estimated
office expenses of the National Research Council for the year 1918.
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NATIONAL RESEARCH COUNCIL
2. That the building at 1023 16th Street has been rented by the Research Council, and
that the twenty-two rooms in the building have already been assigned to provide for the
growing activities of the Council.
3. That in accordance with the action of the Executive Committee at its meeting on
December 4, the proposed recommendations with regard to the organization of a Research
Information Committee have been submitted to the Council of National Defense. These
recommendations were approved, and authority issued for the establishment of three com-
mittees to inaugurate the proposed work. The Committee in the United States consist
of S. W. Stratton, Chairman, representing the National Research Council; Captain Roger
Welles, Director of Naval Intelligence, U. S. N.; and Colonel Ralph H. Van Deeman, Chief
of Military Intelligence Section, Army War College. The London Committee will consist
of Henry A. Bumstead of Yale University, representing the National Research Council,
together with representatives of the Army and Navy Intelligence Services to be appointed;
and the Paris Committee will consist of William F. Durand, Vice Chairman of the Engi-
neering Committee of the National Research Council, representing the Council, with repre-
sentatives of the Army and Navy Intelligence Services to be appointed. The State Depart-
ment has agreed to appoint Mr. Bumstead and Mr. Durand as Scientific Attaches of the
Embassies at London and Paris respectively. Mr. Harold D. Babcock, a physicist at the
Mt. Wilson Solar Observatory, has been appointed Technical Assistant of the Washington
Committee, and it is expected that he will report for duty on January 21, with offices in the
National Research Council building. A request has been made of the Council of National
Defense for funds to provide for the expenses of these three offices. Mr. K. T. Compton
of Princeton University has been appointed Technical Assistant of the Paris committee.
The resignation of Cary T. Hutchinson as Secretary of the National Research
Council was presented and accepted,
The resignation of Raymond Pearl as Chairman of the Agriculture Com-
mittee of the Council was presented and accepted.
Upon nomination of the Chairman of the Council, John Johnston, at present
in charge of the offensive gas warfare work of the U. S. Bureau of Mines,
was elected Executive Secretary of the National Research Council at an annual
salary of $5000, to take effect as soon as Mr. Johnston is able to accept the
appointment and devote his entire time to the work of the Council.
Upon recommendation of the Chairman of the Chemistry Committee, the
following subcommittee was appointed with Chairman as indicated:
Sub-Committee on Chemical Engineering: Chairman, Charles F. McKenna, 50 Church
Street, New York City.
The appointment of the Sub-Committee on Chemical Engineering was requested by the
American Institute of Chemical Engineers, and the Chairman was nominated by the
Institute.
The Chairman of the Chemistry Committee also reported that:
William J. Comstock, formerly of the Chemical Staff of Yale University, has come to
Washington to aid in the work of the Chemistry Committee, to which he will devote his
entire time, and that
The Chairman of the Chemistry Committee has been made a member of an Advisory
Committee of the War Trade Board.
Upon nomination of the Chairman of the Council, Charles B. Davenport
was appointed Vice-Chairman of the Anthropology Committee.
NATIONAL RESEARCH COUNCIL
81
Mr. Merriam, Chairman of the Committee on Relations with State Research
Committees, presented the following report:
It is the opinion of your committee that the greater part of the problem work of the
National Research Council can be handled most satisfactorily through the special commit-
tees or divisions established for research in specific fields of investigation. To a limited ex-
tent phases of these investigations of problems may be turned over to adequately organized
and supported research groups in different parts of the country, some of these groups rep-
resenting educational or research institutions and others being organized under the auspices
of state governments or state Councils of Defense.
As numerous important problems of research relate to the development of natural re-
sources, industries, consideration of health conditions, and other problems of a local na-
ture, it seems desirable in many cases to have an organization of research interests related
to the state, and if possible supported by it. Such organizations might, under existing
conditions, be best cared for as committees under the state Councils of Defense.
It is desirable to have the National Research Council so related to the state research
scientific committees that the results of their investigation may become quickly available
to the central office of the Council, and that the needs of the Council for work of a local
character may be met by the state committees.
Your Committee respectfully suggests the following definition of function, organization,
and relations of State Research Committees:
Function of State Research Committees. Problems involving local needs in the de-
velopment of natural resources, local industries, health conditions, or any matters to which
science may lend its aid; and problems involving local materials, industries, laboratories or
talent, development or use of which would contribute to the good of the nation as a whole
or in part, regardless of questions of needs of the state in which the investigation originates.
Organization of State Committees. In initial organization the state committee should
be small, but widely representative of fields of research. Additions to membership should
be made as actual research progresses. The committees should, at the outset, include
members of state boards covering work in which scientific research plays an important
part, and representatives of scientific organizations or institutions at which significant re-
search is in progress, especially institutions in which research committees are organized.
State research committees should at this time be organized as sub-divisions of state
Councils of Defense, where such councils exist.
Financial support of state committees should come from state funds received by way of
the state Councils of Defense, or from other special funds. It is in all cases desirable to
have secretarial organization permitting full correspondence on all matters relating to the
committee.
Relation of Research Council to State Committees. It is desirable to have the state
research committees affiliated with the National Research Council; the results of work of
these committees should be reported to the state Council of Defense and to the National
Research Council by way of either or both of these bodies; results obtained by the state
research committees should go to the Council of National Defense when needed.
It was voted that the above report be adopted as furnishing the mode of
procedure to be used by the National Research Council in directing its rela-
tions to state research committees.
The Chairman of the Council spoke at length with respect to the adoption
of an organization of the Council devised to meet immediate war needs. The
present organization, adopted in 1916 for a period of one year, is essentially
a peace organization. Under war conditions the Council is engaged almost
82
NATIONAL RESEARCH COUNCIL
exclusively in scientific and research work for the Army, Navy, War Indus-
tries Board, and other Government bodies, and the wide distribution of the
members of its committees has been a source of inconvenience and sometimes
of confusion. Such a war organization would involve the concentration in
Washington of comparatively few men representing the most essential work.
For convenience of operation, it is proposed that closely related subjects be
grouped in Divisions, to avoid such difficulties as have sometimes arisen from
the independent work of committees covering similar fields. The Executive
Committee of each Division is, in general, to be composed of the smallest pos-
sible number of representative men, living in Washington or closely in touch
with the work of the Government.
All of the old committees of the Council will remain in existence, to be called
upon for such work as the various Divisions may assign to them.
He then submitted to the members present a schedule of the proposed war
organization of the Council, which after discussion and upon motion was
adopted, as follows:
War Organization of the National Research Council
General Officers: Chairmen, Three Vice- Chairmen, Executive Secretary, Treasurer,
Assistant Secretary.
Executive Board: General Officers, the Chairmen and Vice-Chairmen of the eight Divi-
sions, the Chairmen of the five Sections of the Administrative Division, and mem-
bers at large.
1. Administrative Division: Sections on Foreign Relations; Governmental Relations;
Relations with State Research Committees; Industrial Relations; Educational Relations.
2. Military Division.
3. Engineering Division.
4. Division of Physics, Mathematics, Astronomy, and Geophysics.
5. Division of Chemistry and Chemical Technology.
6. Division of Geology, Mineralogy, and Geography.
7. Division of Medicine, Hygiene, Surgery, Anatomy, Anthropology, Physiology, Psy-
chology, and Zoology.
8. Division of Agriculture, Forestry, Botany, and Fisheries.
In adopting this plan, it was recognized that part of the work in Zoology would fall
within Division 8.
It was also voted that an Executive Committee of the Executive Board be
appointed to consist of the General Officers of the Council and of the Chair-
men of the Sections of the Administrative Division to serve between meet-
ings of the Executive Board for the consideration of current business.
Upon motion, the present officers of the Council were nominated and elected
as General Officers of the War Organization of the Council as follows:
Chairman, George E. Hale.
First Vice-Chairman, Charles D. Walcott.
Second Vice-Chairman, Gano Dunn.
Third Vice-Chairman, Robert A. Millikan.
NATIONAL RESEARCH COUNCIL
83
Upon motion of Mr. Hale the following additional officers were elected:
Executive Secretary, John Johnston.
Treasurer, Witman Cross.
Assistant Secretary, Walter M. Gilbert.
The treasurer was authorized to sign checks drawn on the bank accounts
of the Council in the Riggs National Bank and with the National Academy
of Sciences.
Upon further motion the following chairmen for sections of the Adminis-
trative Division were nominated and elected:
Section on Foreign Relations, S. W. Stratton.
Section on Relations with State Research Committee, J. C. Merriam.
Section on Industrial Relations, John Johnston.
Upon motion of Mr. Bogert, the Executive Committee of the Administra-
tive Division was requested to serve as a nominating committee for posi-
tions of Chairmen and Vice-Chairmen of the other Divisions and Sections of
the War Organization. Subsequently, Mr. Hale, as spokesman for the nomi-
nating committee, submitted recommendations resulting in the election of the
following persons to be the positions named:
Military Division, C. D. Walcott, Chairman; S. W. Stratton, Vice-Chairman.
Division of Physics, Mathematics, Astronomy and Geophysics, R. A.
Millikan, Chairman.
Division of Chemistry and Chemical Technology, M. T. Bogert, Chairman;
W. H. Walker, Vice-Chairman.
Division of Geology, Mineralogy and Geography, J. C. Merriam, Chair-
man; Whitman Cross, Vice-Chairman.
Division of Medicine, Hygiene, Surgery, Anatomy, Anthropology, Physi-
ology, Psychology and Zoology, Simon Flexner, Chairman.
The Executive Committee of the Administrative Division was also given
authority to make such further appointments as may be necessary to posi-
tions of Chairmen and Vice-Chairmen of Divisions and Sections of the War
Organization, and to determine the number of members at large to be ap-
pointed on the Executive Board.
Mr. Hale explained that preliminary work of organizations had already
been done in connection with the Divisions of Chemistry and Chemical Tech-
nology, of Geology, and of Medicine. Upon his recommendation, an Execu-
tive Committee of the Division of Chemistry 'and Chemical Technology was
appointed to consist of the following persons: Marston T. Bogert, John
Johnston, Arthur A. Noyes and William H. Walker.
He also explained that it is the purpose of the Division of Medicine to cor-
relate all of the medical research work bearing on the war, and that to this end
cooperative plans had been entered into through the Surgeon-General's office
of the Army and other military and civil research agencies.
Upon invitation, Mr. Merriam outlined the proposed work of the Division
of Geology, Mineralogy and Geography.
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NATIONAL RESEARCH COUNCIL
Mr. Hale emphasized the importance of undertaking at present the promo-
tion of industrial research in preparation for post bellum conditions and
activities. Upon his recommendation authorization was given for the ap-
pointment of an Advisory Committee for the Section on Industrial Relations
ft the Administrative Division of the Council, to consist of prominent leaders
of industry in the United States.
Inasmuch as the former membership of the National Research Council is
still maintained, it was decided, upon nomination of the Chairman of the
Council to request the President of the National Academy of Sciences to
appoint the following gentlemen, who will have an active part in the work,
as additional members of the Council: Henry A. Bumstead, Director, Sloane
Physical Laboratory, Yale University; Whitman Cross, Geologist, U. S. Geo-
logical Survey; Charles B. Davenport, Director, Department of Experi-
mental Evolution, Carnegie Institution of Washington; Frank W. DeWolf,
State Geologist of Illinois; Douglas W. Johnson, Professor of Physiography,
Columbia University; John Johnston, Research Department, American Zinc
Lead, and Smelting Company; Philip S. Smith, Administrative Geologist,
U. S. Geological Survey; Colonel Ralph H. VanDeeman, Chief of Military
Intelligence Section, Army War College; Lt. Col. William H. Walker, Assist-
ant Director of the Chemical Service of the National Army.
Mr. Stratton explained the proposed activities of the Research Informa-
tion Committee recently organized, and emphasized the need for the collec-
tion of information by the Research Council with regard to scientific activi-
ties and progress in the United States and abroad bearing upon the war.
Upon invitation of Mr. Hale, extended discussion took place relative to the
future work of the National Research Council in cooperation with the
National Academy of Sciences.
Cary T. Hutchinson, Secretary.
INFORMATION TO SUBSCRIBERS
Subscriptions at the rate of $5.00 per annum should be made payable
to the National Academy of Sciences, and sent to Williams & Wilkins Com-
pany, Baltimore, or Arthur L. Day, Home Secretary, National Academy of
Sciences, Smithsonian Institution, Washington, D.C. Single numbers, $0.50.
CONTENTS
Page
Genetics.' — The Effect of Artificial Selection on Bristle Number in Droso-
phila ampelophtla and its Interpretation . ... By Femandus Payne 55
Zoology.' — The Reactions of the Melanophores of Amiurus to Light and to
Adrenalin By A. W. L. Bray 58
Zoology.— Further Experiments on the Sex of Parthenogenetic Frogs . .
By Jacques Loeb 60
Physics. — The Resolving Powers of X-Ray Spectrometers and the Tungsten
X-Ray Spectrum By Elmer Dershem 62
Physics. — Note on Methods of Observing Potential Differences Induced by
the Earth's Magnetic Fleld in an Insulated Moving Wire
By Carl Barus and Maxwell Barus 66
Astronomy. — Dependence of the Spectral Relation of Double Stars Upon
Distance By CD. Perrine 71
Astronomy . — Hypothesis to Account for the Spectral Conditions of the
Stars By CD. Perrine 75
National Research Council. — Meetings of the Executive Committee
76
i
i
VOLUME 4 APRIL, 1918
PROCEEDINGS
OF THE
NUMBER 4
National Academy
of Sciences
OF THE
UNITED STATES OF AMERICA
EDITORIAL BOARD
Raymond Pearl, Chairman
Arthur L. Day, Home Secretary
Edwin B. Wilson, Managing Editor
George E. Hale, Foreign Secretary
J. J. Abel
J. M. Clarke
H. H. Donaldson
E. B. Frost
R. A. Harper
J. P. Iddings
Jacques Loeb
Graham Lusk
A. G. Mayer
R. A. Millikan
E. H. Moore
A. A. Noyes
Alexander Smith
E. L. Thorndike
W. M. Wheeler
I
Publication Office: Williams & Wilkins Company, Baltimore
Editorial Office: Massachusetts Institute of Technology, Cambridge
Home Office of the Academy: Washington, D. C.
INFORMATION TO CONTRIBUTORS
The Proceedings is the official organ of the Academy for the publica-
tion of brief accounts of important current researches of members of the
Academy and of other American investigators, and for reports on the meet-
ings and other activities of the Academy. Publication in the Proceedings
will supplement that in journals devoted to the special branches of science.
The Proceedings will aim especially to secure prompt publication of original
announcements of discoveries and wide circulation of the results of American
research among investigators in other countries and in all branches of science.
Articles should be brief, not to exceed 2500 words or 6 printed pages,
although under certain conditions longer articles may be published.
Technical details of the work and long tables of data should be reserved for
publication in special journals. But authors should be precise in making
clear the new results and should give some record of the methods and data
upon which they are based. The viewpoint should be comprehensive in giv-
ing the relation of the paper to previous publications of the author or of others
and in exhibiting where practicable, the significance of the work for other
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Manuscripts should be prepared with a current number of the Proceed-
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preparation and insertion. Particular attention should be given to arranging
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References to literature, numbered consecutively, will be placed at the
end of 'the article and short footnotes should be avoided. It is suggested that
references to periodicals be furnished in some detail and in general in accord-
ance with the standard adopted for the Subject Catalogue of the International
Catalogue of Scientific Literature, viz., name of author, with initials following
(ordinarily omitting title of paper), abbreviated name of Journal, with place
of publication, series (if any), volume, year, inclusive pages. For example:
Montgomery, T. H., /. Morph., Boston, 22, 1911, (731-815); or, Wheeler, W.
M., K'dnigsburg, Schr. pkysik. Ges., 55, 1914, (1-142).
Papers by members of the Academy may be sent to Edwin Bidwell Wilson,
Managing Editor, Mass. Institute of Technology, Cambridge, Mass. Papers
by non-members should be submitted through some member.
Proof will not ordinarily be sent; if an author asks for proof, it will be
sent with the understanding that charges for his corrections shall be billed
to him. Authors are therefore requested to make final revisions on the type-
written manuscripts. The editors cannot undertake to do more than correct
obvious minor errors.
Reprints should be ordered at the time of submission of manuscript.
They will be furnished to authors at cost, approximately as follows:
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Charge for first 100 copies $1.10 $1.45 $2.50 $2.50 $2.50
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Copyright, 1918, by the National Academy of Sciences
PROCEEDINGS
OF THE
NATIONAL ACADEMY OF SCIENCES
Volume 4 APRIL 15, 1918 Number 4
DYNAMICAL ASPECTS OF PHOTOSYNTHESIS1
By W. J. V. Osterhout and A. R. C. Haas
Laboratory of Plant Physiology, Harvard University
Communicated by G. H. Parker, February 7, 1918
Although a great amount of attention has been paid to photosynthesis,
nothing is known of the dynamics of the process. This aspect of the matter
especially deserves investigation as furnishing a new point of attack upon
this difficult problem.
We cannot analyze the dynamics of photosynthesis without first securing
accurate data. A preliminary difficulty lies in the control of temperature.
When leaves of land plants are exposed to sunlight, changes of temperature
at once take place in the leaf and it is found 4that even under favorable con-
ditions of control the temperature of the leaf may fluctuate as much as 10°C.
in a half hour period.
To avoid this difficulty, the writers have employed certain aquatic plants,
consisting of thin layers or filaments, whose temperature can be regulated
to a sufficient extent for the purposes of the investigation.
The fronds of the marine alga, Ulva rigida (sea lettuce), are so suitable for
this purpose that most of the experimental work was confined to them, al-
though other material was used for comparison. These fronds consist of
only two layers of cells and are so thin (about 0.078 mm.) that their tem-
perature remains very close to that of the surrounding liquid. A further
advantage of thin fronds is that gaseous exchange is extremely rapid.
To obtain data for the study of dynamics, it is necessary to determine at
frequent intervals how much photosynthesis has taken place. This was ac-
complished by a method elsewhere described.2 This method enables us to
measure quickly and accurately the amount of photosynthesis at definite
intervals, without subjecting the plants to an abnormally high concentration
of CO2 as has heretofore been customary.3 It depends upon the fact that
photosynthesis abstracts carbonic acid from the surrounding solution and
renders it more alkaline. By the use of indicators the degree of alkalinity, and
85
86
BOTANY: OSTERHOUT AND HAAS
consequently the amount of photosynthesis, can be determined with consid-
erable precision.
The amount of photosynthesis is approximately a linear function of the
change in PH value in the range here employed.
In order to measure the degree of alkalinity produced by Ulva under the
influence of sunlight, a piece of the frond was placed in a tube of Pyrex glass
rilled with sea water and closed as described elsewhere.2 The tube was then
placed in a large water bath (the temperature of which fluctuated less than
1°C.) in direct sunlight. If clouds interfered with the sunlight at any time
the experiment was rejected.
Since the plants produce CO2 by respiration this must be taken into consid-
eration. Experiments were conducted under precisely the same conditions,
except that light was excluded. They agree in showing that the respiration
was practically constant. It cannot, therefore, affect the form of the curve
of photosynthesis.
TABLE 1
NUMBER OF MINUTES
AMOUNT OF PHOTOSYNTHESIS
PERIOD
REQUIRED TO
TOTAL NUMBER OF
PRODUCE STANDARD
MINUTES EXPOSED
ALKALINITY
Observed
Calculated
1st
35.7
35.7
1
0.92
2nd
25.9
61.6
2
2.07
3rd
23.3
84.9
3
3.18
4th
21.7
106.6
4
4.23
5th
20.4
127.0
5
5.23
6th
20.3
147.3
6
6.22
7th
20.5
167.8
7
7.22
Average of 5 experiments at 27°=±=0.5°C.
In each experiment the procedure was the same. Freshly collected Ulva
(young, dark green fronds not more than 3 or 4 inches long) was placed over
night in running sea water and covered so that in the morning no light could
reach it. In starting an experiment the Ulva was placed in a closed tube in
sea water containing a trace of alcoholic phenolphthalein and exposed to light
until a definite shade of pink was produced.4 This shade of pink matched
that of a standard buffer solution (whose PH value was determined by the
gas chain) containing the same concentration of indicator as the sea water
(and observed in a Pyrex tube of the same size).
When the standard shade was attained, the time of exposure was noted.
The sea water was then poured out of the tube containing Ulva (the last drop
being removed by shaking), fresh sea water was added, and a new determi-
nation was made of the time required to attain the standard shade.
The results obtained are given in table 1 (average of five experiments).
The table shows that the time required to reach the standard shade steadily
diminishes until a constant value is reached.
BOTANY: OSTERHOUT AND HAAS
87
This result is surprising, but it has been confirmed by numerous experiments
on Ulva, as well as by experiments on Enteromorpha, Spirogyra, Hydrodictyon,
Potamogeton, and other plants.5
It is therefore evident that photosynthesis is a process which shows a
gradual acceleration until a steady rate is attained.6 A question of great in-
terest now presents itself: What is the cause of the initial acceleration and
why is a steady rate attained after a certain length of time?
The suggestion which first offers itself is that photosynthesis belongs to the
class of autocatalytic processes, in which the reaction is catalyzed by one of its
own products. Such reactions begin slowly but as more of the catalyzing
substance is produced the reaction goes on at an increasinlgy rapid rate
until it begins to slow down as the reacting substances are used up. If these
substances are constantly renewed, the reaction will not slow down but
continue to go on more and more rapidly.
In our experiments on photosynthesis the reacting substances are con-
stantly renewed.7 The substances entering into the reaction are presumably
carbon dioxide and water. The concentration of the water reiriains constant,
while as soon as the concentration of the carbon dioxide has diminished by
a very small amount it is brought back to the original point by the renewal
of the sea water.
If photosynthesis were an autocatalytic reaction, it should, under these
conditions, continue to increase in speed as time goes on. As a matter of
fact it soon attains a steady rate. This might be accounted for by sup-
posing that the concentration of the catalyst cannot exceed a certain amount,
being limited by its own solubility. But in that case the rate would increase
more and more rapidly up to a certain point and suddenly become stationary
when the limit of solubility was reached.8 This is not the case. The rate in-
creases rapidly at first then more and more slowly until it finally becomes
stationary.
It might be supposed that the speed of the reaction is checked by the ac-
cumulation of the products of the reaction. In that case, however, the rate
would not become constant but would gradually diminish to zero. Such in-
fluence of the products would be possible only in the case of a reversible reac-
tion and we have no ground for believing that photosynthesis comes under
this head.9
It might also be suggested that the rate becomes constant through the
operation of a 'limiting factor' such as lack of light, carbon dioxide, or of
temperature. But it is evident that the effect of such a factor would be
fully felt at the very start of the reaction and that it could not cause a gradual
falling off in the increase of speed.
This puts clearly before us a fundamental difficulty. The fact that the
rate increases most rapidly at first and then more slowly shows that photo-
synthesis is not an autocatalytic reaction in the usual sense of the word, for in
such a reaction10 the rate would increase slowly at first, then more and more
88
BOTANY: OSTERHOUT AND HAAS
rapidly as time goes on. We must therefore conclude that photosynthesis
belongs in a different category.
The key to the situation is furnished by the figures in the second column
of table 1 which show that if the reaction is catalyzed by a substance, it
must be produced more rapidly at first and then more and more slowly. - It is
also evident that this substance must be limited in amount and that when
its production ceases the rate of photosynthesis stops increasing and becomes
constant. We may assume that the rate of photosynthesis is proportional
to the amount of the catalyst, which we will call C. The figures suggest that
this substance may be produced in the manner characteristic of a monomo-
lecular reaction. We may therefore assume that C is produced by a substance
A, under the influence of sunlight, according to the monomolecular reaction:
A -»C.
We may now proceed to test this assumption by calculating the amount of
photosynthesis which is to be expected after the lapse of a given time.
According to the ordinary equation for a monomolecular reaction,
C = A - Ae
-KT
in which T is time, e is the basis of natural logarithms, and K is the velocity
constant of the reaction.
If the rate of photosynthesis is directly proportional to the amount of C,
we may, for convenience, put
Rate of photosynthesis = ^ = C;
dl
hence
On integration this becomes
A K K
When the rate has become constant we find that a unit amount of photo-
synthesis is produced in 20.4 minutes (average of the last 3 periods in table
1), hence the rate of photosyn theses at that time is 1 -~ 20 .4 = 0.049. This
is by assumption equal to C when A is completely transformed into C and
this is in turn equal to A at the beginning of the reaction. Hence A at the
start = 0.049. We may substitute this value in the equation and find the
value of K by trial. If we put K = 0.049 we get the values given in table 1.
Better agreement with the observed values is obtained by taking lower
values of K. This produces a gradual falling off in subsequent values, but
it is possible that this might actually occur if the experiment could be con-
tinued for a sufficient length of time.
BOTANY: OSTERHOUT AND HAAS
89
The agreement between the observed and the calculated values is very sat-
isfactory except at the start. In this connection it may be pointed out
that at the beginning of a reaction disturbances are to be expected.
It is therefore evident that the assumption justifies itself by giving an ade-
quate quantitative explanation of the observed results. The question then
arises whether it is a natural one. It would seem very probable that the
light produces a substance which accelerates the reaction and unless this
substance is produced in unlimited amount there must come a time when the
rate will become steady (or fall off). The assumption therefore seems to be
reasonable.
It is attractive to form a hypothesis as to the nature of the catalyst. One
might be tempted to suppose that it is chlorophyll but for the fact that some
plants which are deep green may not photosynthesize as rapidly as those
which possess less chlorophyll.11 It is of course possible that the less active
plants are deficient in some essential factor other than chlorophyll. On the
other hand it may be necessary for chlorophyll to be transformed by the
light from an inactive into an active form,12 so that the rate of photosynthesis
depends on the amount of 'active chlorophyll' present This would be anal-
ogous to the well known activation of enzymes by various means.
An equally satisfactory quantitative explanation is obtained if we suppose
the amount of photosynthesis to correspond to the amount of a substance
P, produced (under the influence of light) by the reaction
S^M-^P,
in which S represents a constant source, (i.e., a substance which does not
appreciably diminish during the experiment).
We may suppose that in the morning, before the frond is exposed to the
light, S alone is present. On exposure to light the formation of M and P
occurs. The amount of M will then increase until it reaches a constant value
(when its rate of formation is equal to its rate of decomposition) but the
value of P will continually increase, since it does not undergo decomposition.
When M has reached a constant value we find (putting K as the velocity con-
stant of the reaction M —*P) that the amount of M decomposed in 1 minute
(unit time) is KM; this is also the amount of P which is formed in 1 minute
and since the reaction S— >M produces just enough of M to balance the
loss of M (by transformation into P) the amount of M produced each minute
is KM. Hence if we start in the morning with S alone there will be pro-
duced each minute KM and all of this will be transformed into P except what
is present at any moment as M. Hence the amount of P produced in the
time T is KMT - M.
We may, for convenience, put M — 1 when it has attained its constant
value; the rate of increase of P is then constant and we find that it takes 20.4
minutes to produce 1 unit of photosynthesis. Hence KMT = 1. Substi-
90
BOTANY: OSTERHOUT AND HAAS
tuting in this equation the values of M and T we have 20.4 K = 1 whence
K = 0.049.
At the start of the reaction the value of M is 0: this gradually increases to
1 and remains constant. During this period of increase the value of M may
be calculated as follows: When M has reached its constant value (M = 1)
let us suppose that the reaction S — > M suddenly stops while M — > P con-
times; we shall find that if T minutes have elapsed after this occurrence, the
amount of M which has disappeared is 1 — e~KT. If the reaction S — > M
had not stopped it would have produced enough of M so that (in spite of the
fact that M is constantly decomposing) the amount of M remaining at the
time T would be just enough to balance the loss, or 1 — e~KT. Hence if we
start with nothing but S (the values of M and of P being zero) the amount
of M present after the lapse of any given time T will be 1 — e~KT and the
amount of P will be
p = KT - (1 - e~KT)
This becomes the same as the equation
when in the latter we put K = A as was done in making the calculations
given in table 1. Hence when we substitute the value K = 0.049 in the
equation P = KT — (1 — e~KT) we obtain the values already given in
table 1.
If the chlorophyll takes part in the reaction by decomposing or by com-
bining (as some recent evidence indicates), we might suppose that S repre-
sents inactive chlorophyll, M active chlorophyll and P a derived substance
which combines with C02. At present it does not seem profitable to at-
tempt a more extended discussion of this question. But it may be pointed
out that (as one of us has recently emphasized)13 consecutive reactions of the
type here discussed, are to be looked upon as the rule, rather than as the
exception, in living matter.
It is evident that either of the theories developed above gives a quantita-
tive explanation of the results. Both seem to be based on reasonable assump-
tions. Future investigation must decide which is more useful.
In any event, it is clear that much is to be learned concerning the dynamics
of photosynthesis, and it is hoped that the considerations here set forth
may be of value in this connection.
Summary. — Viva which has been kept in the dark begins photosynthesis
as soon as it is exposed to sunlight. The rate of photosynthesis steadily in-
creases until a constant speed is attained.
This may be explained by assuming that sunlight decomposes a substance
whose products catalyze photosynthesis or enter directly into the reaction.
Quantitative theories are developed to account for the facts.
PHYSICS: K.-L. YEN
91
1 Preliminary communication.
2 The paper will appear shortly in Science, New York, N. S., 1918. All the precautions
mentioned in this account were carefully observed in the present investigation.
3 The methods previously used in studying the photosynthesis of aquatic plants are
not as accurate as the one here described, nor do previous experiments afford the kind of
data needed for our purpose. Cf. Blackman, F. F., and Smith, A. M., Proc. Roy. Soc,
London, (B) 83, 1911, (389).
4 All matching of shades was done under a 'Daylight' lamp, so that uniform conditions
were assured throughout the experiments. Cf. Science, New York, N. S., 42, 1915, (764).
A clear space was left in the tube below the Viva to facilitate comparison of colors. In
any single experiment the buffer may be dispensed with by using as a standard the pink
solution produced by the first exposure. The first exposure should be as short as is con-
sistent with obtaining a definite standard. Experiments showed that the trace of alcoholic
phenolphthalein had no injurious effect.
5 In experiments on fresh water algae a small amount of sodium bicarbonate was added
to the water.
6 This acceleration is not due to the increase in the intensity of light as the sun gets higher
for it was also observed when the experiments were started at noon.
7 When the sea water is not changed during the experiment the curve rises more rapidly
at first then bends over to the right as the supply of CO2 is used up.
8 This is because the catalyst from the moment of its production is in solution. It is
not analogous to a solid going into solution, which dissolves more slowly as the limit of solu-
bility is approached.
9 While respiration is in a sense the opposite of photosynthesis the steps in the process
are apparently quite different from those found in photosynthesis.
10 1, e., under the conditions of the present experiment, where the reacting substances
are kept approximately constant in composition.
11 Aquatic plants taken directly from ice-covered ponds in winter are found to possess
but feeble photosynthetic power, though of a deep green color.
12 The activation of substances by light is well known in photochemistry.
13 /. Biol. Chem., New York, 21, 1917, (585); 22, 1917, (23).
MOBILITIES OF IONS IN AIR, HYDROGEN, AND NITROGEN
By Kia-Lok Yen
Ryerson Physical Laboratory, University of Chicago
Communicated by R. A. Millikan, January 21, 1918
In spite of the great number of investigations devoted to gases the ques-
tion whether an ion is a molecule or an atom carrying an elementary charge,
or whether it is a number of neutral molecules clustering about a charge is
not as yet definitely settled. Both the ' cluster' hypothesis, according to
which an ion is conceived of as a unit elementary charge surrounded by a
satellite of neutral molecules, and the ' small-ion' hypothesis, according to
which an ion is conceived of as a single molecule carrying an elementary
charge, explain equally well the phenomenon which first necessitated the
former, and also the older, hypothesis; this phenomenon being the fact that
the mobilities and the diffusion coefficients of the ions in gases are relatively
PHYSICS: K.-L. YEN
small in comparison with those of the uncharged molecules in the same gases.
They also explain equally well a certain number of other phenomena, but
experiments designed to test directly the validity of one or the other of these
hypotheses led to contradictory results.
The measurement of the mobilities of ions under various pressures and
different electric field-strengths has always been generally conceded as the
mode of attack in the solution of the problem. For if the older, the cluster,
hypothesis is true the cluster would break up when the ion acquired a suffi-
ciently high kinetic energy and the mobility would increase abnormally. But
if the small-ion theory is true there would be no such dissociation and the
mobility would remain normal. Quite a number of such measurements have
been made, and they gave contradictory results. For instance, Latty,1
Kovarick,2 Todd,3 Townsend,4 Franck,5 Moore,6 Haines,7 and Ratner8 found
the mobility to increase abnormally, whereas Chattock,9 Wellisch,10- 11 and
Loeb12 found it normal over a wide range of potentials applied. In view
of these results further experiments seemed desirable and hence the work
herein described was undertaken.
The method here employed was the Rutherford13-Franck14 method as em-
ployed by Loeb.12 The apparatus was fully described in Loeb's articles.
Results: a. Air. — An attempt first to repeat Loeb's work with air gave the
following results:
TABLE 1
Table of Results Obtained for Ionic Mobilities in Air, February-March, 1917
u+
u-
X+ .
X-
P
K+
K-
R
1. 60 cycles, 119 volts
1.12
1.75
168
134
746
1.10
1.72
1.56
1.12
1.75
168
134
746
1.10
1.72
1.56
1.12
1.75
168
134
752
1.10
1.73
1.56
1.25
1.73
168
134
742
1.22
1.70
1.38
Mean
1.14
1.72
1.51 .
2.
14,758 cycles, 5000 volts
1.64
1.98
14,160
12,870
752
1.62
1.92
1.21
1.57
1.84
14,160
12,870
750
1.56
1.82
1.17
1.64
1.98
14,160
12,870
749
1.61
1.95
1.21
1.57
1.84
14,160
12,870
746
1.55
1.81
1.17
1.82
2.10
13,810
12,650
692
1.66
1.92
1.17
2.26
2.61
12,300
11,550
558
1.66
1.91
1.16
Mean
1.61
1.90
1.18
Mean of both sets
1.37
1.81
1.34
U+ =
Mobility of positive ions. U — =
Mobility
of negative ions.
X = Field
strength in volt/cm. P = Pressure in mm. R = K — /K. K = Mobility at 760 mm. pres.
X - IP Max. - 20.70, Min. = 0.18. X + /P Max. = 22.04, Min. = 0.22.
PHYSICS: K.-L. YEN
93
It may be seen from the above table that the mean values of R, the ratio
of the negative to the positive mobilities, are different for the two frequencies
employed, and it appears as though the mobilities did vary — since the ratio
could not vary unless either or both of the mobilities did. But the following
considerations will show that this difference is ascribable to experimental
variations. In the first place, the results of different experimenters, and
even those of the same experimenter, show a maximum variation of almost
30%, for instance, from R = 1.16 to 1.37 (Wellisch), or from R = 1.15 to
1.93 (Loeb). Both of these authors attribute the variations to external varia-
tions of their experiments. Thus a slight external variation of some kind
is liable to cause such a variation in the ratio without the mobilities them-
selves being varied at all. Furthermore, if the mobilities tend at all to vary
with field-strength, their variations would be much greater than are mani-
fested since the field-strength is 168 volt/cm. in one case and 14,160 volt/cm.
TABLE 2
Results Obtained from the Measurements on Hydrogen, May- June, 1917
u+
u-
x+
X-
P
K+
K-
R
14,758 cycles, 4000 volts
5.51
8.20
6669
5668
748
5.43
8.10
1.49
5.92
8.20
6669
5668
748
5.81
8.10
1.38
5.51
8.20
6669
5668
746
5.40
8.10
1.49
8.20
12.21
5668
4723
518
5.58
8.35
1.49
14.94
20.99
4192
3524
290
5.70
8.15
1.41
14.94
20.99
4192
3524
300
5.84
8.35
1.41
Mean
5.56
8.19
1.45
in the other. Or, it may be said that even if the ratio* does vary about 20%
when the field-strength is increased from 169 to 14,160 volt/cm. (about
8333%), it may be considered constant for all practical purposes/ However,
there were enough of the experimental uncertainties to account for the
variation.
Thus the conclusion is that between the field- strength of 168 and 14,160
volt/cm. the mobility of the positive ions remains absolutely normal, and the
mobility of the negative ions remains normal also between 134 and 12,870
volt/cm.
These results more than amply substantiate those obtained by Loeb and
it is therefore quite safe to conclude that the evidences obtained so far point
decidedly in the direction of the small-ion theory.
b. Hydrogen. The results of the measurements in hydrogen with the high
frequency high potential field are shown in table 2.
It may be seen from the table that with a potential gradient of 6669
volt/cm. or X/p = 14.45, the positive mobility remains normal. The nega-
94
PHYSICS: K.-L. YEN
tive mobility also remains absolutely normal with 5668 volt/cm. or X/p —
12.15. Thus it may be concluded that the law Up = constant, where
U = mobility and p — pressure in mm. mercury, is verified for hydrogen
up to these limits.
Besides the normal positive and negative ions the existence of free negative
'electrons in hydrogen was proved. These electrons existed in abundance
when the gas was freshly prepared and disappeared entirely after the gas had
remained in the ionization chamber for about six or eight hours. The dis-
appearance of the electrons might conceivably be the result either of their
fast dissipation into the walls of the chamb*er or of their ready formation
of negative ions with the neutral molecules of either hydrogen or the im-
purities from the sealing wax that had evaporated into the chamber in the
meantime.
TABLE
u+
U-
x+
X-
P
K-
R
60 cycles
5.28
77.8
748
5.21
5.50
8.80
25.0
16.5
746
5.41
8.65
1.52
6.60
11.19
20.0
13.0
600
5.22
8.80
1.62
8.95
13.28
29.5
24.0
498
5.85
8.70
1.48
13.90
22.00
19.8
11.5
300
5.49
8.69
1.58
22.91
31.06
16.5
99.0
198
5.95
8.15
1.34
9.26
28.0
746
9.26
Mean
5.52
8.71
1.57
X - /P Max. = 12.15, Min. = 0.38. X + /P Max. = 14.45, Min. = 0.66.
An effort was made to search for the two other kinds of negative ions which
Haines claimed to have found.7 And as no trace of these other ions could be
found it was thought that the disposition of the apparatus employed might
not have been sufficiently adequate for their detection. Consequently it
was considered desirable to repeat Haines' experiment in order to rectify the
present method. Thus Haines' experimental conditions were reproduced as
exactly as possible according to his descriptions with the expectation of
obtaining similar results.
The results of this operation are shown in table 3.
These results agree with those obtained in the employment of the high
frequency high potential field in showing that no such intermediate negative
ions existed. This, together with a careful study of Haines' curves, led to the
conclusion that in so far as experimental results are concerned there is not a
scrap of evidence, either in Haines' results or in those obtained in the present
experiment, of these other species of negative ions which were claimed to
exist by Haines.
PHYSICS: K.-L. YEN
95
It may be proper to mention here that no sooner had the above conclu-
sion been arrived at than it received corroboration from Wellisch's latest
paper18 in which it was reported that no trace could be found of Haines' ions
B and C.
Incidentally an interesting fact was revealed in the comparison between the
two sets of curves. If was found that the amount of free negative electrons
present in the gas was smaller when under high than when under low poten-
tial. This would seem to suggest that the electrons — or some of them at
least — did actually attach themselves to neutral molecules when a high poten-
tial was applied and thus formed negative ions. This would not be at all
TABLE 4
Results Obtained for Nitrogen, July, 1917
u4
U-
x+
X-
p
K+
K-
R
1. 60 cycles
17.60
22.96
15.0
11.5
60
1.39
1.81
1.30
10.15
26.0
140
1.87
2.81
3.88
47.0
33.5
360
1.33
1.84
1.38
1.27
1.65
51.0
40.0
750
1.26
1.63
1.30
1.36
1.84
50.0
38.0
745
1.33
1.80
1.35
1.34
1.82
49.8
38.0
745
1.31
1.78
1.36
1.32
1.79
1.34
2.
14,758 cycles
5000 volts
1.31
1.84
17,670
14,880
750
1.29
1.82
1.40
1.31
1.84
17,670
14,880
745
1.28
1.80
1.40
1.31
1.84
17,670
14,880
742
1.28
1.80
1.40
2.76
3.93
13,910
10,110
360
1.31
1.86
1.42
2.76
3.93
13,910
10,110
345
1.26
1.78
1.42
1.28
1.81
1.41
Mean of both frequencies
1.30
1.80
1.38
X - /P Max. = 29.0, Min. = 0.05. X + /P Max. = 40.0, Min. = 0.07.
impossible since the tremendous velocity imparted to them by the high
field would enable them to produce ions from neutral molecules by attach-
ing themselves to the latter. It would be interesting to find out where,
that is, at what potential — other conditions remaining the same — this sort
of ionization actually would begin.
c. Nitrogen. — Table 4 shows the results of the mobility measurements in
nitrogen. The maximum potential gradient employed was 17,670 volt/cm.
for the positive and 14,880 volt/cm. for the negative ions. The mobilities
remained absolutely normal up to these limits and the law Up = constant
was found to be applicable here as it was in the case of air and hydrogen.
96
PHYSICS: K.-L. YEN
Here too an abundance of free negative electrons was found, although the
amount was not so great as that found in hydrogen under the same pressure.
Conclusion and Discussion. — As the results of the present experiment ex-
hibit no deviation from the law Up = constant it follows that both the posi-
tive and the negative ions did not disintegrate at the potentials employed.
It may be seen from the tables that the values of X/p were very close to the
values at which sparking would occur in the respective gases. And since the
cluster hypothesis demands the disintegration of the ions when the values of
X/p are much lower than those employed,15 it therefore follows that these
results are directly contradictory to this hypothesis.
On the other hand, the results are in perfect accord with the small-ion
hypothesis. Taking this in conjunction with the results of other experi-
ments, especially those of Wellisch and Loeb, there does not seem any question
at all regarding the validity of this hypothesis.
There remains, however, an experimental fact which the cluster hypothesis
seems to be able to explain better than the small-ion hypothesis, and that is
the difference between the mobilities of the positive and the negative ions.
For, if both the positive and the negative ions are single molecules carrying
elementary charges different only in signs, why should they have different
mobilities? Whereas if the ions are clusters the difference in their mobilities
may be ascribed to the difference between the numbers of molecules constitut-
ing the two kinds of ions.
This difficulty of the small-ion theory, however, is more apparent than real
in view of the recent theories as to the electronic constitution of matter. If
an atom consists of a positive nucleus surrounded by a satellite of negative
electrons held together by the attractive force from the nucleus, the phe-
nomenon of ordinary molecular collision must be attributed to the repulsion
between the two systems of negative electrons in the colliding molecules16,17.
Since, according to the small-ion theory, the only difference between the un-
charged molecules and the ions lies in the number of negative electrons in the
satellites — the negative ion having one more electron, and the positive ion one
less than the uncharged molecules — it follows that the only difference be-
tween the ordinary molecular collisions and the collisions between ions and
uncharged molecules is that between the numbers of electrons in the colliding
systems. It is only reasonable, therefore, to extend the conception . of the
ordinary molecular collision to cover the case of collision between ions and
uncharged molecules. Now since the negative ion has more of these peripheral
negative electrons than the positive ion it follows that the repulsion between
the negative ion and the uncharged molecule is greater than that between the
positive ion and the uncharged molecule; and the attractive force between
the negative ion and the uncharged molecule is smaller than that between
the positive ion and the uncharged molecule. This results in a difference in
the effective mean free paths of the two kinds jf ions. The positive ion, by
virtue of the greater attractive force existing between it and the uncharged
PHYSICS: K.-L. YEN
97
molecules, drags the latter more towards it and thus has a smaller effective
mean free path. The negative ion, with the smaller attractive force, has
a greater effective mean free path. As the mobility varies directly with the
mean free path, it can be easily seen why the negative ions have a greater
mobility than the positive ions.
But the above explanation would not be applicable to the case where the
ratio of the negative to the positive mobility is less than unity, for that would
mean that the attractive force between the negative and the uncharged mol-
ecule is greater than that between the positive ion and the uncharged mol-
ecule, which would be impossible according to the theory upon which the
explanation is based. Fortunately, in such cases the differences between the
positive and the negative mobilities are so small that they are well within the
limits of experimental fluctuations; consequently, until it is conclusively es-
tablished that there are cases where the positive mobilities are greater than
the negative by a quantity much too great to be accounted for by experimental
conditions, the above explanation seems to be the most reasonable one so far
advanced.
The detailed paper has been communicated to the Physical Review.
1 Latty, R. F., London, Proc. R. Soc, (A), 84, 1910.
2 Kovarick, A. F., Physic. Rev., Ithaca, N. Y., 30, 1910, (415).
3 Todd, Phil. Mag., London, (Ser. 6), 22, 1911, (791); June, 1913.
4 Townsend, J. S., London, Proc. R. Soc, (A), 85, 1911.
5 Franck, J., Ann. Physik, Leipzig, 22, 1906, (972).
6 Moore, Physic. Rev., Ithaca, N. Y ., 1912.
7 Haines, Phil. Mag., London, 30, 1915; 31, 1916.
8 Ratner, Ibid., 32, 1916.
9 Chattock, Ibid., 48, 1899, (401).
10 Wellisch, London, Phil. Trans. R. Soc, (A), 209, 1909.
11 Wellisch, Amer. J. Sci., New Haven, May, 1915; Phil. Mag., London, March, 1916.
12Loeb, Physic Rev., Ithaca, N. Y., 8, 1916, (633); these Proceedings, 2, 1916, (633).
13 Rutherford, Cambridge, Proc Phil. Soc, 9, 1898, (410).
14 Franck, Ann. Physik, Leipzig, 21, 1906, (985).
15 Townsend, Electricity in Gases, Oxford, 1915.
16 Rutherford, Phil. Mag., London, 21, 1911, (669).
17Millikan, The Electron, Chicago, 1917.
18 Wellisch, Phil. Mag., London, 32, 1917, (199).
98
PHYSICS: E. H. HALL
THERMO-ELECTRIC ACTION WITH DUAL CONDUCTION OF
ELECTRICITY
By Edwin H. Hall
Jefferson Physical Laboratory, Harvard University
Communicated February 16, 1918
In a paper* presented before the National Academy of Sciences in No-
vember, 1917, I discussed thermo-electric action in metals on the hypothesis
of progressive motion by the 'free' electrons only. I have now extended the
discussion to the case of dual electric conduction; that is, conduction main-
tained in part by the free electrons (electrons F) and in part by the associ-
ated electrons (electrons A), the latter passing directly from atomic union to
atomic union.
I do this because, though we may not at present have a satisfactory theory2
of electric conduction involving such action of the associated electrons, we
are equally far from having a satisfactory theory of conduction as a function
of the free electrons only.
I take it as self-evident that, whereas electric potential-gradient acts upon
both free and associated electrons, tending to carry them in the direction of
decreasing negative potential, free-electron pressure-gradient acts on the free
electrons only. The necessary result of this consideration is the conclusion
that, if electrons (A) as well as electrons (F) can move progressively through
a metal, we shall, in a detached bar of metal having a temperature gradient
from one end to the other, have a constant procession of free electrons from
the place of high electron-gas pressure, the hot end of the bar, toward the
place of low pressure, the cold end, while an equal procession of associated
electrons moves in the opposite direction. For the mechanical tendency of
the free electrons toward the cold end maintains an excess of negative poten-
tial at this end, with a corresponding deficiency at the hot end; and the elec-
tric potential-gradient thus established drives associated electrons from cold
to hot, while it opposes, without being able entirely to prevent, the movement
of free electrons from hot to cold.
The state of mobile electrical equilibrium thus presented to our imagination
involves no violation of commonly accepted principles. The slight, extremely
slight, reduction of electron mechanical pressure below the normal equilibrium
pressure at the hot end of the bar induces there continual passage of the
electrons from the associated to the free state, evaporation, let us say, with
absorption of heat. At the cold end, on the other hand, the very slight ex-
cess of electrical mechanical pressure, above the normal value proper to the
temperature, induces continual passage of electrons from the free to the asso-
ciated state, condensation, let us say, with release of heat, The whole opera-
tion carries heat from the hot to the cold end of the bar, and it is, in fact,
PHYSICS: E. H. HALL
99
somewhat analogous to the action of a steam heating- system, the free-electron
movement corresponding to the stream of steam and the associated electrons
movement to the return flow of the water.
My conception of the action, for a case in which there is no lateral loss or
gain of heat, is set forth diagrammatically in figure 1, in which the dotted
lines indicate movement of the free electrons and the full lines movement of
the associated electrons.3
In my previous paper,1 dealing with the hypothesis of progressive motion of
'free' electrons only, I rejected as unnecessary the assumption of a specific
attraction of metals for electrons. But with the more complicated condi-
tions dealt with in the present paper we cannot avoid this assumption; for
without it we should have thermal conduction without initial difference of
temperature, and so a violation of the second law of thermodynamics, in a
bar of alloy varying in composition from metal a at one end to metal /3 at the
other. There must be no progressive movement of free electrons from one
end to the other, or of associated electrons in the opposite direction, in such
a bar. The superior mechanical pressure of the free electrons at the a end
will produce a slight initial movement establishing a potential gradient along
C
FIG. 1
the bar, the a end becoming positive and the /3 end negative; but the influ-
ence of this potential gradient on the associated electrons must be offset by
a specific atomic attraction directed toward the /5 end. It is reasonable to
suppose that the smaller free-electron density at the /5 end is due to the
superior attraction of the (3 positive nucleus compared with the a nucleus.
The resulting equilibrium, the inhibition of circulation of the electrons from
one end to the other of the bar and back, is analogous to the equilibrium in
a system made up of water, water-vapor, and a solution-column sustained by
osmotic pressure. The upper end of such a column, with its reduced vapor-
pressure, corresponds to the (3 end of our bar with its small free-electron
pressure. The force of gravitation, directed from the top to the bottom of the
column, is analogous to the electrical potential gradient from the (3 end toward
the a end of the bar.
Naturally the question arises whether a bar of one metal having a tem-
perature gradient, and a free electron density rising with the temperature,
has not a differential specific attraction tending to move electrons toward
the cold end. There may be such an attraction, and it will be well for us to
take account of it, but where there is a temperature-gradient we are not
100
PHYSICS: E. H. HALL
obliged to suppose a dead-lock between the potential gradient and this differ-
ential specific attraction. The conception of electron circulation, with thermal
conduction (or convection), in a detached unequally heated bar survives the
admission of specific attraction; but the whole matter now becomes more
involved.
In addition to the potential, P, due to electric charge, we must now think
of a potential, Pa, due to the differential attraction of the unequally heated,
unhomogeneous, metal for the associated electrons, and also of a potential,
Pf, due to the differential attraction of the metal for the free electrons.
Both classes of molecules are subject to the charge-potential P, but elec-
trons (A) only are subject to the potential Pa, and electrons (F) only are
subject to the potential Pf.
Under hypothesis (A): If we assume, as hypothesis (A), that the mechanical
tendency of the free electrons, if acting without electric forces, would produce
equality of pressure from end to end of the bar, the condition of equilibrium
(see fig. 1) in a detached bar hot at one and cold at the other is
g.fl + d{P + Fb).nedl) + nmdAne = - (1)
dl dl J J dl
where (dp/dl) is the gradient of mechanical pressure of the free electrons
along the bar of length /, n is the number-density of the free electrons in the
metal, m is the mass and e the charge of an electron, \x is the coefficient of
mobility of the free electrons through the metal, and ka is the electric con-
ductivity of the metal, so far as conductivity is due to the electrons (A).
A simple formula,
\_
where G is (1/m), connects /j, with the free-electron specific conductivity,
kf. Evidently
G — nv, (3)
where v is the volume of one gram of free electrons in the metal.
Very simple operations, using equations (2) and (3), derive from (1) the
form
r*h
- -^-.dPa = ~- T~.vdp, (4)
kf Ge J ka + kf
*. + *, JkK +
in which the integration extends from the hot end (h) to the cold end (c)
of the bar.
The first member of this equation is the amount of reversible work that
would be done by or on the unit quantity of electricity in passing through the
bar, if it were made part of a closed thermo-electric circuit. This is something
different from, probably smaller than, (Pc — Ph), which is the charge poten-
PHYSICS: E. H. HALL
101
tial-difJerence between the two ends of the bar. The quantity expressed by
the whole first member I shall call the virtual e.m.f., resident in t,he bar be-
cause of its temperature gradient.
The form of the second member shows that the virtual e.m.f. can be repre-
sented by an area on the P-V plane. Thus, if the line A D in figure 2 rep-
resents the pressure-volume relations of the free electrons for the whole
length of the bar, so that
ch
area EADG = I vdp,
we shall have
area EA'D'G = I Kf .vdp,
ka + kj
FIG. 2
provided we make the width of this area correspond at every height to the
value of kf/ (ka + kf) for that height.
Without the conception of dual conductivity and specific attraction we
should, as my previous paper1 shows, have in place of (4) the simple equation
GeX^
with dual conductivity but without specific attraction we should have
th
ka + k
vdp.
Obviously, then, the participation of the electrons (A) in the conductivity
reduces the e.m.f. due to the temperature gradient in the bar. In fact, the
part which associated electrons play in thermo-electric action is analogous to
that played by entrained water in the work done by steam. The larger the
102
PHYSICS: E. H. HALL
proportion of water, the smaller is the mechanical effect per unit mass of the
mixture.
In the isothermal alloy 'bridge/ of composition varying from pure a at
one end to pure 0 at the other end, which is supposed to connect the two
metals at their hot or at their cold ends, we must have, when it stands de-
tached, no cyclic movement of the electrons. Accordingly we get, in place
of equation (1), the two equations
dP
and
dP + dPf =
dP„ = 0
dp
ne
(5)
(6)
FIG. 3
These lead to the following, as the expression for the virtual e.m.f. due to
the non-homogeneity of the isothermal bridge: •
(dP + dPf)
(7)
The first member of (7) is the reversible work that would be done, on the
free electrons only, during the passage of the unit quantity of electricity
through the bridge.
The expression for the work done on the electrons (A) is absent here, for the
reason that, according to equation (5), no reversible work would be done on
them.
For a thermo-electric circuit, made up of a bar of metal a, a bar of metal
/3, and two isothermal alloy bridges a-(3, we find the net, or total, virtual
e.m.f. to be represented by (1 -f- Ge) times the area A' B' C D' in figure 3,
where A B, B C, A D, and D C indicate the pressure- volume relations of one
gram of free electrons in the four parts of the circuit respectively, and A' B' ',
B! C", A ' D', D' C ', are found respectively from the corresponding full lines
by means of the ratio kf -f- (ka + kf), applied as in figure 2.
In spite of the conspicuous part which the specific potentials Pa and Pj
PHYSICS: E. H. HALL
103
play in the local virtual e.m.fs. of the circuit, we can, by making a gap in any
isothermal homogeneous part of this circuit and inserting there an electrometer,
measure the total e.m.f. as a simple difference of charge-potential. The total,
or net, amount of work done by or against the specific attractions which
enter into Pa and Pf is zero for any quantity of electricity which goes com-
pletely through the circuit.
Under hypothesis (B): If, in place of hypothesis (A), we assume that the
mechanical tendency of the free electrons is towards the condition of equilib-
rium which holds for thermal effusion, each local virtual e.m.f. will be rep-
resented by an area like E' A' D' Gf g'e' in figure 4, where E' is the mid-
point of E A' and G' is the mid-point of G D' . But the combination of four
such areas, one for each of the lines A' Bf, B' C' , A' Df, and D' Cf, of figure
3, will give precisely the same net result that is represented in figure 3 by
?
E
FIG. 4
A' B' C' D' . The total e.m.f. is, then, precisely the same under hypothesis
(B) as under hypothesis (A). This is because the fundamental conditions of
p and v, represented by the lines A B, B C, C D, and D A, in figure 3, remain
substantially the same under hypothesis (B) as under hypothesis (A).
1 These Proceedings, 4, 1918, (29-35).
2 For suggestions see a paper by myself in these Proceedings, March, 1917, and one by
P. W. Bridgman in the Physical Review, April, 1917, p. 269.
3 1 am not without hope that the mechanism here suggested will prove to be of great
service in the theory of heat conduction. It seems probable that the free electrons within
a metal are quite incapable, acting as a permanent gas, of accounting for the magnitude of
the metal's heat conductivity. But it is a familiar fact that the heat-carrying power of a
vapor, involving evaporation and condensation, is vastly greater than that of a permanent
gas. It appears, from the imperfect data now at my command, that the operation illus-
trated by figure 1 would give thermal conductivity of the right order of magnitude.
This conception of thermal conductivity, a conception occurring quite incidentally and
unexpectedly, has already been communicated to the American Physical Society in a paper
read at the meeting of December, 1917.
104
PHYSICS: C. G. ABBOT
TERRESTRIAL TEMPERATURE AND ATMOSPHERIC
ABSORPTION
By C. G. Abbot
ASTROPHYSICAL OBSERVATORY, SMITHSONIAN INSTITUTION
Read before the Academy, November 21, 1917
The earth's temperature depends mainly on the balance of incoming solar
energy and outgoing terrestrial energy of radiation. These two classes of
rays lie chiefly in two far-separated regions of spectrum. Of solar rays, 98%
lie between 0.3 and 3.0 microns (jjl) of wave-length. Of terrestrial rays
about the same proportion lie between 5 and 50 microns. According to Abbot
and Fowle's researches, about 40% of the solar rays directed towards the
earth are reflected to space. The earth must radiate to space 1.93 X 0.60
X 0.25, or 0.29 calorie per cm2 per minute on the average from its whole sur-
face to keep a steady temperature in balance with the solar rays received over
the area of its cross section. If the earth's surface was a perfect radiator and
its radiation passed unhindered to space, it would emit according to Stefan's
law 8 X 10~n X (287),4 = 0.55 cal. per cm2 per minute. How shall we
explain the discrepancy between 0.29 and 0.55 calories?
1. Is the earth's surface a perfect radiator? Its surface is about three-
fourths water. Of the remainder much is moist soil or moist vegetation. The
radiative power of the earth must therefore be near that of water. My col-
league, Mr. Aldrich, has lately studied the absorbing and reflecting powers
of water for long-wave rays. He finds that of the rays emitted by lamp-black
paint at 100°C. a layer of water 1 cm. thick transmits none and reflects as
follows:
Incidence 0° 30° 55° 63° 70° 72°
Reflection 2% 3% 1% 10% 17% 22%
As the absorption is 1— (Refl. + Trans.) he computes that of rays reaching
a water surface from a hollow hemispherical enclosing lamp-black-painted
surface at 100°, the absorption would be 90%. Experiments on lamp-black
paint having shown nothing strongly selective about its radiation in this
region of spectrum, we seem justified in concluding, in accord with Kirchoff's
law, that water is a 90% perfect radiator in this region of spectrum. As is
water, so is the earth's surface. Hence we conclude that the earth's surface
sends out 0.50 calorie per cm2 per minute on the average.
2. How much of this does the atmosphere transmit? My colleague Mr.
Fowle has recently published1 results of a long investigation of this subject
in which he studied the spectrum up to a wave-length of 17^t by aid of a spec-
tro-bolometer with rock salt prism. He employed a very long tube in which
the beam traversed paths of air up to 250 meters in length containing quanti-
PHYSICS: C. G. ABBOT
105
ties of water vapor up to the equivalent of 0.3 cm. of precipitable water.
He also observed the solar spectrum to 1 7^6 through paths of atmosphere con-
taining water vapor up to the equivalent of 3.0 cm. of precipitable water.
Since rock salt ceases to be sufficiently transparent beyond 17ju Fowle's spec-
trum work stopped there. But Aldrich, on Mount Wilson, by experiments
not yet entirely finished, seems to have shown that neither incoming sun-
rays nor outgoing earth-rays non-transmissible to rock-salt (that is over. 17/*
in wave-length) can traverse the atmosphere. Assuming that this result
will be confirmed we have the following results from Fowle's and Aldrich' s
investigations representing the output and atmospheric transmission of rays
from a perfect radiator at earth temperature.
Per cent of atmospheric transmission for stated cm. ppt. H20
WAVE-LENGTH
INTENSITY
cm. 0.003
cm. 0.03
cm. 0.3
cm. 3.0
4- 5
50
15
45
70
95
5- 6
142
16
43
66
95
6- 7
242
45
85
95
100
7- 8
315
13
42
85
100
8- 9
360
0
2
40
50
9-10
380
0
0
0
15
10-11
370
0
2
5
40
11-12
350
0
0
4
10
12-13
320
0
0
13
20
13-16
810
100
100
100
100
16-20
510
90
100
100
100
> 20
1,450
100
100
100
100
4— CO
5,300
49
57
66
75
From these results Fowle has computed that in clear weather, when pre-
cipitable water in the atmosphere is 1 cm., the atmosphere transmits 28%
to space of the radiation emitted by the earth's surface. In the tropics where
a load of atmospheric humidity equal to precipitable water of 3 cm. or more
is common, the transmission would not exceed 20% on clear days. A. Ang-
strom has shown2 that on cloudy nights practically all radiation from the
earth's surface to space is cut off. Hence (as it is cloudy half the time on the
average of the earth's surface) out of 0.50 calories per square centimeter per
minute emitted, the average escape to space, taking both clear weather and
cloudy, is only 0.06 calories. As 0.29 calories per cm2 per minute on the
average must leave the planet earth, and as the earth's surface contributes,
only 0.06 calories, it follows that the atmosphere is the main radiating source,
furnishing three-fourths of the output of radiation of the earth as a planet.
Principal sources of the atmospheric radiation in order of their importance
are: (1) The clouds; (2) water-vapor; (3) ozone; (4) carbon-dioxide. Ther
106
PHYSICS: K.-L. YEN
is little difference between the importance of the ozone band at 10 p and the
carbon -dioxide band at 15 \x except that the former falls at a point in the
spectrum where terrestrial radiation is most intense, and where water-vapor
has almost no absorption, while the latter falls at a place where the radiation
is not so intense and where water-vapor also absorbs powerfully.
No ozone band was found by Fowle in his work with the long tube, but in
the solar spectrum it shows strongly. This accords with work of others who
show that ozone is found only at high atmospheric levels. Apparently there
is not enough ozone in the atmosphere to produce complete absorption in its
band at 10 p, and it may be that the earth's temperature would be profoundly
altered if the ozone contents of the air could be changed. If it were possible,
for instance, to charge the surface air above citrus fruit orchards strongly with
ozone on a frosty night, perhaps hurtful frosts could thereby be warded off.
Carbon-dioxide exists in the atmosphere so plentifully that its full possible
influence seems probably to be exerted. No increase of C02 would seem
likely to produce a considerable effect on terrestrial temperature, and it is
probable that the C02 content of the air could be reduced to less than a quar-
ter of its present amount without notable temperature effects.
1 Smithsonian Misc. Coll., Washington, 68, No. 8.
2 Ibid., 65, No. 3, p. 54.
MOBILITIES OF IONS IN VAPORS
By Kia-Lok Yen
Ryerson Physical Laboratory, University of Chicago
Communicated by R. A. Millikan, January 21, 1918
In a former paper on the Mobilities of Ions in Air, Hydrogen, and Nitro-
gen (these Proceedings, 4, 1918, 91), the conclusion was reached that the
so-called cluster hypothesis could no longer claim any reason for its existence
and that the arguments for the small-ion theory should be considered con-
clusive.
It only remained for the small-ion theory to offer an adequate explanation
for the difference between the positive and negative mobilities exhibited by all
experimental results. This difference can easily be explained by the cluster
hypothesis for if the ions were constituted by satellites of molecules sur-
rounding single charges, the difference between the positive and negative
mobilities could be ascribed to the difference between the number of constitu-
ent molecules in a positive and that in a negative ion. But with the small-
ion theory such an explanation is not possible, since all ions are conceived of
as single charged molecules.
In the aforementioned paper, an explanation for this experimental fact
PHYSICS: K.-L. YEN 107
was offered on the basis of the Rutherford nucleus-atom theory. It was
shown there that the difference between the two mobilities is due to the
difference between the numbers of negative electrons in the two kinds of ions.
There exists a greater attractive force between the positive ions and the un-
charged molecules than that between the negative ions and the uncharged
molecules on account of the fact that negative ions have more electrons than
the positive. This results in a smaller mean free path, and hence a smaller
mobility, for the positive ions than for the negative.
From this point of view it is evident that an excess of positive over nega-
tive mobility is scarcely to be expected in either gases or vapors. Since
there has been very little work done on vapors and since some careful measure-
ments of mobilities in them are necessary for the verification of this expla-
nation in particular and of the small-ion theory in general, it was considered
desirable to make some careful determinations in vapors, and hence the
following work was undertaken.
Method and Procedure. — The method and procedure here employed were
the same as those employed in the previous experiment. The only difference
between this experiment and the former is that in the present one only low
frequency alternating field was employed. This was because the vapors
worked with required that pressures be sufficiently low for them to remain
in the vaporized state, and at such pressures the high frequency high poten-
tial oscillating field proved inapplicable on account of the sparking across the
gauze and the collecting plate. However, this difference does not at all
effect the results, as the main purpose of employing the high potential field
was to find out whether the mobilities would increase abnormally, and — since
it had already been proved that they did not — the employment of the high
potential field in the present experiment was entirely unnecessary.
Another difference between the present and the previous experiment is
that in this one a different ionization chamber was used. This chamber was
constructed on precisely the same plan as the former, but covered with a bell
jar of about one-sixth the size of that covering the former apparatus. This
last arrangement is more convenient in that it allowed the contents of the
chamber to be evacuated and refilled with ease, and that the vapors were
rendered as free of impurities as possible.
The vapors were produced by the same method as that employed by
Wellisch.1
The measurements were made in the same manner as before, and the results
calculated from the same formula.
Results. — The following tables show the results obtained for the vari-
ous vapors used. It may be seen from these tables that the results for
all these vapors at the various pressures are perfectly consistent with the
law that the pres'sure times the mobility is constant, and that the mean
values for the positive mobilities are — excepting in the case of C2H5I — ■
smaller than those for the negative mobilities. In the case of C2H5I the mean
108
PHYSICS: K.-L. YEN
values may be considered the same. Therefore, the results of the present
experiment are directly opposed to those obtained by Wellisch in 19091 in so
far as the ratios of the negative to the positive mobilities are concerned.
In table 10 there is comparison between the results obtained by Wellisch
and those obtained by me. It may be of interest to note that in 191 22
Wellisch himself reversed his results for C2H60, C5Hi2, and SO2.
table 1
Sulphur Dioxide (S02)
p
u+
U-
K+
K-
R
60
5.327
5.547
0.421
0.437
1.04
70
4.523
4.523
0.416
0.416
1.00
80
4.935
4.035
0.423
0.423
1.00
90
3.329
3.371
0.394
0.399
1.01
105
2.833
2.895
0.398
0.407
1.02
120
2.669
2.561
0.421
0.404
0.96
Mean
0.412
0.414
1.00
TABLE 2
Ethyl Alcohol (C2H60)
p
u+
u-
K+
K-
R
15
19.728
19.024
0.389
0.378
0.97
20
14.017
14.017
0.369
0.369
1.00
25
11.097
11.097
0.365
0.365
1.00
30
9.513
9.864
0.375
0.388
1.03
40
6.053
7.008
0.319
0.367
1.15
Mean
0.363
0.373
1.03
P = pressure in mm. mercury. U + = Positive mobility. U — = Negative mobility.
K + = Positive mobility reduced to 760 mm. mercury. K — = Negative mobility re-
duced to 760 mm. mercury. R = K — /K +.
TABLE 3
Aldehyde (C2H40)
p
u+
U-
K+
K-
R
30
7.885
8.560
0.311
0.338
1.09
34
7.885
0.352
38
5.993
0.300
43
5.256
5.548
0.297
0.313
1.07
45
5.166
5.350
0.306
0.317
1.05
50
4.832
5.078
0.318
0.334
1.05
55
4.280
4.610
0.310
0.333
1.07
Mean
0.307
0.331
1.07
TABLE 4
PENTANE (C5H12)
p
u+
U-
K+
K-
R
3t) 1
'8.812
12.483
0.347
0.493
1
42
40
7.491
8.812
0.394
0.462
1
18
50
5.993
6.968
0.397
0.445
1
12
50
5.993
6.968
0.397
0.445
1
12
60
4.832
5.448
0.382
0.430
1
12
66
4.540
4.994
0.394
0.434
1
10
Mean
0.385
0.451
1
17
TABLE 5
Ethyl Chlordde (C2H5C1)
p
u+
U-
K+
K-
R
30
7.683
7.885
0.303
0.311
1.02
40
5.762
5.993
0.303
0.317
1.05
40
5.549
5.762
0.292
0.303
1.04
50
4.7S6
5.078
0.313
0.334
1.07
50
4.681
4.833
0.308
0.318
1.03
Mean
0.304
0.317
1.04
TABLE 6
Acetone (C3H60)
p
u+
U-
K+
K-
R
50
3.699
4.035
0.243
0.265
1.09
60
2.959
3.131
0.235
0.247
1.05
64
2.833
2.959
0.239
0.250
1.07
70
2.513
2.665
0.229
0.245
1.07
76
2.336
2.421
0.234
0.242
1.03
80
2.219
2.296
0.234
0.242
1.03
Mean
0.236
0.247
1.04
PHYSICS: K.-L. YEN
109
TABLE 7
Ethyl Acetate (C4H802)
p
u+
U-
K+
K -
R
50
3.309
3.648
0.219
0.240
1.09
60
2.567
3.167
0.229
0.250
1.09
65
2.701
2.900
0.231
0.248
1.07
70
2.421
2.663
0.223
0.245
1.09
75
2.290
2.533
0.226
0.250
1.10
80
2.172
2.334
0.230
0.246
1.07
Mean
0.226
0.247
1.09
TABLE 8
Ethyl Iodide (C2H5I)
p
u+
U-
K+
K —
R
30
5.166
4.833
0.203
0.191
0.94
35
4.104
4.161
0.189
0.192
1.01
50
2.466
2.512
0.162
0.169
1.04
60
2.336
2.296
0.184
0.181
0.98
60
2.141
2.166
0.169
0.171
1.01
Mean
0.181
0.181
1.00
TABLE 10
Comparison
TABLE 9
Methyl Iodide (CH3I)
p
u+
U-
K+
K-
R
50
3.222
3.390
0.212
0.223
1.05
60
2.607
2.926
0.219
0.231
1.06
65
2.572
2.959
0.220
0.236
1.07
70
2.296
2.421
0.212
0.223
1.05
75
2.230
2.270
0.220
0.224
1.02
80
2.043
2.090
0.215
0.220
1.02
Mean
0.216
0.226
1.05
VAPOR
WELLISCH
K.-L
YEN
19091
19152
1917
K+
K-
K+
K-
K+
K -
C2H40
0.31
0.30
0.307
0.331
C2H60
0.34
0.27
0.39
0.412
0.363
0.373
C3H60
0.31
0:29
0.236
0.247
S02
0.44
0.41
0.415
0.414
0.412
0.414
C2H5C1
0.33
0.31
0.304
0.317
C5Hi2
0.36
0.35
0.370
0.440
0.385
0.451
C4H802
0.31
0.28
0.226
0.247
C2H5I
0.17
0.16
0.181
0.181
CH3I
0.21
0.22
0.24
0.233
0.216
0.226
Conclusion. — From the results of the present experiment, it is evident that
the apparent difficulty with the explanation proposed for the difference be-
tween the positive and negative mobilities does not really exist at all. It
only remains for the exponents of the small-ion theory to deduce an exact
formula for the mobility of ions on the basis of the Rutherford-Bohr theory
from which we should expect that the peripheral negative electrons in the
molecules and the ions would play the dominant if not indeed the only role in
collisions.
I wish it to go on record that the present experiment was undertaken at
the suggestion of Prof, R. A. Millikan, and under his direction; and also
to thank Mr. W. R. Westhafer for his assistance in taking some of the
measurements and computing some of the results.
1 Phil. Trans. R. Soc, London, (A), 209, 1909, (249).
2 Phil. Mag., London, 34, 1917, (59).
110
PETROLOGY: IDDINGS AND MORLEY
A CONTRIBUTION TO THE PETROGRAPHY OF THE SOUTH SEA
ISLANDS
By J. P. Iddings and E. W. Morley
Brinklow, Maryland, and West Hartford, Connecticut
Communicated February 18, 1918
A brief statement of the geological structure and general character of the
rocks of the Islands of Tahiti, Moorea, and the Society Group has been given
in a previous number of the Proceedings of the National Academy, from which
it appears that each island is a profoundly eroded volcano, consisting mainly
of basaltic lavas rich in olivine and augite, with inconspicuous feldspar, and
that at five of the volcanic islands there are trachytic or phonolitic lavas which
have been erupted late in the period of activity. In two volcanoes erosion has
exposed coarsely crystallized cores of gabbroic and theralitic rocks with peri-
dotites, and in one case syenites and nephelite-syenites as the latest eruptions.
Nearly seventy years ago J. D. Dana called attention to these syenitic
rocks on Tahiti, and remarked that they were only a feldspathic variety of the
same igneous rocks that constitute the island. Eight years ago Lacroix pub-
lished a description of the alkalic rocks of Tahiti with chemical analyses, lay-
ing particular stress on the syenitic varieties and on the haiiynophyres, with
certain limburgitic lavas, but noting the fact that the preponderant rocks of
the islands are basalts rich in olivine. From the emphasis laid upon the alkalic
rocks, one gets the impression that they are more abundant than is actually
the case. However, their theoretical importance has not been exaggerated.
More recently Marshall has analysed and described phonolitic rocks from the
Leeward Islands and from Raratonga, Cooks Islands, and has analyzed sev-
eral rocks from Tahiti. So there are already a number of chemical analyses
of igneous rocks from the islands of this part of the Pacific Ocean.
In order to extend the investigation somewhat further, and to include the
more common varieties of basalt so as to give a clearer idea of the prevailing
rocks of the islands, chemical analyses have been made of rocks from different
islands of the Georgian and Society groups. These have been placed in
sequence in one table for comparison with one another, and to show the
resemblances among the various lavas of these islands. The analyses have
been obtained in part with the aid of grants 192 and 203, from the Bache Fund
of the Academy. That is, those by Professor Foote and by Dr. Washington.
The microscopical study has also been carried on with the aid of these grants.
As the specimens collected represent over 550 rocks from seven volcanic
islands, it is only possible in this preliminary statement to notice particularly
the 30 specimens whose analyses are published for the first time in the accom-
panying table, with some observations concerning their relations to the rocks
with which they are associated.
The rocks of Tahiti are almost wholly basalts rich in olivine and augite,
PETROLOGY: 1DDINGS AND MORLEY
111
with few or no phenocrysts of feldspar. They differ from one another some-
what in the size and abundance of the phenocrysts of olivine and augite.
At one extreme are basalts with abundant phenocrysts; at the other are ba-
salts without any, but with ill-defined spots which are lighter colored than
the body of the rock. Such basalts form large flows often in superposition,
as at Point Tapahi on the north coast where a strongly porphyritic basalt
forms the lower layer or flow, at the water's edge, and a non-porphyritic
spotted basalt forms the upper flow. The upper rock has been analyzed,
no. 19 in the table, and proves to be a limburgose, bordering on camptonose,
with 8.5% of normative nephelite. The light-colored spots in the rock are
probably due to areas of altered nephelite, or to analcite. The rock is apha-
nitic, and under the microscope is seen to be holocrystalline; composed of
augite, magnetite, ilmenite, and olivine in a matrix of plagioclase with nephe-
lite or analcite. Similar basalt forms a massive flow and has been quarried
near Papeete. A strongly porphyritic basalt rich in olivine, like the rock at
Point Tapahi, is in place on the road farther west. Its analysis, no. 27, shows
it to be uvaldose, a highly mafic rock without normative nephelite. It is
holocrystalline; the groundmass crowded with augite, olivine and magnetite,
with quite subordinate amount of plagioclase feldspar. It is in fact limbur-
gite. These two varieties of basalt are common throughout the islands
visited, a very similar rock, no. 28, having been analyzed from the west coast
of Raiatea. It is, however, somewhat more coarsely crystalline, the indi-
vidual crystals being distinctly visible microscopically. Some of the plagio-
clase feldspars have outer zones of alkalic feldspar, probably soda-orthoclase.
A limburgitic basalt which appears to be a large massive body, exposed in
Fautaua Valley on the trail above the waterfall, is a gray rock with small
miarolitic cavities. It is holocrystalline and consists of abundant subhedral,
violet-tinted augites, of variable sizes, with much colorless olivine, subhedral
magnetite, in part dendritic, and areas of poikilitic plagioclase, with patches
where the matrix is alkalic feldspar and analcite. The chemical analysis is
no. 26 and the norm is relatively high in alkalic feldspar, low in anorthite,
with 7% of normative nephelite. There is 5% of apatite which appears as
thin acicular prisms. A corresponding amount of apatite occurs in a theralite
from Taiarapu, analysis 22. Another basalt from Fautaua Valley is found in
boulders in the stream near the ridge above the falls. Its chemical com-
position, no. 25, is similar to the rock just described, no. 26, but it appears
somewhat differently under the microscope. It consists chiefly of violet-
tinted augite, with abundant colorless olivine, and magnetite, and clusters of
rods of ilmenite, with minute needles of augite. Between these is a small
amount of colorless matrix which is in part plagioclase feldspar. The norm
shows a small amount of anorthite, 19% of feldspathoids, and no alkalic feld-
spar. There is about 2% of calcium orthosilicate which does not appear as
melilite in the mode, and is probably incorporated in the mafic minerals.
This is also a limburgite.
112
PETROLOGY: IDDINGS AND MORLEY
A basalt still richer in olivine, of the utmost freshness occurs on the east
side of Raiatea, its analysis, no. 24, shows 23.97% of magnesia, or nearly 45%
of normative olivine. It is a most beautiful chrysophyre, or limburgite, with a
holocrystalline groundmass crowded with microscopic augites, olivines, mag-
netite and subordinate plagioclase. On the Island of Moorea a limburgite
with similar chemical composition, no. 23, was found in large blocks, but
not in place. It is more coarsely crystallized and resembles a peridotite
megascopically. It is perfectly fresh and has a scant matrix of microscopic
plagioclase. The norms of these highly olivinitic basalts do not contain
normative nephelite, but contain normative hypersthene. The silica is com-
paratively high for the amount of alumina, which is low; the magnesia being
abnormally high.
In the central core of the dissected volcano of Tahiti, and in that of Taia-
rapu, there are coarse-grained theralites which are chemically similar to the
non-porphyritic basalt forming the upper flow at Point Tapahi, Tahiti. Their
analyses are nos. 20, 21, and 22. They are limburgose and limburgose-etin-
dose, and are characterized by notable amounts of normative nephelite, which
is also modal. In no. 22 there is also normative leucite, which, however, does
not appear in the mode, which contains considerable biotite. The theralite
from Vaitipihia, Tautira Valley, Taiarapu, no. 20, is rich in augite, brown
amphibole and biotite, with subordinate plagioclase and nephelite. That
from Maroto River, in the Papenoo Valley, Tahiti, no. 21, is very much like
no. 20, but has less amphibole and a slightly different texture. The other
theralite from Vaitipihia, no. 22, contains large brown amphiboles, sur-
rounded by brown biotite, with little augite, and much apatite. The chemical
compositions of coarse-grained rocks of unusual mineral composition from the
core of Taiarapu are given in nos. 29 and 30. The first is a narrow vein of
pyroxenic rock traversing basalt. It consists almost wholly of slender den-
dritic crystals of augite in a microscopically fine-grained matrix. The norm
has 45% of diopside, 5% of olivine, 26% of anorthite and small amounts of
normative nephelite and leucite. The second rock, no. 30, is a peridotite
composed of augite, olivine, brown hornblende, iron ores and pyrite, with very
small amounts of feldspathic minerals; the norm containing a little normative
nephelite and leucite.
The analyses of other basalts from these islands are given in nos. 14 to
18 in the table. They are camptonose and camptonose-auvergnose, and
are from Moorea, Huahine, Tahaa and Bora Bora. The basalt from Tahaa,
no. 14, is rather coarse-grained and forms a dike near the coast on Rei Point.
It is the rock used for ballast by small boats in this region, and may be found
in the ports on various islands, and is probably the rock called granite by early
explorers. It is a dolerite and looks like a fine-grained gabbro. It is rich in
olivine and its norm contains a small amount of nephelite. The basalt from
Bora Bora, no. 15, is porphyritic, very rich in olivine, and has nearly the
same chemical composition as no. 14. The columnar basalt from Moorea,
PETROLOGY: IDDINGS AND MORLEY
113
no. 17, and the basalt from Huahine, no. 16, are very similar chemically,
while the basalt from the base of Maura tapu on Huahine, no. 18, is lower in
magnesia and higher in lime and alumina. These basalts do not contain
normative nephelite, and differ from one another somewhat in texture.
From the foregoing it is seen that the basaltic rocks of this region, and their
coarsely crystallized phases, which occur in the cores of the volcanoes of
Tahiti and Taiarapu, are normatively nephelite-bearing, except some of the
highly olivinitic varieties, and some others. Nephelite js visibly present in
the modes of the coarsely crystallized rocks, and is possibly present in micro-
scopic crystals in many of the fine-grained and aphanitic basalts, though it is
probable that it is represented by analcite in some instances, either as a pri-
mary mineral, or as a product of alteration.
The trachytic and phonolitic lavas, which are known to occur at five of the
volcanic islands visited, are very similar to one another chemically, as is
shown by analyses 1 to 8. The rocks from Nutae, no. 3, and Point Riri,
no. 6 on Taiarapu, are light gray and but slightly porphyritic, with fissile part-
ing and satin lustre. The first occurs as boulders on the beach associated with
hauynophyre. The second is in place, and is exposed in large blocks. Each
contains a small amount of normative nephelite, and a little that can be iden-
tified as modal nephelite, so that the rocks are properly nephelite-bearing
trachytes, rather than phonolites. They have a microtrachytic texture, the
first one containing small scattered phenocrysts of alkalic feldspar. Similar
rocks occur on Huahine, nos. 1 and 5. They are darker colored and more
fissile. Microscopically they appear to contain abundant minute crystals of
nephelite, and to be characteristic phonolites. However, most of the rect-
angular crystals are alkalic feldspars and not nephelite, as their index of re-
fraction shows. These rocks also are nephelite-bearing trachytes and not
properly phonolites. The same is true of similar massive rocks from Raiatea,
the fissile mass forming the top of Mount Tapioi, no. 4, and the rock of the
sugar-loaf dome on the east side of the island, no. 2. These rocks are nephelite-
bearing trachytes with small amounts of nephelite. The rock from the top
of Mount Tapioi contains minute crystals of what appear to be sodalite scat-
tered through the feldspars. Similar nephelite-bearing trachytes with less
nephelite form large bodies of rock on Moorea, the analysis of one of them
being given in no. 8.
Some varieties of these trachytic rocks, occurring on Taiarapu, contain
hauynite in small crystals, and 12% of normative nephelite and are properly
phonolites. Analysis 7 is from such a rock. One variety, no. 11, from the
beach at Tautira consists of alkalic feldspar and andesine, with some nephelite
and sodalite, and contains abundant small phenocrysts of brown hornblende,
with much titanite and few augites and micas. Chemically it is very similar
to a tephritic trachyte from Bauza, Columbreta, described by Becke. Its
symbol in the Quantitative System of Classification shows that it is transi-
tional. In the qualitative system it corresponds to a nephelite-latite, or
114 PETROLOGY: IDDINGS AND MORLEY
Table of Chemical Analyses and Norms of Lavas from South Pacific Islands
1
2
3
4
5
6
7
8
9
10
61 08
01 . yo
A 9 9H
OZ . ZU
61 H7
Ol . U/
A 9 A A
OZ .44
6>\ on
01 . yu
AO A8
OU . 45
C8 Q/1
05 . 54
Kl ai
0 / . 01
CA 11
00 . 00
00 . Oo
ALO„
18 79
±0 . / Z
17 qi;
1 / . 50
17 77
1 / . / /
16 . 0/
1 8 37
lo . O /
10 IK
iy . 00
90 30
zu . OU
1 6 A 7
10.4/
1 Q AA
15 . 44
18 73
15 . 1 0
9 1A
Z . 04
9 31
z .01
9 18
Z . 16
1 87
1 .0/
9 A6
Z . 40
9 3A
Z . 04
9 7/1
Z . /Tr
9 8A
Z . 54
c; SO
0 .5y
A 3/1
4. 04
"FpO
1 1 7
1.1/
O QC
u . yo
1 AO
1 . Tty
n £7
U . 0/
n 66
U . OO
1 10
1 . iy
n aa
U . 04
A 79
4 . / Z
9 AO
Z . OU
O O/l
u .y4
Mo-n
u . oy
0 83
U . oO
0 88
U . 00
n 69
u . oz
n A6
U . TtO
u . / 0
u . OU
n sa
U . 50
1 O/l
1 .U4
1 • 07
1 .y /
1 no
1 . uy
1 . OO
1 30.
1 ik
1 . 00
n ce
U . 05
1 68
1 . Oo
1 aa
1 . OO
9 A1
Z . Ol
9 70
Z . /U
1 AO
0 . ou
7 16
6 74.
7 90
7 QK
/ . yo
6 ^0
u . ou
7 AS
/ . 45
R 06
O . UO
A 3A
4 . 04
C f\A
0 . 04
0 . 00
C 80
O . 5U
^ s7
0.0/
0 . OO
c 3A
0 . 00
s on
0 . yu
5 79
0 . / z
c 07
0 . y /
A 80
4.5Z
1 8C
0 . 50
ii2vv r
1 fK
n qc
u . yo
1 71
1 . / 1
n 39
u . oz
1 ko
1 . oz
n 87
U .0/
n Ae
U . Oo
1 A3
1 . 40
1 8 C
1 . 50
1 71
1 . / 1
tt n
fi A9
U . 4Z
n 36
u . OO
n 1 1
U . 1 1
n 1 7
u . 1 /
n ai
u . Ol
n 9 k
u . zo
0 31
U . Ol
U . OO
O CO
U . OZ
O QO
U . 5U
Ti02
0.26
0.57
0.94
0.62
0.20
0.72
0.72
0.51
0.88
0.91
Zr02
0.12
0.00
C02
none
0.03
P205
0.03
0.14
tr.
0.09
0.01
0.16
0.13
0.42
0.61
0.74
CI
0.08
F
n. f.
S
none
0.04
Cr203
tr.
tr.
tr.
tr.
tr.
0.02
0.00
0.00
tr.
MnO
0.30
0.24
0.05
0.21
0.26
0.14
0.12
1.39
0.11
0.33
BaO
none
0.14
0.07
1.02
SrO
0.00
0.01
100.57
100.27
99.99
100.38
100.34
100.47
100.03
100.42
100.13
100.24
Norms
1
2
3
4
5
6
7
8
9
10
Q
7.02
0.60
33.92
34.47
33.36
33.92
31.69
35.03
33.92
35.58
28.36
22.80
ab
51.87
52.92
50.83
51.87
52.40
46.63
41.39
40.35
36.68
47.68
an
1.67
1.11
1.39
1.67
6.12
4.73
4.45
9.73
13.07
ne
4.83
2.27
3.69
5.40
6.53
4.54
11.93
1.42
C
2.45
0.41
Z
0.18
2.31
di
2.65
3.67
3.89
3.34
2.48
1.08
2.16
4.80
wo
0,23
hy
2.60
4.90
ol
0.28
0.28
0.98
0.35
5.81
mt
3.25
2.32
2.09
1.62
2.31
2.32
0.23
4.18
6.03
1.62
il
0.61
1.06
1.82
1.22
0.46
1.37
1.37
0.91
1.67
1.67
0.64
0.80
0.80
0.16
0.64
2.56
1.76
3.20
ap
0.34
0.34
0.34
0.34
1.01
1.34
1.68
etc
1.50
1.31
1.87
0.49
2.14
1.26
1.08
1.96
2.37
2.51
100.53
100.39
100.20
100.67
100.49
100.31
100.06
100.47
100.01
100.14
1. 1.5.1. (3)4. phlegrose-nordmarkose, nephelite-trachyte, road S. of Mt. Paeo, Huahine.
2. I'. 5.1. (3)4. phlegrose-nordmarkose, nephelite-trachyte, E. base of Sugarloaf peak,
Raiatea.
3. I'. 5.1. (3)4. phlegrose-nordmarkose, nephelite-trachyte, Nutae, Taiarapu, Tahiti.
4. I'. 5.1. '4. nordmarkose, nephelite-trachyte, Mount Tapioi, Raiatea.
5. I'. 5.1. '4. nordmarkose, nephelite-trachyte, S. W. base of Mauratapu, Huahine.
6. I'. 5.1(2). 3-4. phlegrose-nordmarkose, nephelite-trachyte, Point Riri, Taiarapu, Tahiti.
7. I'. (5)6.1'. '4. nordmarkose-miaskose, phonolite, Vaitia, Tautira valley, Taiarapu.
8. 'II. 5.1(2). 3. monzonose-ilmenose, nephelite-trachyte, Papetoai valley, Moorea.
9. (I)II. '5.2.3'. pulaskose-monzonase, latite, Road, 1 km. E. of Papetoai, Moorea.
10. (I) II. 5.2. 4. larvikose-akerose, kohalaite, Second spur W. of Mt. Tapioi, Raiatea.
Nos. 1,2, 4, 5, 6, 7, 9, 10 by H. W . Foote; No. 3 by H. S. Washington; No. 8 by E. W. Morley.
PETROLOGY: IDDINGS AND MORLEY 115
Table op Chemical Analyses and Norms of Lava erom South Pacific Islands
ll
12
1;
14
15
16
17
18
19
20
Si02
52.11
50. 11
50.73
47
60
46.55
46
96
46.01
47 .55
44.74
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a vTT
c rot E = - — , div H = 0,
Of
we adopt as an elementary solution
_ 1 bA Ail b 12>f
H = rot A, E = — - — — V3>, ^ = div A + - — , p = — - — , pv = cV^,
' c bt c bt c bt
where
Jot
f(r) V log [s.r - c(t- r)] rfr,
$ = ~ JjTW I log [S.r - C (t - r)] dr.
In these expressions s is a unit vector depending on r, r denotes the radius
vector from the point with co-ordinates £(t), r/(r) £* (t), to the point with co-
ordinates x, y, z, while a is defined by the equation
[x - £ (a)]2 +[y-V (a)]2 + [x - { (a)]2 = c2 (/ - a)2; a ^ /.
The function Sl> is given by the formula
• *--/<«),
where
» = f(a) [x - f (a)] + ,'(a) [y - ,"(«)] + f (a) [s - - <2(* - «)•
This elementary field corresponds to a state of affairs in which electric
charges of a concentrated form are created and travel along straight lines with
the velocity of light, the directions of these lines being specified by the different
values of the unit vector s. Whenever a concentrated electric charge is cre-
ated an amount of electricity which will just compensate it is fired out in all
directions and provides an elementary 'aether' which is the seat of the electro-
magnetic field of the concentrated charge. A concentrated electric charge
and its elementary aether lie at any instant on a sphere whose centre is at the
point where these charges originated1 ; if now this point moves with a velocity
PHYSICS: H. BATEMAN
141
less than the velocity of light the different spheres bearing electricity that exist
at time t do not intersect and if the arbitrary function f(a) is never zero
there will be a sphere through each point of space so that our elementary aethers
will fill the whole of space; if however the function f(a) is sometimes zero, for
axemple if it is zero when a is less than ao, then the elementary aethers will
not fill the whole of space.
If we subtract from the above field another one of the same type in which
the unit vector function s has a different value we obtain a field in which
pv and p are zero except in the neighbourhood of the concentrated electric
charges, there is thus a cancelling of electricity when the two elementary
aethers are superposed and we get an aether in the ordinary sense of the
word. The field is now one in which concentrated charges of opposite signs
are continually produced by a process of separation analogous to that described
by Heaviside in 1901. The field thus obtained belongs to the type in which
there is a rectilinear flow of energy and no accumulation of energy at any point
of space : the energy in such a field may therefore be regarded as kinetic energy
or energy of motion.
The most general field that possesses the property just mentioned and the
additional property that the volume charge and current in the aether are
zero outside the singularities of the field is obtained by writing
M = H + *E = cF(a,(3) (VaXV/3) =iF (a,(3) \~Va -^V^
where a and are defined by equations of type
z - ct =f(a,(3) + (x + iy) 0 (a,(3), % + ct = g(a,(3) - *-f^L
f, g and 6 being arbitrary functions of a and /3. It may be remarked that
M.M = 0 and that 0 is a solution of the wave equation.
In all the fields of the above type electricity or magnetism travels along
straight lines with the velocity of light (the case of a plane wave of light
is, however, an exception). To obtain fields in which electricity or mag-
netism travels with a velocity less than that of light we must superpose fields
of the above type in such a way that there is a cancelling of nearly all the
concentrated electric or magnetic charges. It is fairly easy to prove that
the field of an isolated electric pole moving with a velocity less than that of
light can be regarded as the limit of two superposed radiant fields of the type
obtained by subtracting two of our elementary solutions. According to this
idea the electricity at an electric pole is continually being renewed, moreover,
it is the electric charge itself which is directly responsible for the effects pro-
duced at a distance, but to understand fully the production of these effects
we must consider how this charge is constituted remembering how the field
142
PHYSICS: H. BAT EM AN
was built up from four of our elementary fields. It is important to notice in
this connection that the volume density of electricity and electric current
in an elementary field are independent of the direction in which the concen-
trated charges move; this simplifies matters when we want to ascertain the
structure of the aether for an electric pole that is built up in a specified way.
When a number of radiant fields are superposed a cancelling of concentrated
electric charges seems to be necessary in order that the principle of the con-
servation of energy may hold and in order that steady states of motion may be
possible. Even if the cancelling is not complete everywhere it must at least
be sufficient to prevent any free electricity from going to infinity. If this
less stringent condition is adopted it is possible to admit fields in which the
charge associated with an electric pole fluctuates slightly and electric charges
are fired from one electric pole to another. It may be possible to explain
gravitation in this way for it will soon be realised that the necessary fluctua-
tion of charge is exceedingly small. The question may also be raised whether
it is necessary for there to be a complete cancelling of the charges in the ele-
mentary aethers when a number of elementary fields are superposed. If the
answer is in the negative the volume densities of electricity and convection
current will be derivable from a function which satisfies the wave-equation
at points not occupied by matter.
Summing up the essential features of the present theory, we may say that
all electric charges are supposed to really travel along rectilinear paths with
the velocity of light; this implies that when electricity appears to move with a
smaller velocity it is made up of different entities at different times being
constantly renewed so to speak. The fact that an electric charge which has
been moving along a rectilinear path with the velocity of light has no sur-
rounding field2 is quite consistent with the present view, for all electric charge
arises from electric separation3 and its aether is created in the process, conse-
quently an electric charge which has moved along a rectilinear path for all
time with the velocity of light would have no aether to support a field.
When we admit the mathematical possibility that the electric charges in
the universe have not existed in the free state for the whole of time we find
that it is by no means certain that the aether fills the whole of space and this
raises some interesting philosophical questions. Some of the logical diffi-
culties4 in the ideas of contact action and action at a distance are avoided
in the present theory because an electric charge at a point P produces an
effect at a distance point Q for the simple reason that either a portion of the
charge itself, or a portion of the compensating charge that was created at the
same time, actually goes to Q and helps to produce the particle that is acted
upon, or rather the entity that represents the particle at the moment under
consideration.
Passing on to a brief consideration of some more familiar types of fields
we shall superpose the fields of point charges using Lienard's potentials
PHYSICS: H. BATEMAN 143
. e v(a) , e c
A = - , $ = - •
4:ir v 47T y
We shall be interested chiefly in the effect of an operation analogous to differ-
entiation. Let us suppose that the co-ordinates of the point charge at time
a depend on a parameter /3 as well as a and let b denote the vector with com-
ponents d£/d/3, drj/dft d£/dft then if f is a function of a and (3 it is easy to
prove that
_d
d/3
as
When / = dco (a, /3)/da this formula may be written in a more convenient
form by making use of the relations
*(i)+*(A+i(L)+*n) = o,
dx \ v / d;y \ *> / ds \ v ) dt \v J
fc'A + 4- f'J* 4- A = A
* ^ ^dj ^ dz d* da
where the operators in the last equation are supposed to act on a function of
a and /3.
We thus obtain the equation
1 M = A p frfafll-u-fr [1 sfa^l + A P bfa>^l+d P d(co>a)1
r da/ dx d (ft a) J dv d (ft a) J dz d (ft a) J d/ L" d (ft «) J
In particular we have
Aif^-iTAfi/ 'M-V^YLAfi/V^- A^l
d/3 4tt Ldv V V d/3 * d/3/J dz \ A ^ dft/ J d* V ¥/J
d/3 , 4r Ldx \v d/3 J dy d/3 J dz (.r dft
Writing p = eb/47r, we find that for an electric doublet of moment 47rp the
electric potentials are
A = rot{l(vXp)}-|{lp},*=Cdiv{ip}.
This of course is a simple generalisation of the well known result due to Hertz
and Righi.
It is well known and easy to verify that the same electromagnetic field
may be derived from the magnetic potentials.
B =
crot{^}"^l€(vx4o=div€(vx4
144
PHYSICS: II. BAT EM AN
with the aid of the formulae
E = rotB, H = 1 ^ + m
c ot
Let us now write
M = H + iE = i rot L ^ - ^ + VA,
c ot
L = B - i A = — - + ic rot G, A = Q - i<$> = - c div G;
Ot
then in the case of an electric doublet we have
G = i[p+i(vxP)].
To obtain the field of a magnetic doublet we write iq instead of p for the field of
a magnetic pole of strength ju is derived from the magnetic potentials
47T ^ 47T ^
If m = q — ip and
G = - -fm + * (v X m)l = SM, say,
V [_ C J V
the derived field is that of an electric doublet and magnetic doublet which
move together. When the vector g is given it is easy to determine the moment
4-7rp of the electric doublet and the moment 4-7rq of the magnetic doublet.
The function g(a)/v may be regarded as analogous to the fundamental
potential function \ jr of electrostatics and Hertzian functions of higher order
may be derived from it by differentiation just as potential functions involving
spherical harmonics are derived from l/r by differentiation according to
a method developed by Maxwell.
Let us regard £, 77, f , g as functions of a and a parameter /3 then we obtain
by differentiation a new Hertzian function whose x-component is
It should be noticed that this expression for Gx contains differentiation with
regard to x, y and z but not t so that there is apparently a lack of symmetry.
This is due to the fact that a is taken to be independent of (3; we can easily
introduce a term involving a differentiation with regard to t by making use
of the identity
>>=*(?K(0
but it is generally simpler and more convenient to retain the former expression.
MATHEMATICS: O. E. GLENN
145
The process of differentiation may be carried out any number of times
with respect to different parameters using formulae of differentiation analogous
to the above. When the various derivatives are added together the result
indicates that the natural generalisation of a series of spherical harmonics of
form
So (0,0) ^(0,0) +S2 (0,0) +
is the following type of series of Hertzian functions of different orders
G = 15 + div + div div (^) + div div div + .
Here go, a0, ai, bo, bi, bs . . . . are arbitrary vector functions of a. It should be
remarked that the vector with suffix n is treated as the vector in forming the
n divergence while the other vectors are treated for the moment as scalar
quantities. The product of k vectors which occurs in the (k + l)th term is
to be regarded as a tensor of the kth. order with k components each of which is
a product of components of the separate vectors; there appear to be enough
arbitrary functions in a sum of products of this type with k = 0, 1, 2, . — , K
for the representation of the sum of a number of Hertzian functions up to
order K.
1 As each shell of electricity moves outwards it induces a secondary separation of elec-
tricity so that electricity flows back to a new position of the primary singularity (£, 77, f)
and tends to maintain the electric separation. The volume density of the compensating
electricity created at the primary singularity isthus not p but is proportional to ^r/r, it is this
electricity which is regarded as forming the elementary aether associated with the primary
singularity and it is this electricity which, on account of its displacement from the concen-
trated charge, is directly responsible for the field.
2 See for instance Wilson, E. B., Washington Acad. Sri., 6, 1916, (665-669).
3Larmor, J., London, Proc. Mathe. Soc, 13, 1913, p. 51.
4 Whitehead, A. N., The Anatomy of some Scientific Ideas, The Organization of Thought,
London, 1917, p. 182.
INVARIANTS WHICH ARE FUNCTIONS OF PARAMETERS OF THE
TRANSFORMATION
By Oliver E. Glenn
Department of Mathematics, University of Pennsylvania
Communicated by H. H. Donaldson. Read before the Academy, November 21, 1917
A systematic theory and interpretation of invariantive functions which
contain the parameters of the linear transformations to which a quantic
146
MATHEMATICS: 0. E. GLENN
fm of order m is subjected has not been formulated, although a paper on
invariants1 published in 1843 by Boole treated certain functions of this type.
These were the concomitants of forms under transformations which rotate
cartesian axes inclined at an angle w into another set with inclination w'\
invariants which contain the parameter w. Orthogonal concomitants, which
are special cases with w = J -ir, were made the subject of a number of later
papers2, notably by Elliott and by MacMahon.
I have considered a general doctrine of such concomitants for the transfor-
mation with four parameters
T: %i = aiXi + c^', #2 = Po%i + fttfa'j D = aift — 0:2ft 4= 0.
The elements of the methods are based upon the two forms
£ = 2/30*i + (ft -ai-f- A)*2, 77 = 2(30Xi - (ft - <*i - A)^2;
whose roots are the poles of T, and the expansion of fm in terms of £, 77 as
arguments. The quantity A employed here is the square root of the dis-
criminant of the form
J: ft*i2 + (ft — ai)xiX2 — q2%2.
The coefficients (pm-2i (i=0, . . . . , m) in the expansion of fm are invariants of
a new type3 belonging to the domain 22(1, T, A) of rational polynomials in the
coefficients of /m and those of Ty increased by adjunction of A. These inva-
riants compose a fundamental system in R. They satisfy the invariant
relations
Vw-2i (* = 0, . . , m), (1)
in which p is one of the two factors of D in R :
P = K«i + ft+A). (2)
When one seeks complete systems for the given domain R(l, T, 0), free
from A but including rationally the coefficients of T, it is found that the con-
comitants are in one to one correspondence with those invariantive products
m
for which the exponent of p in the invariant relation P' = paDhP, is zero.
The conclusion is then drawn that concomitants in 22(1, T, 0) are in one to
one correspondence with the solutions of the diophantine equation
m
is'2*<(«- 2i) + p - a = 0.
i=0
(3)
MATHEMATICS: O. E. GLENN
147
This infinitude of concomitants therefore forms a system which possesses
the property of finiteness,4 and the fundamental invariants are furnished by
the finite set of irreducible solutions of 5 = 0.
In the ternary realm the lines joining the three poles of the transformation
T on three variables furnish three linear forms in terms of which any quantic
fm in three variables can be expanded. The coefficients in this expansion
urnish complete systems in each of several domains. In particular, if T
is the transformation which rotates cartesian axes in three dimensional space,
x = h%' + hy' + hz',
y = m\x' + why' + W3Z7,
2 = n\x' + n^y' +
the coefficients being the well-known direction cosines of three axes, the
invariant triangle on the poles consists of the lines
Ui m (h + nx e±id) x + (m8 + n2 e±iQ) y + (». - h + l^e^9 + e*2ie) z = 0,
fo = (h + ni) x + (m3 + fh) y + (»3 — /i — M2 + 1) z = 0,
where 0 is a definite auxiliary angle. The coefficients in the expansion of fm
in the arguments f±h f0 are invariants belonging to the domain of complex
numbers, while the finiteness of complete systems in the real domain is de-
termined, and the fundamental concomitants are given, by the finite set of
irreducible solutions of the linear diophantine equation
m m-i
2 2 xf (m-i-2j)+(3-a= 0. (4)
i=0j = 0
The Invariants of Relativity.— Among numerous important particular cases
of the above theory is the transformation of space and time coordinates in the
theory of relativity, known as the transformation of Einstein.5 This consists
of
Ti: t = n(cH' + vx')/c, x = n {vt' + *') c, y = y', z=z\
where /i = V(6'2 ~~ " ^2) is the time, c the velocity of light, v the relative
velocity of the moving systems of reference and x, y, z space coordinates.
For these unitary substitutions, £ = ct + x, rj = ct — x and the invariant
relations are
r = pi, v' = p-%
in which (Cf. (2))
P = a/ c — v / y/ c + v .
We now find
J : c2*2 - x\
148
MATHEMATICS: O. E. GLENN
this being an absolute universal covariant of T\ for all values of the relative
velocity V.
A binary form fim(t, x) in t and x, whose coefficients are constants or
arbitrary functions of the quantities left fixed by T%, has a finite system of
non-absolute invariants corresponding to the forms in the system f or fm belong-
ing to R (1, T, A), and a finite system of absolute concomitants analogous to
the system for/m in the domain R (l, T, 0). To obtain the concomitants of
fim(t, x) one may either particularize those of fm under T, making the substi-
tutions which reduce T to 2\, or, the invariants under Einstein's transforma-
tions can be developed ab initio by the methods described above for T, the
arguments of the expansion of f\m being now £ = ct + x, 77 = ct — x. These
invariantive functions represent invariant loci in four dimensional space if
the time t is interpreted as a fourth dimension. All are free from v.
A . paper in which the above theory and applications are developed in detail
and which includes tables of the relativity invariants computed for the general
fim in the case of the non-absolute systems, and for the orders 1 to 3, inclusive,
in the case of the absolute systems, is to appear in the Annals of Mathematics.
1 Boole, Cambridge Mathematical Journal, 3, 1843, (1).
2 Elliott, London, Proc. Math. Soc, 33, 1901, (226).
3 0. E. Glenn, New York, Trans. Amer. Math. Soc., 18, 1917. (443)
4 Hilbert, Leipzig, Math. Ann., 36, 1890, (473).
5 Einstein, Leipzig, Ann. Physik, 17, 1905. Lorentz, Einstein, and Minkowski, Das
Relativitdtsprinzip, 1913, p. 27. R. D. Carmichael, The Theory of Relativity, 1913, p. 44.
INFORMATION TO SUBSCRIBERS
Subscriptions at the rate of $5.00 per annum should be made payable
to the National Academy of Sciences, and sent to Williams & Wilkins Com-
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CONTENTS
Page
Astronomy.— Some Spectral Characteristics of Cepheid Variables
By W. S. Adams and A. H. Joy 129
Physics.— Types of Achromatic Fringes By Carl Barus 132
Physics. — Interference of Pencils Which Constitute the Remote Divergences
from a Slit By Carl Barus 134
Astronomy.— A Study of the Motions of Forty-eight Double Stars ....
By Eric Doolittle 137
Physics.— The Structure of an Electromagnetic Field . . . By H. Bateman 140
Mathematics— Invariants Which are Functions of Parameters of the Trans-
formation By Oliver E. Glenn 145
siiiiiiiiiiiiiiiiiiiiisi»iiin»aiiuii:!UMifimiMiii£Wiiriiiumnffh§iBiiia>nu£^f]2^
S3
I
VOLUME 4 JUNE, 1918 NUMBER 6
PROCEEDINGS
OF THE
National Academy
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OF THE
UNITED STATES OF AMERICA
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Papers by members of the Academy may be sent to Edwin Bidwell Wilson,
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Prooi will not ordinarily be sent; if an author asks for proof, it will be
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PROCEEDINGS
OF THE
NATIONAL ACADEMY OF SCIENCES
Volume 4 JUNE 15, 1918 Number 6
EFFECTS OF A PROLONGED REDUCTION IN DIET ON 25 MEN
I. INFLUENCE ON BASAL METABOLISM AND NITROGEN
EXCRETION
By Francis G. Benedict and Paul Roth
Nutrition Laboratory, Carnegie Institution op Washington, Boston
Read before the Academy, April 22, 1918
A year ago, realizing that this nation faced a food shortage, several members
of the staff of the Nutrition Laboratory decided that positive evidence re-
garding the effect of a prolonged restriction in diet would give knowledge of
possible use in an imminent emergency. Such data seemed especially impor-
tant as exact experimentation on a large number of men and women, including
many with peculiar dietetic habits and a supposedly low metabolism, had failed
to indicate that the basal or maintenance metabolism of any particular class
of persons or, indeed, of any single individual (making due allowance for dif-
ferences in weight), is materially lower in energy requirement than the basal
metabolism of the average individual. Since the law of the conservation of
energy obtains in the human organism, it is clear that with uniform mainte-
nance metabolism, the food requirement must also be fairly uniform. On the
other hand, no evidence is available as to the actual effect of a reduction in
diet, continued over a considerable period of time. Accordingly, a research
was carried out by the Nutrition Laboratory during the past winter in which
the effect of a low diet upon a group of normal adults was studied for a period
of several months.
If the food intake is reduced below the maintenance level and the basal
requirement remains constant, it is plain that there must be drafts upon pre-
viously-stored body reserves. In any study of the effect of a reduced diet,
since we are dealing primarily with the question of energy rather than with a
specific ingredient of the food, there must be the strictest control of the diet,
so that the exact intake of energy over relatively long periods may be known.
This involves, with human subjects, a degree of personal integrity and veracity
that cannot be assumed but must be demonstrated.
149
150
PHYSIOLOGY : BENEDICT AND ROTH
For subjects we selected 12 young men from a considerable number of
volunteers from the student body of the International Y. M. C. A. College in
Springfield, Mass. The average age of the men was twenty-three years.
For a period of four months these men were kept upon a much restricted diet,
with an energy content of approximately one-half to two-thirds of their
caloric requirements prior to the test. During the first few weeks there was a
distinct drop in body weight. When the body weight had fallen on the aver-
age 12%, the calories in the diet were increased so as to prevent further loss
in weight. The measurement of the caloric consumption at this sustained
weight level would indicate the true caloric requirement for maintenance.
For control 12 men from the same student body, living under exactly the
same conditions save for the dietetic restrictions, were likewise studied and
their food intake occasionally measured for periods of four or five days.
It was impossible to place all the men in respiration chambers and study
their metabolism during the entire twenty-four hours, for it was realized that
these men were, first, college students, and second, volunteers for scientific
experimentation, and that their college duties, both intellectual and physical,
must be carried out; hence they were all cautioned at the beginning of the
study not to restrict their activities in any way. Even with the best conditions
it could not be assumed that the muscular activity of both groups of men
would be exactly alike throughout the period of observation. It thus seemed
best to make the measurements of the metabolism upon a uniform basis, ex-
cluding uncertain and, more particularly, uneven muscular activity. For this
purpose all of the first group of men were studied during periods of complete
muscular repose and without food in the stomach, so as to obtain the basal
metabolism practically every morning from the 27th of September, 1917, to
the 3rd of February, 1918. The individual measurements were controlled
by a group study with a large respiration chamber in the Nutrition Laboratory
in which the 12 men slept every alternate Saturday night; the metabolism
during deep sleep was thus obtained. No individual tests were made with
the control squad, but group measurements were obtained on the alternate
Saturday nights and used for comparison with the group results obtained for
the diet squad.
Prior to the dietetic restriction, the basal metabolism, measured inside the
large respiration chamber at night, was the same with the first and second
squads, thus giving admirable proof that a group of 12 men was sufficiently
large for our purpose. In addition to the observations on weight and basal
metabolism, records were obtained of the total nitrogen in the food, feces,
and urine during the entire four months, frequent observations were made of
the pulse and respiration rate, total ventilation of the lungs, alveolar carbon
dioxide, energy requirement for walking a definite distance at a definite
speed, the blood (including counts of the red and white corpuscles and dif-
ferentials, and determination of the haemoglobin), the blood pressure and
rectal and skin temperatures. Clinical examinations were also made, as
PHYSIOLOGY : BENEDICT AND ROTH
151
well as measurements of the body surface, strength tests, and extensive psycho-
physiological examinations of the neuro-muscular processes. The effects of
the prolonged reduction in diet on these various functions were striking.
Those dealing primarily with basal metabolism may be summed up as follows:
1. A gradual reduction in weight to a point 12% below the initial weight
took place during a period of from three to ten weeks, with low calories and a
moderate amount of protein in the food intake. The normal demand of the
men prior to the dietetic alteration ranged from 3200 to 3600 net calories.
One squad of 12 men subsisted for three weeks on 1400 net calories without
special disturbance.
2. After the loss in weight of 12% had been reached, the net calories re-
quired to maintain this weight averaged about 2300, or approximately one-
third less than the original amount required.
3. At the end of the reduction in weight, the actual heat output during the
hours of sleep, as computed by indirect calorimetry, was approximately one-
fourth less than normal, thus giving a rough confirmation of the lowered
number of calories found by actual measurement of the food intake. That
there was no seasonal variation in metabolism was shown by the constancy
in the metabolic level of the control squad.
4. The heat output by indirect calorimetry per kilogram of body weight
and per square meter of body surface was essentially 18% lower than at the
beginning of the study.
5. The analyses of food, feces, and urine were sufficiently complete to per-
mit a nitrogen balance to be made and it was found that throughout the
period of loss in weight and for some time subsequent thereto, there was a
marked loss of nitrogen to the body. In round numbers these men each lost
approximately 150 grams of nitrogen. There is an intimate relationship
between this ' surplus nitrogen' and the metabolic level. Removing what we
may designate as 'surplus nitrogen,' we believe distinctly lowers the stimulus
to cellular activity.
6. The nitrogen output per day at the maintenance diet of 2300 net calories
was about 9 grams. A control group of 12 men, living substantially the same
life and eating in the same dining room, but with unrestricted diet, showed a
nitrogen output of 16 to 17 grams per day.
7. The pulse rate was astonishingly lowered. Many of the men showed
morning pulse rates as low as 33 and daily counts of 32, 31, and 30 were
obtained; at least one subject gave six definite counts on one morning of 29.
8. The blood pressure, both systolic and diastolic, was distinctly lowered.
9. The skin temperature, as measured on the surface of the hands and fore-
head, was, with some subjects, considerably lower than normal. With most
of the men normal temperatures prevailed.
10. The rectal temperature was practically normal.
The general picture that the men presented at the end of the test or at their
minimum weight was one of noticeable emaciation, particularly in the face,
152
PSYCHOLOGY : W. R. MILES
but all the men continued the usual college activities with no obvious re-
duction in stamina.
Two of the men had chronic bad noses. One was operated upon during the
test and the other should have been. Aside from these two, the prevalence
of colds during the period was about the same as with the other college stu-
dents. During the study three men underwent ether narcosis for operations
(on nose, foot, and hemorrhoids) and made rapid recoveries. One man at the
lowest period of weight contracted what was diagnosed by three physicians
as typhoid fever, although the final course of the disease seemed to leave the
diagnosis somewhat in doubt. He ran a very high fever, and was critically
ill for some time, but has made a complete convalescence and recovery and
has returned to college.
The most noticeable discomfort experienced by the subjects was a feeling
of cold, which it is only fair to say might be due in large part to the severity
of the past winter. In general, notwithstanding the very great reduction in
the metabolism (which we believe was due to the removal from the body of
the stimulus to cellular activity of approximately 150 grams of 'surplus nitro-
gen'), the whole period of lowered food intake had no untoward effect upon
the physical or mental activities of these men, and they were able to continue
successfully their college duties.
The control squad, having demonstrated the absence of a seasonal variation
in metabolism for about three months, were put for a period of three weeks
upon a restricted ration of less than one-half their previous calorie con-
sumption. In all details the picture exhibited by the first squad was
strikingly duplicated by the second squad, although, as the loss in weight
was obviously not so great (6% as compared with 12%) the phenomena
were quantitatively somewhat less emphasized.
The entire research will be published in conjunction with our co-workers,
Drs. Walter R. Miles, and H. Monmouth Smith, in a monograph of the
Carnegie Institution of Washington in the near future.
EFFECTS OF A PROLONGED REDUCTION IN DIET ON 25 MEN
II. BEARING ON N EURO-MUSCULAR PROCESSES AND MENTAL
CONDITION
By Walter R. Miles
Nutrition Laboratory, Carnegie Institution of Washington, Boston
Communicated by F. G. Benedict. Read before the Academy, April 22, 1918
It is obvious that any adequate investigation of prolonged reduction in
diet must include observations of the neuro-muscular processes and general
mental condition of the individuals studied. In the low-diet research the
psychological measurements were made at the Nutrition Laboratory on Sat-
PSYCHOLOGY: W. R. MILES
153
urday evenings and Sunday mornings when the men were in Boston for the
bi-weekly group metabolism experiment in the large respiration chamber.
After a standard evening meal the subjects came to the laboratory and
were available during a period of approximately four hours. Of this time
about one hour was spent on measurements which could be given to the men
as a group. This was done in the library where table space and other con-
ditions were adequate. Particular attention was given to the matter of
lighting. The men were assigned seats which they occupied at each session
although it was not believed that one location in the room was more favorable
than another for the group experiments. A considerable period was allowed
for preliminary adjustments, announcements, questions and a general quieting
of the men before beginning the evening session.
The first measurement was a test of accuracy or steadiness of movement in
tracing between parallel lines with many right-angle turns. The tempo was
set by the metronome beating half seconds. The subject was instructed to
start at a signal, to avoid contact with the boundary lines, and to make one
straight line for each beat of the metronome. Each contact with a boundary
line was counted an error.
Other measurements which could be suitably given by the group method
were : Discrimination for the pitch of tones, using tuning forks and resonators as
source (150 judgments); discrimination and cancellation of specified number
groups on a printed page of numbers, the task being to mark each pair of
successive digits which, when added, equaled 11; the addition of one-place
numbers arranged in columns of ten during a test period of ten minutes; and
the memory span for lists of 4-letter English words pronounced in tempo and
without stress.
Psychological measurements of men on reduced diet
Group Method:
1. Accuracy in tracing between irregular parallel lines.
2. Discrimination for the pitch of tones.
3. Discrimination for specified number groups on a printed page.
4. Addition of one-place numbers for a period of ten minutes.
5. Memory span for 4-letter English words.
Individual Method:
6. Strength of grip; hands tested alternately.
7. Changes in pulse rate occasioned by short periods of exertion.
8. Latency, amplitude and refractory period of the patellar reflex.
9. Reaction time for turning the eye to a new point of regard.
10. Reaction time for speaking 4-letter words.
11. Continuous discrimination and reaction in finding serial numbers.
12. Sensory threshold for vision.
13. Sensory threshold for electric shock.
14. Speed and accuracy of the eye movements.
15. Number of finger movements performed in ten seconds.
16. Efficiency in traversing a right-angle maze.
17. Speed and accuracy in performing certain clerical tasks.
154
PSYCHOLOGY: W. R. MILES
The measurements taken by the 'individual method' employed much
technical apparatus. The general nature of these observations is indicated
above. The apparatus was distributed in three rooms, which opened off a
common hallway, and with the aid of two assistants it was possible to make
psychological measurements with four of our subjects at the same time, each
man serving a total of about seventy minutes. The measurements were
grouped according to expediency. Nos. 6, 11, 16 and 17 (strength of grip,
finding serial number, traversing the maze, and the clerical tasks) were such
that two subjects could work in one room without disturbing each other.
Nos. 8, 10, and 15 (patellar reflex, word reactions, and finger movements)
formed a convenient group for a second room, since they all relied on the
Blix-Sandstrom kymograph for chronographic record. The thresholds for
vision and electric shock were determined in the third room, the main psycho-
logical laboratory. In this room, also, the distinctive measurements for the
morning sessions were made. These included Nos. 7, 9, and 14, i.e., changes
in pulse rate with exertion, reaction time of the eye, and speed of eye move-
ments, together with more determinations of strength of grip and finger
movement speed.
Most of the techniques used in the low-diet research, particularly those
given by the individual method, had been previously elaborated in connection
with other problems with the object of securing measurements and procedures
which could be repeated on the same individual without large practice changes.
Great care has been taken to make the measurements as objective and free
from personal bias as possible; it will be noted that most of them have a dis-
tinct physiological trend. The avoidance of all practice effect and influence
from changes in interest and attention is an ideal which of course is never
quite reached in psychological investigation; however, the fortnight interval
between sessions was a favorable circumstance for minimizing these factors
in the present work.
Careful instructions preceded each measurement, both group and indi-
vidual, and it is a pleasure to record the remarkable cooperation and serious
attitude of the men who served as subjects.
It has not been possible thus early to get all the data into final form for
comparison. Pending this it is unwise to make dogmatic statements. Final
results are available for some of the measurements and the samples given in
the table are thought to be representative. Separate averages for the two
groups of men are presented in parallel columns headed 'D. S.' (Diet Squad;
these men were on low diet from October 4, 1917, until February 3, 1918)
and 'C. S.' (Control Squad; these students continued their normal diet up to
January 8, 1918, and were then on reduction until January 28, 1918). The
values in black face type are under normal condition of diet.
PSYCHOLOGY: W. R. MILES 155
Illustrative results from psychological measurements during prolonged reduction in diet
MEASUREMENTS
NO. 1
TRACING
NO. 4 ADDITION
NO. 6 GRIP
NO. 14 EYE
MOVEMENTS
NO. 15 FINGER
MOVEMENTS
!, 1918
Average errors
per line
Total col-
umns in 10
minutes
Per cent of
error
Average kilos
for both hands
Average time
in sigma
Number in 10
seconds
4 months
February 1
D. S.
c. s.
D. S.
c. s.
D. S.
c. s.
D. S.
c. s.
D. S.
c. s.
D. S.
c. s.
5.7
5.6
47.3
47.5
21.5
19.7
68.7
66.0
-d ^
£ 3
5.9
5.6
50.2
46.9
16.3
10.9
47.6
52.8
95
92
65.6
65.2
J ^
6.0
4.6
51.4
48.7
19.0
7.8
48.1
54.3
97
96
66.6
65.6
S.S
5.4
4.7
54.0
49.6
19.9
10.8
46.9
52.8
97
91
64.2
64.7
5.3
4.8
52.6
42.5
15.1
9.6
45.7
53.5
98
92
64.3
66.5
"J
4.1
4.4
52.7
46.9
17.0
14.0
44.9
54.1
100
95
63.4
64.2
WS
4.7
3.5
52.8
48.7
18.4
10.7
46.2
53.2
64.9
62.4
a
a;
m
4.4
3.9
52.8
51.1
14.2
8.7
45.9
53.3
65.4
61.4
3.3
3.3
53.4
56 8
13.2
11.7
45.8
63.5
67.6
Accuracy of movement in tracing between parallel lines shows a gradual
improvement as the experiment progresses. The diet squad did slightly
poorer in the first two sessions after the beginning of reduction and their
errors are a little larger than found with the control squad up to December 8.
The performance of the control squad, however, continues to improve when
on the low diet, hence no definite effect is established.
As would be expected, the efficiency in adding one-place numbers gradually
improved. The change, however, is remarkably small. When plotted, the
curve for total number of columns added in ten minutes is almost a straight
line. The most prominent fluctuation is with the control squad on their last
normal date, when it so happened that the best adder (a man who had for-
merly been a bank clerk) was absent from the group work. The percentage of
error is larger for the diet squad and contrasts with the other group in that it
fails to decline proportionately as much. On the first reduction day (Janu-
ary 13, the men had been on 1400 net calories per day since January 8) for the
control squad there was an increase in error.
In strength of grip the diet squad are definitely below the control, but the
three reduction dates for the latter squad show no definite change in strength.
Therefore the different level between the two squads cannot be interpreted as
due entirely to the low diet condition. Unfortunately it was impossible to
begin all the tests on the same date, since preliminary instruction required
considerable time at the first session, and no normal is here available for the
diet squad.
The eye movements, a type of muscular coordination which is peculiarly in-
dependent of voluntary control, show for the diet squad a progressive reduc-
tion in speed amounting in all to about 5%. The normal performance of the
156
PSYCHOLOGY: W. R. MILES
control squad was not regular, which detracts from the significance of the
lengthening in the compared two low-diet sessions.
The diet squad made their best score in finger movements on their one
normal date, and from this there was a drop of about 6%, which continued
irregularly until January 26. The performance of the control squad is fairly
even and at a lower level than the normal for the other men and it shows also
a decline on the three low-diet dates.
The many extra-laboratory observations of the men, their subjective im-
pressions, and general physical and mental performance are of interest.
Statements from the diet squad men were commonly such as these: "I feel
fine, except that I notice the cold, am weak in the legs and seem to lack
'pep;' " "I find it best to study immediately after my meals, and when I
begin to feel hunger, I occupy myself with the typewriter or other light physi-
cal work;" "The reduction in diet would not be hard to undergo if everyone
else at the college were doing it." Opposite the impression of weakness in
the legs may be set the record of one of the men, who after being on reduced
diet for fifty-six days, led a hare and hound race over a course of approxi-
mately 8 miles, running the distance in fifty-four minutes, winning the race by
eleven minutes. This man stated that he never felt better after a long distance
run.
The men are said to have satisfactorily kept up their college work during
the period. And while it might be criticised that the work would be judged
leniently by those who were watching the experiment, it should be empha-
sized that the experiments themselves, the bother of complete collection of
urine and feces, the many early morning respiration measurements, and the
frequent trips to Boston, made a heavy draft on the time and energy of the
men, which their fellow students did not have to bear.
On February 1, 1918, eleven of the diet squad were pitted against 11 selected
men from the College at Springfield and placed in an arm-holding contest
for endurance. The arms were held extended, palms down, at the level of the
shoulders. The number of men falling out were practically the same in both
squads; as a matter of fact, 7 of the diet squad and 8 in the competing squad
were still holding their arms out in the prescribed manner sixty minutes after
the trial started. It was not anticipated that the contest would be so long,
and other engagements made it necessary to stop at the end of the hour.
Whatever one may think of this as a real test of endurance, it is significant
that the men who had been on reduced diet for four months were not appreciably
inferior.
Basing judgment on the more objective laboratory measurements, in general
it must be concluded that a prolonged reduction in diet produces some de-
cline in neuro-muscular activities, but this does not seem nearly as definite
nor as large as the changes in metabolism and allied measurements. The
psychological changes were not such as to materially interfere with a satisfac-
tory discharge of the common duties of student life.
PHYSIOLOGY: H. M. SMITH
157
EFFECTS OF A PROLONGED REDUCTION IN DIET ON 25 MEN
III. INFLUENCE ON EFFICIENCY DURING MUSCULAR WORK
By H. Monmouth Smith
Nutrition Laboratory, Carnegie Institution of Washington, Boston
Communicated by F. G. Benedict. Read before the Academy, April 22, 1918
Of the various forms of muscular activity which might have been chosen
for a quantitative study of the efficiency of the human machine under a pro-
longed period of reduced diet, that of walking was selected since it is the most
common and necessary exercise, the element of training is practically negli-
gible, and the results can be expressed in common and well understood terms.
The principle employed in this study consisted of the measurement of the
gaseous exchange during the period of walking, and from the oxygen consumed
and its known heat value for the determined respiratory quotient the energy
requirement was calculated by indirect calorimetry.
The heat requirements thus found may be considered in two ways: (1) as the
total cost to the individual to walk a given distance including that fraction
of heat which is necessary to maintain the body organs at their normal func-
tions and irrespective of the differences in the amount of body weight trans-
ported, or (2) it may be considered on the basis of the cost to the individual
to move a unit mass of body weight a unit distance, over and above the cost
for the maintenance of the body at some selected basal condition, such as lying
or standing quietly. In other words it would be the cost of the superim-
posed work of walking. In reporting the energy requirement by the latter
method it is necessary to know this resting or basal metabolism as well as
that of walking.
The problem then was to determine the gaseous exchange of the subjects, at
rest and walking, both before and after reduction of diet, and from the differ-
ences in the heat developed compute the average energy expended for each
man under the different conditions.
Of the various methods of determining the gaseous exchange, the closed
chamber principle with gas analyses for carbon dioxide and oxygen at the
beginning and end of the experiment was selected for the walking experiments.
Accordingly an air-tight sheet-iron chamber was built large enough to
enclose a power-driven treadmill with a man walking on it. The chamber was
irregular in shape with a total volume of approximately 2400 liters. Suitable
arrangements were installed for controlling the speed of the mill and record-
ing the distance traveled and the number of steps taken.
The temperature of the chamber was determined by six resistance ther-
mometers suitably placed and connected in series with a Wheatstone bridge
and galvanometer placed in an adjoining room. Two electric fans stirred the
air within the chamber while a blower capable of moving 1000 liters of air a
158
PHYSIOLOGY: H. M. SMITH
minute carried the air through a pipe extending from the front of the chamber
to a drier and thence back into the rear of the chamber. In this pipe of
moving air was placed the psychrometer and from it the gas samples were with-
drawn for analysis.
During the period of walking pulse records were continuously made by
means of electrocardiograms.
The carbon dioxide was determined in duplicate by means of two Haldane
portable gas analysis apparatus, while the oxygen was found by means of the
Sonden apparatus.
Two groups of 11 and 12 men respectively were under investigation. One
squad, designated as the diet squad, was on a reduced ration from October 4
to February 3, while the other squad, known as the control squad, acted as a
control until January 8 when it also went on a reduced diet until January 28.
The first experiment was made on January 6 with the 12 men of the control
squad two days before their reduction of diet began. Each man walked in
the chamber for twenty-four minutes at a rate close to 69.5 meters per minute.
After a preliminary period of four minutes, during which time the necessary
TABLE 1
Reduced Diet and Heat Required per Man During Horizontal Walking, Rate 69.
Meters per Minute (2.5 Miles per Hour)
SQUAD
CONDITION
TOTAL HEAT
REQUIRED PER MAN
PER KILOMETER
HEAT REDUCTION
FROM NORMAL
cal.
per cent
Control. . . .
Normal
62.2
20-day diet
53.5
14
Diet
4-month diet
48.4
22
adjustments were made, the experiment proper began and continued for
twenty minutes. The gas samples were drawn at the start and end of this
twenty-minute period and from the increase in the percentage of C02 and the
decrease in the percentage of O2 the respiratory quotient was found and the
energy expended was computed.
The average total heat, thus measured, figured on a kilometer basis, is given
in table 1 and amounts to 62.2 calories.
After this squad had been on a reduced diet for twenty days the experi-
ment was repeated and it was then found to cost each man on an average 53.5
calories per kilometer. No experiment was made with the diet squad in
September as the chamber was not in readiness at the beginning of the study,
but on February 3 after four months' dieting an experiment made under the
same conditions as the two preceding showed an average expenditure of 48.4
calories per kilometer.
As the average normal weights of the members of the two squads before
dieting began differed from each other by only 0.5 kilogram, and since the
basal metabolism of the two squads as determined in a large respiration cham-
PHYSIOLOGY: H. M. SMITH
159
ber under normal conditions was alike, a comparison of the three sets of
experiments may fairly be made. This shows a drop in the energy expended
per man per kilometer of 8.7 calories for the twenty-day diet and of 13.8
calories for the four months' diet.
That this drop in the energy requirement is not wholly due to the fact
that there was less body weight to be moved may be seen by considering the
heat requirements from the second viewpoint, viz., on the basis of a kilogram
of body weight transported one horizontal meter.
In considering the energy requirements on this basis, it is usual to deduct
from the total heat measured that portion which may be ascribed to the
basal requirements of the body in a position of rest. Therefore, in addition
to the series of walking experiments just described there was also conducted a
series of experiments while the subjects were standing quietly. These were
carried out with a portable respiration apparatus in an adjoining room imme-
diately preceding the walking experiment. The difference between the stand-
ing and walking metabolisms may then be attributed to the superimposed
TABLE 2
Reduced Diet and Heat Required per Kilogram of Body Weight in Walking 1
Horizontal Meter
SQUAD
CONDITION
HEAT PER
HORIZONTAL
KILOGR AMMETER
GAIN OVER NORMAL
g.—cal.
per cent
Normal
0.610
Control ...
20-day diet
0.561
8
Diet
4-month diet
0.522
14
requirement due to walking, and from the distance walked in unit time and the
body weight, the requirement per horizontal kilogrammeter may be obtained.
The three sets of experiments figured upon this basis are given in table 2.
Here is shown a decreasing energy requirement from 0.610 gram calorie per
horizontal kilogrammeter for the control squad in normal condition to 0.522
gram calorie for the diet squad after subsisting four months on a diet of about
two-thirds normal. This reduction in the energy from 0.610 to 0.522 gram
calorie per horizontal kilogrammeter amounts to an increase in efficiency of
approximately 14%.
The results of these experiments are quite positive and show a marked sav-
ing in the energy requirements for walking in favor of the reduced diet whether
considered on the basis of the gross energy expended which represents the
real cost to the individual and to the national food reservoirs, or on the basis
of the energy required per horizontal kilogrammeter. Although the results
here submitted are confined to one form of muscular activity nevertheless
it is believed that the quantitative results obtained would be duplicated if
other forms of muscular work were studied.
160
ZOOLOGY: C. E. McCLUNG
POSSIBLE ACTION OF THE SEX-DETERMINING MECHANISM
By C. E. McClung
Zoological Laboratories, University of Pennsylvania
Communicated by H. H. Donaldson. Read before the Academy, November 20, 1917
Sex is the dual expression in organisms of a common series of characters
which are unequally and reciprocally developed in the individuals of the two
classes, the essential and primary difference between which is the presence of
germ cells of two types — ova in the female, sperm in the male. Sex is not a
necessity for reproduction or for biparentai inheritance: it is required in re-
production of highly complex organisms. It exhibits many modifications of
appearance and intensity in different groups and ranges from apparent cor-
respondence of the two classes to wide extremes of dimorphism. While this
gradation prevails for organisms in general, the individual is usually fixed in
its status of differentiation. In exceptional cases the individual may possess
the primary characters of both sexes or may alternately exhibit one or the
other. The measure of difference in any case is cellular. The first observable
cellular difference consists in a differentiation of conjugating cells into larger
passive food-laden ova, and smaller, active sperms. Similarly the individual,
ripe germ cell of either class appears definitely fixed in its character. The
primary measure of difference between the two types of germ cells is now
demonstrated to be nuclear, and, specifically, chromosomal. Sex is thus shown
to be a cellular problem.
Any conception of the sex determining mechanism must conform to the
different conditions of range and intensity of sexuality manifested by organisms.
As the conditions in one type of sexuality can not be substituted for another,
so the character of the determinant in one case can not be implied directly
in another. The details of the mechanism are variable in correspondence
with the conditions it determines.
In one type, in which the relation was first determined, the alternative
character is definitely fixed and the body cells are individually and independ-
ently male or female in type. The mechanism of determination here shows
itself to be characterized by a difference of one chromosome more in the female
than in the male. This is a particular chromosome, marked by such peculiari-
ties in the male as to make it readily determinable. Since this element is the
measure of the differences between the male and female types of cell, and
therefore the measure of the difference between the male and female animal,
a study of its differential behavior should be of value in arriving at conclusions
regarding the nature of sex and the method of its determination.
The two principal observations upon which an explanation of the operation
of the sex determining mechanism must rest are (1) the duplex and alternative
chromosome series, paralleling the double control and alternative inheritance
of characters, and (2) the physical state of the active chromosomes. Sex,
ZOOLOGY: C. E. McCLUNG
161
being a case of strict alternative heredity, would necessarily require a method
of control which should unfailingly operate to produce one or the other condi-
tion, and, since the numbers of males and females are approximately equal, it
should also conform to this numerical requirement. The presence and be-
havior of the accessory chromosome supplies the theoretical demands of such
a control. It is exactly alternative in its apportionment to the male cells,
producing two equal and differentiated classes; and, aside from their unequal
speed of approach to the egg, and selective attraction by it, should go into
exactly half the ova. This behavior has been determined accurately and is
no longer questioned.
The alternative mechanism is evident in the behavior of the accessory chro-
mosome. It has not been clear why there should be a double condition of the
sex chromosome in the female — in this respect conforming to the ordinary
conditions — and a single representation in the male. The condition obtains
however and in this fortunate circumstance we find the most promising ap-
proach to an understanding of the essential character of sex and the method
of its determination. Of great significance here is the fact that, in the mechan-
ism of the germ cells, there exists nothing of functional value in one sex that
is not contained in the other. For the differential element of the problem
we have therefore to look, not for something that is in itself male or female,
but for some factor which, in operation under one set of conditions, will so
control a series of characters as to give it the aspect which represents maleness;
under another set of conditions the alternative state of femaleness. How
then does this differentiator function?
The simplest conception of its action, perhaps, would be to ascribe to it
some specific power which, exerted to a certain degree, might eventuate in
the aspect of maleness, while in double that effect the series of characters
would be female. In essence this is the quantitative theory. It does not
however conform to any of our ideas of the alternative, or allelomorphic, action
of the chromosomes. What our experience with regard to chromosome action
dictates so far is this : One control for a character is sufficient for its elabora-
tion; two controls do not exhibit the sum of their action but find themselves in
opposition and usually one or the other prevails (probably for the single cell
one always does) ; additional controls are apparently without effect.
Genetic experiments also show that in cases of sex-linked inheritance a
single control in the male has the same effect as a double identical control in
the female, and that, if the factors in the female are opposed to each other,
such a single control as is fully effective in the male is then only half as potent.
The evidence accordingly relates to conditions of cell constitution and
explanations must be in terms of cell organization and known functions. In
this respect a comparison of the sex chromosomes of the male and female at the
critical time when their germ cells are being prepared for union is most in-
structive. While in the female there is apparent no unusual activities of the
sex element, as compared with the other chromosomes, in the male there are
162
ZOOLOGY: C. E. McCLUNG
well marked differences both in time and degree of its action. If the results
of the activities of the cell are due to the ordered interaction of its parts, then
any change in the rate of any one of its controlling elements, or any modification
of its time of action, must essentially affect the product. The sex-chromosome
during the development of the male germ cells exhibits all the signs of such a
differential action. In the first stages it is much more active than the other
chromosomes, as is evidenced by the large surface it exposes at the time of
greatest cellular interaction. Not only is this true but it is more independent,
having its substance isolated in a separate region. From this behavior it
is clear why it should, in the single condition here, be quite as effective in its
action as the duplex element of the female, if similar activities prevail in the
body cells.
At a later stage, when it is almost certain that the new relations between
controls of characters are being established, the sex chromosome is withdrawn
and has its surface reduced to the least possible extent. It gives every evidence
of inactivity, and, indeed, at this time has no occasion for action, since it has
no homologue with which to react. In cases, unlike the Orthoptera, where
there is a member to pair with it, the behavior is much the same and the genetic
evidence would indicate the absence of any reaction.
Undoubtedly this is indicative of the real difference between the female and
male organization, and, when fully understood, will point to the meaning of
sex. It is possible that we have here the explanation of the greater variability
of the male, for if a part of the control system is thus withdrawn from action
at the time of reorganization it would, almost inevitably, affect the entire
result. Here it may be recalled that there has been much dispute regarding
the general significance of sexual reproduction, some holding that it is to
ensure variation, others that it is to control or prevent it. Since both of these
ends must, in some measure, be attained is it not entirely possible that the
sexes represent, in part, such a division of labor? In this connection it may
be pointed out that the history of the sex chromosome is such as to fit it
exactly for the role of furthering these two purposes. It passes alternately
from the male to the female line, in the one being subject to the relative in-
stability of its unpaired condition, in the other being an orderly member of a
balanced series, forced to react with its mate as do the other chromosomes.
There is a possibility that in the male, the sex chromosome being unmated, or
opposed by an inactive element, may be more free to react with the other
chromosomes and in this way change their constitution, being in turn affected
by the reaction. By the nature of its transmission it must, after this experi-
ence, pass into the female line where its relation to the complex is necessarily
different. The contrast in these two conditions is obvious and the interpreta-
tion strongly suggested.
Where there is a mate to the sex chromosome in the male the genetic results
would indicate that it has no function, and the very fact that it may indiffer-
ently be present or absent suggests its inactivity. This element, of all the
GEOLOGY: E. B LAC KW ELDER
163
chromosomes, is confined to the male line and it is possible that its loss of
function is due to a lack of variable reaction. It experiences in effect, a most
intensive form of inbreeding and shows the characteristic results of such un-
varying reactions. For it, there is no opportunity to eliminate greater or less
variables, as is the case with the x-element during maturation in the female.
The ultimate problem is, of course, to determine why such a difference between
homologous elements should exist.
THE STUDY OF THE SEDIMENTS AS AN AID TO THE EARTH
HISTORIAN
By Eliot Blackwelder
Department of Geology, University of Illinois
Communicated by J. M. Clarke, March 29, 1918
Objectives of the Earth Historian. — We are, of course, still immensely far
from our ultimate goal, which is a complete understanding of all the past
states and events of the earth, or as Professor Salisbury used to put it, "the
complete geographies of all past epochs." Progress toward this unreachable
goal will be most favored if the advance is made rather uniformly, all along
the front. It is true that such progress is often made by pushing out salients,
but the further extension of such salients is usually impossible without cor-
responding support from the flanks.
In the past we have gone ahead much farther along certain lines in geologic
history than along others. The history of life and of faunal succession has
been cultivated assiduously for generations and is, on the whole, much better
understood than other phases of the subject. Although not so well known in
detail, the history of diastrophism is now fairly well blocked out and the mere
continuation of studies already under way is likely to afford us in the near
future a serviceable understanding of the sequence of major earth movements.
The most backward points in the general advance just now are in two sectors:
That of the history of climate, and that of the principles of chronology and
correlation.
The importance of climate arises from the fact that it is one of the most
powerful factors, if not indeed the dominant factor, controlling not only the
sculpture of the land but the nature of the deposits that are made both on land
and in the sea.
Secondly, the principles of correlation must be understood better than they
are now, before we can bring into their proper time relations the various events
and conditions of which the sediments give us record. In spite of the im-
pressions in elementary text books of geology, I think it will be generally
admitted, by those who have carefully considered the question, that we do not
yet know these principles with satisfactory accuracy. If we did, we should
164
GEOLOGY: E. BLACKW ELDER
not have such anomalies as the actual interbedding of strata in Montana
containing marine invertebrates assigned to the Cretaceous with those con-
taining land plants identified as Eocene; or as the Triassic in Idaho resting
conformably on rocks containing only Pennsylvanian fossils. Many other
cases of similar perplexity will occur to those who have had much to do with
age questions in stratigraphy. All things considered, it seems to me that the
improvement of correlation methods and a more general acceptance of these
improvements is at the present time the thing most to be desired by the
earth historian, for nowadays it is one of the chief causes of friction among us.
What service can the study of the sediments and sedimentary rocks render
in connection with these two problems? First it offers the best and most
comprehensive means of working out the history of climate. We already
understand rather fully the climatic significance of such deposits as beds of
coral limestone, of tillite, and of saline formations. We have probably reached
a similar comprehension of the red beds, loess, and certain othei4 types, although
we are not yet fully agreed among ourselves regarding them. Before long we
may expect to know as fully the climatic significance of the coal-bearing gray
sediments, and eventually even of most of the marine deposits. For even
among the, latter no matter how great the importance of the work of bacteria,
algae, foraminifera, and other organisms is, it becomes increasingly evident
that the very activities and processes of these organisms are largely dominated
by climate, either directly or indirectly, and that they are forced to make a
record of climatic changes in the marine sediments to which they contribute.
For example, the prevalence of siliceous in place of calcareous ooze in the
Antarctic Ocean is probably due to biochemical factors that depend on climate.
The study of climatic history is not only necessary for its own sake as a
division of the larger earth history, but it has an important bearing upon the
attainment of the other desideratum, namely, more reliable correlations,.
Climatic changes are widespread in their influence. Some, like the cooling
off during the last glacial period, seem to have affected the whole earth. They
influence both land and sea deposits, and hence leave their impress on all
sedimentary formations. In comparison with the slow progress of geologic
events, the effects of climatic change are felt quickly. We seem justified in
believing that altered climates do not ordinarily migrate slowly from region
to region, and on this assumption it may generally be presumed that the
results are essentially simultaneous over large areas. For these reasons cli-
matic changes should serve as very delicate indicators of time relations. They
are likely to be especially valuable because their record is most clear in the
terrestrial sediments, where fossils — our customary reliance — are apt to be
rare or absent.
From the earliest days of geology attempts have been made to correlate
strata in different places by means of lithologic character. Many of these
attempts have met with either failure or only partial success. In compara-
tively recent years, however, more refined methods have yielded much better
GEOLOGY: E. BLACKW ELDER
165
results. For example, Rogers and Stone in their recent study of the Lebo
shale of Montana have shown that it can be identified over large areas by its
andesitic particles, which record eruptions of volcanos farther west at a single
epoch in Cretaceous times.
In the future it will undoubtedly be possible to make far greater use of the
physical characteristics of sedimentary rocks in correlation — not so much by a
direct matching of similar rocks as by an indirect process of first elaborating
from the rocks the climatic and physiographic conditions and their changes in
time, and then correlating these. It should in fact be as feasible to correlate
by means of climatic history as to correlate by diastrophic history. Indeed
it is already beginning to be the practice of the most progressive stratigraphers
to make their correlations not simply on the basis of faunas nor on the basis
of diastrophism, but on the compound basis of life, climate, topography, vul-
canism, and diastrophism with due regard to their mutual relations and
dependences and their relative values. It is my own expectation that this
practice will soon become general.
What is Needed. — We may reasonably hope to understand eventually all
of the sedimentary rocks at least as well as we now know any; but at present
our knowledge is very uneven, being tolerably complete for some types and
very slender for others. Among the sediments which are as yet but partly
understood the following may be mentioned by way of illustration of our
needs: limestone conglomerates and oolites, sedimentary iron ores, chert,
jasper, etc., gray flags and shales with lean faunas, dolomites, phosphorites,
greensands, black oily shales, lithographic limestones, and rhythmically
alternating shale and limestone. Of course, there are many others.
To advance more rapidly this part of the scientific battle front, several
things are needed. Among the most useful are the prolonged and intensive
studies of certain modern types of deposits and the processes of their deposi-
tion, as illustrated by the investigations that have been carried on recently
by T. W. Vaughan and his associates in the Florida region, as well as by the
careful study of mountain stream work by G. K. Gilbert in California. Some
of these problems are too large to be attacked by most individuals, but require
for their successful execution the aid of our strongest scientific institutions and
the cooperation of a number of investigators over a period of years.
Hardly less valuable are the close and detailed studies of ancient sedimen-
tary rocks, such as Barrell's interpretation of the Mauch Chunk shale, the study
of the western Red Beds by C. W. Tomlinson, and of the dolomites by half a
dozen or more geologists in the last few years. Probably this method must be
our sole reliance in the case of certain peculiar sediments which, so far as known,
are not being formed on the earth at the present time. These are illustrated
by the thick, rich beds of phosphorite in Idaho and perhaps by the stratified
iron ores of eastern Brazil.
Our understanding can be advanced in a most helpful way also by careful
experimentation, such as that on sun-cracks reported by E. M. Kindle, or the
166
GEOLOGY: E. BLACKW ELDER
bacteriological experiments of Drew and others on the precipitation of calcium
carbonate from sea-water and the formation of oolites. On the whole there
has been much too little of this sort of work in the last few decades, perhaps
because sedimentary studies have been left largely to the stratigrapher who
is rarely, by force of habit, a laboratory experimenter. We shall need in this
work the cooperative aid of expert chemists, bacteriologists, and others not
ordinarily interested in geologic matters. The whole subject of diagenesis,
or simultaneous alteration of sediments, is doubtless in the province of the
bio-chemists and colloid chemists, if only we could induce them to assume the
task.
It might seem, at first thought, superfluous for me to recommend the thorough
combing of the geological literature for material on the nature and origin of the
sediments. But it is a fact, by no means sufficiently appreciated by most of
us, that the amount of buried treasure of this kind is really enormous. A
few years ago, while engaged in the study of phosphorite deposits, I was
astonished to find that the papers published in France and England during the
seventies contained a much clearer and more comprehensive interpretation of
phosphatic deposits than could be found in any American text-book or ref-
erence work published since 1900. In fact, it was perfectly evident that
most even of the more valuable of these foreign papers had never been seen by
the authors of the compendia mentioned, nor even by Americans who had
published important papers on the phosphatic rocks. I believe it is a fact
that one of the greatest services that can be rendered, just now, to the advance-
ment of our knowledge of sediments and sedimentary rocks would be the
thorough investigation, digestion, and summarizing of what is already in
print on the various types of sediments. It would vastly increase our effective
working knowledge and might conceivably double it, for it must be clear that
a fact or a theory which is lost is as useless as one that has never been found out.
Chemical analyses give much valuable information regarding sedimentary
deposits. Not infrequently the general conditions of origin as well as the
nature of the rock, can be inferred at once from the analysis. We have far
too few of them, and it is one of the minor discouraging conditions of the
study that even those we have are in many instances rendered useless by the
omission of essential facts.
Furthermore, a great many analyses are published with only the most
meager information regarding the source of the material. It is obviously of
very little value to the sedimentationist to know that a certain analysis per-
tains to a Cretaceous shale from Mt. Diablo, California, because the mountain
contains several distinct types of shales of Cretaceous age. In that case even
the brief statement that it was a gray sandy shale with abundant fragmentary
mollusks and echinoderms would greatly enhance the value of the analysis.
The same benefit might be conferred by noting that the specimen came from a
particular bed in a carefully described section already published. It is for this
reason that the great number of analyses in Clarke's Data of Geochemistry,
GEOLOGY: E. BLACKW ELDER
167
have only a small fraction of the value to the sedimentationist that they might
just as well have had if the facts had been adequately stated. We need, there-
fore, more analyses, more comprehensive analyses, and especially more fully
annotated analyses.
Probably our broadest, even if not our deepest, fund of information for the
interpretation or sedimentary formations comes from the descriptions of
sections by stratigraphers and by field geologists in general. Here, as in the
case of the chemical analyses, the sedimentationist meets with frequent dis-
appointment, simply because the exact and detailed observations, which alone
could make the section valuable for his purposes, have been largely or entirely
omitted. We have thousands of stratigraphic sections in which successive
beds are described as 'yellow sandstone,' £gray shale,' 'fossiliferous limestone,'
etc., leaving the reader to guess as best he may the significant characteristics
of the strata. Of course, the author of a report usually gives descriptions that
are adequate for his own purposes even if not for those of others who may go
to it for light. On the other hand those geologists who make it a practice to
describe colors carefully, to note textures, the presence of cross-bedding,
ripple-marks, sun-cracks, nodules, forms of grains, character of cements,
nature, abundance, and distribution of fossils, to say nothing of mineral
content, forms of large versus small grains, type and amplitude of cross-
bedding and ripple-marks and the nature of the filling in sun-cracks, are a
source of joy to the student of the sediments. Unwittingly perhaps, they are
rendering us a valuable service. We only regret their scarcity.
Many of us are necessarily limited in the geographic range of our first-
hand study of sediments and sedimentary processes. Others who have had
the good fortune to visit distant regions, and especially the less known parts
of the earth, such as the tropics and the arctic countries, can often with very
little trouble collect observations and material which may later, in the hands
of a trained student of sedimentation, yield important information for which
we might otherwise have to wait for decades. The amount of such data now on
hand in American universities and museums is very small when compared with
that which is available for a study of volcanic rocks or fossil faunas.
These are some of the ways in which the study of the sediments and the
sedimentary rocks can be forwarded not only by the special devotees of that
branch of geology but also by anyone who takes an intelligent interest in the
matter.
168
ZOOLOGY: G. H. PARKER
THE GROWTH OF THE ALASKAN FUR SEAL HERD BETWEEN
1912 AND 1917
By G. H. Parker
United States Seal Investigation, 1914
Read before the Academy, April 23, 1918
The apprehension with which the condition of the Alaskan fur seal herd
was viewed some half decade a^o has disappeared in consequence of the
steady growth of the herd. Few animals have been more closely watched
and counted from year to year than the Alaskan fur seals and their remark-
able habits of breeding exclusively on the Pribilof Islands and of assembling
there each summer in one immense complex family render these counts of no
small biological interest. It is probable that in late July and early August
of each year every living Alaskan fur seal (Callorhinus alascanus) is either
on one of the Pribilof Islands or in the immediately adjacent sea. Thus an
annual complete rendezvous of this species takes place in an almost unique
way, and this rendezvous gives opportunity for a census of the fui seal such
as is possible in scarcely any other undomesticated animal.
Table I exhibits in several particulars the numerical conditions of the herd
from the summer of 1912, when detailed counting was begun, to that of 1917.
The numbers in this table are taken from the successive reports on the state
of the herd as given out in the publications of the United States Bureau of
Fisheries (Osgood, Preble, and Parker, 1915; Bowers and Allen, 1917; Smith,
1917; Fisheries Service Bulletin, No. 30). The counts in the years 1912 and
1913 were made under G. A. Clark; those in 1914 under a group of six in-
vestigators, B. W. Harmon, T. Kitahara, J. M. Macoun, W. H. Osgood,
G. H. Parker, and E. A. Preble; and those of 1915, 1916, and 1917 under
G. D. Hanna.
Table 1 opens with an enumeration of the new-born pups for the seasons
under consideration. From 1912 to 1916 inclusive these enumerations were
made as direct counts of the numbers of pups on the beaches by methods
well established on the islands. In 1916, owing to the increase in the num-
ber of pups, direct counting was accomplished only with difficulty, and in
1917, in consequence of still greater increases, it was found necessary to re-
sort in part to a method of estimates. Hence it is believed that the num-
bers for 1916 and particularly for 1917 are not so accurate as those for the
preceding years.
In no feature is the growth of the herd indicated more clearly than in the
yearly increase in pups. This increase ranges in a progressive series from
81,984 in 1912 to 128,024 in 1917. The nature of this increase can be appre-
ciated best when the numbers are plotted in some such way as in Graph 1
in which the abscissas represent years and the ordinates numbers of pups in
ZOOLOGY: G. H. PARKER
169
TABLE 1
Numerical Statement of the Condition of the Alaskan Fur Seal Herd from 1912
to 1917 Inclusive
YEAR
PUPS
HAREM BULLS
AVERAGE HAREM
IDLE BULLS
ESTIMATED
TOTAL HERD
1912
81,984
1,358
60.4
113
215,738
1913
92,269
1,403
65.8
105
268,305
1914
93,250
1,559
59.8
172
294,687
1915
103,527
2,151
48.1
673
363,872
1916
116,977
3,500
33.4
2,632
417,281
1917
128,024
4,850
26.4
11,683
468,692
thousands. Here it will be seen that the successive counts, with the excep-
tion of one, lie almost exactly on a curve such as would describe the com-
mencement of an autocatalytic process. This type of curve when complete
shows in the beginning an accelerated increase, after which it approximates
more nearly to a uniform rate till a decline of this rate sets in due to a check-
ing of autocatalysis by retarding factors. The decline ceases when auto-
catalysis is balanced by the conditions unfavorable to it. This form of
curve is usually applied to the growth of an individual, but there is no reason
why it should not apply also to the growth of a population, which after all is
protoplasmic growth and hence dependent upon autocatalysis. It is, there-
fore, not surprising to find that the increase in pups should follow a curve
characteristic of such a process. The period of accelerated increase, as
Graph 1 shows, extended from 1912 to 1914 or 1915. The period over which
a more nearly uniform rate of increase was maintained began in 1914 or 1915
and extended to the last reported count, 1917. How much longer it will
continue cannot be stated. Eventually, as numbers augment, the beaches
on which the breeding occurs will become overcrowded, shortage of food may
supervene, epidemics due to unfavorable conditions may appear, and these
and other like influences will cut down the rate of increase until the herd,
having arrived at its maximum number, will stand at a constant level. Just
as it is impossible to predict how long after 1917 the steady increase will be
maintained, so also it is impossible to foretell when equilibrium will be reached.
The only pup count that fails to fall in line with the interpretation of the
growth of the herd just given is that of 1913. This count when considered in
relation to the other counts is some six thousands too high. When the pup
census of 1914 was made public, it was pointed out (Osgood, Preble, and
Parker, 1915, p. 41) that the increase of this year over the preceding one was
very slight, as a matter of fact only a little over 1%, whereas the increase
of 1913 over 1912 had been 12.5%. Clark (1916, p. 608) also commented
critically on these numbers and stated that "The results gave a gain of only
1%, without any adequate explanation for the irregularity," the implication
being that the count of 1914 was deficient. Now that there are in all six
counts that may be compared, it is quite obvious, as an inspection of Graph
170
ZOOLOGY: G. H. PARKER
7 7
/ /
/ /
Graph 2
Graph 3
GRAPH 1. ALASKAN FUR SEAL PUPS BORN IN THE SEASONS 1912 TO 1917 INCLUSIVE
The abscissas represent years and the ordinates numbers of pups in thousands (table 1).
The actual numbers counted, except those for the year 1913, fall on a curve represented by
the full line which has been extended one year by extrapolation. All counts on the curve
are probably low, the dotted curve indicating the direction of their real values.
GRAPH 2. NUMBERS OF HAREM BULLS (A) AND OF IDLE BULLS (B) IN THE ALASKAN FUR
SEAL HERD OF THE SEASONS 1912 TO 1917 INCLUSIVE
The abscissas represent years, the ordinates numbers of bulls in thousands (table 1).
The curve for harem bulls (A) is extended one year by extrapolation.
GRAPH 3. THE AVERAGE HAREM IN THE ALASKAN FUR SEAL HERD OF THE SEASONS
1912 TO 1917 INCLUSIVE
The abscissas represent years, the ordinates numbers of females in the average harem.
The curve has been extended one year by extrapolation.
ZOOLOGY: G. H. PARKER
171
1 shows, that it is not the count of 1914 that is anomalous but that of 1913-
Why this should be so extraordinarily high is difficult to state. It is per-
fectly clear to any one who has counted pups on the rookeries of the Pribilofs
that even the most accurate count is bound to fall short of the real num-
ber, so that the magnitudes indicated by the dotted line between 1912 and
1917 in Graph 1 show the directions in which the real numbers lie rather
than the solid line of actual enumerations. But even admitting that all the
enumerations, except that of 1913, are low, there is no reason to suppose that
these are so far low as would be implied on the assumption that the count
of 1913 is the most nearly accurate count of them all. It seems impossible
that Clark should have improved his method so much between 1912 and 1913
as to have found as large an increase as is implied in the count of 1913. Such
increases based on assumed improvement in method do not appear among the
several counts by Hanna. But in whatever way this discrepancy in the counts
may be explained, it must at least now be clear that the count of 1914 agrees
well with the majority of the other enumerations and that the count that is
exceptional is that of 1913.
Another way of indicating the growth of the herd as seen in the numbers
6f pups, is the percentage of annual increase in this constituent. From time
to time statements have been made as to what this percentage under normal
conditions should be. Thus Clark (1917, p. 499), selecting the increase in
1913 (12.5%) and in 1916 (13.0%), concluded that these figures "may be
taken as fixing with reasonable exactness the rate of growth at about 13%."
Hanna (Bower and Allen, 1917, p. 92) has expressed the opinion that about
12% is the normal rate of increase. How these numbers compare with the
actual figures of the last five years can be seen in table 2.
TABLE 2
Increase of Pups in the Alaskan Fur Seal Herd from 1913 to 1917 Inclusive
YEAR
NUMBER OF
GIVEN YEAR
PUPS IN THE
| PRECEDING YEAR
ACTUAL
INCREASE
PERCENTAGE INCREASE
1913
92,269
- 81,984
= 10,285
12.5+
1914
93,250
- 92,269
- 981
1.1-
1915
103,527
- 93,250
= 10,277
11.0+
1916
116,977
-103,527
= 13,450
13.0-
1917
128,024
-116,977
= 11,047
9.4+
9.4
Here it will be noted that the percentage increase varies from 1.1 to^l3.0
with an average of 9.4. This computation included the very anomalous
count of 1913, but even if this were replaced by a number such as would be
indicated by Graph 1 (86,000) such a replacement would not materially alter
the general average. The percentage increase in 1913 would then be 4.9
172
ZOOLOGY: G. H. PARKER
instead of 12.5 and in 1914, 7.8 instead of 1.1 and the general average would
be 9.2 instead of 9.4. Thus for the last five years the annual increase of pups
has averaged a little over 9% and is probably nearer 9.5 than 9. Hence both
Clark's figures and Hanna's are obviously too high for the present state of the
herd. In fact Clark's assumption of 13% is quite unwarranted for he gives no
reason for accepting this number rather than the other chosen by him, 12.5.
The average rate of increase indicated in table 2, 9.4%, would bring
about a doubling of the number of pups in approximately eight years. If no
untoward conditions arise, it is fair to expect that in 1920 about twice as
many pups will be born as were born in 1912.
Beside the annual increase in the number of pups born, the Alaskan fur
seal herd has given evidence of growth in the increase of its harem bulls.
These bulls, which are the sexually mature males that have succeeded in
having associated with them one or more breeding females, are perhaps the
most accurately counted element in the whole herd. The determination of
their numbers between 1912 and 1917 was made by direct count. The re-
sults of this census are given in the column in table 1 marked 'harem bulls'
where it will be seen that they represent an increasing series running from
1358 in 1912 to 4850 in 1917. The distribution of their rates of increase de-
scribes a curve (Graph 2, A) not unlike that seen for the pups. An extra-
polation on the basis of this curve leads to the prediction that the number
of harem bulls in 1918 will be somewhat over 6000.
The average harem for a given season is the average number of females
associated with the harem bull of that season. It is a derived number found
by dividing the number of females as indicated by their pups for a given
season by the number of harem bulls for that season (table 1). If the males
of the herd have been considerably reduced in numbers, as might result
from excessive killing, the number in proportion to that of the females would
be naturally small and conseauently the average harem would be large.
Such a condition, if excessive, would be an unfavorable sign in the herd
and improvement would be marked by a decrease in the size of the average
harem. The course of events in this particular between 1912 and 1917 is
represented in table 1 the details of which can be better appreciated by ref-
erence to Graph 3. In this it will be seen that the average harem presented
its most unfavorable condition in 1913 after which there was a steady im-
provement to 1917 in that the average number of females to each harem bull
fell from 65.8 to 26.4. It is to be remembered, however, that the extremely un-
favorable point in the curve, 1913, is dependent upon the anomalous pup
count of that year. Had this count been in line with the others, the average
harem for 1913 would have been very near those of 1912 and 1914. The
subsequent change, however, would not have been affected and this reduc-
tion can not be looked upon as anything but a favorable sign. From the
extrapolation in Graph 3, there is good reason to believe that the average
harem will be even smaller in 1918 than it was in 1917.
ZOOLOGY: G. H. PARKER
173
The idle bulls, to turn to another element in the herd, are those males
that have attained breeding age but that have failed to obtain one or more
females. They usually occupy less favorable areas on the outskirts of the
rookeries and may even move from place to place. They can be counted
with almost as much accuracy as the harem bulls, but their occasional mi-
grations make their count somewhat uncertain. In 1917 the idle bulls were
so numerous that it was deemed wise to subdivide them into two classes, idle
bulls proper or those with fixed positions on the breeding grounds but with-
out females, and surplus bulls or those that were unable to find positions on
the breeding ground and that usually resorted to other parts of the beaches
notably the bachelors' hauling grounds. These two classes are combined in
table 1, 1917, under the single head 'idle bulls.'
The idle bull indicates a maladjustment in the breeding conditions of the
fur seal. This feature has already been pointed out as evidence of imperfect
adaptation in this species (Parker, 1915). As already stated, in the fur seal,
as in most other higher animals, the numbers of males and females at birth
are very nearly equal. When the breeding period arrives, however, one male
associates himself with a large number of females, the lowest average harem
in the last five years being over 26 females to one male. Consequently, not-
withstanding the fact that the male breeding period is only six to eight years
(Clark, 1916, p. 608) as contrasted with the longer female period of approxi-
mately ten or eleven years, many males do not procure females. Thus the
idle bulls are a measure of this natural maladjustment within the herd.
In a wholly natural state of the herd they would undoubtedly be repre-
sented by considerable numbers. Their presence, at least in large num-
bers, can never be anything but a detriment. They are continually stirring
up strife not only among themselves but also among the breeding bulls and
they are accountable for the maiming and the death of many young seals.
They are the individuals that in the period of their best pilage should have
been killed for their skins and their excessive numbers indicate poor man-
agement of the herd. Their history during the period under consideration is
shown in table 1 and more strikingly in Graph 2, B. Here it will be seen
that the numbers of idle bulls remained small from 1912 to 1915 after which it
increased considerably in 1916 and enormously in 1917.
This constitutes the one unfavorable feature in the recuperation of the herd,
for it marks the effective appearance on the beaches of the first real element
that is detrimental. Fortunately it is within reasonably easy control, for the
fur seal herd is open to the same kind of management that chickens or cattle
are. In these stocks, as in the fur seals, the sexes are approximately equal,
at birth and in both instances, although good management calls for a careful
rearing and preservation of females, it also demands the retention of only
such males as are necessary for breeding, the excess being drawn off for market
purposes. This is clearly what should be done with the surplus male seals,
a step that out government is now prepared to take (Smith, 1917, p. 92).
174
PA THOLOG Y : BERG A ND KELSER
It is only to be regretted that this step was not taken earlier, for the large
number of idle bulls now in the herd is both a detriment to that body and a
positive loss of once good skins. This menace in the growth of the herd has
been repeatedly pointed out (Clark, 1914, 1916, 1917; Osgood, Preble, and
Parker, 1915) to those having the matter in charge.
The last column in table 1 contains the estimated annual totals for the
herd. These numbers are highly artificial in that they are largely made up
of computed elements and they are, therefore, so remote from direct ob-
servation that their detailed consideration is scarcely worth while. The
fact that all elements of the herd have separately increased between 1912
and 1917 is reflected in the increase of these calculated totals from 215,738
in 1912 to 468,692 in 1917.
In conclusion it may be stated that since 1912 the steady increase in the
numbers of pups born, and of harem bulls and the decrease since 1913 of
the average harem are most favorable signs in the growth, of the herd. The
one unfavorable feature during this period is the considerable increase in
idle bulls in 1915, 1916, and especially in 1917. This increase, which can be
eventually checked, shows that active commercial killing should have been
restored some years ago.
Anonymous, Washington, Fisheries Serv. Bull., No. 30, 1917, (6-7).
Bower, W. T., and Aller, H. D., Alaska Fisheries and Fur Industries in 1916, Washington,
1917, 118 pp.
Clark, G. A., New York, Science, N. S., 39, 1914, (871-872); Ibid., 44, 1916, (608-609);
New York, Amer. Mus. J., 17, 1917, (497-499).
Osgood, W. H., Preble, E. A., and Parker, G. H., Washington, Bull. U. S. Bur. Fisheries,
34, 1915, 1-172, 18 pis., 24 maps).
Parker, G. H., Philadelphia, Proc. Amer. Phil. Soc, 54, 1915, (1-6).
Smith, H. M., Washington, Ann. Rep. Comm. Fisheries, 1917. 104 pp.
THE DESTRUCTION OF TETANUS ANTITOXIN BY CHEMICAL
AGENTS
By W. N. Berg and R. A. Kelser
Pathological Division, Bureau of Animal Industry, Washington
Communicated by R. Pearl, April 13, 1918
The ultimate object of this work is a solution of the problem of the chemi-
cal nature of antitoxins and their preparation in the pure state. That this
would be attained was not expected in view of the numerous previous in-
vestigations which left these problems unsolved. But it seemed highly
probable that data would be obtained which would throw some light on the
subject.
Up to the present time numerous investigators attempted to separate anti-
toxins from their associated proteins, but without complete success. The
PATHOLOGY: BERG AND KELSER
175
well known tetanus and diphtheria antitoxins are examples of preparations
containing all or nearly all of the immunity units present in the original
serums, but only a part of the proteins. Thus, Homer1 (p. 400) concentrated
a tetanus serum containing 100 units per cubic centimeter and 6% of protein,
obtaining an antitoxin that contained 900 units per cubic centimeter and 19%
of protein. In this process 10% of the antitoxic units were lost, the antitoxin
was nine times as potent as the serum from which it was derived, but it con-
tained only three times as much protein. The failure of all attempts to
obtain a protein-free antitoxin preparation has led some investigators to the
conclusion that the antibody or group of antibodies which constitutes the an-
titoxin is one of the serum proteins and hence cannot be completely separated
from protein. The concentration of the antitoxin without a similar concen-
tration of protein is regarded by others as an indication that the antitoxin
may be a body of non-protein nature.
Under these conditions any test which would conclusively decide whether
an antitoxin is or is not identical with a serum protein, would have both a
practical and a theoretical interest. The following test was decided upon
because of its promising nature. If an antitoxin, tetanus antitoxin, for ex-
ample, is a substance of non-protein nature, it should be possible to prepare
artificial digestion mixtures containing the antitoxic serum or antitoxin de-
rived therefrom, in such fashion that the protein would undergo digestion
without loss of antitoxin. Appropriate chemical measurements would indi-
cate the extent of proteolysis, while inoculation experiments on guinea pigs
would indicate whether there was any loss of antitoxic units. If, on the other
hand, the antitoxin is a protein and its power to immunologically neutralize
the corresponding toxin is a function of the intact protein molecule, then the
antitoxin would be destroyed in every case where the protein had undergone
cleavage, regardless of whether the cleavage was caused by a proteolytic enzyme
or other chemical agent. Due regard must of course be had for the possible
destruction of the toxin by the chemical agents used.
Several different antitoxic preparations were exposed to the action of
trypsin-sodium carbonate solution or to pepsin-hydrochloric acid for com-
paratively long periods of time, with suitable controls. At proper intervals
the extent to which digestion had taken place was measured chemically and
compared with the loss of antitoxic units; the latter were determined by
guinea pig inoculation as described by Rosenau and Anderson2. The results
may be summarized as follows:
1. Tetanus antitoxin in 0.5% sodium carbonate solution was slowly and
completely destroyed. At the same time no significant chemical changes in
the proteins were detected.
2. In solutions amphoteric or faintly acid to litmus strips, trypsin destroys
the antitoxin and at the same time the associated proteins are digested. The
rates of antitoxin destruction and protein splitting were substantially the same.
176
MINERALOGY: G. P. MERRILL
From (1) it follows that antitoxin destruction may take place with or without
protein splitting.
3. In solutions containing trypsin and 0.5% sodium carbonate the results
were the same as in (2).
4. Tetanus antitoxin in 0.2% hydrochloric acid was completely destroyed
in three or more days. During this time no significant chemical changes in
the proteins were detected.
5. In neutral solutions pepsin did not affect the antitoxin.
6. In pepsin-hydrochloric acid, proteolysis and antitoxin destruction pro-
ceeded simultaneously.
These results tend to indicate that tetanus antitoxin is a substance of
non-protein nature. But the stability of the antitoxin is so dependent upon
that of the protein to which it is attached, that whenever the protein molecule
is split, the antitoxin splits with it.
The experimental details are given in the Journal of Agricultural Research,
1918.
1 Homer, A., J. Hygiene, London, 15, 1916, (388-400).
2Rosenau, M. J., and Anderson, J. F., Hygienic Lab. Bull., No. 43, 1908.
TESTS FOR FLUORINE AND TIN IN METEORITES WITH NOTES
ON MASKELYNITE AND THE EFFECT OF DRY
HEAT ON METEORIC STONES
By George P. Merrill
Department of Geology, United States National Museum, Washington
Communicated by E. W. Morley, April 29, 1918
The following is a partial report on results obtained in continuation of
work under a grant from the J. Lawrence Smith Fund of the National Academy
of Sciences.
1. On Fluorine in Meteoric Stones. — So far as I am aware the occurrence
of fluorine has never been recognized in meteoric stones. Meunier1 records
its presence as doubtful. Fletcher in his Handbook does not mention it at
all, nor is it mentioned by Cohen nor by Lockyer in his Meteoritic Hypothesis
as one of the elements even recognizable by the spectroscope. Nevertheless,
the occurrence of a calcium phosphate has often suggested its possible pres-
ence, and the wide distribution of this phosphate in meteoric stones, which I
have shown of late2 seemed to warrant further tests, particularly as new and
more refined methods for its detection had been discovered. Opportunity
for these tests was recently afforded by Dr. E. T. Wherry when engaged upon
the investigation of some fossil bones for Dr. Hrdlicka in the Museum lab-
oratories. The method consists in the digestion of the material in concen-
MINERALOGY: G. P. MERRILL
177
trated sulphuric acid in a small flask heated to 200°C. in a paraffine bath, the
process being continued foffour to five hours. The gases evolved are bubbled
through water, the fluorine being retained in water solution (in a U tube). In
ordinary work it is customary to titrate the solution thus obtained with a
standard alkali, but inasmuch as the meteoric samples tested contained both
chlorides and sulphides, which would yield hydrochloric acid and sulphur
dioxide, it was necessary to make the solution first alkaline with sodium
hydroxide and evaporate nearly to dryness in a platinum dish on the water
bath, the resulting concentrated solution being then added to a standard peroxi-
dized titanium solution in a colorimeter. Fluorine has the power of de-
colorizing or at least reducing the intense yellow color of this titanium solu-
tion, even when present to an amount not exceeding 0.001%.
Three samples were tested — Bluff, Texas; Allegan, Michigan; and Waconda,
Kansas, in each of which phosphoric acid (P2O5) to the amount of 0.25% has
been recorded, and in all of which the phosphate had been recognized micro-
scopically. Amounts of from 10 to 20 grams were used in the tests, and in
not a single instance did the titanium solution show the least sign of the
presence of fluorine. It would seem safe to assume, then, that in these cases
at least the element was not present.
2. Further Tests for Tin in Meteorites. — It will be recalled that in my re-
port on previous investigations, I stated that no traces of tin had thus far
been found by us. Incited, however, by the work of Derby3 1 was led to fol-
low up the matter still further. Derby, it will be remembered, reported
1.18% tin in the schreibersite of the Canon Diablo iron. Concerning this, he
states, "Tin has not been reported (i.e., previously) possibly because the solu-
tion has usually been made in aqua regia in which it would only appear through
a special research. In the present case, the solution was made in plain nitric
acid and the tin appeared as oxide and was verified by blowpipe tests."
Having obtained a considerable quantity of material, chiefly schreibersite
and cohenite with some carbon from various digestions of the Canon Diablo
iron in dilute hydrochloric acid, I submitted it to Dr. Whitfield with the
request that he examine the same with no other end in view than the deter-
mining of tin, if present. The results were negative. Two lots of 5 grams
each were taken and dissolved in nitric acid as described by Derby. Not a
trace of tin could be found, either in the first solution, as oxide, or by treating
the solution with hydrogen sulphide, in the customary way.
On the assumption that there is no error in Derby's work, we must assume
as suggested by him, that the tin does not belong to the schreibersite but to
another mineral that is not generally distributed throughout the meteoric
mass so that it only appears in certain portions of the residue.
3. On Maskelynite. — In a very large proportion of the stony meteorites I
have described, or studied, mention is made of a colorless, interstitial ma-
terial either quite isotropic or slightly doubly refracting, with rather low index
of refraction, which, following Tschermak and others, I have called, though
178
MINERALOGY: G. P. MERRILL
often with mental reservations, maskelynite. The material first described
under this name, it will be remembered, was found as a prominent con-
stituent of the meteorite of Shergotty, and was sufficiently abundant to allow
a satisfactory determination of all of its properties, including chemical com-
position. All occurrences since noted are of microscopic dimensions — mere
interstitial areas of rarely more than two or three millimeters in diameter,
and determinable properties so nearly negative that the referring of the min-
eral to maskelynite has been more in the nature of an acknowledgment to the
quality of Tschermak's work than to actual determinations on the part of those
describing it. This certainly was true in my own case,4 and it was not until
I was studying the stone of Holbrook, Arizona (1912), that I separated par-
ticles and by the recently introduced immersion method determined the
index of refraction to be 1.51, which, according to Larsen's tables, is that
of an oligoclase glass. Since that writing I have followed up the matter as
systematically and thoroughly as time and opportunity will permit, and
have reached the conclusion, pronounced without hesitation, that the min-
eral is in all cases feldspathic, ranging in composition from oligoclase to an-
orthite, and owes its condition to a fusion since the original crystallization of
the stone, followed by a cooling too rapid to allow it to regain its normal
properties.
These conclusions are based upon examinations of a large number of sec-
tions in which I have found the mineral in all stages from a glass essentially
isotropic with the low index (1.51) mentioned above to one plainly biaxial
but without crystal outlines, cleavage, or other recognizable properties, with
indices of 1.543 and 1.545, and in one case (Ness Co.) 1.56. Also, in forms
where the mineral is largely isotropic but still retains, in places, traces of
plagioclase twinning. It is this last feature, it should be stated, that causes
me to consider it a re-fused feldspar, rather than a residual and original
feldspathic glass.
These observations, it will be observed, are supplemental and corroborative
of those of Tschermak.5 The subject seems worthy of this extended notice,
not merely on account of the new observations, but since Farrington in his
recent Meteorites remarks concerning the mineral that "Its exact nature is
yet to be determined."
Attention should be called, in this connection, that an elevation of tem-
perature sufficient to fuse a feldspar without at least partial destruction of the
olivine would be impossible but in an atmosphere completely devoid of all
oxidizing gases. (See further under Effects of Heating, below.)
4. Effects of Heating Meteoric Stones at Various Temperatures. — The fact
that Meunier had transformed meteoric stones of his aumalite group into
tadjerites, by heating to redness, suggested the availing myself of oppor-
tunities offered by the Pennsylvania Zinc Company at their works at Palmers-
ton, Pennsylvania. A series of prepared specimens, including two cubes,
one each of the Estacado and Homestead meteorites, some 10 mm. in di-
MINERALOGY: G. P. MERRILL
179
ameter, were introduced into pits bored in fire-brick, and sealed up with fire-
clay. These bricks were then placed on top of a gas-fuel zienc smelter, where
they were allowed to remain for a period of four months, and in an atmosphere
in which oxidizing influences were reduced to a minimum. The exact tem-
perature could not be determined, but a cube of the Casas Grandes iron in
one of the pits was completely fused and absorbed into one of the bricks,
indicating a temperature not less than 1450°C. The results on the two stones
were as follows:
Estacado, Texas. — This, a veined crystalline chondrite of a dark gray color,
fine and compact texture, consists essentially of olivine and enstatite with
smaller amounts of pyrrhotite and nickel-iron. Before heating, the silicates
are colorless and limpid, and the metallic constituents scattered in small gran-
ules fairly uniformly throughout the mass. The roasting resulted in producing
a slight glaze on the exterior surface of the cube. The color was much dark-
ened, becoming uniformly dull black. Although remaining firm and hard,
the stone became filled with fine vesicles. The thin section under the micro-
scope seemed at first completely amorphous. In strong sunlight, however,
the silicates, although nearly opaque and without action in polarized light,
were of a deep dull red, indicating a certain amount of oxidation of the iron.
The interstices were filled with a fine, dust4ike, opaque and amorphous matter
which is impossible of determination. The particles of metal had been fused
and the material diffused throughout the ground to appear in the form of
minute blue points in reflected light. With the exception of the metal not a
single one of the original constituents was recognizable.
Homestead, Iowa. — This is a dark gray, homogeneous, hard and firm stone
belonging to Brezina's brecciated gray chondrite group. The mineral com-
position, as determined by Wadsworth, is olivine, enstatite, pyrrhotite, iron,
and base. Lasaulx is quoted as having noted the occurrence of a feldspar.
I find, in addition, a polysynthetically twinned pyroxene and a calcium phos-
phate in small quantities. After the roasting, the color is dull black and the
texture finely vesicular, although firm and hard. As was the case with the
Estacado stone, it is so opaque in thin sections as to almost entirely obscure
its original structure. The silicates are altered in the same manner, though
the olivine is the most affected; the metal is likewise diffused, and attempts
at making a photo-micrograph from the slides resulted in complete failure.
As it was evident the experiment had been carried too far a second attempt
was made in the museum laboratory at lower temperatures and for shorter
periods.
Small pieces of the Homestead meteorite, of 2 or 3 grams weight, were
roasted in a covered crucible at a low red heat for periods of one-half and one
hour each, the gas flame playing freely up and around the crucible. The
external manifestations of this heating were a change in color to dark gray
and a fusion, on the outer surface, of the troilite granules. A thin section
showed the nickel-iron to be unchanged, though the troilite had been broken
180
MINERALOGY: G. P. MERRILL
up to a greater or less extent. The principal change lay in the finer siliceous
material occupying the interstices of the other minerals which had turned, in
part, black and amorphous. A like change had taken place along the borders
of the chondrules and cleavage and fracture lines of the larger phenocryst,
giving them the appearance of having been injected with, some dark coloring
fluid. The amount of change was proportional to the length of time in heating,
as shown in figures 1, 2 and 3.
Figure 1 is from the unaltered stone and 2 and 3 from fragments heated
for one half and one hour respectively. It will be noted that there is an in-
crease in the amount of black opaque matter in 2 and 3 over that in 1. In the
piece roasted for a full hour the fine interstitial silicates have become wholly
changed to the black matter which penetrates the borders of the chondrules and
other crystal aggregates, until a condition is reached so closely resembling
that shown in sections of the McKinney (fig. 4) and Travis County (fig. 5)
black chondrites as to apparently leave no doubt as to the correctness of
Meunier's view to the effect that such are but phases of chondritic stones
which have been altered through a re-heating subsequent to their first crystal-
lization. It should be added that these roasted pieces are partially restored
to their original color by digestion in hydrochloric acid and sodium car-
bonate, showing that the change is one that has influenced chiefly the olivine.
Incidentally attention may well be called to the manner in which the blacken-
ing of the stone first manifests itself along cleavage and fracture lines in
figure 5.
It should be noted further that it is doubtful if all of the dark color in these
black chondrules is due to roasting, since some of them heated in a closed
tube give evidence of the presence of a small amount of a hydrocarbon.
1 Encyclopedic Chimique, 2, appendix 2, Meteorites.
2 Amer. J. Sci., New Haven, 43, 1918, (322).
*Ibid., 49, 1895, (101-110).
4 See my papers on the meteorites of Holbrook, Arizona, Smithsonian Misc. Coll., Wash-
ington, 60, No. 9, 1912; Modoc, Kansas, Amer. J. Sci., New Haven, 21, 1906, (356-360);
Rich Mountain, North Carolina, Proc. U. S. Nat. Mus., Washington, 32, 1907, (241-244);
Thomson, Georgia, Smithsonian Misc. Coll., 52, 1909, (473-476); Fisher, Minnesota, Proc.
U. S. Nat. Mus., 48, 1915, (503-506); and Coon Butte, Arizona, (Mallet), Amer. J. Sci.,
21, 1906, (351).
5 See Cohen's Meleoritenkunde, pp. 311-314, Figure 2 on plate 17 or Tschermak's Die
Mikroskopische Beschafenheit der Meteoriten will apply equally well to the majority of
occurrences.
Fig. 3
Fig. 4
CHEMISTRY: F. W. CLARKE
181
NOTES ON ISOTOPIC LEAD
By Frank Wigglesworth Clarke
United States Geological Survey, Washington
Read before the Academy, April 23, 1918
One of the most remarkable discoveries in the field of radioactivity, has
been the fact that the elements of highest atomic weight, uranium and
thorium, are unstable, and undergo slow transformations into other sub-
stances; especially into helium and lead. The lead thus produced is iden-
tical with normal lead in its spectrum and its distinctively chemical
properties, but different in its atomic weight; and this difference, which is
thoroughly established, is of peculiar significance. The purest lead fron^
uranium minerals has an atomic weight fully a unit lower than that of or-
dinary lead, while that from thorium minerals is nearly a unit higher. These
are the extreme differences, so far as the present evidence goes; but the ac-
tual determinations of the atomic weights of these isotopes of lead show
wide variations due to differences between the minerals from which the lead
was obtained. Furthermore, these isotopes differ from ordinary lead in
specific gravity; one being lighter and the other heavier than ordinary lead,
these differences being proportional to the variations in atomic weight. Con-
sequently the three kinds of lead have the same atomic volume, and occupy
the same place in the periodic classification of the chemical elements.
Ordinary or normal lead differs from isotopic lead in one important re-
spect, namely, its atomic weight is constant, and the actual determinations
vary only within the limits of experimental uncertainty. This constancy was
established by Baxter and Grover,1 who studied lead from a number of dis-
tinct sources. Their material was derived from four mineral species; galena,
cerussite, vanadinite, and wulfenite, and also from commercial lead nitrate.
Furthermore, the minerals examined came from seven widely separated
localities; two from Germany, and one each from Australia, Missouri, Idaho,
Washington, and Arizona. The lead in each case was carefully purified,
and converted into chloride, with which the determinations of atomic weight
were made. The method of determination was the standard method long
in use at Harvard, and based upon large experience and the most thorough
technique. The values found for the atomic weight are shown in the fol-
lowing table:
Source Atomic weight of lead
Commercial nitrate 207 . 22
Cerussite, New South Wales 207 . 22
Cerussite, Eif el Mountains, Germany 207.20
Galena, Joplin, Missouri 207.22
Cerussite, Wallace, Idaho 207 . 2 1
Galena, Nassau, Germany 207.21
Vanadinite and wulfenite, Arizona 207.21
Galena, Metalline Falls, Washington 207 . 2 1
182
CHEMISTRY: F. W. CLARKE
A series of analyses of lead bromide gave values practically identical with
these.
This evidence as to constancy of atomic weight is conclusive, but it has
also been confirmed by three investigations by Richards and his colleagues
in this country, and by Honigschmid in Vienna. These later determinations
were made as checks upon determinations of the atomic weight of isotopic
lead derived from uranium minerals.
In 1914 Richards and Lembert2 published their determinations of the
atomic weight of isotopic lead. Their results may be summarized as follows :
Source Atomic weight
Lead from Ceylonese thorianite 206 . 82
Lead from English pitchblende 206.86
Lead from Colorado carnotite 206.59
Lead from Bohemian pitchblende 206 . 57
Lead from North Carolina uraninite 206.40
Two years later another series of determinations by Richards and Wads-
worth3 appeared. The average results obtained were as follows:
Source Atomic weight
Australian carnotite 206 . 375
Colorado carnotite 207 . 004
Broggerite, Norway 206 . 122
Cleveite, Norway , 206 . 085
Still another series of six determinations by Richards and Hall4 on lead
from Australian carnotite gave a mean value for the atomic weight of Pb =
206.415.
In a preliminary study of lead from Bohemian pitchblende, Honigschmid5
found values for the atomic weight ranging from 206.719 to 206.749. In
a later investigation by Honigschmid and Horovitz,6 lead was extracted
from three different minerals, namely, the purest Joachimsthal pitchblende,
a crystallized uranium ore from Morogoro, German (?) East Africa, and
broggerite from Norway. The average values for the atomic weight were
as follows:
Source Atomic weight
Pitchblende 206.406
The Morogoro ore 206 . 042
Broggerite 206.067
All of these determinations of atomic weight, including those of Baxter
and Gover on normal lead, were made by the same method, the same care
as to purity of materials, and the same refinements of technique. Even
Honigschmid, now in Vienna, had worked on atomic weight determinations
with Richards, and so was familiar with the best procedure. The results
obtained are therefore strictly comparable.
For the atomic weight of thorium lead the data as yet are scanty, and
based entirely upon material derived from Ceylonese thorite and thorianite.
CHEMISTRY: F. W. CLARKE
183
From the specific gravity of thorite lead Soddy7 has deduced the atomic
weight of Pb = 207.64; and Honigschmid8 from analyses of lead chloride
prepared from Soddy's original material has found Pb = 207.77. This
value, however, is probably too low for the true thorium lead, for the reason
that thorite, with a preponderant proportion of thoria, also contains some
uranium. The thorite lead, therefore, must contain both isotopes, but with
the higher one in much the largest quantity. The thorianite lead studied
by Richards and Lembert had a still lower atomic weight, namely Pb =
206.82, which shows that this variety of the metal is not of uniform character.
That the atomic weight of uranium lead is extremely variable has already
been shown. In order to interpret this variability its sources must be studied
both geologically and mineralogically. On the geologic side of the question
the uranium ore can be divided in to three principal classes, which are sharply
distinct. The definitely crystallized varieties of uraninite occur in coarse
pegmatites, associated with feldspar, quartz, mica, beryl, and other minor
accessories. The massive pitchblende is found in metalliferous veins, together
with sulphide ores of copper, lead, iron, zinc, and so forth. As for carnotite,
that is a secondary mineral, found commonly as an incrustation on sandstone,
and often, also upon fossil wood. There may be other modes of occurrence,
but these are the most distinctive.
In chemical composition the uraninites, as shown by Hillebrand's9 splendid
series of twenty-one analyses, fall into well defined groups. All contain
uranium oxides, ranging from 65 to 90%, the low figures, however, represent-
ing altered material. The crystallized, pegmatitic uraninites are charac-
terized by their content in thoria and other rare earths, from 6 or 7 up to as
much as 11%. They also contain subordinate proportions of lead, and the
largest amount of helium. In broggerite and cleveite, however, lead is in
excess of thoria. The massive pitchblendes, on the other hand, contain no
thoria, usually much lead and little or no helium. That from Black Hawk,
Colorado, is exceptional. It is intimately associated with sulphide ores,
but contains little lead, and zirconia instead of thoria. Carnotite, which is
quite unlike uraninite, is essentially a vanadate of uranium and potassium,
with very little lead and no helium. It is, however, an important source
of radium.
It is now possible to correlate, at least roughly, the composition of the
several minerals with the determinations of the atomic weight of uranium lead,
although for a perfect comparison we should have analyses of the actual ores
from which the various samples of lead were obtained. On theoretical grounds
it is supposed that the true atomic weight of uranium lead is not far from
206, and only determinations which approach that value are those which
represent crystallized uraninite, including the varieties broggerite and cleve-
ite. These minerals all contain helium, so that there seems to be a relation
between the formation of these two degradation products of uranium. The
184
CHEMISTRY: F. W. CLARKE
minerals also contain thorium, which would tend to raise the atomic weight
and so complicate any discussion of the figures. The most brilliantly crys-
tallized uraninite, that from Branchville, Connecticut, contains 85% of
U03 + U02, with about 7% of Th02, 4.35% of PbO, and a maximum, 0.4%
of helium. The atomic weight of lead from that source, unfortunately, has
not been determined; and it is doubtful whether material enough for accurate
investigation could be obtained.
The other determinations of the atomic weight of uranium lead give values
much above 206, and even approaching 207. This is especially true of the
lead from pitchblende, which contains no thorium and little if any helium.
Its association with sulphide ores, however, leads to the suspicion that it may
contain ordinary lead, perhaps in the form of occluded or dissolved galena.
The atomic weight of the lead derived from it would, therefore, be that of
a mixture, and not of the isotope alone. The carnotite lead would also
seem to be a mixture, but of what kind is not clear.
The atomic weight of isotopic lead now seems to be a complex of at least
three quantities, namely, the atomic weights of normal lead, uranium lead,
and thorium lead, in varying proportions. Since the atomic weights of the
two isotopes differ from that of normal lead in opposite directions it is difficult
to determine in any particular case the relative proportions of the three
modifications of the element. It has been suggested that normal lead is a
balanced mixture of its isotopes; but the constancy of the atomic weight of
the ordinary metal seems to negative that supposition. In order to fulfill
this condition it would be necessary that the isotopes should always commingle
in equal or at least definite proportions; which is extremely improbable.
The apparent variations in the atomic weight of lead, as shown in the older
determinations, are due to varying methods, imperfect technique, different
values for the atomic weights of the other elements with which that of lead
is compared, and experimental errors. The modern determinations, which I
have already cited, are the only ones that are strictly comparable.
The suggestion that the lead contained in uranium ores is partly normal
lead is not new. It has been advanced by other writers,10 but the variable
atomic weight of uranium lead gives the supposition a decided emphasis.
It now acquires new importance because of its bearing upon certain attempts
to use the ratio between uranium and lead in uranium minerals as a datum
for computing the age of the earth. For this purpose the ratio has been
employed by Boltwood,11 who calculated it from almost all the trustworthy
analyses of uraninite and its nearly allied species, and from it deduced their
ages. These ages differ exceedingly. For a crystallized uraninite from
Connecticut he found the age to be 410,000,000 years, and for Ceylonese
thorianite 2,200,000,000 years. These calculations, and others, like them,
involve two assumptions; first, that the rate of change from uranium to lead
is accurately known, and secondly that all the lead was of radioactive origin.
CHEMISTRY: F. W. CLARKE
185
The latter assumption is now seen to be extremely doubtful for the varying
atomic weights prove that more than one kind of lead must be considered.
Thorium lead especially must be taken into account, for many uraninites
contain it, and in thorianite the percentage of thoria is more than five times
that of uranium oxide. The ratio of lead to its parent elements is therefore
much less than Boltwood assumed, and the calculated age of thorianite is
vastly reduced. Boltwood, however, doubted the derivation of lead from
thorium, a fact which was not definitely known at the time his paper was
written. The evidence of the atomic weights is also much later.
Furthermore, the, doubtful applicability of Boltwood's method to chrono-
logical measurements has been shown by G. F. Becker;12 who applied it to
the analyses of rare-earth minerals from one locality in Llano County, Texas.
The figures given by Becker are as follows:
Mineral Analyst Calculated age in years
Yttrialite Mackintosh 11 ,470,000,000
Yttrialite Hiliebrand 5,136,000,000
Mackintoshite Hiliebrand 3,894,000,000
Nivenite Mackintosh 1,671,000,000
Fergusonite Mackintosh 10,350,000,000
Fergusonite Mackintosh 2,967,000,000
These ages differ enormously, even between two analyses of the same
mineral. This evidence, taken together with the evidence from the atomic
weights, seems clearly to show that the uranium-lead ratio is not applicable
to the determination of the age of minerals. It is quite certain that not all
of the lead in uranium ores is of radioactive origin. In pitchblende, for ex-
ample, which contains no thorium, the determinations of atomic weight
range from 206.40 to 206.88, figures far in excess of the theoretical 206.00 which
is assigned to pure uranium lead. Normal lead, perhaps in solid solution,
must be present in such ores.
What, now, is the fundamental difference between normal lead and isotopic
lead? The answer to that question must be largely speculative; but specu-
lation is legitimate when its purpose is to stimulate future research. One
difference at least may reasonably be assumed, namely, that normal lead is
the product of an orderly evolution of the chemical elements; and that isotopic
lead is a product of their decay. Creation is one process, destruction is the
other.
Forty-five years ago13 I ventured to suggest that an evolution of the ele-
ments had actually occurred. It was clearly indicated by the progressive
chemical complexity of the heavenly bodies, from the chemically simple
gaseous nebulae, through the hotter stars and the sun, to the finished planets
like our earth. At first, hydrogen and helium were the most abundant
and conspicuous elements, then elements of higher atomic weight gradually
appeared, and at the end of the process there was the chemical complexity
of the earth, in which the free elements had in great part been absorbed
186
CHEMISTRY: F. W. CLARKE
and replaced by a multitude of compounds. On this basis hydrogen and
helium seem to be the oldest of the known elements, while uranium and thorium
are the youngest of all. Lead is older than uranium and thorium, for its
lines appear in the solar spectrum, in which the other two elements have
not as yet been recognized. Lead, however, is vastly more abundant than
either uranium or thorium, and is more likely to have been originally their
progenitor than their child.
Up to this point we have a reasonable interpretation of definite evidence,
beyond this, imagination must come into play. It is fair to assume that
the process of evolution was extremely slow, and that each element was de-
veloped gradually and passed from an unfinished to a finished stage. The
chemical atoms are now known to be extremely complex structures, each
with an electropositive nucleus surrounded by electrons in rapid motion.
That such a structure could have been developed instantaneously, with no
previous preparation, is hardly probable, for the process was one of con-
densation, from lighter to heavier, and that, it would seem, must have ac-
quired time. The process was one from relative simplicity of structure to
relative complexity, and with the maximum condensation, as shown by
uranium and thorium, a minimum of stability was reached. That is, so far as
we now know; for less stable atoms may have been formed, to exist for a brief
period and then vanish. Some of the radioactive elements which appear
as products of the decay of uranium are of this kind. On that theme, more
later.
That the atoms of the elements above helium in the scale of atomic weights
could not have been formed instantaneously is indicated by their structure.
It has been shown that they are built up of smaller particles, of electrons,
and also in part, perhaps, of preexistent helium. Such particles, approach-
ing one another, at first in irregular proportions, are supposed to have formed
the atoms in question; but that exactly the right proportions for stability
were found at once is hardly conceivable. There must have been a period
of selection, in which the unavailable particles were discarded, probably to
be used in other structures later. For each new chemical atom a definite
balance between electropositive and electronegative particles was required,
and also the establishment of a stable configuration. When these condi-
tions were fulfilled the atom of an element was complete. As I have already
said we can fairly assume that there was a distinct passage from an unfinished
or incipient structure to a finished one of permanent stability. Further-
more, as shown by the spectra of stars and nebulae, the elements of relatively
low atomic weight were first formed, and those of higher atomic weight came
later. The older elements were also developed in the largest quantities, and
are therefore the most abundant. The later elements are as a broad general
rule much scarcer. This rule is not absolutely exact, but it expresses some
well known general relations. The very simple and very stable primordial
CHEMISTRY: F. W. CLARKE 187
helium, however, is now relatively rare; but there is evidence to make us be-
lieve that it was largely consumed in building other elements. Its present
observed emission by radium is evidence in favor of this supposition.
In this evolutionary hypothesis with its subsidiary speculations there is,
I think, nothing incompatible with present knowledge. In matters of detail
it is unavoidably incomplete; but notwithstanding its imperfections it bears
very^directly upon a consideration of the later phenomena of radioactive decay.
Here the process of evolution is reversed and rapid changes take the place
of slow ones. Furthermore, the normal elements are supposed to be veri-
table store-houses of potential energy; which, in radioactive changes becomes
partly kinetic. Radium, for example, gives forth heat continuously; and
its rate of decay can be observed in the laboratory.
Through the investigation of radioactive transformations more than thirty
new substances, elements or pseudo-elements, have been discovered. Some
of these are extremely evanescent, lasting only for seconds or even fractions
of a second; others are relatively long lived. All of them, however, are
more or less unstable, and change, slowly or swiftly, into other things. Some
of them are metallic, like radium, polonium, and actinium; others appear
as emanations which belong to the group of the chemically inert gases. One
of these, helium, is continuously being generated from radium. Some,
again, are iso topic with bismuth or thallium; and four of them are said to
be isotopes of lead. These are Radium B, Thorium B, Actinium B, and
Radium D. The first three are short lived, and endure only for a few min-
utes or hours, but Radium D, also known as radio-lead, is assigned a probable
life period of 24 years, and given theoretically an atomic weight not far from
210. In its chemical relations it cannot be distinguished from lead.
All four of these isotopes may have been present in uranium lead at the
time of its formation, but it does not seem possible that even a trace of them
could persist in the lead which is now extracted from uraninite or thorianite.
They are therefore negligible in our consideration of the evidence which
is now supplied by the study of the atomic weights, except in so far as they
show the probable derivation of uranium lead and thorium lead from the two
higher elements. The essential point is that all these varieties of lead are
products of degradation, and in that respect differ fundamentally from the
normal product of evolution. The thirty or more new substances which
have been revealed to us by the study of radioactivity are all matter in a
a state of transition from instability towards some stable form, which may
be lead, or bismuth, or thallium, or some other element which has not yet
been recognized as an end product of these mysterious changes. As these
products are approached we have them in an incomplete condition, nearly
but not quite identical with the permanent elements: This may be the char-
acter of isotopic lead. The fact that uranium lead is radioactive shows
that it is still undergoing change; and that its atoms have not acquired the
188
CHEMISTRY: F. W. CLARKE
exact composition and configuration which give to normal lead its uniformity
and stability. Whether or not the process of change can continue until
normal lead is formed, it is impossible for us to say.
The atoms of the chemical elements, are, as I have already said, extremely
complex, but their structure is not yet completely understood. To some
part of each kind of atom its chemical properties and its spectrum are proba-
bly due. It is conceivable that this part may be the earliest to form, with
its surrounding rings or envelopes at first not quite adjusted to permanent
stability. With the final adjustment the isotopes as such should disappear,
and the normal element be completed. This is speculation, and its legitimacy
remains to be established. A careful comparison of the spectra of the ele-
ments from thallium up to uranium might furnish some evidence as to its
validity. The spectrum of uranium, for example, may contain lines which
really belong to some of its derivatives.
Note. — Since this paper was written, one by Professor Barrell14 has appeared,
in which the use of the uranium-lead ratio for determining the age of minerals
is defended. There are also two papers by Holmes and Lawson,15 and another
by Holmes,16 in which the same position is taken. There is evidently room
for further discussion of the subject, but as yet I see no good reason to change
my own views.
[Published by permission of the Director of the U. S. Geological Survey.]
1J. Amer. Chem. $oc, Easton, Pa., 37, 1915, (1027).
2 Ibid., 36, 1914, (1329).
3 Ibid., 38, 1916, (2613).
4 Ibid., 39, 1917, (531).
5Zsch. Elektrochem., Halle, 20, 1914, (457).
6 Monatsh. Chem., Vienna, 36, 1915, (355).
7 Nature, London, 94, 1915, (615).
8 Chem. Abst., 11, 1917, (3173). From Physik. Zs., 18, 1917, (114).
• Washington, U. S. Geol. Survey, Bidls. 78 and 90. Also in Bull. 591, pp. 366-368. Hille-
brand discusses the mode of occurrence of these minerals, much as I have done.
10 See Joly, Phil. Mag., (6), 22, 1911, (354). and Becker, Bull. Geol. Soc. Amer., 19, 1908,
(134).
11 Amer. J. Sci., New Haven, (4), 23, 1907, (86).
12 Bull. Geol. Soc. Amer., (4), 19, 1908, (134). See also Zambonini, Rome, Atti Acc. Lincei
(5), 20, part 2, 1911, (131).
13 Popidar Science Monthly, January, 1873.
14 Bull. Geol. Soc. Amer., 28, 1918, (745).
15 Phil. Mag., (6), 28, 1914, (823), 29, 1915, (682).
16Proc. Geologist's Assoc., London, 26, 1915, (289).
INFORMATION TO SUBSCRIBERS
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CONTENTS
Page
Physiology. — Effects of a Prolonged Reduction in Diet on 25 Men. I. In-
fluence on Basal Metabolism and Nitrogen Excretion
By Francis G. Benedict and Paul Roth 149
Physiology. — Effects of a Prolonged Reduction ln Dlet on 25 Men. II.
Bearing on Neuro-Muscular Processes and Mental Condition
By Walter R. Miles 152
Physiology.' — Effects of a Prolonged Reduction ln Dlet on 25 Men. III. In-
fluence on Efficiency During Muscular Work. By H. Monmouth Smith 157
Zoology.' — Possible Action of the Sex-Determining Mechanism
By C. E. McClung 160
Geology. — The Study of the Sediments as an Aid to the Earth Historian .
By Eliot Blackwelder 163
Zoology.— The Growth of the Alaskan Fur Seal Herd Between 1912 and
1917 ByG.H. Parker 168
Pathology. — The Destruction of Tetanus Antitoxin by Chemical Agents . .
By W. N. Berg and R. A. Kelser 174
Minerology. — Tests for Fluorine and Tin in Meteorites with Notes on
Maskelynite and the Effect of Dry Heat on Meteoric Stones ....
By George P. Merrill 176
Chemistry.— Notes on Isotopic Lead. . . . . By Frank Wigglesworth Clarke 181
VOLUME 4 JULY, 1918 NUMBER 7
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PROCEEDINGS
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NATIONAL ACADEMY OF SCIENCES
Volume 4 JULY 15, 1918 Number 7
ON THE REPRESENTATION OF A NUMBER AS THE SUM OF ANY
NUMBER OF SQUARES, AND IN PARTICULAR OF
FIVE OR SEVEN
By G. H. Hardy
Trinity College, Cambridge, England
Communicated by E. H. Moore, May 21, 1918
1. The formulae concerning the representation of a number as the sum of
5 or 7 squares belong to one of the most unfamiliar and difficult chapters in
the Theory of Numbers, and only one proof of them has been given. The
proof depends on the general arithmetx theory of quadratic forms, initiated
by Eisenstein and perfected by Smith and Minkowski. This theory, of
which a systematic account will be found in the fourth volume of Bachmann's
Zahlentheorie gives a complete solution of the problem of any number s of
squares not exceeding 8. Beyond s = 8 it fails.
When s is even there is an alternative method. This method, which de-
pends on the theory of the elliptic modular functions, is much simpler in idea
than the method of Smith and Minkowski; and it has another very important
merit, that it can be used — within the limits of human capacity for calcula-
tion— for any even value of s. Thus Jacobi solved the problem for 2, 4, 6 and
8. In these cases the number of representations can be expressed in terms of
the divisors of n. Suppose, e.g., that 5 = 8; and let us write, generally,
oo
l
where q = e™ Then
\l+q 1-q2 1+q* 1 - q* )
and r8 (n) is 16 2 53 if n is odd and 8 2 <5q — 8 2 ? if n is even, 8 denoting
189
190
MATHEMATICS: G. H. HARDY
a divisor of 8q a even, and 5i an odd divisor. When 5 exceeds 8 the formulae
are less simple, and involve arithmetical functions of a more recondite
nature. Liouville gave formulae concerning the cases 5 = 10 and 5 = 12,
and Glaisher1 has worked out systematically all cases up to s = 18. More
recently important papers on the subject, to which I shall refer later, have
been published by Ramanujan2 and Mordell.3 In the latter paper the whole
subject is exhibited as a corollary of the general theory of modular in-
variants.
The primary object of my own researches has been to deduce the formulae
for s = 5 and s = 7 from the theory of elliptic functions, and so to place the
cases in which 5 is odd and even, so far as may be, on the same footing. The
methods which I use have further important applications, but this is the one
which I wish to emphasize at the moment. The formulae which I take as my
goal are the formulae
given by Bachmann (pp. 621, 655). Here n as an odd number not divisible
by any square (so that there is no distinction between primitive and imprimi-
tive representations); m runs through all odd numbers prime to n; B is 80,
160, 112, or 160, according as n is congruent to 1, 3, 5 or 7 (mod. 8); and C
is 448, 560, 448 or 592 in similar circumstances. These formulae are the cen-
tral formulae of the theory: they involve infinite series, but these series are
readily summed in finite terms by the methods of Dirichlet and Cauchy.
With them should be associated the formula
where A is 24, 16, 24, or 0: but this formula, as we shall see, stands in some
ways on a different footing.
2. My new proof of the formulae (1) and (2) was arrived at incidentally in the
course of researches undertaken with a different end, that of finding asymptotic
formulae (valid for all values of s) for rs(n) and other arithmetical functions
which present themselves as coefficients in the expansions of elliptic modu-
lar functions. In a paper4 shortly to appear in the Proceedings of the London
Mathematical Society, Mr. Ramanujan and I have developed an exceedingly
powerful method for the solution of problems of this character, and applied
it to the study of p(n), the aumber of (unrestricted) partitions of n. This
method, when applied to our present problem, introduces the function
a)
(2)
MATHEMATICS: G.'H. HARDY
191
e,(?) = l+^2 (Sj^)f (qe-™/k), (4)
where
'A, k
and the summation applies to k = 1, 2, 3, . . . , and all positive values
of h less than, of opposite parity to, and prime to k (h = 0 being associated
with k = 1 alone). The coefficient of gw in Qs(q) is
and our method leads to the conclusion that
rs(n) = xs(n)+0(nh), (6)
at any rate for every value of s exceeding 4.
When 5 is even, F(q) is an elementary function; and (Si, kY is easily expressi-
ble in a form which does not involve the 'Legendre-Jacobi symbol'
(;->
The function Xs(n) is then susceptible of a variety of elementary transforma-
tions and it was shown by Ramanujan, in the second of his two papers quoted
above, that Xs(n) is identical with rs(n) when s = 4, 6 or 8. In what follows
I confine myself to the case in which s is odd, merely remarking that my method
(which is entirely unlike that used by Ramanujan) leads directly to an alterna-
tive proof of his results.
3. When 5 is odd, F(q) is not an elementary function. But it is not diffi-
cult to prove that
F
every term on the right hand side having an argument numerically less than
Istt. Further, Si, k = S^l Sf,,k> and the first factor can always be expressed in
a simple form. Suppose, to fix our ideas, that s = 5. Then Si,k = (— 1)A&2.
Substituting from this equation and from (7) into (4), and effecting some ob-
vious simplications, we obtain
e, <*) = i + 2 ^tt^ nrhrnv (8)
fif Vk [{h-kr)lY
where now h assumes all values of opposite parity to and prime to k. This
formula may be simplified further by multiplying each side by
192
MATHEMATICS: G. H. HARDY
We then find
(9)
the summation now extending to k = 0, 1, 2, . . . and all h of opposite parity
to k. This is our fundamental formula, when s = 5. Two steps remain:
first, to prove the identity of 05(g) and #5; secondly, to deduce the formulae of
Smith and Minkowski.
4. The first step presents no very serious difficulty, for it involves nothing
beyond an adaptation of the ideas used by Mordell in his paper quoted in §1.
We prove first that 9s behaves like #5 in respect to the linear modu-
lar transformations r = r + 2, r = — 1/T; so that 95/#5 is an invariant of
the modular sub-group called by Klein-Fricke and Mordell r3. Secondly, by
studying the transformation r = (T — 1)/T, we prove that 65/#5 is bounded
in the 'fundamental polygon' associated with T3. It then follows that the quo-
tient is a constant which is easily seen to be unity. In all this the only
difficulty arises from the use of certain reciprocity-formulae satisfied by Gauss's
sums.
We now transform (9) by effecting the summations with respect to h,
using certain contour integrals of a type common in the work of Lindelof
and other writers. We thus obtain
a fundamental identity which contains the whole theory of the representation
of numbers by sums of 5 squares. The symbols j and n alone require expla-
nation; j runs through the complete set of least positive residues of 0, l2,
22, . . . ,(k — l)2 to modulus k, each taken as often as it occurs; and i±k
is the multiple of k deducted in order to arrive at such a residue. And the
remainder of the work is purely arithmetical. Picking out the coefficient
of qn, we obtain a series for r&(n) which is found, after some reduction, to be
equivalent to the series given by Bachmann.
4. The formulae which correspond to (10) for s = 7 and s = 3 are
3 ( 1,3,5,... j w = 0
mk +j
(10)
2,4,6,... j m = 0
PHYSICS: A. ST. JOHN
193
10 ( 1,3,5,... K j m=0
2,4,6 i w=0 )
«?3 = i + s 2 ~~t~ - 2 2J («* 9"*^ (12)
(l,3,5,... » i w=0
CO I
+ 2 t2 2 +i) * ^ •
2,4,6,. . . i m=0 )
The interpretation of j and /x is as before, except that, when k is even, j is a
residue of one of the numbers \k, \k + l2, . . . , \h + (k — ' l)2. These
identities embody the theory for 7 or 3 squares. It should be noted however,
that the application of my method becomes very much more difficult when
s = 3, as the double series used are then not absolutely convergent; and in fact
the only proof of (12) which I possess consists in an identification of the results
which it gives with those already known.
I conclude by a word concerning the cases in which s>8. Here, when s is
odd, we are on untrodden ground. We have the asymptotic formula (6);
and we can evaluate Xs(n) as when s = 5 or 7, thus obtaining a series of new
results. But it is no longer to be expected that our results should be exact,
and I have verified that, when s = 9, they are not exact, even when n = 1 .
1 Glaisher, J. W. L., Proc. London Math. Soc, (Ser. 2), 5, 1907, (479-490).
2Ramanujan, S., Trans. Camb. Phil. Soc, 22, 1916, (159-184); Ibid., (in course of
publication).
s Mordell, L. J., Quart. J. Math., 48, 1917, (93-104).
4 Hardy, G. H., and Ramanujan, S., Proc. London Math. Soc, (Ser. 2), 17, 1918, (in
course of publication).
THE CRYSTAL STRUCTURE OF ICE
By Ancel St. John
Department of Physics, Lake Forest College
Communicated by R. A. Millikan, April 30, 1918 '
During the winter of 1916-1917 the crystal structure of ice was investi-
gated by means of the X-rays. The photographic method originated by
deBroglie1 was used with certain modifications suggested privately by Dr.
A. W. Hull. The source of energy was a Coolidge tube with tungsten target
excited by an induction coil with mercury turbine interrupter. At first the
194
PHYSICS: A. ST. JOHN
apparatus already set up for another investigation was used, being kept cool
by leaving the laboratory windows open. This method was very uncertain
on account of the erratic weather and was otherwise unsatisfactory and was
discarded after a single good photograph had been obtained. The spec-
trometer system was then enclosed and the chamber kept cool by cans of ice
and salt. By this means the temperature could be kept reasonably constant
but it was found virtually impossible to mount and maintain a specimen
long enough to get a satisfactory photograph, probably on account of the pres-
ence of the salt vapor. Upon the recommendation of Prof. A. G. Webster a
grant was made from the Rumford Fund of the American Academy of Arts
and Sciences, Boston, in aid of the investigation which made it possible to
install a small ammonia refrigerating machine loaned by the Automatic
Refrigerating Company and to build a specially adapted spectrometer mounted
in a well-insulated refrigerator box. With this equipment the temperature
could be maintained indefinitely and there was no further trouble from melt-
ing of specimens. A marked tendency to sublimation, however, was trouble-
some until each specimen was mounted in a gelatine capsule when equilibrium
was quickly established between the crystal and its vapor. Protected in
this manner specimens were preserved for days.
Commercial artificial ice was first investigated as it shows marked pris-
matic structure. Unfortunately the prisms are distorted through pressure
in the formation of the ice so that it is difficult to identify cleavage planes.
Some photographs show spectral bands but no sharp lines upon which to
base calculations. The investigation is to be pursued further, however,
as it is probable that sufficiently small crystals or slices of crystals will give
sharply defined lines. In a second procedure a thin layer of ice, about 2
mm. thick, was allowed to form on a pan of tap water. It was difficult to
identify individual crystals and more difficult to isolate them for mounting
but occasionally a reasonably good specimen was secured and mounted so
that the axis of rotation bore a definite relation to the original surface of the
ice. Orientation with respect to other axes was a matter of guess work,
usually wrong as the results showed. Nevertheless several satisfactory
photographs were obtained from specimens prepared in this manner, in fact
the calculations are based entirely on them. In a third method ice was frozen
out of a weak salt solution. In this way a large crop of thin specimens show-
ing distinct cleavage planes could be secured. Owing to the failure of the
source of power the investigation was interrupted at this point and has not
yet been renewed. One photograph was obtained showing distinct spec-
tral bands but no identifiable lines, possibly on account of the mixture of
microscopic salt crystals with the ice. The method is promising and is to
be pursued further at a convenient season.
Ice is commonly assigned to the hexagonal system of crystals2 and is con-
veniently referred to a triangular space lattice each cell of which has sides
PHYSICS: A. ST. JOHN
195
a and a height c. An elementary triangular cell of such a structure will
have a volume V = \/3a?c/4:. If the density is p, the mass of a molecule m
and the number of molecules per cell n, the mass of the cell is nm = 3a2cp/4:.
For ice2 c/a = 1.4026, p = .91 gm/cml, w = 29.73 X 10~24 gm. The mole-
cular weight is taken, as the arrangement of diffracting centers is funda-
mentally that of the molecule, each pair of hydrogen atoms being presuma-
bly near an oxygen atom. These values gave
a = (54.35»)* X 10~8 cm.
For triangular lattices the following values of n occur: simple lattice, n =
J; two interpenetrating lattices, n = 1; three interpenetrating lattices, n =
f or f ; four interpenetrating lattices, n — 2.
Values of a, a/2, (the spacing of the 1210 planes), ay/3/2 (the spacing of
the 1010 planes and ca (the height of a cell) have been computed and are
given in columns 2, 3, 4 and 5 of table 1. When h is the distance of the plate
TABLE 1
-
4
5
6
•
10
ii
n
x io-
■s cm.
h
= 19.00 cm.
h
= 14.75 cm.
a
a/2
ai
ca
ZlOTO
zoooi
31130
^10 10
^00 0 I
l
2
3.01
1.50
2.60
4.22
2.67
1.54
0.95
2.07
1.20
0.74
3
4
3.44
1.72
2.98
4.83
2.33
2.35
0.83
1.81
1.04
0.65
1
3.79
1.89
3.38
5.32
2.11
1.18
0.76
1.65
0.92
0.59
I
4.33
2.16
3.75
6.08
1.85
1.07
0.66
1.44
0.83
0.51
from the axis of rotation, x the distance of a given line from the undeviated
central image, d the distance between planes in the crystal, X the wave-length
of the radiation and N the order of the spectrum x/h = N\/d, giving the
relations d = NXh/x and x = N\h/d. The wave-length used was the K
line of tungsten X = .211 X 10~8 cm. In certain cases h was 19.00 cm., in
others 14.75 cm. Values of x corresponding to these values have been cal-
culated for the three fundamental spacings of each of the forms having values
of n already givin. They are shown in columns 6 to 11 of table 1. The val-
ues of x determined from the four plates used in the calculations and the
corresponding values of a are given in tables 2 to 5. The average value
of a is 4.74 X 10~8 cm. indicating four interpenetrating lattices. From
talb 4 it appears that the 0001 spacing is c/2, i.e., the four sets of basal planes
occur in pairs. A number of plausible models having such arrangement
exist. They may be differentiated by the spacings of the pyramidal planes.
It may be shown that in mterpenetrating triangular lattices pyramids hav-
ing indices of the form (nO~p) have spacings according to the relation
a r-
^nOnp = K2VS sin- ^nOnp,
196
PHYSICS: A. ST. JOHN
where <£nOnp is tne anSle between the planes and the basal pinacoid 0001
and K is a factor varying from pyramid to pyramid in the same model and
with different models for the same pyramid, its value depending upon the
grouping of the planes in a given form. Values of this quantity have been
TABLE 2 TABLE 4
h = 19.00 cm. h = 14.75 cm.
INDEX
X
d X 108cm.
o X 108 cm.
INDEX
X
d X 108 cm.
o X 10s cm.
1010
0.97
4.13
4.77
0001
0.96
3.25
4.78
1.98 (2)
4.05
4.68
1.92(2)
3.24
4.82
2.93 (3)
4.11
4.74
oilo
1.50(2)
4.15
4.79
1120
1.70
2.36
4.72
2.25 (3)
4.15
4.79
3.40(2)
2.36
4.72
10l2
1.22
2.55
4.68
0110
0.95
4.22
4.87
2.45 (2)
2.54
4.67
1.92 (2)
4.18
4.82
3034
2.90
1.07
4.81
2.90(3)
4.15
4.79
1120
2.65 (2)
2.34
4.68
2110
1.70
2.36
4.72
3032
4.5-5.2
1.19-1.38
3.40(2)
2.36
4.72
2021
4.80(2)
1.30
4.72
1010
1.95 (2)
4.12
4.76
3031
4.0-4.5
0.69-0.78
4041
5.5-6.0
1.04-1.13
4. 76^0.04
4.74±0.06
TABLE 3
h = 14.75 cm.
INDEX
*
d X 108cm.
0 X 108 cm.
2110
1.34
2.32
4.64
2.70 (2)
2.31
4.62
1010
2.20(3)
4.25
4.91
3.00(4)
4.15
4.7-9
1100
1.50 (2)
4.15
4.79
2110
1.35
2.31
4.62
Average
4.73±0.10
TABLE 5
h = 14.75 cm.
INDEX
X
d X 108cm.
0 X 108cm.
0001
1.85 (2)
3.38
4.78
2.80(3)
3.34
4.76
1011
1.5-2.0
3.1-4.2
5.40(6)
3.46
4.70
10T2
2.40(2)
2.58
4.75
1013
1.60
1.94
4.72
3032
2.50
1.24
4.70
Average
4.72±0.04
determined by inspection of the models and are tabulated in table 6. The
data of table 4 are consistent only with the distances calculated for model
IV, which is therefore taken to represent the structure. In the tabulations
but four models have been considered as these are all that satisfy reasonable
considerations of symmetry.
The, investigation shows that ice is properly assigned to the hexagonal
system, that it consists of four interpenetrating triangular lattices, and that
the fundamental spacings are
GEOLOGY: W. M. DAVIS
197
a = 4.74 X 10-8 cm.; h = 6.65 X 10"8 cm.
dn20 = 3.79 X 10~8 cm.; c?10Io = 2.37 X 10~8 cm.; d000l = 3.32 X 10~8 cm.
The arrangement of the lattices is conveniently explained by referring the
origin of each lattice to two unit axis making an angle of 120° and a third
TABLE 6
Values of K and Corresponding Approximate Values of x When h = 14.75 cm.
INDEX
4>
Sin tf>
MODEL I
MODEL II
MODEL III
MODEL IV
K
X
K
X
K
X
K
X
1011
58°18'30"
0.8509
i
2
1.8
r •
0.9
1
0.9
1
0.9
1012
39° 9' 9"
0.6293
1
1.2
1
1.2
1
1.2
1
1.2
1013
28°22' 0"
0.4751
1
2
3.1
1
1.6
1
1.6
1
1.6
2021
72°50'20"
0.9555
1
4
3.2
i
2
1.6
3.2
1
3
2.4
3031
78°22'13"
0.9795
1
6
4.5
1
2.2
4.5
1
6
4.5
3032
67°37,36"
0.9248
1
3
2.6
1
3
2.6
2.6
1
3
2.6
3034
50°32'15"
0.7720
1
3
2.9
1
3
2.9
2.9
1
3
2.9
4041
81°13'30"
0.9886
1
8
6.6
1
2.2
9
3.3
1
4
3.0
mutually perpendicular to these. The coordinates of the origins are then
0,0,0; if ,1/ss; if, }; 0,0, (z + 2)/2z.
The values of z, that is the relative displacement of the two planes making
up a basal pair, is uncertain and needs further investigation. This requires
a careful determination of the. relative intensities of the spectra of different
orders reflected from the 0001 planes and was beyond the scope of the present
investigation. Conditions of symmetry suggest a value of z = 6, but this is
purely conjectural.
The investigation was pursued under the direction of Prof. A. G. Webster
of Clark University in the Physics Laboratory of the Worcester Polytechnic
Institute.
1 Paris, C.-R. Acad., Set., 157, Nov. 17, 1913, (924-926).
2 Dana, System of Mineralogy, 1888 ed., p. 205.
FRINGING REEFS OF THE PHILIPPINE ISLANDS.
By W. M. Davis
Department of Geology and Geography, Harvard University
Read before the Academy, April 23, 1918
A series of large-scale charts recently published by the United States Coast
and Geodetic Survey for certain parts of the Philippine islands are, apart
from their value to commerce, of much scientific interest in connection with
198
GEOLOGY: W. M. DAVIS
the coral-reef problem by reason of the great volume of carefully ascertained
facts that they present. They are in various respects more detailed and more
accurate than the Admiralty and Hydrographic Charts hitherto available.
Many of the islands are thus shown to have more or less minutely embayed
shore lines, indicative of the subrecent or recent submergence of an eroded
land surface. This is particularly true of Palawan, the southwesternmost
member of the group, which has a shore line of most intricate pattern where
its western side is indented by Malampaya sound: there can be no question
that the coastal features of this kind exhibited on Palawan and many other
members of the Philippine group result from the recent partial submergence
of an uneven land surface.
According to Darwin's theory of coral reefs, in the form usually presented,
shores of submergence should be fronted by barrier reefs; but the Malampaya
district of Palawan is not so fronted; its reefs, where they occur, belong to the
fringing class, and since Darwin's time fringing reefs have been associated
with stationary or emerging shores. Barrier reefs are indeed exceptional
in the Philippines, in spite of the repeated occurrence of embayed shore
lines on many islands, and the question therefore arises whether the theory of
upgrowing reefs on intermittently subsiding foundations is incorrect or in-
complete. The object of this paper is to point out that the theory, as ordi-
narily stated, is incomplete, and that the element needed to complete it is
to be found in a seldom-quoted passage from Darwin's own writings, as follows:
"If during the prolonged subsidence of a shore, coral-reefs grew for the first
time on it, or if an old barrier-reef were destroyed and submerged, and new
reefs became attached to the land, these would necessarily at first belong to
the fringing class " (Coral Reefs, 124).
This passage may be understood as meaning that the " prolonged subsi-
dence" of an island might be too rapid to permit reef growth, until a pause
allowed the establishment of a fringing reef; and also that the rapid subsi-
dence of an island would destroy and submerge a barrier reef previously
formed around it during slower subsidence, whereupon a fringing reef would
be formed on the new shore line. Thus interpreted, the passage affords
a satisfactory explanation of the frequent association of fringing reefs with
shore lines of submergence in the Philippines and in certain other archipelagoes,
even though such reefs may elsewhere be found on stationary shore lines or on
shore lines of emergence. Fringing reefs thus formed may be described as
"of a new generation:" they will evidently lie unconformably on the eroded
rocks of the shore belt, and their unconformity, as well as the embayments
of the shore line, will indicate their association with submergence. The con-
tact of fringing reefs with the marine sediments that ordinarily characterize
a non-embayed shore line of emergence would be essentially conformable.
Whether the shores of the Philippines now for the first time have reefs
formed upon them, according to the first clause in the above quotation from
Darwin, or whether the existing fringes are the successors of "destroyed
GEOLOGY: W. M. DAVIS
199
and submerged barrier reefs," according to the second clause, may be deter-
mined for certain islands by the abundant off-shore soundings. Thus in the
case of Palawan, its embayed western coast does not descend rapidly to great
depths, but is fronted by a well defined submarine platform, 20 or 30 miles
wide, along the seaward edge of which a discontinuous rim rises towards but
not to the surface ; the rim can be most reasonably explained as an incomplete
upgrowth from a barrier reef of an earlier generation on the outer margin of a
broad lagoon. It is not possible, in our present ignorance of the geology of
Palawan, to determine whether the drowned barrier reef was formed by up-
growth during slow and long continued subsidence, or by outgrowth during a
long-enduring still-stand of the island; but in either case, the great breadth of
the lagoon plain appears to be the product of a long lasting process, and thus
contrasts strongly with the new fringing reefs of the Malampaya district,
which are so narrow as to be inconspicuous on charts of the largest scale.
Evidently, therefore, the rapid submergence by which the barrier reef of
Palawan was drowned must be of recent date.
Similar conclusions may be derived from other parts of the Philippines,
where embayed shore lines, relatively narrow fringing reefs, and well defined
submarine platforms are frequently found, although no islands are so striking
in these respects as Palawan. The platforms cannot be reasonably ascribed
to marine abrasion during a higher stand of the islands or a lower stand of
the ocean, for the island shores are not clift; and the submergence of the plat-
forms cannot be accounted for by a rise of ocean level, which must everywhere
be of the same date, amount and rate, for the platforms vary in depth, and
the new fringing reefs vary in breadth. The depth of the Palawan platform
for example, increases from 25 or 30 fathoms at its southwestern end to 55 or
60 fathoms near its middle, and then decreases again toward the northeastern
end ; and the fringing reef, which is hardly chartable near the mid-length of the
island where the platform is deep, has a width of 1 or 2 miles at the south-
western end of the island where the platform is relatively shallow.
On the other hand, the northeastern coast of Samar, on the opposite side of
the archipelago from Palawan, has a moderately sinuous shore line with delta
flats that diminish the initial size of its bays, and fringing reefs that reach
forward a mile or so from its points; here the latest submergence cannot be so
recent as that of Palawan. But instead of being benched by a submerged
platform, the sea bottom off shore from Samar sinks rapidly to a great depth.
Moreover, there are long stretches of the coast of Luzon which are neither
embayed by arms of the sea, nor enclosed by barrier reefs, nor fronted by
submarine platforms: Luzon, unlike many other of the Philippines, has a con-
siderable extent of coastal lowlands, as if the growth of fringing reefs, or the
outwash of detritus, or the emergence of the former sea border had increased
its low littoral area. Again, Cebu and Negros, which occupy a somewhat
central position in the archipelago, are described by Becker as terraced with
elevated reefs up to altitudes of 2000 feet or more. The diverse shore features
200
GEOLOGY: W. M. DAVIS
of the different islands are therefore best explained by local changes of land
level, unlike in date, in direction, in amount and in rate.
It is particularly the rapid rate, the recent date, and the considerable amount
of subsidence often indicated that are of significance in the coral-reef problem;
and this is true not only for the Philippines but also for the other archipelagoes
between Asia and Australia. Embayed shore lines indicative of submer-
gence are common though by no means universal in all this region, but well
developed barrier reefs are rare. Before the reefs of Cebu and Negros were
elevated, and before the platform of Palawan was depressed, barrier reefs must
have been more extensive than now in the Philippines, and possibly in the
other island groups also; but today no examples of these forms are to be found
in the archipelagoes that can compare with the great barrier reefs of north-
eastern Australia and of New Caledonia; few of the many small islands in the
archipelagoes are enclosed by well developed encircling reefs, like those of
the Fiji and Society groups; and atolls, which are so striking a feature of the
open Pacific, are relatively uncommon in the archipelagoes.
The best explanation of the small development of barrier reefs and atolls
in the archipelagoes is to be found, not in the lack of subsidence, which is
elsewhere so intimately associated with reef development, for geological and
physiographic evidences of subsidence abound on many islands ; and surely not
in the prevalence of unfavorable conditions as to the temperature and purity
of sea water, for fringing reefs flourish; but largely in the occurrence of sub-
sidence of so rapid a rate and in some cases of so great an amount, as to have
submerged pre-existing reefs. Moreover the subsidences appear to be in
many cases of so recent a date that the new fringing reefs are still narrow; it
is presumably for this reason that the drowned barrier reefs and atolls have
not yet had time to grow up again to sea level. Added to this is the frequent
occurrence of recent uplifts in the archipelagoes, whereby weak marine sedi-
ments, overwashed by an abundance of alluvium from rejuvenated rivers, have
come to occupy the shore line of certain islands, thus discouraging even the
growth of fringing reefs, as around much of the coast of Borneo and along
the southern coast of Java; but this aspect of the problem cannot be discussed
here.
In view of these facts and inferences the Australasian archipelagoes must be
considered much more unstable than the floor of the central Pacific. In that
vast region, where reef upgrowth has generally kept pace with changes
of level, and where atoll and barrier-reef lagoons have been filled with sedi-
ments to a moderate depth, Darwin appears to have been right in conclud-
ing that "the subsidence thus counterbalanced must have been slow in an ex-
traordinary degree" (115). Not only movements of depression but modern
movements of elevation also have been of moderate measure in the central
Pacific, for none of the occasional elevated atolls found there have an altitude
of more than a few hundred feet: it is only in Tonga and Fiji that greater
measures of modern uplift are recorded, the greatest altitude of a reef in Fiji
GEOLOGY: W. M. DAVIS
201
being 1030 feet: uplifted reefs in the Australasian archipelagoes are found at
altitudes of 2000 and 3000 feet.
On the other hand, the instability of the Australasian region is attested not
only by the evidence afforded by coral reefs, but also as above noted, by many
geological researches; those by Molengraaff and Abendanon are particularly
instructive in this respect, and fully confirm Darwin's statement: — "North of
Australia lies the most broken land of the globe, and there the rising parts are
surrounded and penetrated by areas of subsidence" (143). Hence while Dar-
win's general conclusion that " the rate of subsidence has not exceeded the up-
ward growth of corals" (115) seems to hold true for the central Pacific, it is
not valid for the region of the archipelagoes. The not infrequent occurrence
there of subsidences at a rate sufficient to drown coral reefs ought to satisfy
those objectors to Darwin's theory who have urged that it demands too great
a uniformity, if not also too slow a rate in the movements of the earth's crust
in oceanic areas. But let it be noted that rapid movements of subsidence,
and also fringing reefs of a new generation which are formed along a shore
where rapid subsidence had drowned pre-existing reefs, were explicitly recog-
nized by Darwin as of possible occurrence — witness the first quotation from
his Coral Reefs, above.
Fringing reefs of a new generation on shores of submergence should there-
fore be accepted as accounted for by Darwin's theory quite as well as other
fringing reefs, and indeed as contributing their share towards verifying the
theory, even though its author did not recognize any actual fringing reefs as
of this origin. He colored all fringing reefs red on his chart, as indicating
non-subsiding coasts; for even after pointing out the possibility of their forma-
tion where "prolonged subsidence" has taken place, he added: "I have no
reason to believe that .... any coast has been coloured wrongly
with respect to movement indicated" (124). His information about the
Philippines was scanty; he colored all their fringing reefs red, as indicative of
stationary or rising coasts.
There can indeed be little doubt that a number of other islands also, which
have unconformable fringing reefs along their embayed shores, were wrongly
classed by Darwin, who took no account of embayments or of unconformities.
Striking instances of this kind might be pointed out in the Solomon group,
where the small island of Fauro, for example, which is described by Guppy as
a deeply denuded volcanic wreck, has a shore line of marked irregularity, a
narrow fringing reef, and a well developed submarine platform from 40 to
70 fathoms in depth: such a combination of features proclaims intermittent
subsidence after long-continued subaerial erosion, the last movement being more
rapid than reef upgrowth; yet all the members of the Solomon group are col-
ored red on Darwin's chart, because the little information he had about them
gave "a presumption that they are fringed" (167). Other examples of new
fringing reefs on shores of submergence are found on the granitic islands of the
Seychelles in the western Indian ocean, as will be again noted below. The
202
GEOLOGY: W. M. DAVIS
Andaman islands in the Bay of Bengal are elaborately embayed, and a sub-
marine platform several miles in breadth and from 20 to 40 fathoms in depth
adjoins them; a bank of similar depth, measuring 35 by 10 miles lies not
far away to the east; yet these islands have no barrier reefs and only very
narrow and discontinuous fringing reefs; their submergence must be very
recent. If the postglacial rise of ocean level were the cause of all these sub-
mergences, reefs should everywhere be of about the same volume: as a matter
of fact they vary in volume enormously. The fringing reefs of southwest
Palawan, of Yap in the western Pacific, and of Rodriquez in the southern
Indian ocean are two or three miles wide; various atoll and barrier reefs are
half a mile or a mile wide. Others are much narrower, and still others are
discontinuous, or so imerfectly developed as not to reach sea level: finally,
some submarine banks are flat, without any reef rim. These irregular values
speak for variable subsidence of the reef foundations, not for a uniform rise of
ocean level.
The occurrence of subsidence in the Australasian region at a more rapid
rate than that of coral upgrowth has an interesting bearing on the origin of
the numerous submarine banks, of various depths down to 40, 50, or 60
fathoms, in the China sea. It is evident that if islands suffer a movement of
subsidence rapid enough to drown their barrier reefs and thus to develop
fringing reefs of a new generation, the same subsidence would completely sub-
merge neighboring atolls. Furthermore, if the rapid subsidence of a group of
islands were of so recent a date that the resulting fringing reefs are still nar-
row, the drowned reefs of the submerged atolls might still remain below sea
level, even if the amount of submergence had not been great enough to kill
all their corals.
Now in view of the proximity of the China sea to the Philippine Islands, it
seems reasonable to suppose that its floor has shared some of the many move-
ments by which the islands of the archipelago have been disturbed; hence
the submarine banks of that deep basin are best explained, following Darwin's
theory, as drowned atolls not yet rebuilt. The date as well as the rate and
the amount of a subsidence is therefore of importance in determining whether
the atolls that it drowns shall still be submerged. Certainly recent submer-
gence, presumably due to subsidence, has affected the Macclesfield and certain
other large submarine banks of the China sea, for corals are growing on the
rims of many of them, but have not yet built the rims up to the sea surface.
On the other hand in spite of the proximity of the unstable Philippines, the
Glacial-control theory explains the Macclesfield bank, which is taken to be
a typical example of its kind, as the remains of a huge volcanic cone, origi-
nally as large as Hawaii, which stood still long enough to be worn down to
small relief in preglacial time, and which, still fixed, was truncated by abra-
sion at a lower level while the ocean was depressed about 40 fathoms during
the Glacial period. So long enduring a stability seems improbable enough
even for the central Pacific, and much more improbable for a next-door
neighbor of the Philippines.
GEOLOGY: W. M. DAVIS
203
It may be noted that if the surface forms of the mid-Pacific atolls are con-
sidered alone, they can be accounted for very satisfactorily by the Glacial-
control theory, which was invented chiefly to explain the special features
that they present: but as atolls occur in association with barrier reefs in the
Caroline, Society, Fiji and other groups, and as the central islands within the
barrier reefs present features which, although perfectly accounted for by
Darwin's theory of intermittent subsistence, cannot be accounted for by the
Glacial-control theory, its apparent success in explaining atolls is thereby
discredited, all the more so in view of the recent discussion by Skeats of the
boring in the Funafuti atoll (Amer. J. Sci., New Haven, 45, 1918, 81-90).
The chief value of the ingenious Glacial-control theory may therefore be
found not so much in its postulate of the prevalent stability of reef-bearing
islands, or in its assumption that reef corals were killed and that reef-bearing
islands were abraded while the ocean was chilled and lowered in the Glacial
period, but in the emphasis that it gives to changes of sea level from climatic
causes as a factor in the coral-reef problem; for it is manifest that if the post-
glacial rise of sea level coincide in time with the subsidence of an island, the
resulting submergence will be at an accelerated rate and of an increased
amount; while if the fall of sea level occasioned by the oncoming of a glacial
epoch coincide with a subsidence, the resulting submergence will be at a re-
tarded rate and of a decreased amount. It cannot however be supposed that two
processes so unlike in cause as external climatic changes and internal crustal
deformations should be closely related in time; their coincidences must be
fortuitous. Throughout the central Pacific the rate and amount of recent
submergence have not been as a rule too great to be compensated by reef
upgrowth; witness the abundant atolls and barrier reefs. But in the region
of the Australasian archipelagoes compensation of submergence by reef up-
growth has frequently been unsuccessful; witness the rarity of well developed
barrier reefs and the almost entire absence of atolls. As the climatic changes
of ocean level must have been everywhere the same, the factors which have
determined the success or the failure of reef upgrowth would appear to be
the rate, the amount and the date of subsidence.
It may be added that submarine banks, of such form that they are best ac-
counted for as drowned atolls, are rare in the Pacific. A group of ten or more
of them is known in an island-free space north of Fiji : several extensive banks
also occur in Tonga. Exception must therefore' be made in favor of a rapid
submergance only for these relatively few examples of submerged Pacific
atolls, and the rule that the great majority of Pacific atolls have not been sub-
merged faster than the rate of reef upgrowth is thereby proved. In the Indian
ocean, on the other hand, the number of submarine banks bears a larger
proportion to that of atolls, and the Indian ocean is generally regarded by
geologists as the seat of greater and more recent movements of depression
than the Pacific. Recent and rapid subsidences of moderate amounts may
therefore be plausibly regarded as of more general occurrence in the Indian
204
PATHOLOGY: W. S. HALSTED
than in the Pacific ocean. The recent date and the rapid rate of subsidence
appear to be of greater importance than its amount in the case of the Great
Chagos bank, where the submergence does not seem great enough to drown
the reef-building corals. Here the muddy central area is 40 or 50 fathoms
deep; it is bordered by an irregular sandy bank from one to 5 miles or more in
breadth and from 15 to 20 fathoms in depth, on the outer margin of which
rises a rim about a mile in width, and only 5 or 10 fathoms in depth; singularly
enough, there is little living coral on the outer rim, though knobs of growing
coral rise from the central depression. The diameters of the whole mass range
from 50 to 75 miles: its form suggests that a prolonged stationary period,
during which a broad atoll-reef was developed, was followed by a subsidence of
about 10 fathoms, after which a shorter stationary period permitted, the up-
growth of a narrower reef; then a rapid and presumably recent subsidence
of 5 or more fathoms ensued, since which no effective reef growth has taken
place, possibly because, according to Daly's suggestion, the submerged corals
were smothered by wave- and current-shifted sediments.
Unfortunately no archipelagoes comparable to those of the Australasian
region are present in the Indian ocean to give evidence in the case, but it may
be noted that a few high islands which occur in association with the Indian
ocean banks — chiefly the granitic islands in the area of the great Seychelles
bank — have narrow and unconformable fringing reefs on their deeply eroded
and well embayed shores; thus they repeat in a small way the more abundant
and therefore more compulsory evidence that is provided by the charts of the
Philippines. Further details on these topics are given in an article on "Sub-
marine Banks and the Coral Reef Problem," now in course of publication in the
Journal of Geology, and in an article on the "Subsidence of Reef-encircled
Islands," soon to appear in the Bulletin of the Geological Society of America.
DILATION OF THE GREAT ARTERIES DISTAL TO PARTIALLY
OCCLUDING BANDS
By William S. Halsted
Medical School, Johns Hopkins University
Read before the Academy, April 22, 1918
The incentive to the work was primarily the desire to cure aneurysms of the
abdominal aorta and common iliac arteries.
The method usually employed for the cure of aneurysm is the simplest, viz.,
the ligation of the affected artery proximal and as close as feasible to the
aneurysm. The aorta has been ligated 25 or more times in man, and always
with fatal result. Death has been due to hemorrhage or overtaxed heart.
Neither gangrene nor paraphlegia has ever resulted from ligation of the aorta
PATHOLOGY: W. S. HALSTED
205
in man. We found, in dogs, as was to have been expected, that fine, completely
occluding, ligatures (sizes C or E sewing silk) applied to the thoracic aorta
just below the arch would cut through in about two days, and invariably
with promptly fatal hemorrhage; whereas coarse ligatures usually made their
way through the aorta wall very slowly and without leakage of blood. A
connective tissue diaphragm often forms in the wake of these broader threads
and the lumen of the vessel may be more or less completely reestablished.
It occurred to me after much experimentation that occlusion of the aorta
to a degree not sufficient fatally to overburden the human heart might effect
the cure of an aortic aneurysm. Knotted ligatures we found to be unsuitable,
for a desired degree of constriction or obliteration could not be accurately
obtained nor could the crushing of the arterial wall be invariably avoided.
Tapes of various materials were tested — of cotton, of chromicized intestinal
submucosa, of elastic tissue obtained from the aorta, of aponeurotic white
fibrous tissue. These were applied in spiral or cuff form. Best suited to the
purpose were bands of metal, of aluminum, accurately rolled in cylindrical
form by a little instrument of this kind (exhibit). In the use of these metal
bands it was impossible to crush the arterial wall, and the desired amount of
obturation could be obtained with precision, and also maintained.
The infolded and snugly opposed intimal surfaces under the compressing
band have in no instance adhered to each other, and for the reason that the
pressure necessary to produce even a very slight reduction in the lumen of the
vessel has, in my experience, invariably caused atrophy of its wall. When the
occlusion is complete the necrotic arterial wall included in the metal band be-
comes replaced by a solid cylindrical cord of fibrous tissue, the substitution
taking place from the ends.
An interesting incidental observation which we have made in the course of
our experiments with the metal band is this; that a dilation of the artery occurs
just below a band when the degree of constriction is of the proper amount.
This observation apparently explains in a measure the occurrence of aneu-
rysms of the subclavian artery distal to a cervical rib. Analyzing 525 clinical
cases of cervical rib we found 106 in which the subclavian artery had been
compressed, and that in 21 of these, aneurysm or dilation of this vessel distal
to the site of constriction had been noted.
As to the cause of these aneurysms, five of which have come to the knowl-
edge of the collators, there has been varied conjecture. Commentators are,
however, agreed that the occurrence of the dilation would have been less in-
comprehensible to them had it manifested itself on the proximal instead of the
distal side of the compression. Attempts have been made to explain the
phenomenon, and the following suggestions offered as to its possible cause:
(1) Weakening of the wall of the subclavian artery from erosion by the rib.
(2) Variable or intermittent pulse pressure occasioned by the normal excur-
sions of the arm.
206 PATHOLOGY: W. S. HALS TED
(3) Vasomotor and vasa vasorum disturbances leading to modified nutri-
tional activities in the wall of the artery.
In casting about for an explanation of these aneurysms there constantly
obtruded itself the picture of the dilated arterial trunks which, I find from the
study of about 400 cases, has occasionally been noted on the cardiac side of
arterio-venous fistulae. In our own clinical and experimental cases, dilation
of the artery proximal to the fistula has occurred invariably. For this re-
markable manifestation, likewise, no satisfactory cause has been assigned.
There might, I thought, be a common cause for both — for the dilation of the
subclavian artery distal to the cervical rib, and for the dilation, central to the
arterio-venous fistula, of the artery concerned in its formation. Hence, for
a number of years, in the course of various experiments in partial occlusion of
the arteries, I had somewhat in view the possibility of the production, beyond
the point of constriction, of a dilation of the artery, analogous to the dilations
which have been observed in cases of cervical rib.
Four years ago when after many trials I had altogether despaired of having
the hope realized, I was startled, on examining the abdomen of a dog whose
aorta had been constricted for about six months to see that each of the branches
of trifurcation had become dilated almost to the size of the main aortic trunk.
With this observation as incentive, Dr. Mont Reid and I, the following win-
ter, constricted the abdominal aorta just above its trifurcation, in many
dogs and at intervals explored and reexplored the abdominal cavities, but with
negative result. Finally, on investigating the abdomen of the last dog we
found the hoped-for dilation. The degree of obturation of the aorta was ac-
curately determined on sacrificing the animal, and the following year the experi-
ments were more advantageously repeated because of the data obtained from
this case. Now, that we have apparently determined the relative amount
of constriction required to give the most pronounced results we are able in
almost every instance to produce the dilation.
As regards the cause of the dilation produced experimentally we may I
think, conclude that it is not to be found in any of the three factors which
have been proposed as responsible for the dilation observed in cases of
cervical rib, viz., (1) vasomotor paralysis, (2) trauma and (3) variable blood
pressure.
Ad. 1. Vasomotor Paralysis, (a) The vasomotor nerves and the vasa
vasorum are destroyed by the moderately constricting and totally occluding
bands quite as surely as by those which, occluding almost totally, have produced
the greatest amount of dilation, (b) Only a portion of the circumference of
the subclavian artery is exposed to the pressure of the cervical rib and the
scalenus anticus muscle and hence only a fraction of the vasomotor nerves or
vasa vasorum could be pressed upon.
Ad. 2. Trauma, (a) The dilation is usually fusiform and distal to the rib.
(b) Trauma is excluded as a factor in the experimental dilations.
Ad. 3. Variable Blood Pressure, (a) Patients suffering from the pressure-
PATHOLOGY: W. S. HALS TED
207
pain of cervical rib rarely make wide excursion movements of the arm. (b)
The degree of occlusion is constant in the experimentally constricted vessel.
When an arterial trunk is ligated it becomes occluded to the first proximal
and first distal branches and ultimately reduced to a fibrous strand.
From observations which we have made on man and dogs I am quite sure
that there may be a remarkable fall in blood pressure in what I have termed
'the dead arterial pocket,' while there is still little if any sign of diminution
in the caliber of this portion of the vessel. For example, the right common
carotid was ligated by the writer in a case of aneurysm of the external carotid.
About 3 months later, in the course of an operation for the excision of the un-
cured aneurysm, the internal carotid, dead-pocketed between the circle of Willis
and the, carotid ventricle, was freely exposed for a considerable distance. It
had lost its cylindrical form, being flat and tape-like, and, although evi-
dently possessing a considerable lumen, seemed to be empty. When incised,
a few drops of blood oozed without pulse from the little cut. The artery was
then resected. Its wall was thickened on one side but the lumen was still
perhaps three times that of a radial artery. Similar observations I have made
twice on the external iliac of the dog after occlusion of this vessel at its origin
from the aorta. In the dead pocket between the aorta and the origin of the
circumflex iliac and common trunk of the epigastric and obturator arteries
the blood pressure must have been almost nil, because from a little slit in the
apparently normal arterial wall of the relatively empty external iliac artery the
blood escaped very slowly in a tiny, almost pulseless jet about 1 cm. high;
whereas, from the femoral artery, below the profunda, the blood spurted nor-
mally from a similar knife-prick.
Hence in an artery doomed to obliteration, it would seem that the blood
pressure may be lowered before the occlusion process sets in — the lowered
pressure being, perhaps, the immediate factor leading to the obliteration.
Can these observations have any bearing upon the explanation of the dila-
tion of the aorta above its trifurcation and of its triad branches in the dog
after partial occlusion; of the dilation of the carotid in the human subject
which I have observed in one case after partial occlusion of the innominate
combined with ligature of the first and third portions of the right subclavian; and
of the aneurysm of the third portion of the subclavian in cases of cervical rib?
In 1906 Dr. Richardson and I made the observation that after partial oc-
clusion of the thoracic aorta the maximum pressure may be permanently
lowered and the minimum pressure permanently increased distal to the con-
stricting band; and in recent experiments Dr. Reid and I have observed that
after constriction of the lower abdominal aorta the diastolic pressure may be
so increased and the systolic pressure so lowered as to reduce the pulse pressure
by nearly one half. The blood stream in this case, passing with greater veloc-
ity and less pressure through the band prevents the obliteration of the artery
to the nearest branch, the pocket being not a dead one as it is in the case of
208
PATHOLOGY: W. S. HALSTED
total obliteration. The blood in this pocket beyond the constriction streams,
presumably, in whirlpools, somewhat as in the vein and, also, as in the artery
in arterio-venous fistula; the thrill, not palpable at first if the occlusion has
been nearly complete, later may be perceived with the finger; and the bruit,
always audible with the stethoscope, becomes louder as the peripheral arterial
resistance increases.
To these factors, then — to the abnormal play of the blood in the relatively,
as distinguished from the absolutely dead pocket and to the absence of normal
pulse pressure, essential probably to the maintenance of the integrity of the
arterial wall, we may have to look for the solution of our problem.
We have completely occluded the aorta just above the trifurcation only in
dogs. Usually there has been no distal dilation, and in a previous paper I
made the statement that dilation had not been observed below a totally oc-
cluding band. Since then, however, a slight degree of dilation, distal to the
completely obturated vessel, has taken place in three instances. A dilation of
this ventricle-like portion of the aorta between the band and the trifurcation
might be expected even in case of complete occlusion, for the anastomosis is
very free in this situation and the dead pocket is usually, and perhaps always
too short to become obliterated. Lumbar branches may be given off just below,
as they are just above the band.
In two instances I have made the following observation in testing, during
the life of the animal, for the patency of the aorta under the band. Pressure
with the finger immediately above the band shut off the pulse in what we term
the ventricle; whereas, pressure with the back of the scalpel-blade, made as
close to the band as possible, did not. In these cases there was a patent lum-
bar artery so close to the proximal edge of the band that pressure by the
finger obliterated it, whereas, the knife blade which could be brought to bear
on the aortic wall between this little artery and the upper edge of the band did
not interrupt the flow in this important asastomotic branch. The contribu-
tion of this little artery to the anastomotic bloodstream was sufficient to con-
vert an impalpable into a palpable pulse. A palpable pulse in the ventricle
below the band is so invariable, whether the aorta has been completely oc-
cluded or not, that the patency of the artery under the band cannot be defi-
nitely determined during the life of the animal unless temporary occlusion of
it between the band and the nearest lumbar artery obliterates or decidedly
influences the pulse in the ventricle. If pressure above the band does not
affect the pulse just below it we may conclude that obturation is complete.
Fortunately it occurred to me a few days ago to restudy, with reference to
the possibility of finding depicted a dilation of an artery below a ligature, the
sketches of surgeons who in bygone years had experimentally ligated the blood-
vessels of animals. I was delightfully surprised to find, in the beautifully
illustrated volume of Luigi Porta1 published in 1845 two drawings which por-
trayed a pronounced dilation of the aorta and its ventricle immediately below
PATHOLOGY: W. S. HALSTED
209
the site of ligation. The ligatures in the two dogs had been applied eight and
fifteen months before the death of the animals. There is a great bundle of
dilated vessels — the vasa vasis — bridging the gap between the retracted ends
of the divided aorta.
Thus three-quarters of a century ago this great, perhaps the greatest sur-
geon of Italy, furnished irrefutable proof of a remarkable phenomenon which
must eventually have interest for the physiologist, the pathologist and the
surgeon. Luigi Porta describes the drawing but makes no further comment
upon the dilation.
Before the introduction of antiseptic surgery by Lister, thrombosis quite
invariably followed ligation of an artery, and it was to the organization of the
thrombus that the surgeon looked for the prevention of secondary hemorrhage
and for the preservation of the life of the patient. If thrombi formed in these
two cases of Porta they must have been eventually absorbed, for the distribu-
tion of the dilated vasa vasis proves that the aortic free ends were patulous, and
we have further proof of this in the dilation of the aortic ventricle just below
the site of the ligation.
In the course of my experiments in partial occlusion of the arteries I have
often studied the illustrations, carefully I thought, in Luigi Porta's work, but
not until I scanned them with the particular object in view did I discover the
dilations so strikingly manifest. I wonder if anyone has ever commented upon
or been interested in these two observations of Porca.
In the human subject I have in one instance observed a remarkable dilation
of an artery distal to a partially occluding band. In this case an aluminum
band was applied to the innominate artery for the cure of a subclavian
aneurysm. A few weeks later, the aneurysm being uninfluenced by this
procedure, the subclavian artery was ligated both proximal and distal to the
sac, and a cure effected. Three years later a quite cylindrical dilation of the
right common carotid was observed; and now, twelve years after the application
of the band, the common carotid artery is strikingly dilated throughout its
entire length. The band on the innominate can be palpated; the blood is
coursing through it, and distal to the band is a distinct bruit (exhibit).
Summary. — 1. A partially occluded artery (abdominal aorta, innominate,
carotid, subclavian) may dilate distal to the site of constriction.
2. The dilation is circumscribed and has been greatest when the lumen of
the artery (the aorta) was reduced to one-third or perhaps one-fourth of its
original size.
3. When the obturation has been slight in amount dilation has not been
observed; of 7 cases of complete obstruction there was a very moderate degree
of dilation in 3, and none in 4.
4. Complete or partial occlusion of the thoracic aorta may be followed by
dilation central to the point of constriction.
5. Dilation or aneurysm of the subclavian artery has been observed twenty-
seven or more times in cases of cervical rib.
210
PHYSICS: A. A. MICHELSON
6. The dilation of the subclavian is circumscribed, is distal to the point of
constriction, and strikingly resembles the dilation which we have produced
experimentally.
7. The dilation of the artery proximal to an arterio- venous fistula and distal
to a partially occluding band may prove to be referable to the same cause.
8. When the lumen of the aorta is considerably constricted the systolic
pressure may be permanently so lowered and the diastolic pressure so increased
that the pulse pressure may be diminished by one-half.
9. The experimentally produced dilations and the aneurysms of the sub-
clavian artery in cases of cervical rib are probably not due to vasomotor par-
alysis, trauma, or sudden variations in blood pressure.
10. The abnormal, whirlpool-like play of the blood in the relatively dead
pocket just below the site of the constriction, and the lowered pulse pressure
may be the chief factors concerned in the production of the dilation.
11. Bands, rolled ever so tightly, do not rupture the intima.
12. Intimal surfaces, brought, however gently, in contact by bands or liga-
tures do not, in our experience, unite by first intention, for the force necessary
to occlude the artery is sufficient to cause necrosis of the arterial wall.
13. The death of the arterial wall having been brought about by the pres-
sure of the band, a gradual substitution of the necrotic tissue takes place, the
new vessels penetrating it from both ends. It is, I believe, in this manner
that an artery becomes occluded, and it is thus that a fibrous cord forms within
the constricting band.
rLuigi Porta. Dalle alterazioni patologiche delle arterie per la legatura e la torsione
Milano, 1845, pp. 350, 351, plate V, figs. 3 and 5.
ON THE CORRECTION OF OPTICAL SURFACES
By A. A. Michelson
Ryerson Physical Laboratory, University of Chicago
Read before the Academy, April 23, 1918
In a recent number of the Philosophical Magazine, an interesting method for
correcting optical surfaces by means of the interferometer, was developed by
Mr. Twyman. While nothing in the paper indicates that the method is
limited to relatively small surfaces, it would appear that such an application
to mirrors and lenses of the size of modern astronomical telescopes can hardly
be contemplated as this would involve interferometers of at least equal
dimensions.
It was hoped that a modification of Mr. Twyman's method, with an inter-
ferometer of usual size, could nevertheless be employed for large lenses or
mirrors.
PHYSICS: A. A. MICHELSON
211
It was found, however, unless the two optical paths of the interferometers
were equal, which would involve the presence of a second lens equal to the
one to be corrected, that the circular interference bands are extremely small
and difficult to observe.
The following simple, fairly direct method, obviates all these difficulties and
has given excellent results.
A silt in the focus of the mirror or lens to be tested is illuminated by light from
a Nernst glower, concentrated by means of a microscope objective and a total
reflection prism. The light returns immediately above the prism forming an
image of the slit which is viewed through a microscope with a TV inch objective.
A series of screens (an adjustable double slit would be much better) with two
rectangular apertures are placed in succession in front of the lens or mirror
to be tested; one of the apertures being central and the other at varying dis-
tances from, the center.
The resulting diffraction figure will be a series of bands parallel with the slit,
and the position of the central band (achromatic in white light) will remain
constant if the adjustment is right and the mirror perfect.
The error in light waves will be half the observed error in fractions of the
fringe-width.
The lens or mirror is rotated through the entire circumference, at intervals
of 45 degrees or less, and the same operation repeated; and the results plotted
on the corresponding chart, which gives accordingly the error in light-waves
at every selected point of the surface.
This process applied to a 5-inch achromatic lens showed errors so small that
artificial errors were introduced by placing in the path of the pencil a plane
parallel plate which had been made roughly cylindrical by retouching locally.
The errors were then measured as described, and amounted to about seven-
tenths of a light wave at the greatest. The corrector plate was again retouched
by local polishing, and after a half dozen trials (time occupied being about
six hours) the errors were reduced to the order of one- or two-hundredths of a
light- wave; and the resulting image (which was badly astigmatic) was rendered
practically perfect.
It is clear that such a process may be applied to even the largest astronomical
mirrors or lenses, both in the original figuring and in the final correction;
further, this final correction may be made upon the auxiliary plate, thus incur-
ring no danger to the objective.
With evident modification the method applies to the correction of prisms
and gratings. In the latter, however, since the light must be nearly homogene-
ous, there may not be sufficient intensity to observe the interference fringes
under the high magnification required.
It may therefore be of advantage to apply the interferometer (replacing
one of the mirrors by the grating) or even more simply, by observing the inter-
ference of the light reflected from a plane surface with that diffracted from the
grating.
212
PHYSICS: A. A. MICHELSON
In either case, when the adjustment is perfect, the fringes are concentric
circles — which remain constant when the eye or the observing telescope is
moved about in any direction, if the grating is perfect; and if not, measurement
of the diameters of the circles gives the error.
If, however, the difference of path in the interferometer is small, a curious
singularity is presented. The interference fringes are no longer circles but
complicated forms expressible by the formula:
A = (y — yQ) (x2 + y2) + ax + @y.
Further details will appear in a coming number of the Astrophysical Journal.
INFORMATION TO SUBSCRIBERS
Subscriptions at the rate of $5.00 per annum should be made payable
to the National Academy of Sciences, and sent to Williams & Wilkins Com-
pany, Baltimore, or Arthur L. Day, Home Secretary, National Academy of
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CONTENTS
Page
Mathematics. — On the Representation of a Number as the Sum of any Number
of Squares, and in Particular of five or seven . . . . By G, H. Hardy 189
Physics.'— The Crystal Structure of Ice By Ancel St. John 193
Geology. — Fringing Reefs of the Philippine Islands . . . ByW.M. Davis 197
Pathology. — Dilation of the Great Arteries Distal to Partially ^Occluding
Bands By William S. H aisled * 204
Physics. — On the Correction of Optical Surfaces . . . . By A. A. Michelson 210
iiiuiiiDHiiiiiiiitii
VOLUME 4
AUGUST, 1918
NUMBER 8
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Volume 4 AUGUST 15, 1918 Number 8
HEREDITARY TENDENCY TO FORM NERVE TUMORS
By C. B. Davenport
Station for Experimental Evolution, Carnegie Institution of Washington
Read before the Academy, April 23, 1918
The term multiple neurofibromatosis is applied to a rather rare condition
characterized by the appearance of numerous sessile or pedunculated swell-
ings or tumors of varying consistency and size. These may be present from
birth, tend to grow larger and may even become confluent over a con-
siderable area. Examination shows that they are fibrous tumors and fre-
quently contain one or more nerve fibers or, if more deep seated, may be
enlargements of the perineurium of nerve trunks. They are due to cell pro-
liferations of the connective tissue sheaths of nerves.
The course of the disease is influenced by metabolic changes in the body.
Thus pregnancy frequently stimulates growth of the small tumors which have
been present from birth. In other cases even the changes of puberty are
associated with the first marked development of the tumors. After various
zymotic diseases, arsenical and lead poisoning, rapid growth of the tumors
has been observed. The numbers of tumors may be very great, as many
as 2000 or 4000. The tumors may be stimulated to grow by external me-
chanical agencies also, such as the irritation of a sword belt.
Associated with the tendency to form tumors is the production of pig-
mented spots or patches in the skin — of a cafe au lait color. Such patches
when of small size may grow into colored moles or small tumors. On au-
topsy tumors are frequently found on the deeper lying nerves.
Multiple neurofibromatosis is a rare condition ; it is found in only about 1 in
2000 cases that present themselves to medical clinics or private practitioners
for skin diseases. Despite this there are many cases in the literature where
2 to 6 members of a family show some of the symptoms. The fact that
only blood relatives are affected indicates that the disease is not a communi-
cable one and it is equally certain that it is not induced by infection through
213
214
MATHEMATICS: D. N. LEHMER
the placenta. The two sexes are nearly equally apt to be affected — of 243
affected persons 56.8% are males. The disease tends to recur without a
break in the generations and is equally apt to come down the male and the
female line. Consequently it looks as though the hereditary factor in neuro-
fibromatosis is a dominant one. In each affected fraternity, indeed, about
50% of the individuals are affected, as is expected if it is a dominant trait.
Actually 43.5% were found affected. In some cases, however, a generation is
skipped — a result that can be explained on the hypothesis of occasional failure
of dominance.
The symptoms of neurofibromatosis are very diverse. But inside of one
family they are apt to be alike. This speaks strongly for the hypothesis of an
inheritance factor. Similarly the location of the principal tumors is apt to be
the same in one family, although it shows the greatest diversity in different
families. Other multiple tumors are inherited in the same way as neuro-
fibroma ta. Thus the tendency to form vascular tumors of the skin and
mucous membranes has been shown by Osier (1901) and others since to be a
dominant one. Polyadenomata are inherited similarly. Likewise the tend-
ency to form pigmented patches in the skin (ephilides) was shown by Ham-
mer to be a dominant trait. To this same group of heredity belong epi-
dermolysis bullosa, angioneurotic oedema, and persistent hereditary oedema,
also such skin diseases as psoriasis, porokeratosis and ichthyosis.
In not a few cases the removal of neurofibromata has been followed by
malignant growths, at the same spot. It is plain that neurofibromata are
in some way related to cancerous growths. The fact that neurofibromata
have an inheritable basis strengthens the view that cancers in general have
such a basis.
The complete paper will be published jointly with Dr. S. A. Preiser.
ARITHMETICAL THEORY OF CERTAIN IIURW1TZIAN
CONTINUED FRACTIONS
By D. N. Lehmer
Department of Mathematics, University of California
Communicated by E. H. Moore, April 2, 1918
The following research is the outcome of the discovery, made some three
years ago, that the denominators of the convergents of order 3n, 3n — 2, and
3n — 6, as well as the numerator of the convergent of order 3n — 3 in the regular
continued fraction which represents the base of Naperian logarithms, are all
divisible by n. The convergents recur modulo n with a period of 6n when n
is odd, and with a period of 3n when n is even.
MATHEMATICS: D. N. LEHMER
215
To account for these curious theorems, and to place them in their proper
setting, it was found necessary to study a more general type of continued
fraction first investigated by Hurwitz.1 The regular continued fraction for
the Naperian base was discovered by Roger Cotes2 to be (2, 1, 2, 1, 1, 4, 1, 1,
6, 1, 1, 8, 1, 1,. . . .)j or as we may write it (2, 1, 2n, 1, 1), n = 1, 2, 3,. . .
The proof of the remarkable sequence of partial quotients was first given by
Euler,3 by means of the theory of the Riccati equation. Euler established a
number of other interesting expansions, such as:
(l,l,4»+l), rc = 0, 1, 2, 3, ... .
(l,s(2»+l) - 1,1), n = 0, 1, 2, 3, . . . .
((4» + 2) j),» = 0, 1, 2, 3, ... .
The continued fractions studied by Hurwitz may be written in the form;
(ft, to, q$, • • ■ qr, ) ], (11)
y = r0[sin (4 + cn (2 fo) + M cos (4 + tt) v. sn (2 Ki>) dn (2 2&>)].(12)
If x' = r0 cn (2 y' = fir0 sn (2 Kv) dn (2 z' = a cn2 (2 (13)
it is found that the locus of the point P'{x' , y' , z') is a quartic C4 in space, and that
P' is obtained by rotating the point P (x, y, z) of the pendulum curve C about the
z-axis through an angle— (A + it) v, i.e., through an angle negatively proportional
to the time associated with P in the motion.
Imposing upon (11) and (12) the same condition of periodicity, as in the
general case, the resulting curve in the xy -plane becomes a rational algebraic
curve of order 2 k. The angle corresponding to the period 2 wi is, as before,
$ = 2kir/mi, k and mi being relatively prime. For a given odd mi there are
'{mi — l)/2 curves of this type, for an even mi, there are (mi — 2)1 2 such curves.
In both cases there are m\(k — 1) real double points.
When mi is odd there is just one curve among the set whose double-points are
■all real. Its degree is 2 k = m\-\- 1.
When mi is even, there is no such curve.
In case of an odd mi the polar equation of the curve has the form
p2k + alP2k-2 + a2p2k-4+ .... +a.p2<+0+ a4)
(blP2Xl + b2P2X>+ .... +bjP2 + b) pWl cos mid = 0,
in which a ± 0, \i > A, > X3 > ... >*1, and 2 Xi + mi ^ 2 k — 1. In
cartesian coordinates (14) may be written in the form
>(x2 + y2)k + at (x'+y2)*-1 + a2 (x2 + y2)k~2 + .... + as (x2 + y2) + a +
{bi (x2 + y2)^ + b2 (x2 + y2)Xs + • • • • +hj (x2+y2)+b\. (15)
Transforming this curve by
x = d= Vx''-y'/2-2y''-l / y", y = (/' + l) / f ,
or using isotropic coordinates, transformations which do not change the
character of the isotropic points, and "placing the curve on the analytic tri-
angle," the result is obtained that the isotropic points absorb together
(k- \) {2 k- mi - 1) (16)
double points, which when added to the mi (k — 1) real double-points, gives
(k — 1) (2 k — 1), i.e., the maximum number of double points which a curve
of order 2 k may have. Thus we have verified directly from the equation,
that the curve is rational, as proved before. When the curve has all double
points real, then its degree is mi + 1 = 2 k, so that from (16) the number of
BOTANY: C. DRECHSLER
221
imaginary double points is clearly zero, which is another verification of pre-
vious results. (16) is also true when mi is even. Polar and cartesian equa-
tions for mi even may be established in a similar manner as in (14) and (15).
3. Examples. — When mi = 3, 2 k = 4, the polar and rational parametric
equations of the curve3 are
p4 - Rp3 cos 3d - ?L R2P2 + ^-R* = 0
?-Ut2+3 2t(3-5t2) ,D n
4 a + t2)2 4 (i + t2)2
When mi = 4, 2 k = 6, cartesian and polar equations of the curve are
S(X2 -|_ 3,2)3 _ 24(x4 + y4) - 32 x2y2 + 39(x2 + y2) - 18 = 0,
3 p^ - (2 cos 49 + 22)p4 .+ 39p? - 18 = 0.
As m and & increase, the construction of the equations with numerical co-
efficients becomes increasingly difficult.4
1 Greenhill, Les Fonctions Elliptiques et leurs Applications, chap. III.
2 Tannery et Molk, Elements de la Theorie des Fonctions Elliptiques, 4, pp. 176-192; Appell:
Train de Mecanigue Rationnelle, 1, p. 494.
3 This curve is known and was investigated by G. de Longchamps: /. Math. Elementaires,
4, 1885, 269-277; also by H. Brocard: /. Math. Speciales, (Ser. 3), 5, 1891, 56-64.
4 A curve of this type may be symbolically denoted by C^J. Tabulations of all curves,
with their real and imaginary double points as far as Cll have been made, also actual graphs
of Cl, Cl, C\. C\-
THE TAXONOMIC POSITION OF THE GENUS ACTINOMYCES
By Charles Drechsler
Cryptogamic Laboratories, Harvard University
Communicated by R. Thaxter, May 14, 1918
To the genus Actinomyces are usually assigned a variety of peculiar and
very minute filamentous organisms, widely distributed in nature, concerning
the taxonomic relationship of which divergent views have been held. Most
of the earlier medical writers, whose attention was centered on forms associ-
ated with human and animal diseases, placed the genus with the pleomorphic
bacteria. Others recognized conidia in the clavate elements produced by one
of these pathogenic forms, Act. bovis, within the animal body, and referred this
parasite to the Fungi. These elements were later shown to represent de-
generative structures; but as subsequent investigations on a number of species,
including various saprophytic forms, as well as the common potato scab
222
BOTANY: C. DRECHSLER
organism and several pathogenic types clinically similar to Act. bovis, revealed
decidedly fungoid characteristics, not only in the profusely branched condition
of the vegetative thallus when grown in culture, but also in the production of
an aerial mycelium and Oidium-like spores, the view that the genus is to be
placed with the Hyphomycetes has continued to receive support.
According to another view which has gained quite wide acceptance, Actino-
myces represents an intermediate group and a phylogenetic connection between
the Bacteria and the Fungi. It is held that the genus originated either as the
result of the development of bacterial forms possessing a tendency toward the
branched condition, like the tubercle and the diphtheria organisms; or as the
result of the reduction of hyphomycetous types, which, in their ultimate
stages, yielded the much simpler true bacteria.
In order to determine the merits of these contending views, the writer
subjected a large number of saprophytic species isolated from the soil, air,
etc., as well as several virulent strains of the potato scab organism secured
from Mr. M. Shapavalov, to morphological study. The results may be
summarized as follows:
(1) The vegetative thallus of Actinomyces consists of a mycelium com-
posed of profusely branching hyphae, the terminal growing portions of which
are densely filled with protoplasm. Toward the center of the thallus, the
vacuoles increase in size, and may be associated with the presence of meta-
chromatic granules; the latter having nothing in common with bacterial
endospores or 'micrococci,' for which they were mistaken by early observers.
(2) The vegetative mycelium attains an extent incomparably greater than
the branching figures recorded for bacteria of the acid-fast group; and the
hyphae lack the uniformity in diameter generally characteristic of the
Schizomycetes.
(3) The aerial mycelium produced on suitable substrata by most species,
occurs, usually, in the form of a mat of discrete fructifications; but in other
species, these fructifications are frequently combined to form numerous pecul-
iar erect Isaroid sporodochia.
(4) In any case, each individual fructification represents a well characterized
sporogerious apparatus, consisting of a sterile axial filament bearing branches
in an open racemose, or dense capitate arrangement. The primary branches
may function directly as sporogenous hyphae, or may proliferate branches of
the second and of higher orders; sporogenesis, in the latter case, being confined
to the terminal elements, the hyphal portions below points of attachment of
branches remaining sterile.
(5) Two tendencies in the development of fructifications are recognizable,
one leading to an erect dendroidal type in which successively proliferated
fertile elements undergo processes of sporogenesis in continuous sequence; and
the other leading to a prostrate, racemose type, in which sporogenesis is de-
layed in the older branches until the younger branches have also attained their
ERRATA
Due to printer's error the figures upon pages 225-228 were printed in the August, 1918
issue in incomplete form.
When binding the volume substitute the pages herewith for those in the August, 1918
issue.
BOTANY: C. DRECHSLER
223
final extension. The majority of species show these tendencies combined in
different ways.
(6) The sporogenous hyphae of most species are coiled in peculiar spirals
sometimes resembling the spores of the hyphomycetous genus Helicoon.
These spirals exhibit pronounced specific characteristics in the number, diam-
eter, and obliquity of their turns, and especially in the direction of rotation
(whether dextrorse or sinistrorse).
(7) Sporogenesis, where it can be followed, begins at the tips of the fertile
branches and proceeds basipetally. In the larger number of species the proc-
ess involves the insertion of septa, which in certain cases, are relatively very
massive, and in others, so thin as to be barely discernible. The disposition of
these septa while the delimited spores undergo maturation processes, varies
with the species: (1) they may remain more or less unaltered; (2) they may
suffer a median split, the two resulting halves being then separated as the
result of the longitudinal contraction of the young spores, leaving alternate
portions of hyphal wall completely evacuated; (3) or they may first become
considerably constricted and subsequently converted into non-stainable
isthmuses connecting the mature spores. The apparent absence of septa in
the sporogenous hyphae of other forms, is, perhaps, attributable to optical
difficulties.
(8) Granules are readily differentiated in the spores of many species, which
possess the staining properties and uniformity of size characteristic of nuclei;
they generally occur singly, but in the larger spores of a few forms, two are often
found occupying diagonally opposite positions.
(9) As in the vegetative thallus, metachromatic granules occur in the
aerial mycelium, being very rarely found in spores or sporogeneous hyphae
but becoming very abundant in degenerate sterile hyphae.
(10) The older axial filaments of some species show marked distensions,
which, in extreme cases, result in figures simulating Leptomitus. These arise
as local distensions at the points of attachment of the more extensive lateral
sporogenous processes. Cuneate modifications of the sterile axial filaments
below the origin of branches, also occur.
(11) Curious spherical structures appear regularly in some forms, both
in the sterile axial hyphae, where they may contain either a median septum or
a number of peripheral metachromatic granules, and in the sporogenous hyphae
where they are associated with the regularly spaced septa.
(12) The spores germinate readily in suitable solutions, producing from
one to four germ tubes, the approximate number being more or less character-
istic of the species.
(13) Owing to the absence of any well defined bacterial characteristics, the
writer is of the opinion that the view that Actinomyces represents a transition
between the Hyphomycetes and the Schizomycetes, as well as the phylo-
genetic corollary based upon it,, may safely be abandoned. If mere size is
to be regarded as important, it would appear to be equally profitable to look
224
ASTRONOMY: H. SHAPLEY
for bacterial affinities in some ascomycetous and sphaeropsidaceous forms,
the hyphae of which are similarly very minute. It is doubtful whether far-
reaching taxonomic generalizations can be based upon the 'acid-fast' staining
reaction, especially as this reaction has not played a very important role in
mycological research. There seems to be no adequate reason why the genus
should not be classed, in an unqualified manner, with the Hyphomycetes, as a
Mucedineous group with tendencies toward an erect Isaroid habit.
A more complete illustrated account will appear shortly in the Botanical
Gazette.
STUDIES OF MAGNITUDES IN STAR CLUSTERS, VIII. A SUM-
MARY OF RESULTS BEARING ON THE STRUCTURE
OF THE SIDEREAL UNIVERSE
By Harlow Shapley
Mount Wilson Solar Observatory, Carnegie Institution of Washington
Communicated by W. S. Adams, May 21, 1918
In the preceding communication of this series1 methods were discussed for
the determination of the relative distances of a considerable number of globu-
lar clusters. The methods have now been developed so as to give not only
relative values but also fairly reliable absolute distances for all globular clus-
ters, and for all variable stars of the Cepheid class for which periods and ap-
parent magnitudes are known. A rather detailed summary of the procedure,
its accuracy, and the results of a thorough application of the methods, has
been given in the February issue of the Publications of the Astronomical Society
of the Pacific. The present"note will be confined to a synopsis of the more im-
portant results pertaining to the probable extent and arrangement of the
sidereal system. The detailed discussion is appearing in a series of papers in
the Astro physical Journal, and will be separately published as Contributions
from the Mount Wilson Solar Observatory, Nos. 151-157.
Extending to the globular clusters the work of Miss Leavitt, Hertzsprung,
and Russell on the Cepheid variables of the Small Magellanic Cloud and of
the galactic system, we have been able to establish beyond question the inter-
dependence for these variables of absolute luminosity and period of light vari-
ation. By combining the apparent and absolute magnitudes, the distances and
positions in space have been determined for about 140 Cepheid variables,
most of which are much more distant than any objects for which parallaxes
have been directly measured. Figure 1 shows their distribution.
The distances of globular clusters are of a different order of magnitude from
those heretofore entering stellar investigations. Although the average naked-
eye star is near as compared with many Cepheid variables, the most remote
Cepheid now known is not so far away as the nearest globular cluster. The
ASTRONOMY: H. SHAPLEY
225
available astronomical records contain 69 clusters that appear definitely to
belong to the globular classification. Further work on very faint and distant
objects will probably add a few to the present list, but within a distance of
100,000 light-years of the sun the survey appears to be complete. Keeping
this limitation in mind, we may examine the collected data for signs of a gen-
eral organization.
The apparent concentration of the globular systems to a southern region of
the Milky Way has long been known. It now appears, upon closer investiga-
tion, that few if any typical globular clusters are to be found within 5° of the
galactic plane; and, when actual positions in space are substituted for appar-
ent positions, this suggested avoidance of the mid-galactic region reveals
0 10 20 30 40|' s»5Pm O /6CF
i 1 1 1 : 1 >' n — : ' "A i I \J i~ '
-20 1 I I I
FIG. 1. DISTRIBUTION OF CEPHEID VARIABLES
The unit of distance is 100 parsecs. Ordinates are distances from the galactic plane;
abscissae are projected distances in the plane. Open triangles and black dots designate, re-
spectively, cluster-type variables and Cepheids with periods in excess of a day. The near-
est globular cluster, co Centauri, is just outside the boundary of the diagram on the right.
RU Bootis, indicated by an arrow, is too far above the plane to fall within the figure. The'
semicircles, with radii of 500 and 1000 parsecs (tt = 0".002 and0".001), indicate how distant
most of these variables are as compared with the average star of the tenth magnitude or
brighter (x > 0".004, Kapteyn). Between the broken horizontal lines, ±1750 parsecs, lies
the equatorial galactic region devoid of globular clusters.
itself as a total absence of compact clusters from the domains of space that
appear to contain most of the known sidereal bodies.
The striking distribution of globular clusters in galactic longitude is well
shown in the projection of their positions on the galactic plane in figure 2.
Apparently the clusters themselves form a large flattened system, the center
226
ASTRONOMY: H. S HAP LEY
of which, in the galactic plane, is between 60 and 70 thousand light-years
distant in the general direction of the dense star clouds of Sagittarius and
Scorpio.
The projection of the positions of clusters on a plane perpendicular to the
Milky Way, and parallel to the direction of this center from the sun, is illus-
trated in figure 3. The shaded portion of the diagram indicates the equatorial
region, toward which globular clusters crowd but in which they are not found;
its thickness appears to be only three or four per cent of its extent along the
galactic plane.
There can be little doubt that the galactic plane defined by the faint stars
and by the Milky Way clouds is also a symmetrical and fundamental plane
for the system of globular clusters. In other words, the distribution of clus-
ters shows that, notwithstanding their great dimensions, they are subordinate
FIG. 2. THE SYSTEM OF GLOBULAR CLUSTERS PROJECTED ON THE PLANE OF THE GALAXY
The galactic longitude is indicated in the margin. The 'local system' is completely
within the smallest circle, which has a radius of a thousand parsecs (3260 light-years).
The larger circles, which are also heliocentric, have radii increasing by intervals of 10,000
parsecs. The dotted line indicates the suggested major axis of the system (if ellipsoidal),
and the cross the adopted center. The dots are about five times the actual diameters of the
clusters on this scale. Nine clusters more distant from the plane than 15,000 parsecs are not
included in this diagram.
members of the far greater galactic system. Their arrangement and the rela-
tive densities of various parts of the Milky Way clouds strongly suggest that
the whole sidereal system is roughly outlined by the positions of globular clus-
ters, and that all known celestial objects — stars, nebulae, clusters — are mem-
bers of a single unit.
The mean diameter of the proposed system appears to be at least 300,000
light-years; its most conspicuous feature is the equatorial segment, which ap-
parently is thickly populated with stars throughout its whole extent. From
Auriga
90°
270°
Scorpio
ASTRONOMY : H. SHAPLEY
227 4
this viewpoint the Milky Way is mainly a phenomenon of depth; its extent,
as seen from the sun, is something like three times as great in the direction of
the center as in the opposite direction toward Auriga and Taurus. The tes-
timony of the star frequencies in the Milky Way clouds does not disagree with
the supposition of a remarkably eccentric position of the solar system.
Slipher's radial velocity observations of the brighter globular clusters2 indi-
cate that seven out of eight of those with high galactic latitudes are approach-
ing the sun (and probably the equatorial segment) with such high velocities
that, unless greatly retarded, they will have entered the dense stellar regions
within an interval of time which appears to be short as compared with the
probable history of a stellar system. The absence of such clusters from the
0 +100 +200 +300 +400 +500
•100
+300
+200
+100
•100
-200
♦5l4t
•
•
•
•
•
m
•
•
• •
t •
• •
• •
• •
• •
•
•
•
o
o° °°
o
o
o u
o o 0 o
o
0 oo
O 0
o
0
0
o
0
c
0
0
o
o
+20
-20
FIG. 3. PROJECTION OF THE POSITIONS OF GLOBULAR CLUSTERS ON A PLANE
PERPENDICULAR TO THE GALAXY
Illustrating (1) the absence of clusters from the mid-galactic region, (2) their symmetrical
arrangement with respect to the Galaxy, (3) the eccentric position of the sun (the cross)
with respect to the center of the system of clusters. The ordinates are distances from the
galactic plane, R sin /?; the abscissae are projected distances in the direction of the center,
R cos 0 cos (X — 325°). The unit of distance is 100 parsecs (326 light-years); each
small square is 10,000 parsecs on a side. On this scale the actual diameter of each cluster
is about one-fifth the diameter of the circles and dots. The cluster N.G.C. 4147 is outside
the boundary of the diagram, as indicated by the arrow.
Galaxy thus becomes the more remarkable. The globular systems nearest the
galactic plane are in general the least condensed. This result and the distribu-
tion of stars in certain open clusters suggest the possibility that upon approach-
ing the galactic regions globular clusters may be disrupted and transformed
into open galactic groups.
The galactic center as derived from the clusters is nearly at right angles to
the direction of center obtained by Walkey and Charlier from statistical inves-
228
ASTRONOMY: H. SHAPLEY
tigations of the brighter stars. The stars of spectral type B, according to
Charlier,3 form a flattened system of some 2000 light-years radius, which he
identifies with the general stellar universe; the group is very small, however,
as compared with the system now outlined by globular clusters, and we may
assume instead that these B stars comprise a localized stellar organization.
To test further for the existence of a limited local cluster, situated far within
the bounds of the equatorial segment and perhaps comparable in some re-
spects with other open galactic groups, an investigation has been made of the
galactic arrangement of the brighter stars. Details of this study are given in
Mount Wilson Contribution No. 157. In brief, a verification is obtained of
the presence of a local cluster, for which the following properties are indicated :
(a) it contains very nearly all the B stars brighter than the seventh magnitude
(the remainder appearing to be members of the intermingling and surround-
ing galactic field), a majority of the A stars, and large numbers of those of
Y in parsecs
-300 -150 0 +150 +300 +450
+1001 1 1 1 1 1
340° 70° 160° 250° 340°
Galactic Longitude
FIGS. 4a AND 4b
Fig. 4a. (Above) Projection of the local cluster of B stars on a plane perpendicular to the
Galaxy, — adapted from the data shown in Plate IV of Charlier's memoir. The inclination
of the cluster's central plane to the Galaxy has been partially eliminated by Charlier.
The projected center of the system of B stars, as derived by him, is at the origin of co-ordi-
nates; the present work suggests that the central plane of the B stars is much nearer the sun
(whose position is indicated by the cross) than Charlier supposed. The projection of the
true galactic plane appears as a broken inclined line, and the distance of the sun and the
local cluster north of it is to be noted. Short vertical lines across the curve show the limits
of distance adopted for the solution represented by Fig 46.
Fig. 4b. (Below.) Solution for the inclination of the local cluster to the galactic plane,
based upon 400 stars of spectral- type B. Owing to the sun's position to the north, the central
plane has a dip of 5°.
redder spectral types; (b) its central plane is not more than 30 light-years
south of the sun and may be much nearer; on the other hand the true galactic
plane, as defined by Cepheid variables, faint stars, and the galactic clouds,
is approximately 175 light-years south of the center of the local cluster (fig. 4a) ,
(c) the central plane, at least for the brighter stars, in inclined about 12° to
GEOLOGY: H. L. FAIRCHILD
229
the galactic plane, with nodes in longitude 70° and 250° (figs. 4a and 4b);
(d) the diameter is of the order of 2500 light-years.
The above results lead to a simple interpretation of star-streaming. The
motion of an open cluster through the general star-fields of the equatorial seg-
ment must give rise to stellar drifts, and it is a natural assumption that the
observed streaming in the neighborhood of the sun is wholly due to such a
cause. According to this view, stars of Stream I belong to the large moving
cluster surrounding the sun; those of Stream II belong to the galactic field.
The motion of the cluster as a whole is in the galactic plane, nearly radial from
the galactic center, and there is considerable evidence of internal motion
within the cluster. In all the details examined, this hypothesis appears to be
in agreement with the observed systematic motions of the stars.
1 Shapley, H., these Proceedings, 3, 1917, (479-484) ; Mt. Wilson Communication, No. 37.
2 Slipher, V. M., Popular Astronomy, Northfield, Minn., 26, 1918, (8).
3 Charlier, C. V. L., Meddelanden fran Lunds Astro omiska Observatorium, U psala, (Ser.
2), No. 14, 1916, (1-108).
GLACIAL DEPRESSION AND POST-GLACIAL UPLIFT OF
NORTHEASTERN AMERICA
By H. L. Fairchild
Department of Geology, University of Rochester
Communicated by J. M. Clarke, June 4, 1918
The geophysical theory of isostacy is excellently illustrated by the up and
down (diastrophic) movements of northeastern America in relation to glacia-
tion. The amount and the area of land depression beneath the ice sheet,
and the land uplift subsequent to the removal of the ice, is fairly proportionate
to the thickness and extent of the latest ice cap.
The fact is evident that the area covered by the latest continental ice
sheet, the Labrador (Quebec) glacier, stood much beneath its present altitude,
relative to sea-level, when the ice melted off ; and that the recent uplift has
brought the land to its present position. The evidence of the uplift is abun-
dant; many high-level beaches and sand-plains facing the open sea and extending
far up the valleys in Canada, New England and New York, with the occurrence
of abundant marine fossils hundreds of feet above the ocean. These facts have
been recognized for quite a century, and many observations are recorded in
the geologic literature of Canada and America. But up to the present time
the full amount of submergence and the extent or limits of the drowned area
have not been determined beyond dispute. The full amount of the down-
and-up movement has nearly always been underestimated, because the con-
spicuous or more evident marine features are generally of inferior and later
230
GEOLOGY: H. L. FAIRCHILD
water levels, while the initial or summit features are commonly weak and
unobtrusive; or the latter lie so far inland and are so detached as to be unrecog-
nized in their genesis and relationship, being commonly referred to glacial
origin. However, the summit or initial level at any point is the critical and
essential element in the problem.
Several years of study in the Hudson-Champlain, Ontario and Connecticut
valleys has determined the position of the uplifted and tilted marine level.
In the Hudson-Champlain Valley the ancient estuary features rise from zero
south of New York City to 740 feet on the north boundary of New York, and
to over 800 feet on the north line of Vermont. Comparison of these features
with similar phenomena in the Connecticut Valley gives the direction of the iso-
bases (lines of equal uplift) as 20 degrees north of west by south of east; or 20
degrees east of north for the direction of steepest tilting. This figure is in close
agreement with the determinations of Coleman, Goldthwait, Spencer and Taylor
for the later deformation of the glacial lake shore lines in the Great Lakes area.
GEOLOGY : H. L. FAIRCHILD
231
It has also been found that in the Ontario Basin the vertical interval be-
tween the tilted plane of Lake Iroquois and the plane of the sea-level waters
(Gilbert Gulf) is 290 feet. Extension of the isobases of total uplift westward
over the Ontario Basin gives very close accordance with the facts of observa-
tion in that field.
With the large area of New York State, Ontario basin and western New
England as a well-determined base it has been possible to extend the study
eastward over New England and eastern Canada. The result is shown in the
accompanying map with at least close approximation to accuracy. On the
small scale the map is somewhat generalized. The broken lines are entirely
hypothetic only in the Mississippi Valley, where the land uplift may be more
complicated in time and form. Except in the district west of Indiana and Michi-
gan the map shows the rise of the continent subsequent to the removal of the
latest ice sheet.
For Laborador and Newfoundland reliance is placed on the published data
of R. A. Daly, with some help from unpublished figures of A. P. Coleman and
J. B. Tyrrell.
Precaution is taken in this study to discriminate between features produced
by sea-level waters and by glacial waters. In the inland areas, in order to
avoid doubt or cavil as to glacial waters, the main dependance has been placed
on the summit deltas of streams with southward flow, or with flow directed
away from the receding ice margin. In the extended paper, noted below, will
be found a description of field methods, and discussion of criteria for discrimi-
nating marine features.
The map shows apparently direct relation between the ice sheet and the
diastrophic land movement. The area of uplift is the area of glaciation, and
the amount of uplift is proportionate to the supposed thickness of the spread-
ing ice cap. The map also shows the effect of land and sea on the flow and
reach of the ice sheet. The ice deployed on the land but was inhibited by the
sea; thus producing more rapid flow and steeper gradients along the radii
toward the nearer sea shores. An independent ice cap is indicated for
Newfoundland.
For the fuller discussion, in both methods and results; for description of the
uplifted sea-level features in western New England, Maine, St. Lawrence and
Ottawa valleys, Gaspe peninsula, New Brunswick, Nova Scotia, Labrador and
Newfoundland; and for discussion of possible effects of any change in ocean
level, the reader is referred to the formal paper in the Bulletin of the Geological
Society of America, volume 29.
Former papers by the writer bearing on the subject of recent land uplift are as follows:
Pleistocene marine submergence of the Connecticut and Hudson Valleys, Bull. Geol. Soc.
Am r., New York, 25, 1914, (219-242).
Pleistocene uplift of New York and adjacent territory, Ibid., 27, 1916, (235-262).
Post-Glacial marine waters in Vermont, Burlington, Rep. Vermont State Geologist for
1915-16, 1917, (1-41).
232
BOTANY: LIPMAN AND WAYNICK
Poat-Glacial submergence of Long Island, Bull. Geol. Soc. Amer. 28, 1917, (279-309).
Post-Glacial features of the upper Hudson Valley, N. Y. State Museum, Bull., 195, 1917.
Post-Glacial uplift of northesastern America Bull. Geol. Soc. Amer., 29 (in press) , 1918.
A BACTERIOLOGICAL STUDY OF THE SOIL OF LOGGERHEAD
KEY, TORTUGAS, FLORIDA
By C. B. Lipman and D. D. Waynick
College of Agriculture, University of California
Communicated by A. G. Mayer, May 21, 1918
Inasmuch as the coarse calcareous sands of the islands off the Florida Coast,
and of similar ones, represent very recent geological material, and since they,
therefore, offer an opportunity of determining the early bacterial flora which
establish themselves there, it was decided to carry out some studies on typical
samples. Dr. A. G. Mayer, Director of the Marine Biological Laboratory of
the Carnegie Institution, situated on Loggerhead Key, Tortugas, Florida,
supplied us with the necc ssary samples for our study. Three large samples
were collected, which answer to the following descriptions, for which we are
indebted to Dr. Mayer:
No. 1. In region thickly covered with Suriana maritimi bushes. About twenty feet
north of stone wall built in 1868 and in a place where probably no man has trodden for 30
years or more. This sample is of an average depth of about 7 inches beneath the surface.
No. 2. Sand from the surface to 6 inches in depth from the northern end of Loggerhead
Key. The region is barren of vegetation, no plants having ever grown within 200 feet of
the place from which sample was taken. It is about 6 feet above high tide level on the crest
of the island. Probably no man has walked here for 10 months previously.
No. 3. From an average depth of 15 inches below the surface in a place densely wooded
with Suriana maritima. Same locality as Sample No. 1.
We thus had a soil and a subsoil sample from a part of the island in which
large bushes (Suriana maritima) have established themselves as a permanent
association. We also had a surface sample of very coarse, white, calcareous
sand or grits, on which plants have never grown. It is to be noted, also,
that there has been little or no opportunity for the contamination of these
samples by the habitation or tread of man. The flora which now characterize
the soil or sand material must take their origin either from the sea water,
which now surrounds and which at one time probably covered them, or from
winds carrying dust from older soils. The samples were collected by Dr.
Mayer with the greatest care, large sterile bottles with cotton stoppers having
been employed as containers. The cotton stoppers were doubly protected
against contamination while in transit.
The studies carried out included counts of bacteria in the various samples,
isolation and identification of pure cultures of the important bacteria and
BOTANY: LIP MAN AND WAY NICK
233
fungi growing on mannite, beef, and synthetic agar, the determination of the
soils ammonia and nitrate producing powers, of their nitrogen fixing powers,
and of the isolation and study of the nitrogen fixing organisms found. In this
preliminary note, we give merely a brief general statement anent our findings
and reserve for another paper the more detailed discussion of the results
obtained.
Bacterial Counts. — In the surface soil from the wooded part of the island, as
many as a million organisms per gram were found when beef agar was used
as a medium. Less than half as many organisms developed on synthetic
agar and only about TV as many on mannite agar. In the subsoil from the
same spot, there were approximately rV as many organisms developing on
beef agar as on the surf ace soil and of synthetic agar the corresponding number
was about TV that of the surface soil on beef agar and less than \ that on syn-
thetic agar. The subsoil developed only one organism per gram on mannite
agar.
In the highly calcareous sand free from vegetation, there were only about
8000 to 9000 organisms per gram of material on both beef and synthetic agar
and only TV as many on mannite agar.
Nitrogen Transforming Powers of the Soils. — Both soil and subsoil from the
wooded part of the island show powers of producing ammonia from dried blood
nitrogen about equal to those of a poor sandy soil. The calcareous sand which,
as has been observed above, contains relatively few organisms, possesses,
nevertheless, a power of producing ammonia about three-quarters as great as
that of the other soil material.
As regards nitrifying power, all the soils seem to be very feeble, if indeed they
possess any such power appreciably. The amount of nitrate produced by the
subsoil of the wooded part of the island seems to be above the limit of error,
but, curiously enough, the surface soil produces no nitrate from sulphate of
ammonia. The calcareous sand appears to produce a small quantity of nitrate
from sulphate of ammonia, but the amount so formed may be within the limit
of error. From the small amount of nitrogen which the soil itself contains,
which in no case attains 0.01%, all of the samples seem to be powerless to pro-
duce nitrate. Dried blood in the quantities used seems to be no more satisfac-
tory than sulphate of ammonia. These facts make possible some interesting
speculation as to the nitrogen nutrition of the plants growing on the island,
which we shall discuss in a future paper.
Nitrogen Fixing Powers and Organisms. — Perhaps the most interesting re-
sults obtained in these studies were those on the nitrogen fixing powers and
organisms of the soil materials in question. All the samples gave characteris-
tic Azotobacter films in mannite solution, the surface soil from the wooded
land giving the heaviest film and the characteristic deep black pigment forma-
tion usually ascribed to A. chroococcum. The subsoil from the wooded land
and the calcareous sand produced thin discontinuous films and little or no
pigment. All the films, on microscopic examination, showed typical Azoto-
234
ZOOLOGY: P. H. COBB
bacter cells. Judging, therefore, from the very small number of organisms
which are found in the calcareous sand, Azotobacter, a nitrogen fixing organ-
ism, seems to be one of the earliest and one of the most numerous organisms.
The nitrogen fixing power of the soils as measured by the ordinary laboratory
test in solution cultures, in contrast with their nitrogen transforming powers,
seem to be as vigorous as those of excellent soils. It is interesting, moreover,
that the calcareous sand fixed about f as much nitrogen in the tests mentioned
as the surface soil from the wooded land and about f as much as the subsoil
of the same land.
Space does not permit a consideration here of some of the pure cultures of
bacteria and fungi which were isolated from the soil samples studied. Three
species of Actinomyces found appear to be new and as yet remain unnamed.
Some of the common organisms of all soils were found, including bacteria,
Actinomyces, and fungi. These will all be described in detail in a forthcoming
paper, mention of which has already been made above.
It is a privilege to acknowledge again our obligation to Dr. A. G. Mayer
for his kindness in sending the samples and for his interest in the work. We
also express thanks to Dr. H. J. Conn and to Dr. S. A. Waksman for assisting
in identification of a few cultures of bacteria and of Actinomyces, respectively.
AUTONOMOUS RESPONSES OF THE LABIAL PALPS OF
ANODONTA1
By P. H. Cobb
Zoological Laboratory, Harvard University
Communicated by G. H. Parker, June 19, 1918
Although the ciliary responses of the labial palps of pelecypods have been
much studied, the muscular movements of these organs have been entirely
neglected. If one valve of an Anodonta is cautiously chipped off leaving the
subjacent mantle-lobe intact and the animal resting in the opposite valve,
the mantle-lobe thus freed may be folded back so as to expose the parts of
the animal lying within the mantle chamber. In this way the labial palps
in an almost undisturbed condition may be exposed and worked upon.
In such a preparation the external palp is to be seen resting on the internal
one and both are quite flat. If, now, the external palp is touched with a blunt
pointed instrument, particularly in its mid-dorsal region, the organ quickly
buckles in on its dorsal edge close to its attachment to the mantle and soon
after begins to curl from its free tip toward its attached base. On stimulating
the internal palp, it responds as the external one does. Both palps in respond-
ing curl away from their opposed faces. The vigor of their response is ap-
parently proportional to the stimulus. Grains of sand dropped on the outer
face of the external palp affect it as a slight mechanical stimulus, which calls
ZOOLOGY: P. H. COBB
235
forth some curling but almost no buckling. Currents of water when driven
against the palp have very little effect as stimuli unless they are strong enough
to indent the palp.
The palps are also open to chemical stimulation and the responses thus
called forth are commonly much more pronounced than those due to
mechanical stimulation. The chemical stimuli employed consisted in solu-
tions of a number of common salts, acids, and alkalis, of such non-electrolytes
as ethyl alcohol, sugar, urea, quinine and so forth, and of mixtures such as
beef extract and the like. These were used in varying concentrations and to
all, except sugar, a reaction much like that seen in vigorous mechanical stimu-
lation was observed. In reaction to chemical stimulation, however, the palp
showed a tendency to roll up tightly from the tip rather than simply to curl
upon itself.
Electricity is also a stimulus for the palp. A faradic current just strong
enough to be slightly stinging to the human tongue caused the palp to respond
as to a mechanical stimulus. In efficiency the electrical stimulus was appar-
ently midway between the mechanical and the chemical stimuli.
A jet of hot water that emerged from the container at 54°C. caused the palp
to curl vigorously when it was directed on that organ in water at 16.5°C.
A similar jet of water at the temperature of that in which the clam was, had no
stimulating effect on the palp.
A beam of sunlight, or of strong electric light, or a sudden burst of light from
flash-light powder had the remarkable property of causing the palp to curL
The response, which of course occurred well under water, though slower in.
its appearance than the responses to other forms of stimuli, followed so quickly
on the stimulus that there was no doubt that the light, and not some accom-
panying disturbance, was the effective agency.
The surprising feature in all these responses is that they take place as ef-
fectively on a palp that has been freshly cut from a clam as on the palp intact..
Careful comparative inspection of the reacting palps disclosed no obvious dif-
ference between the efficiency of these organs when normally attached to the
clam and after they had been severed from it. On cutting a palp from a clam
for experimental work, it is well to allow it to remain at least a quarter of an
hour in quiet water before subjecting it to stimulation. Such a palp is re-
sponsive for about an hour and a half after removal. This condition shows
that the palp contains within itself the neuromuscular organization necessary
for all the responses described in this paper, and that it, therefore, possesses an
autonomy even more complete than that of the vertebrate heart and compara-
ble with what is shown by the tentacle of an actinian.
It is intended to continue the line of investigations suggested by these
studies and to extend them to the histology of the parts concerned.
1 Contributions from the Zoological Laboratory of the Museum of Comparative Zoology-
at Harvard College. No. 311.
236
PHYSICS: F. C. BLAKE
THE DEPTH OF THE EFFECTIVE PLANE IN X-RAY CRYSTAL
PENETRATION
By F. C. Blake,
Department of Physics, Ohio State University
Communicated by E. H. Hall, May 25, 1918
In determining the value of (h' by means of X-rays Blake and Duane1 (p.
636) found out by experiment that the 'depth of the effective plane' was 0.203
mm. for the case of calcite, using X-rays of a wave-length 0.454 A. An
attempt is made in this note to explain this theoretically.
Call n the coefficient of true absorption and r the reflection coefficient.
Suppose a parallel beam of X-rays strikes the crystal face at glancing angle 6.
Then if A0 is the amplitude of the primary beam the total effect at the ioniza-
tion chamber is the sum of the various reflections from all those planes of
atoms that are able for any reason to play a part at the ionization chamber.
Call the last plane of atoms that is thus effective the rath plane. Figure 1 will
render the situation clear. Let AB-IJ represent the parallel beam of X-rays
as determined by the slit-width s. The reflected beam bdf, for instance, is the
sum of the various reflections at b, d, and f. Ray AB suffers partial reflection
at A and arrives at a with amplitude A0l ~Mc/ csc 6 where it again suffers reflection.
The reflected part has the amplitude rA0l csc(?at a and by the time it gets to
c its amplitude has been reduced to rAol~2tJdcscd. Thus the total amplitude
along any reflected ray bdf situated a distance x away from the first reflected
ray A I is
rA0(l + e-2fldcsc9+e-^icscd+ .... + £T2w^csc*), m which =
2d cos 9
This gives for the amplitude of the ray bf,
I — e~2 (*+« /xdcscfl \—e sin 0 cos 0
rA0 t— 5 — 2 — reducing to rA0 >
1_e-2t*dcsc8 > * 2 fid CSC d
very approximately.
(Call D\ the mean depth of the ray bdf. Then
1 p SUl $ COS Q on n
rA0— =nrA0e-2txDlC5Cd.
2(id csc 6
Solving for Dx we have
^ sin 0 , \x% ( v
PHYSICS: F. C. BLAKE
237
FIG. 1.
Now the 'effective plane' was defined by Blake and Duane1 (p. 632) as that
plane at which if reflection for all the rays occurred at that plane only the effect
at the ionization chamber would be the same as actually does occur due to
238
PHYSICS: F. C. BLAKE
the different reflections for all the planes of atoms playing any part. In ac-
cordance with this definition, if D is the depth of the 'effective plane' and if
for the moment we limit ourselves to that portion of the reflected beam o- width
s, viz., AI-BJ, it is clear, since for the separate rays we must add not ampli-
tudes but intensities, that we must get D by integrating Di throughout the
region s and taking mean values. Thus if we were concerned only with the
reflected beam of width s we could get D from (1) by replacing the parenthesis
But the reflected beam is not of width s only. Rather must we consider the
effect of rays that penetrate the crystal to depths much greater than the plane
through B. Consider for instance the ray AB penetrating to the plane through
K say, where it is reflected along the direction KQ and emerges from the crys-
tal at Q. At L, M, Nj 0 the ray KQ is reinforced by reflections in phase with
one another, but at P and Q there are no reinforcements since the initial beam
is determined by the slit width s. Accordingly the amplitude of the ray KQ
upon emergence is
where q is the number of the plane through 0. In other words the amplitude
of the ray KQ upon emergence is
where X\ is the distance (measured parallel to the slit s) between the incident
ray through Q and that through O, and x2 is the distance between the ray
through Q and that through K. Necessarily x2 — %i must equal s. Accord-
ingly to get our mean penetration D for all the rays that penetrate into the
crystal beyond the reflected ray BJ we must replace the parenthesis in (1) by
Having found the mean penetration for all the rays between 0 and s and that
for all the rays between s and °° it is a simple matter to get the mean of these
means, which should be, finally, the depth of the 'effective plane.'
Now in the above expressions the value of n is the amplitude coefficient of
absorption while what is experimentally measured is the intensity coefficient
of absorption. If we accordingly replace 2/jl in the above expression by p we
have as our expressions for the depth of the effective plane the following:
For the X-rays contained in the triangle ABJ,
by
g sin 0 cos 0 — g sin Q cos 0
PHYSICS: F. C. BLAKE
239
n, sin 0 . »s
D' = log,
M 2sin0cos0£-J^ (l-e 2sm7co*o) ^J. (2)
and for the X-rays contained in the parallelogram BK 00 00 OJB,
_ I ye 2sin0cos0_e 2 sin ^ cos ^ ^xj
sin 0 . ps (3)
log.
/ - ^ \ ri cm
2 Sill 0 COS 0 \1 — 6 2sin0cos0y _ | g sin 0 cos 0 . ^
Now Blake and Duane, in determining the maximum positions of the ioni-
zation chamber corresponding to a given value of 0 had in one case made 0
equal to 4°18', which corresponded to a wave-length X equal to 0.454 A, Us-
ing Duane's formula for the absorption, viz., m/pai= 14.9 X3 we get m/pai =
1.394. Applying Bragg's formula for the atomic absorption coefficient, a,
say, we have
a == [ioi/£ = kN4,
where k is a constant and cc the atomic weight. Thus we get
aM = 37.79 a~\ ACa = 211.7
Halsted, Hillebrand, Howard, Howell, Iddings, Kasner, Lillie, Meltzer, Men-
del, T. C. Mendenhall, Merriam, Michelson, Millikan, E. S. Morse, Moulton,.
E. L. Nichols, E. F. Nichols, A. A. Noyes, W. A. Noyes, H. F. Osborn, Pearl,
Pupin, Ransome, Reid, Rosa, Schlesinger, Erwin F. Smith, Stratton, Thom-
son, Ulrich, Van Hise, Van Vleck, Walcott, Webster, Welch, Wheeler, D<
White, Wilson, Woodward.
BUSINESS SESSIONS
The President announced that the Home Secretary, Mr. Arthur L. Day
would not be present, owing to absence from the city on matters relating to
war.
REPORTS from officers of the academy
The annual report of the President to Congress for 1916 was presented and
distributed.
The President presented the following communication from Mr. R. S.
Woodward, resigning the chairmanship of the Committee on the Barnard Medal :
April 9, 1918.
The Home Secretary,
Dear Sir:
Permit me to tender through your office to the Council of the National Academy of Sci-
ences my resignation as Chairman of the Committee on the Barnard Medal. Like our late
colleague, Profesor William James, I find that with advancing years it is desirable to relieve
oneself of what he fittingly called "life's baggage." Having assisted at the birth of many of
our American Societies and served them in one way or another for many years, and having
acted as the Chairman of the Committee on the Barnard Medal for a decade, I am disposed to
think it will be advantageous for me, for the Academy, and for contemporary society to
transfer the duties of the Chairmanship of the Committee in question to a younger man.
Faithfully yours,
Robert S. Woodward.
Moved: That the resignation of Mr. Robert S. Woodward as Chairman of the Com-
mittee on the Barnard Medal be accepted with regret, that Mr. T. H. Morgan be elected a
member of the Committee, and that Mr. A. A. Noyes be elected Chairman. (Adopted.)
The President announced the following changes in the personnel of the Sec-
tions and Committees:
Section of Geology and Paleontology: J. M. Clarke, Chairman.
Section of Botany: Erwin F. Smith, Chairman.
262
REPORT OF THE ANNUAL MEETING
Section of Anthropology and Psychology: J. Walter Fewkes, Acting
Chairman.
Local Committee: Whitman Cross, Chairman, David White, Frederick
L. Ransome, Raymond Pearl, Edward 0. Ulrich.
Other committee appointments with dates of expiration, were as follows:
Program: E. L. Thorndike to serve unexpired term of J. McKeen
Cattell 1920.
Henry Draper Fund: George E. Hale, to succeed himself, 1923.
J. Lawrence Smith Fund: E. S. Dana t© succeed himself, 1923.
Comstock Fund: E. L. Nichols to succeed himself as member and Chair-
man ,1923.
Marsh Fund: Charles Schuchert to succeed himself, 1921.
Murray Fund : William H. Dall to succeed himself as member and Chair-
man, 1921.
Marcellus Hartley Fund: Henry F. Osborn and Michael I. Pupin to suc-
ceed themselves, 1921.
Barnard Medal: A. A. Noyes, Chairman; T. H. Morgan to succeed R. S.
Woodward.
The report of the Treasurer was presented in printed form and approved.
The report of the Home Secretary was presented as follows:
April 22, 1918.
The President of the National A cademy of Sciences.
Sir: I have the honor to present the following report on the publications and member
ship of the National Academy of Sciences for the year ending April 24, 1918.
No Scientific Memoirs have been published during the year, but "The Complete Classi-
fication of the Triad Systems in Fifteen Elements," by H. S. White, F. N. Cole and Miss L.
D. Cummins, recommended to be published as one of the Memoirs of the National Academy
of Sciences, was approved by the Committee on Publication and is now in the hands of the
Public Printer. The actual publication may be delayed, owing to war conditions.
Of the Biographical Memoirs, that of John Shaw Billings, by S. Wier Mitchell, with
the Scientific Work of John Shaw Billings, by Fielding H. Garrison ; and William Stimpson, by
Alfred G. Mayer, have been published. The former has been distributed, while that of Stimp-
son has just come from the printer. The manuscript of the Biographical Memoir of James
Wright Dana, by L. V. Pirsson, Cleveland Abbe, by W. J. Humphreys, and William Bullock
Clark, by John M. Clarke, are in the hands of the Committee on Printing; that of Benjamin O.
Peirce, by Edwin H. Hall, is now in galley proof.
The Annual Report for 1917 has been published and is ready for distribution. The Pro-
ceedings of the Academy have been published regularly and have reached the third number of
the fourth volume.
Four members have died since the last meeting. William Bullock Clark, elected in 1908,
died July 27, 1917; James M. Crafts, elected in 1872, died June 21, 1917; Arnold Hague,
elected in 1885, died May 15, 1917; Franklin Paine Mall, elected in 1907, died November 17,
1917, and one foreign associate, Adolf von Baeyer, died in August, 1917.
Fifteen new members were elected in April, 1917, making 157 active members on the
present membership list; one honorary member and 36 foreign associates.
Arthur L. Day, Home Secretary.
REPORT OF THE ANNUAL MEETING
263
REPORTS FROM COMMITTEES ON TRUST FUNDS
A report was received from the Directors of the Bache Fund, signed by Ed-
win B. Frost (Chairman), stating that since the annual meeting of the Academy
in April, 1917, grants Nos. 205-209 (as announced in the Proceedings, p.
273, below) had been made; and that reports on these and previous grants had
been received as follows :
No. 193, C. A. Kofoid, University of California, for assistance in securing animals in the
Indian jungle and in their preparation for study in research on the intestinal protozoa. Mr.
Kofoid is serving as Major in the Sanitary Corps and the work is being continued by re-
search assistants on the material collected during Mr. Kofoid's travels.
No. 202, W. C. Allee, Lake Forest College, Illinois. Research concluded on 'The salt
content of natural waters in relation to rhectaxis in Asellus," Biol. Bull., Woods Hole, 32, 93-971.
Preliminary results on first phases of investigation concerning a possible correlation between
C02 production and phototaxis are completed and are in the hands of the editors of /. Exp.
Zool., Philadelphia. Research is in progress concerning the cause of formation of aggregations
of may-fly nymphs and other reactions, and to C02 production. Also effect of molting on both
above factors; also as to effect of the cyanides on respiration and reactions to various stimuli.
No. 203, J. P. Iddings, Brinklow, Maryland. The chemical analysis of igneous rocks
collected in Asia and Australasia is completed and the results published in the Proceedings of
this Academy. The work with the microscope and thin sections will continue for some
years to come.
No. 204, Irving W. Bailey, Bussey Institution, Harvard University, for field data for a
study of environment upon the anatomical structure of angiosperms. Cancelled and the
money returned to the Treasurer because it was found impracticable for Professor Bailey to go
to Guatemala under present war conditions.
No. 205, T. H. Goodspeed, University of California. Between 20,000 and 25,000
measurements in the flower-size investigations on Nicotiana were made duringt he summer
and fall of 1917. These experiments are to be concluded during the summer and results pub-
lished thereafter.
No. 206, Reginald A. Daly, Harvard University. The deep sea thermograph has been
completed and a description has been published by its designer, Mr. Harry A. Clark,
in Bull. Mus. Comp. Zool., Harvard College, 61, No. 15.
No. 209, Cecil K. Drinker, Harvard Medical School. Research still in progress. A
paper, entitled "The factors concerned in the appearance of nucleated red blood corpuscles
in the peripheral blood. II. Influence of procedures designed to increase the rate of blood
flow through the blood-forming organs — hemorrhage and infusion," by Cecil K. Drinker
Katharine R. Drinker and Henry A. Kreutzmann, was published in /. Exp. Med., 27, 383-
397, 1918.
The Directors have voted to transfer to capital account the sum of $2,575,
which has been carried for a number of years as 'invested income, 'together with
$425 of current income, so that the principal of the fund now stands at $59,000.
An effort is being made to pay the American collaborators of the 'Nomen-
clator Animalium Generum et Subgenerum' the amounts due them for their
work. A grant of $1,000 was made in 1913 to Professor F. E. Schulze, of Ber-
lin, specifically for assistance by American men of science in this undertaking
It now seems probable that these men can soon receive their compensation.
After providing for this liability of $1,000, the cash on hand available for grants,
on April 15, 1918, is $10.81.
264
REPORT OF THE ANNUAL MEETING
A report was received from the Trustees of the Watson Fund, signed by
A. 0. Leuschner (Chairman), W. L. Elkins, and G. C. Comstock, stating that
grants Nos. 16-17 (as announced below, p. 273) were recommended. Re-
ports on previous grants were as follows:
No. 14, John A. Miller, Sproul Observatory, Swarthmore College, is expending his ap-
propriation for the services of an assistant in parallax determinations. A list of 50 paral-
laxes, together with a list of observations and reductions, has been published. A second list
of 50 should be ready before the beginning of January, 1919.
No. 15, Herbert C. Wilson, Goodsell Observatory, Northfield, Minn., is expending the
appropriation for the services of an assistant in measuring and reducing photographic plates
of asteroids for position and magnitude. The measurement and reduction of 97 plates has
been completed. For 71, the results are published in Pub. Goodsell Obs., Northfield, Minn.,
No. 5. Of the 26 unpublished measures, 15 are of plates of seven Watson Asteroids. A
highly satisfactory color screen suitable for the 16-inch telescope has been made by R.
J. Wallace, Research Laboratories of the Cramer Dry Plate Company.
A report was received from the Committee on the Henry Draper Fund,
signed by W. W. Campbell (Chairman), as follows:
No awards have been made in the past year: the reduced size of many observatory and lab-
oratory staffs, because of war activities, has not permitted normal development of new meth-
ods in astrophysics, and there have been no urgent calls for special instruments.
A grant of $500 made to W. W. Campbell two years ago, to provide the mounting of an
ultra-violet spectrograph for use with the Crossley reflecting telescope, was expended, and the
finished instrument was described in Lick. Obs. Bull., Berkeley, No. 291, in May, 1917. This
instrument has been used by Mr. Wright in photographing the spectra of all the brighter
planetary nebulae in the northern two-thirds of the sky.
A grant of $300 made in April, 1917, to Professor Joel Stebbins, of the University of
Illinois, and a similar grant in like amount made earlier, are being applied, in accordance
with agreement, in payment of part-time salary of an assistant to Dr. Stebbins in order to
further the latter's development of the photo-electric cell photometer and the application
to the study of variable stars. Quoting from Professor Stebbins' report dated April, 1918:
"The photo-electric photometer has been improved until it is now from ten to twenty times
as sensitive as the selenium photometer. We can measure the brightness of stars three
magnitudes fainter than those which it was possible to observe with the selenium instru-
ment. About a dozen new bright variable stars have been discovered, of which eight have
been announced at meetings of the American Astronomical Society. We are also carrying
on studies of several known variables." In further agreement with the terms of the grant,
the University of Illinois has arranged to continue the assistant on full time in Professor
Stebbins's department after the close of the present academic year.
A report was received from the Committee on the J. Lawrence Smith Fund,
signed by E. W. Morley (Chairman), stating that the Fund now has a cash
balance of income of $1188.85 and a balance of invested income amounting to
$1532.50, recommending grants No. 9 (as announced below, p. 274), and
containing the following reports on previous grants :
No. 3, Edmund O. Hovey, American Museum of Natural History, New York, received in
1909 a grant of $400 to aid in the study of certain meteorites. The pressure of adminstra-
REPORT OF THE ANNUAL MEETING
265
tive duties has been so severe that the investigation is suspended, at least for a time, and Dr.
Hovey proposed to return the grant. The Committee hesitated, but at last accepted the pro-
posal, and the amount of the grant, together with interest, has been repaid, to the Treasurer
of the Academy.
No. 4, C. C. Trowbridge, Columbia University, New York, has received from 1909 to
1917, grants amounting to $1400 to aid in the study of meteor trains. The work of the last
year has consisted of the further collection of illustrations of meteor trains and the study of
spectrum observations. No further grant is sought. A letter from the recipient follows.
Dear Professor Morley:
I beg to submit herewith a brief report relative to the grant made to me from the J. Law-
rence Smith Fund for aid in work on the atmosphere of the earth and on the trains of meteors.
The progress for the year 1917 has been as follows: Work has been continued on the collec-
tion of illustrations of meteor trains; on the study of meteor train theories, and study of
the spectrum observations.
It has been shown that there is good reason to believe that the spectra of trains observed in-
dicate a gas phosphorescence similar to that of 'active' nitrogen (nitrogen in the phosphores-
cent state) rather than the light from hot metals as believed by the various observers. Fur-
ther observations of importance have been made on the auroral features of the meteor train
zone. This phase of the investigation is bound up with meteor train study for the following
reasons :
The meteor train zone and the main aurora are the same; the potential gradient across
this zone is probably the cause of the visual effects in both cases. The drift of the atmos-
phere as shown by drifting trains in the meteor train zone unquestionably has an important
bearing on the electric discharges which cause the auroral glow.
Financial Statement
Total funds received to December 31, 1916 $1,153.50
Total expenditures to December 31, 1916 1,020.67
Balance, December 31, 1916 $132.83
(as per financial statement submitted March 26, 1917)
Received from Treas., Nat. Acad. Sciences, March 22, 1917 250.00
Total $382.83
Expenditures in 1917
January M. M. King, typewriting $2.40
February Science reprints 8.00
March Exchange on Washington check 10
March 12 Geo. Merritt, Jr., asst. 23 hours 13.80
April 2 J. Boldtman, photographer 1.50
April 2 Bureau of Supplies, Columbia Univ 1.20
April 30 J. Boldtman, photographer 3.40
May 1 Geo. Merritt, Jr., assistant 19.60
May 10 Bur. of Supplies, Columbia Univ 1.60
June 1 Amy E. Davis, assistant 36.00
June 15 Mabel Weil, assistant 62.70
June 18 Printing, New Era Printing Co 5.89
$156.19
266
REPORT OF THE ANNUAL MEETING
Cash on hand, December 31, 1917
Balance in Corn Exchange Bank $149.90
Cash 1.45
Balance in Washington Savings Bank 75.29
. $226.64
Condensed Statement
Total funds received. $1,403 . 50
Total expenditures to December 31, 1917 $1,176.86
Balance 226.64 1,403.50
Respectfully yours,
C. C. Trowbridge.
No. 6, S. A. Mitchell, University of Virginia, University, Virginia, received in 1915 a
grant of $500 to aid in securing observations of paths and radiants of meteors, and in com-
puting orbits when the observations are sufficient; further grants of $300 were made in
1916 and 1917. The war lessened the number of observations secured, during 1917, but
this lessened number amounted to 4,231, making the whole number of observations about
19,000. An abstract of results for 1917 has been published by Dr. Olivier in a recent number
of Popular Astronomy.
No. 7, George P. Merrill, United States National Museum, received last November a
grant of $400 to aid in further study of certain elements in meteorites. Of this grant he has
spent $185, and there remains to his credit $215.
A report was received from the Directors of the Wolcott Gibbs Fund, signed
by C. L. Jackson (Chairman), stating that during the past year no application
was received for a grant from the Fund, and owing to the disorganization of
chemical research by the war, it was not thought worth while to try to get
applications; that the unexpended income of the Fund amounts to $360.87;
and that holders of grants have reported as follows:
Nos. 2 and 5, M. E. Holmes, of Connecticut College, finds that the exacting duties of her
new position will prevent her from continuing her research, and has returned the unex-
pended balance of the two grants amounting to $86.32.
No. 6, G. P. Baxter, Harvard University, has spent $194.31 for material and apparatus
since the last report. No platinum was bought, as the war had rendered it too expensive. The
three researches described in the last report have been finished, and accounts of the results
will be published soon. These were (a) Electrolytic Deposition in a Mercury Cathode, and
the Atomic Weight of Cadmium, with C. H. Wilson. A slight loss was discovered, and cor-
rected experimentally, after which eight determinations gave the atomic weight of cadmium
as 112.40. (b) Impurities in Silver and Iodine, with L. W. Parsons. In 1 gram of the sil-
ver used for atomic weight determinations 0.004 mgm. of gas were found; in the iodine, 0.002
mgm. of gas. Most exacting spectroscopic tests showed no impurities in the silver. These
results dispose of the criticisms of P. A. Guye on the Harvard atomic weight determinations,
(c) The ratio of Arsenic Trioxide to Iodine, with L. A. Youtz. The atomic weight, 74.96,
was found for arsenic. In addition a fourth research has been started. (d) The Atomic
Weight of Mercury, with Matsusuke Kobayashi. All these res8arches but the last have been
stopped by the enlistment of the graduate students in war service.
Nos. 4 and 7, W. D. Harkins, University of Chicago, has bought a vacuum pump for
$55.00, and is about to buy one still more efficient. He has studied the "Secondary Valence
REPORT OF THE ANNUAL MEETING
267
and Werner's Co-ordination Number from the Standpoint of the Ammines of Cobalt" with
G. L. Clark. The existence of the salt CoCl2IONH3 has been established; and the phe-
nomena observed in the formation of this compound have been studied, and some of
its physical constants. The work was broken off by the enlistment of Mr. Clark in the serv-
ice of the Government before it could be brought to an end. It will be continued as soon
as possible, as it promises to show either that Werner's constitution of the cobaltammines is
incorrect, or that his co-ordination number must be changed from 6 to 10. Other results of
great interest are also indicated.
No. 8, R. L. Datta, Presidency College, Calcutta, has sent orders for organic chemicals
amounting to £20, but has received none because of the war.
A report was received from the Committee on the Marsh Fund, signed by
E. H. Moore, Chairman, recommending grant No. 2 (as announced below, p.
274) and containing the following statement:
No. 1, J. M. Clarke, State Museum, Albany, reports progress in the assembling of mate-
rial for his study of mutualism, symbiosis, and dependent life among animals.
A report was received from the Committee on the Murray Fund, signed by
Wm. H. Dall, Chairman, as follows:
On November 1, the sum to the credit of the Murray Fund was $569.61. The Treasurer
suggested and as Chairman I approved of the investment of the major part of this sum in
Liberty bonds, which (should the Council decide to offer the medal this year) could readily
be turned into cfsh
A report was received from the Committee on the Comstock Fund, signed
by Edw. L. Nichols,. Chairman, as follows:
Five years having nearly elapsed since the first award of the Comstock prize to Professor
(now Lieutenant Colonel) R. A. Millikan, the committee met in Philadelphia at the time of
the November (1917) sessions of the Academy, four members being present. After careful
consideration of various suggestions previously made in writing at the request of the chair-
man, the committee unanimously recommended that the second award of the Comstock
Prize be made by the Academy to Samuel Jackson Barnett, Professor of Physics at Ohio
State University, for his investigations on Magnetization by Rotation.
In this research the following fundamental and very important facts were established:
(1) that there are within the iron currents of negative electricity in orbital revolution,
(2) that these gyrostatic systems have inertia and are capable of definite orientation or
arrangement by the rotation of the body without the action of any external magnetic field,
(3) that such orientation manifests itself as a magnetization of the body as a whole.
The committee further recommended that as in the case of the first award, the value of
the prize be $1,500.00.
The President presented recommendations from the Committees on the
Henry Draper Medal and the Daniel Giraud Elliot Medal and Honorarium
for the following awards which were approved by the Academy:
American Museum of Natural History,
New York, February 7, 1918.
My dear Mr. Day:
Thanking you for your letter of February sixth and the return of my letter of January
ninth, as Chairman of the Committee on the award of the Daniel Giraud Elliot Gold Medal, I
268
REPORT OF THE ANNUAL MEETING
believe that the committee will agree that Dr. Frank M. Chapman, of the American Museum
•of Natural History, in view of his memoir, "The Distribution of Bird-life in Colombia, a con-
tribution to a biological survey of South America," Bulletin of the American Museum of Nat-
ural History, Volume XXXVI, 1917, pages 7-10 (Roman), 1-729 (Arabic), is entitled to first
consideration and premiership for the year 1917, as having produced the most earnest single
work in zoology, the result of six years serious exploration and research, namely, from Decem-
ber, 1910, until the publication of the volume in December, 1917.
As chairman of the committee, I respectfully submit this as a substitute report, with the
approval of my colleagues.
Fortunately, Doctor Chapman is one of the most distinguished of the many followers of
Dr. Joel Asaph Allen, and he was also closely associated with Dr. Daniel Giraud Elliot;
consequently I trust the Committee will regard the award of the medal as eminently
appropriate.
Respectfully submitted,
Henry Fairfield Osborn, Chairman.
Mount Hamilton, January 19, 1918.
-Dear Dr. Day:
I have just sent you'the following night letter:
"I herewith certify nomination of Walter S. Adams, Mount Wilson Observatory,
for his investigations in astrophysics, by Draper Committee for award of Draper
Gold Medal. I hope Council can make award practicable at this year's meeting."
Dr. Walter Sidney Adams has discovered and developed a method of determining the
distances of the stars, by means of the spectrograph, which the Henry Draper Committee
believes is one of the great advances in modern Astronomy. Like most methods of high
value, its fundamentals are exceedingly simple. The basic fact is that certain lines are en-
hanced in the spectra of stars of high absolute luminosity, and certain other lines are en-
hanced in the spectra of stars of low absolute luminosity; in other words, the intensities of
certain lines increase continuously with increasing absolute luminosities, and the intensities
of certain other linds increase continuously with decreasing absolute luminosities. The ap-
proximate distances of a few hundred of the nearer stars, measured by the older methods,
are known. These distances enable us to compute the absolute magnitudes or luminosities
of those stars. The correlation of these absolute magnitudes and the estimated relative in-
tensities of the critical lines in their spectra have given Mr. Adams the power to determine
the functional relations connecting these elements, and thus to determine the absolute mag-
nitudes of stars not yet observed for distance. Knowing the magnitude of a star as ob-
served from the earth, and the absolute magnitude of the same star as determined by the
spectrograph, the solution of a simple equation yields at once the value of the star's distance.
Here is a powerful means of extending the list of stars whose distances are known, and the
Committee confidently expects that the method will be applied successfully to thousands of
stars which are too distant for successful attack by the earlier methods. The method should
in due time tell us much concerning the linear scale of the nearer parts of our stellar system.
The secondary applications of the method to astronomical problems are likewise of great
promise.
Mr. Adams has applied the spectrographic method to the determination of the distances
of more than five hundred stars, of the Harvard spectral classes F to Mb inclusive, and a com-
parison of his results with those obtained by the older methods, as to rapidity and accuracy,
is a subject for congratulation.
The method has not yet been applied satisfactorily to stars of certain spectral classes, but
it is hoped that the dependence of such spectra upon absolute luminosities or other elements
may be found in the near future.
Dr. Adams's contributions to other lines of astronomical research have been many,, exten-
sive and fruitful. We mention three:
REPORT OF THE ANNUAL MEETING
269
The spectrographic determination of the sun's rotational speeds by comparing the mo"
tions of approach of the eastern limb and the motions of recession of the western limb with
the apparent motions of approach or recession of points on the solar meridian passing
through the earth. The results form a monumental contribution to the complicated and
still unsolved problem of the solar rotation.
His long exposures on the spectra of the present-day faint remnants of new stars formerly
brilliant have shown that these stars are now of the Wolf-Rayet type.
The more thorough application of high dispersion spectroscopy to the study of the sun's
chromosphere. Prior to the establishment of the Mount Wilson Solar Observatory, this
was essentially a total solar eclipse problem. Stratification of the chromosphere has been
studied by Adams without an eclipse at least as successfully as it had formerly been studied
at times of total solar eclipse.
Respectfully submitted,
W. W. Campbell, Chairman.
GENERAL BUSINESS
The following report from the Editorial Board of the Proceedings of the
National Academy of Sciences was presented by the Chairman, Raymond
Pearl:
1. Three volumes of the Proceedings have been completed, and four numbers of the
fourth volume have been issued.
The statistics as to the make-up of the third volume, both in respect of subject matter
and of source of the contributions, have been printed in the Annual Report of the Academy
for 1917, and need not now be repeated except so far as covers one point.
The statistics of articles by members of the Academy as compared with articles by non-
members are interesting mainly in showing a progressive diminution in the percentage of
articles by members, despite the increase in membership of the Academy. If there are ob-
stacles which can be removed and which hinder members of the Academy from printing in
the Proceedings, would it not be well to make efforts to remove them? The Academy repre-
sents the highest point in American research, and if the Proceedings should actually con-
tain articles representing the totality of the investigations of members of the Academy it
would become thereby largely representative of all American research and of very high grade,
and furthermore it would be more truly the Proceedings of the Academy in the sense that cor-
responding publications of foreign academies are representative of their research.
2. At the Autumn meeting the terms of office of five members of the Editorial Board ex-
pired, and new appointments were made by the Council as follows: Jacques Loeb, W. M.
Wheeler, E. B. Frost, E. L. Thorndike, and E. H. Moore.
3. At the Autumn meeting the Board decided to put into operation certain changes in the
typographical make-up of the Proceedings in the interest of economy. These changes have
been made with satisfactory results.
4. The Editorial Board is of the opinion that in view of the now established and recognized
position of the Proceedings as a medium of scientific publication, the members of the
Academy might well contribute more of their own papers to its pages than they now do,
both from the standpoint of self-interest as well as from a sense of duty to the Academy and
what it stands for. In this connection the Board would recommend that the Academy adopt
as a general principle the policy of requiring each recipient of a grant for research from any
of its special funds to publish some account of the results of the researches under the grant
in the Proceedings.
5. If the above recommendation is adopted, the Board would further recommend that the
Acadeny suggest to the several committees having in charge trust funds from which grants
are made that whenever accounts of researches under grants are published in the Proceed-
270
REPORT OF THE ANNUAL MEETING
ings there shall be paid over from the Trust Funds out of which the grants are made, to the
Proceedings account, if such action be permissible under the terms of the bequest, a sum
of money to cover the expense of the publication at a rate of $6.00 per printed page.
Anent the above report the following recommendations were submitted
from the Council and adopted-
That the following recommendations from the Editorial Board of the Proceedings be
approved by the Academy and that the Home Secretary be instructed to bring these recom-
dations to the attention of the members of the Academy and the chairmen of the trust funds.
That members of the Academy be requested to contribute their own papers to the
Proceedings.
That the policy of requiring each recipient of a grant for any research from any of the
special funds to publish an account of the results of the researches under the grant in the
Proceedings be approved,
That the Academy request the committees and trustees of the several trust funds of the
Academy from which grants are made that whenever accounts of researches under grants are
published in the Proceedings there shall be paid over from the Trust Fund out of which the
grants are made, to the Proceedings account, if such action is permissible under the terms of
the bequest, a sum of money to cover the expense of the publication.
A report was received from the Finance Committee of the Proceedings,
signed by C. B. Davenport, Chairman, F. R. Lillie, and Raymond Pearl, as
follows :
The estimated net cost of the Proceedings for 1918 is $5,600.00.
The estimated income is as follows:
From subscriptions (provided each member of the Academy becomes
responsible for one subscription) $1,800.00
One-third guarantee fund of $2,500 833 . 00
Estimated income of Billings Fund 187.00
Sundry other income (members dues, $850, N.R.C., $400, Dr. Walcott,
special, $100) ! 1,350.00
Total estimated income $4,170.00
Total estimated deficit $1,430.00
If recommendation of the Editorial Board that space for reports of special grants in Pro-
ceedings be specially paid for be adopted, this deficit will be reduced to $1,200.00.
The Committee plans to raise funds to meet this deficit.
A report was received from the Auditing Committee, signed by C. G. Ab-
bot, Chairman, W. F. Durand, and A. L. Day, certifying the accuracy of the
Treasurer's books.
The Chairman of the Research Council, Mr. Hale, presented a verbal report
in which he called attention to the printed report of the Research Council which
had appeared in the Annual Report of the National Academy of Sciences.
The following amendment to the Constitution was presented from the Com-
mittee of the Whole and adopted:
That the constitution be amended by substituting in Article II, Section 1, line 3 (Report,
1916) the word four for the word six so that it will read for a term of four years ....
REPORT OF THE ANNUAL MEETING
271
to take effect on the expiration of the term of office of the present incumbents or in case
of a vacancy.
Article II, Section 1, when amended to read:
Section 1. The officers of the academy shall be a president, a vice president, a foreign
secretary, a home secretary, and a treasurer, all of whom shall be elected for a term of four
years, by a majority of votes present, at the first stated meeting after the expiration of the
current terms, provided that existing officers retain their places until their successors are
elected. In case of a vacancy, the election for four years shall be held in the same manner
at the meeting when such vacancy occurs, or at the next stated meeting thereafter, as the
academy may' direct. A vacancy in the office of treasurer or home secretary may, however,
be filled by appointment of the president of the academy until the next stated meeting of the
academy.
The President, in closing, gave the present status of the aeronautical work
that is being carried on bv the Academy for the country.
ELECTION OF OFFICERS AND MEMBERS
Two Members of the Council. — W. H. Howell to succeed himself, term
expiring in 1921; C. G. Abbot to succeed John M. Coulter, term expiring in
1921.
The following persons were elected as new members of the Academy.
Robert Grant Aitken, Astronomer, Lick Observatory, California.
George Francis Atkinson, Botanist, Cornell University, Ithaca, New York.
George Daved Birkhoff, Mathematician, Harvard University, Cambridge, Mass.
Percy Williams Bridgman, Physicist, Harvard University, Cambridge, Mass.
Stephen Alfred Forbes, Zoologist, Urbana, Illinois.
John Ripley Freeman, Engineer, Providence, Rhode Island.
Charles Judson Herrick, Neurologist, University of Chicago, Chicago, Illinois.
Ludvig Hektoen, Pathologist, University of Chicago, Chicago, Illinois.
Frank Baldwin Jewett, Engineer, Western Electric Company, New York, New York.
Walter Jones, Physiologist, Johns Hopkins University, Baltimore, Maryland.
Irving Langmuir, Chemist, General Electric Company, Schenectady, New York.
Charles Elwood Mendenhall, Physicist, University of Wisconsin, Madison, Wisconsin.
John Campbell Merriam, Paleontologist, University of California, Berkeley, California.
Henry Norris Russell, Astronomer, Princeton University. Princeton, New Jersey.
David Watson Taylor, Engineer, Admiral and Chief of the Bureau of Construction
and Repair, United States Navy.
SCIENTIFIC SESSIONS
Two public lectures on the William Ellery Hale Foundation were given
on April 22 and 23 by John C. Merriam, of the University of California, on
the Beginnings of Human History from the Geologic Record.
Four public scientific sessions were held on April 22 and 23 at which the
following papers were presented:
Francis G. Benedict: The effects of a prolonged reduced diet on twenty-five college
men: I. On basal metabolism and nitrogen excretion.
Walter R. Miles (introduced by F. G. Benedict) : The effects of a prolonged reduced
diet on twenty-five college men: II. On neuromuscular processes and mental condition
(illustrated).
272
REPORT OF THE ANNUAL MEETING
H.Monmouth Smith (introduced by F. G. Benedict) : The effects of a prolonged reduced
diet on twenty-five college men : III. On efficiency during muscular work and general mus-
cular condition (motion pictures) .
W. S. Halsted: The partial occlusion of great arteries in man and animals (illustrated).
S. J. Meltzer: Three papers (illustrated), (a) The favorable effect of subcutaneous in-
jection of magnesium sulphate in tetanus, (b) The possible danger of intravenous injec-
tion of magnesium sulphate, (c) The antagonistic and curative action of calcium salts in
these cases.
Henry Fairfield OsBorn: The Liberty field hospital ward. Designed on the unit con-
struction plan. Portable. Adapted to American overseas summer and winter service
(motion pictures).
Simon Flexner: The war and medical research (illustrated).
Edward Kasner: Conformal geometry.
S. J. Barnett (by invitation. Comstock prize recipient): Magnetism by rotation.
A. A. Michelson: On the correction of optical surfaces.
W. W. Campbell: Some recent observations of the brighter nebulae (illustrated).
R. A. Millikan: Physical researches for the war.
F. W. Clarke: Notes on isotopic lead.
Lawrence J. Henderson (introduced by Raymond Pearl) : The physico-chemical prop-
erties of gluten.
Thomas Wayland Vaughan (introduced by David White): Correlation of the tertiary
formations of the southeastern United States, Central America and the West Indies.
W. M. Davis: Coast survey charts and fringing reefs of the Philippine Islands
(illustrated).
Henry Fairfield Osborn and William K. Gregory: Recent researches on the skeletal
adaptations and modes of locomotion of the Sauropod Dinosaurs (illustrated).
Charles D. Walcott: Some additional data on the Cambrian Trilobites (illustrated).
C. R. Van Hise: The development of Governmental regulations during the world war.
C. Hart Merriam: The big bears of North America.
G. H. Parker: The growth of the Pribilof fur-seal herd betv^en 1912 and 1917
(illustrated).
Henry H. Donaldson: A comparison of the growth changes in the nervous system of the
rat with the corresponding changes in man (illustrated) .
Robert M. Yerkes (by invitation): Measuring the mental strength of an army
(illustrated).
Arthur Gordon Wf)bster: Some considerations on the exterior ballistics of a gun of 75
miles range.
J. P. Iddings: Biographical memoir of the late Arnold Hague.
C. G. Abbot: Perodicity in the variation of the sun.
John M. Clarke: Biographical memoir of the late William Bullock Clan.
Edwin H. Hall: Ionization in solid metals.
E. L. Nichols and H. L. Howes: On the types of decay of phosphorescence.
REPORT OF THE ANNUAL MEETING
in
AWARD OF MEDALS
The following medals were awarded at the annual dinner on the evening of
April 23, 1918, at the -Cosmos Club:
The Comstock Prize of $1500.00, to Samuel Jackson Barnett, of Ohfo State
University, for his investigations in magnetization by rotation.
The Henry Draper Medal, to Walter S. Adams, of the Mt. Wilson Solar
Observatory, California, for his investigations in astrophysics.
The Daniel Giraud Elliot Gold Medal and Honorarium, to Frank M. Chapman,
of the American Museum of Natural History, for his memoir, " The Distribu-
tion of Bird Life in Colombia, A Contribution to a Biological Survey of South
America," Bulletin of the American Museum of Natural History, 36, 1917,
-(vii-x, 1-729).
RESEARCH GRANTS FROM TRUST FUNDS OF THE ACADEMY
During the twelve months preceding the Annual Meeting of the Academy
the following grants for the promotion of research were made from the Trust
Funds of the Academy.
GRANTS FROM THE BACHE FUND
No. 205, T. H. Goodspeed, University of California, $100. For studies of inheritance in
Nicotiana hybrids.
No. 206, Reginald A. Daly, Harvard University, $700. For the completion of the deep
sea thermograph designed and partly constructed under Grant No. 194. In continuation of
No. 194.
No. 207, T. H. Gronwall, New York City, $300. To complete and extend mathemati-
cal researches on conformal representation.
No. 208, A. Franklin Shull, University of Michigan, $400. To investigate the cause of
sex production and the life cycle of rotifers, together with artificial modification of life cycle;
differential factors in fertilization of male-producing and female-producing rotifers; sex de-
termination and the life cycle of the thrips; cause of sex production, wing production, and
other cyclical phenomena in aphids.
No. 209, Cecil K. Drinker, Harvard Medical School, $350. For the closer study of the
factors involved in extension of unchecked red cells and leucocytes in the dog.
GRANTS FROM THE WATSON FUND
No. 16y Herbert C. Wilson, Goodsell Observatory, $300. For a continuance of the work
of the determination of the position and brightness of asteroids (chiefly those discovered by
Watson) by the photographic method, together with a study of the brightness of some variable
stars. (Supplementary to Grant No. 15).
No. 17, John A. Miller, Sproul Observatory, $500. To measure plates for determin-
ing stellar parallaxes (Supplementary to Grant No. 14).
274
REPORT OF THE ANNUAL MEETING
GRANTS FROM THE J. LAWRENCE SMITH FUND
No. 9. S. A. Mitchell, University of Virginia, $300. To continue his researches on the
paths, radiants, and orbits of meteors. (Supplementary to Grant No. 8.)
GRANT FROM THE MARSH FUND
No. 2, M. Ferdinand Canu, Versailles, France, $250. For investigations in cooperation
with Dr. R. S. Bassler, of the United States National Museum, of the early tertiary bryozoa
of North America.
INFORMATION TO SUBSCRIBERS
Subscriptions at the rate of $5.00 per annum should be made payable
to the National Academy of Sciences, and sent to Williams & Wilkins Com-
pany, Baltimore, or Arthur L. Day, Home Secretary, National Academy of
Sciences, Smithsonian Institution? Washington, D.C. Single numbers, $0.50.
CONTENTS
Page
Genetics. — Hereditary Tendency to Form Nerve Tumors
By C. V. Davenport 213
Mathematics. — Arithmetical Theory of Certain Hurwttzian Continued Frac-
tions % .... By D.N. Lehmer 214
Mathematics. — On Closed Curves Described by a Spherical Pendulum . .
By Arnold Emch 218
Botany. — The Taxonomic Position of the Genus Actinomyces
By Charles Drechsler 221
Astronomy. — Studies of Magnitudes in Star Clusters, VIII. A Summary of
Results Bearing on the Structure of the Sidereal Universe ....
By Harlow Shapley 224
Geology. — Glacial Depression and Post-Glacial Uplift of Northeastern
America . By H. L. Fair child 229
Botany. — A Bacteriological Study of the Soil of Loggerhead Key, Tortugas,
Florida By C. B. Lipman and D. D. Waynick 232
Zoology. — Autonomous Responses of the Labial Palps of Anodonta ....
By P. H. Cobb 234
Physics. — The Depth of the Effective Plane in X-Ray Crystal Penetration
By F. C. Blake 236
Zoology. — The Myodome and Trigemino-Facialis Chamber of Fishes and the
Corresponding Cavities in Higher Vertebrates By Edward Phelps Allis, Jr. 241
Genetics. — The Effect of Inbreeding and Crossbreeding Upon Development
By D. F. Jones 246
National Research Council, Executive Order Issued by the President of
the United States, May 11, 1918 251
— — , Minutes of the Second Meeting of the Executive Board of the
War Organization in Joint Session with the Council of the National
Academy of Sciences 3 252
, Minutes of Third Meeting of Executive Board of War Organization 256
, Report of the Annual Meeting 261
VOLUME 4
SEPTEMBER, 1918
NUMBER 9
PROCEEDINGS
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PROCEEDINGS
OF THE
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Volume 4 SEPTEMBER 15, 1918 Number 9
METALLIFEROUS LATERITE IN NEW CALEDONIA
By W. M. Davis V h,
Department of Geology and Geography, Harvard University
Communicated June 24, 1918
A recent paper on lateritic ore deposits by W. G. Miller1 gives among other
matters an account of the composition of the nickel- and cobalt-bearing lat-
erite of New Caledonia, but does not call attention to the physiographic rela-
tions of the laterite, probably because the physiography of the island has been
little discussed in published articles. Even the manifest evidence of sub-
mergence given by its embayed shore line has hardly been mentioned by the
students of its geology. The mature sea cliffs, which usually cut off the hard-
rock highlands along the northeastern coast and which frequently descend,
except for narrow fringing reefs, into ten or twenty fathoms of water, contrast
strongly with the rounded hills and sloping lowlands of weaker rocks that
dip gradually under sea level along the southwestern coast; but the contrast
has only been treated empirically if at all in accounts of the island. Further-
more, the form of the northeastern cliffs, the depth of the reef-enclosed lagoon
in front of them, and still more the form of the embayed valleys that interrupt
the cliffs, all taken together, indicate that the cliffs were cut by waves while
the island stood several hundred feet higher than now, and that this higher
stand occurred during a subrecent period of the physiographic development
of the island when the northeastern coast must have been unprotected by coral
reefs for a time long enough for the cliffs to be worn back several miles; but
these physiographic contributions to the historical geology of the island, not
being attested by fossiliferous stratified deposits, appear to have been over-
looked. As long as elements so important as these in the historic geology of
New Caledonia land forms remain unstated, the origin of its superficial ore
deposits will necessarily be unsolved.
The most significant features in connection with the ore deposits are the
highlands on which they lie. Although the greater part of the mountainous
island is of irregular form and varying altitude, there are certain districts,
275
276
GEOLOGY: W. M. DAVIS
particularly those occupied by serpentine rocks, which are characterized by
rolling highlands of moderate relief at altitudes of 600, 800 or 1000 feet. These
seem to be elevated peneplain areas; they are trenched by relatively steep-
sided valleys, and are adjoined either by surmounting residual mountains,
presumably formed of more resistant rocks, or by the lower hills and lowlands
of the southwestern coast where weaker rocks prevail. The erosion of the
subdued southwestern lowlands and of the narrow valleys in the highland areas
has evidently been accomplished after the partial peneplanation of the island
and its subsequent elevation, and during the same period of higher stand that
witnessed the cutting of the sea cliffs along the northeastern coast, previous
to the recent submergence by which the shoreline was embayed. The amount
of the recent submergence may well have been from 600 feet or more; the pre-
vious upheaval of the northeastern side of the island, before its cliffs were cut,
was probably at least twice as great, for the sea-cliffs today, in spite of being
partly submerged, not infrequently still show 600 or 1000 feet of their height
above water. The absence of all consideration of these inferences in the
geological accounts of New Caledonia affords a striking illustration of the con-
trast between the older geological philosophy that based its theories only on
the structure of rocks and their mineral and fossil contents, and the newer
philosophy of geology which broadens the older one by adding thereto a reason-
able consideration of surface forms and their evolution.
During my relayed trip around the island on three trading steamers, sup-
plemented by local sail-boat excursions, in June and July, 1914, the rolling
highlands were recognized as elevated peneplains at many points on both coasts.
Where their vegetation is scanty, as is often the case, the soils of the highland
slopes are laid bare in rain-washed gulleys which disclose their varied colors,
dark or black at the surface and usually a strange mixture of vivid reds and
ochres beneath. At certain points the open workings of the highland laterite
mines were seen, and at one harbor where a steamer touched for an afternoon
I had time to climb the slopes and inspect the excavations. The residual
nature of the deposits was manifest enough. The boulders, referred to in
Miller's paper as lying at the bottom of the loose deposits and as affording a
rim or coating that is scraped off and added to the ore pile, are perhaps partly
concretionary in origin, but some of them appeared to be incompletely decom-
posed rock kernels lying almost in place within a matrix of more disintegrated
material. It is significant that the abundant hill-side detritus is not worked;
ore of paying richness and quantity seems to be limited to the highland areas.
It is further significant that, as is usual in such residual deposits, analyses of
the highland ore deposits show a much higher percentage of nickel and cobalt
than is found in the underlying serpentines.
In view of all this it seems reasonable to infer that the ore deposits are the
result of surface enrichment by leaching and concentration during the later
stages of the above-mentioned cycle of peneplanation, and that they have been
undergoing removal rather than further accumulation and enrichment in the
GEOLOGY: W. M. DAVIS
277
later cycle of erosion introduced by elevation; the removal thus initiated is still
continued in spite of the still later subsidence.
The general sequence of changes by which the present form of the island
has been evolved from a subcontinental land of Tertiary or earlier time may
be outlined as follows. A composite land mass of large, perhaps continental,
extent, consisting hereabouts of deformed crystalline and Mesozoic rocks, was
eroded to mountainous or moderate relief, AB, in the background block
of figure 1 ; it was then reduced in area by down-warping, probably in tertiary
time, whereby the surviving land area must have gained an embayed shore line,
C, D, as in block 2. If coral reefs had previously existed around the border
of the larger land, they must have been drowned by rapid submergence, for the
FIG. 1. THE PHYSIOLOGICAL DEVELOPMENT OF NEW CALEDONIA
adjoining seas are very deep. New reefs may have been formed in the later
stages of submergence, enclosing a lagoon, C.
The reduced island of block 2 must have stood still long enough to suffer
reduction to small or low relief, except in its areas of most resistant rocks, as
in block 3 ; the serpentine areas were mostly reduced to peneplains at this time.
The embayments formed in the shore line at the beginning of this cycle of
erosion were presumably in time filled with deltas that advanced into the
reef-enclosed lagoon, as at E; the deltas may indeed have grown so far as to
overwhelm and smother the reef, whereupon it would be cut away by the waves
which would in time attack the worn-down land, retrograding its peneplains
in low cliffs and spreading the detritus from them and the rivers on the
shallow floor of the adjoining sea, F; for this change from a reef-fronted and
prograded coast of submergence in an early stage of an erosion cycle that
278
GEOLOGY: W. M. DAVIS
had been introduced by warping to a reef -free and retrograded coast in an old
stage of the cycle is a most natural consequence of a long stationary period in
the history of an island in the coral seas.
Another warping is then inferred, chiefly because the change from the sub-
continental land of block 1 to a narrow island adjoined by deep seas on both
sides, is not likely to have been accomplished in a single period of deformation.
This warping must be supposed to have affected the island unsymmetrically,
as in block 4, probably drowning any previously formed barrier-reefs along the
southwestern coast, and re-embaying the shore line there, where a new barrier
reef, G, would be developed, but this last point is not essential; at the same time
the northeastern coast appears to have been uplifted, so that a coastal plain
of marine sediments, such as may have accumulated in the shallow sea, F, was
there added, as at H. The reason for the last inference is that the elevated
peneplain areas along the northeastern side of the island were cut back in
cliffs by the sea in the early stage of the cycle introduced by this elevation;
and the simplest way of accounting for this is to suppose that the elevation here
laid bare a narrow coastal plain, covered with loose sediments, on the shore line
of which reef-building corals could not establish themselves, and on which the
waves could therefore work unimpeded. No other supposition can so reason-
ably account for the abrasion of cliffs along one side of an island in the coral
seas during the early stages of a subrecent cycle of erosion.
Block 4 is then gradually transformed into block 5, in which the weak-rock
areas of the southwestern coast are again worn down to moderate relief, and
the reef -enclosed lagoon is largely filled with delta plains, as at /; and in which
the uplifted peneplains of stronger rocks along the northeastern coast are dis-
sected by narrow valleys and cut back in high cliffs, as at K. A recent sub-
mergence has converted block 5 into block 6, drowning the previously developed
delta plains of the southwestern coast, where the reef has grown higher and the
sea has advanced farther than before on the lowland border, thus leaving the
broad lagoon, L, of today between the young shore line of submergence and
the barrier reef; the same recent submergence has partly drowned the cliffs
of the northeastern coast, so that their valleys are now beautifully embayed,
and a barrier reef has grown up from the sea bottom in front of them, as at M.
It is chiefly upon the highland peneplains back of the cliffs of this coast, and
upon similar highland areas which occur along the northwestern half of the
other coast, that metaliferous laterites occur.
Abundant variations on the earlier stages of the foregoing scheme may be
proposed. The changes here outlined are probably much simpler than the
changes that have actually taken place, and some of the changes here indi-
cated are very uncertain. For example the cutting back of the embayed coast,
D, in block 2, to the low cliffs, F, of block 3, is by no means assured; but the
unsymmetrical warping by which block 3 was transformed into block 4 seems
to be essential as a means of reasonably providing for the development of sea
cliffs in a relatively early stage of the cycle of erosion on one side of the island
GEOLOGY: W. M. DAVIS
279
where the rocks are hard, while no cliffs are developed on the other side of the
island, even though the cycle of erosion on the weaker rocks that there prevail
advanced in the same measure of absolute time to a late stage of development,
when reef extinction and retrogressive abrasion are expectable occurrences.
The prevention of cliff development on the southwestern coast is favored by
assuming that the submergence which lowered block 5 to block 6 was caused
by progressive subsidence. In any case, the general submergence by which
block 5 is changed to block 6 is easily demonstrated. It is therefore in view
of some such geologically modern sequence of moderate deformation and pro-
longed erosion as is here sketched, uncertain and shadowy in its earlier stages,
better certified in its later stages, that the development of the ore-bearing
laterites must be explained.
The enrichment of the present ore deposits could not have begun on the
serpentine areas in the immature stages of the earlier cycle of erosion in which
block 2 was worn down to block 3, for at that time the valley-side slopes,
profiles 1, 2, figure 2, were steep enough, just as they are in the immature
stage, profiles 1', 2' ', of the present cycle in the serpentine areas, to allow the
FIG. 2. RELATION OF ORE-BEARING LATE RITE TO TWO CYCLES OF EROSION
removal of disintegrated rock about as fast as it was weathered. Even during
the mature stage, profile 3, of the earlier cycle, removal rather than accumula-
tion must have prevailed; but as the later stages of the cycle were reached,
soil removal from the subdued hills, profiles 4, 5, between the wide-open valleys
must have been much slackened; the thickness of the disintegrated materials
there occurring and with it the surface enrichment of the metallic ores by down-
ward concentration must have thenceforward increased as the subdued hills
were worn down to the gentler and gentler gradients of old age, as in profile 6;
and the area on which concentration was important must have been on the low
swells between the broad valleys. If these inferences are correct, it follows
that the nickel and cobalt content of the greater part, MNO, of the primeval
rock mass has been carried away and deposited on the adjoining sea floor,
and that the deposits now worked contain chiefly the concentrated savings from
only a quarter or a sixth of the primeval total, shaded in the upper half of
figure 2. This explanation traverses Glasser's supposition'2 that the serpentine
masses have not been much eroded; for in view of their form alone, apart from
the evidence of erosion given by ore concentration, that supposition seems
untenable.
280
ANATOMY: H. H. DONALDSON
Again, the submature or mature main valleys, profile 2', or the prentcyclees
presumably excavated beneath the wide-open old valleys of the earlier cycle,
have not as yet encroached greatly upon the ore-bearing part of the inter-
valley highlands, profile 6. The encroachment and removal will be greater and
greater as the main valleys of the present cycle are widened, profile 3', (the
recent submergence is not indicated here) and as branch valleys are extended
headward into the highland by retrogressive erosion. Still later, profile 4',
the highland surfaces of the earlier cycle and their residual laterite cover will
be completely worn away; but finally, when old age is again approaching,
profiles 5' and 6', new deposits will again be formed by rock disintegration and
ore concentration on the subdued and lowering inter-valley hills of the future,
just as happened in the past.
The superficial laterite ores of the serpentine highlands in New Caledonia
therefore seem to be local as to area of development and intermittent as to
time of origin and duration of occurrence. The same relations presumably
obtain in a general way regarding the limonite and bauxite deposits of our
Appalachian valleys.
1 Report, Ontario Bureau Mines, No. 26, part 1, 1917.
2 Richesses minerales de la Nouvelle Caledonie, Ann. des Mines, 1903-04.
A COMPARISON OF GROWTH CHANGES IN THE NERVOUS SYS-
TEM OF THE RAT WITH CORRESPONDING CHANGES
IN THE NERVOUS SYSTEM OF MAN
By Henry H. Donaldson
Wistar Institute of Anatomy and Biology, Philadelphia
Read before the Academy, April 23, 1918
For a number of years the albino rat has been used for the study of growth
changes which occur in the brain between birth and maturity.
As occasion offered, the results obtained from the rat have been compared
with those from man, in order to determine how far the rat might be used for
the study of the corresponding problems in man.
As all of these studies were in the field of growth, and as growth is a function
of age, it became necessary in order to make the cross reference, to determine
the equivalent ages of the rat and man.
Two observations were available for this determination.
1. The rat doubles its birth weight in 6 days, while man takes 180 days —
giving a ratio of 1 to 30 days. From this it would appear that the rat was
living 30 times as fast as man.
2. Again, a rat of 3 years is very old — so that I have ventured to compare a
rat of this age with a man of 90 years. Once more the rat appears to be living
30 times as fast as man.
ANATOMY: H. H. DONALDSON
281
For working purposes we assumed that 1 day in the life of the rat was equiva-
lent to 30 days in the life of man, and that the equivalent ages in these two
animals were represented by equal fractions of the span of life.
One adjustment is necessary however in dealing with the data for the nervous
system. The brain of the rat at birth is less mature than that of man at birth,
and it is not until the rat is 5 days old that the brain is in the same phase as
that of man at birth.
In making any comparison therefore the data for the rat at 5 days of age are
arranged to coincide with the data for man at birth. Using the foregoing
methods, four comparisons have been made between the growing nervous
system of the rat and that of man.
The first chart is for the growth in the weight of the entire brain of the rat
from birth to maturity, compared with that of man. When the human brain
r_ Mt BRAIN WEIGHT ON AGE
QMS RAT MAN GMS
-#- 1415
6 7 8 9 10 II 12 13 14 15 16 17 18 19 20 21 22 YEARS
73 85 97 122 146 170 194 219 244 268 DAYS
CHART 1
Showing the increase in the brain weight of the albino rat on age (broken line and dots)
and compared with this the increase in the brain weight of man at the equivalent ages (solid
line) . The values for equivalent ages are on the same ordinate.
weights are reduced, and the comparison is made in the way described, the
two graphs run well together. Thus, at equivalent ages, the brain in these two
forms has undergone nearly the same degree of enlargement.
Chart 2 shows the percentage of water in the rat's brain at different ages.
The graph indicates a rapid, followed by a slow loss of water, with advancing
age. I have found only four corresponding records for man, namely at birth,
2 years, 9.5 years and 25 years, and these are entered by the heavy black dots
at the equivalent ages on the graphs for the rat. The coincidence is good.
It has been determined that this loss of water is due to the progressive
accumulation of myelin in the nervous system (Donaldson, '16) and the infer-
ence is therefore justified that the formation of myelin is progressing in a like
manner in the two forms — only it progresses 30 times as fast in the rat.
282
ANATOMY: H. H. DONALDSON
PERCENTAGE OF WATER
I AGE IN DAYS ]68
0 20 40 60 80 100 130 160 200 240 280 320 360
CHART 2
Showing on the upper graph the percentage of water in the brain of the albino rat from
birth to 365 days. The four heavy dots represent the observation for man entered at equiva-
lent ages. The graph for the percentage of water in the spinal cord is not discussed.
ALBINO RAT
TH!
ESS
OF C
ORT
EX.
H
U A
■ i ■ rv.
s
>
4
b^— -
//jf /
' /
■' /
BR/
VIN WEIG
HT
.Ql 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 10 11 12 13 14 i.5 16 17 18 1.9 20 ^
CHART 3
From Sugita '17, chart 9. Giving in millimeters the corrected thickness of the cerebral
cortex of the albino rat; H, in the horizontal section; S, in the sagittal section; F, in the frontal
section; A, the heavy line, represents the average of all of the measurements. The two
heavy dots represent two incidental values for the human cortex — after reduction — entered
at the equivalent ages.
ZOOLOGY: R. W. HEGNER
283
The third instance is the maturing of the cerebellum, represented by the
completion of the Purkinje cells and the disappearance of the external granule
layer. In the rat these events occur between birth and 20 days of age, Addison
'11. Like events occur in the human cerebellum and are completed in man at
nearly the equivalent age. When the cerebellum has so far matured, locomotor
control is attained in both forms, and thus this series of histological adjust-
ments and locomotor control are accomplished at nearly equivalent ages in
both the rat and man.
Finally, Dr. Sugita ('17) has just completed a study of the growth in thick-
ness of the cerebral cortex of the rat, and the graph A in chart 3 shows that
the mature thickness is nearly attained at the age of 20 days. There are at
present no systematic studies on this point for man, but two incidental obser-
vations, entered as heavy dots, agree with the inference that at 15 months,
the equivalent age, a like degree of completeness is reached by the human
cerebral cortex, and therefore that only slight growth in the thickness of the
human cortex is to be expected after this age.
There are therefore five prime events in the growth history of the nervous
system of the rat, namely: (1) increase in total weight; (2) decrease in the
percentage of water; (3) accumulation of myelin; (4) maturing of the cerebel-
lum; (5) the attainment of the mature thickness of the cerebral cortex, all of
which takes place at ages equivalent, or nearly equivalent, to those at which
they occur in man.
It appears then that by the use of equivalent ages we have a satisfactory
method for making a cross reference between the rat and man, and because
the growth changes are similar in both forms, the rat may be used for further
studies on the growth of the nervous system with the assurance that the
results so obtained can be carried over to man.
Addison, William H. F., Wistar Inst., Philadelphia, J. Comp. Neur., 21, 1911 (459-481).
Donaldson, H. H., Ibid., 26, (1916), (443-451); these Proceedings, 2, 1916, (350-356)..
Sugita, Naoki, /. Comp. Neur., 28, 1917, (511-591).
VARIATION AND HEREDITY DURING THE VEGETATIVE
REPRODUCTION OF ARCELLA DENT AT A
By R. W. Hegner
Zoological Laboratory, Johns Hopkins University
Communicated by H. S. Jennings, June 15, 1918
The conclusions of several investigators, that the genotype is constant in
organisms that are multiplying by fission, have recently been put in question
by the work of Middleton1 (1915) on Stylonychia and by Jennings2 (1916) on
Difflugia. Middleton obtained two lines of Stylonychia from a single specimen
284
ZOOLOGY: R. W. HEGNER
that differed constantly and markedly in their fission rate. Jennnings has
shown that the descendants of a single specimen of Difflugia may be separated
into a number of diverse lines that differ from one another in their heritable
characteristics. The work herein described is part of an investigation that is
being made of the species problem in the genus Arcella and the principal prob-
lem attacked is : Can heritably diverse lines with respect to spine number and
diameter of shell be distinguished among the descendants of a single specimen
of Arcella dentata produced by simple fission?
Arcella dentata (fig. 1) is a microscopic protozoon belonging to the lowest
class, the Rhizopoda. It is as simple as any animal organism it is possible to
FIG. 1. OUTLINE DRAWINGS OF SPECIMENS OF ARCELLA DENTATA BELONGING TO FAMILY
A, The progenitor of the entire family; B, a typical member of the low line E; C, a typical
member of the high line A ; D, the small progenitor of the line EM; E, a small specimen from
the line ED; F, the largest specimen from the line ED.
obtain that has measurable characteristics. It varies in diameter from 73
microns to 150 microns and in spine number from 7 to 20. It multiplies vege-
tatively and rapidly and the characteristics of the shell are not modified by
growth or by the environment, and are heritable but variable. In all, 6474
specimens were studied. Of these 171 were collected from a pond on the
campus of the Johns Hopkins University at Homewood, Baltimore; 746 were
reared from 70 of these specimens; and 5557 were obtained from the single
specimen numbered 58. The number of generations represented by the prog-
eny in family 58 was 69 and the average interval between generations was
two and one-half days.
F
NO. 58. X 207
ZOOLOGY: R. W. HEGNER
285
One hundred 'wild' specimens were first selected at random from a large
number taken from the pond. These varied in spine number from 7 to 13,
and in diameter from 23 to 33 units (each unit being 4.3 microns). A marked
correlation (0.325^0.060) was found between the spine number and diameter
of these specimens.
Small families were then reared from 70 'wild' specimens selected so as to
include large, small, and medium sized organisms. Seven hundred and forty-
six specimens were obtained in this way, ranging in number from only 2 or 3
to 149 per family. The mean spine number of the families ranged from 10.40
to 14.07. Variations in spine number occurred among the descendants of
Non-
Before selection
selection Six selection periods Four nonselection periods 3 selection periods periods
39 days 64 days 35 days 23 days 1 1 days
. 7 gen. 22 generations 18 generations 15 gen. 7 gen.
198 spec. 1218 specimens 1325 specimens 722 specimens 224 spec.
13.15
17.54
12.80
Uij
i o/
: *
. 11.68: ■
f
10.87
/^J138
<^>#
10.62
11.26/ \X 1
m
S
m
o
^$32
/ i
/ i
/ N: /
-4l084
8.00/
/ 1 8.81
■
•
FIG. 2. DIAGRAM SHOWING THE MOST IMPORTANT HERITABLY DIVERSE LINES DERIVED
FROM A SINGLE SPECIMEN OF ARCELLA DENT ATA (NO. 58) BY FISSION
The character used was spine number. The letters indicate the designation of the lines,
and the numbers are the mean spine numbers.
single specimens during fission and these variations were in part inherited.
It was found that the hereditary constitution of the different families was
different with respect to spine number and the conclusion was reached that a
'wild' population consists of a large number of heritably diverse families so far
as spine number is concerned, and also probably as regards diameter, since
spine number and diameter are closely correlated.
The main problem was next undertaken, i.e., an attempt was made to isolate
heritably diverse lines from among the descendants of a single specimen produced
286
ZOOLOGY: R. W. HEGNER
by vegetative reproduction. A specimen, numbered 58 (fig. 1, A) was chosen
for this work because it was near the mean of the species in diameter and spine
number, and multiplied rapidly. Figure 2 shows the principal results of the
experiments. During the thirty-nine days before selection was begun 198
specimens were obtained from number 58, representing 7 generations. These
varied in spine number from 8 to 13, with a mean of 10.87. Selection was then
inaugurated and carried on for six periods totalling sixty-four days. During
this time 1192 specimens were reared, belonging to 22 generations. The
work was divided into periods so that any changes due to environmental con-
ditions would be revealed, and also because one investigator can take care of
only a few hundred specimens at one time, and when the limit has been reached
a new selection has to be made. At first all parents and progeny were kept
until the end of each selection period, but later selection was also practiced
during the periods. An effort was made to obtain a line (A) with a high mean
spine number and another line (E) with a low mean spine number. Specimens
within the high line that possessed 12 or more spines were selected and those
within the low line with 10 or less. Past performance was used as the basis of
selection, i.e., specimens in the high line that had a high spine number and had
near relatives with a high spine number were chosen, and similarly specimens in
the low line that had a low spine number and had near relatives with a low
spine number were chosen for continuing the lines. During the six selections
periods the differences between the mean spine numbers of the two lines were
as follows: —0.07, 0.50, 0.40, 0.48, 0.84, and 1.16, and the mean difference was
0.55. The coefficients of correlation between parents and progeny with
respect to spine number during these periods were 0.060 ± 0.076, 0.220 ±
0.039, 0.186 ±0.042, 0.185 ±0.040, 0.403 ± 0.044, and 0.512 ±0.039.
Selection was then stopped and during four periods totalling thirty-five
days, no selection was practiced. As many specimens as could be taken care
of were kept during this time and as soon as one divided the 'parent' was
eliminated and the offspring kept. In this way 1325 specimens were obtained
belonging to 18 generations. At first regression occurred in both lines but
later the mean difference between them remained almost constant. These
differences for the four periods were 0.94, 0.07, 0.41, and 0.43, and the mean
difference was 0.46. The decrease in the difference after selection was stopped
was probably due to the production and inclusion within the high line of low
spined specimens that would have been eliminated during the selection periods
and within the low line of high spined specimens that likewise would have been
eliminated. Each line, however, should give rise to as many high as low
spined specimens, and hence the means of each would not vary after an equi-
librium had been reached and the difference between them would be permanent.
The coefficients of correlation between parents and progeny within the high
line during these four periods was 0.170 ± 0.027 and within the low line
0.197 ±0.024.
The low line (E) was then subjected to selection in a similar way and a high
ZOOLOGY: R. W. HEGNER
287
line (EG) and a low line (EH) were obtained during three selection periods of
twenty-three days during which 722 specimens were produced belonging to 15
generations. The average difference between the mean spine numbers of the
two lines during these three selection periods was 0.30. These selection periods
were then followed by a nonselection period of 1 1 days during which 224 speci-
mens were obtained belonging to 7 generations. The difference between the
means of the two lines during this nonselection period was 0.44. It was con-
cluded from these studies that two lines heritably diverse with respect to spine
number, had been isolated from among the descendants of the low line (E).
Measurements were made during part of the nonselection periods to deter-
mine whether or not the diversities in spine number in lines A and E were
accompanied by similar diversities in diameter. One hundred and twenty-
seven specimens from the high line gave a mean diameter of 27.26 units of 4.3
microns each and 136 from the low line a mean diameter of 26.92 units. The
difference of 0.34 unit shows that the two lines were different in diameter as
well as in spine number, and that on the average the greater the diameter the
more numerous are the spines. A marked correlation was found between the
diameters of the parents and those of their progeny, the coefficient of correla-
tion being 0.489 ± 0.035. A high correlation also existed between spine
number and diameter, the coefficient of correlation being 0.255 ± 0.042.
Measurements were also made of the diameters of 384 of the progeny
of the two branches (EG and EH) of the low line (E). These showed a mean
difference in diameter of 0.26 unit corresponding to the difference in spine
number.
These data prove that the descendants of a single specimen of Arcella
dentata produced by vegetative reproduction differ slightly from one another in
their hereditary constitution (fig. 1 , B and C) and that heritably diverse lines
may be isolated from among them, differing both in spine number and in diam-
eter, and that these two characters are closely correlated. These heritably
diverse lines resemble certain of the families that were reared from 'wild'
specimens, and suggest that differences in the hereditary constitution of these
wild specimens may have originated in the same way.
During the course of this investigation several branches were studied that
arose from what seemed to be "mutations." These are indicated in figure 2
by the lines EM, ED, EDA , EDB, and EDC. These all appeared in the low
line. Specimen EM had 8 spines and was only 18 units in diameter (fig. 1, D).
Its parent had 10 spines and was 27 units in diameter. A large number of
descendants (403) were reared from this small specimen, but it was found that
the small diameter and lesser number of spines did not persist, but that the
progeny of the fourth generation had regained the diameter and spine number
of the low line from which EM was derived. The origin of this small specimen
was therefore probably due to environmental conditions. Studies of this and
certain other small specimens seem to show that it takes three or four genera-
tions for the progeny of a very small specimen to regain the normal diameter
and spine number of the parental line.
288
GEOLOGY: W. E. EKBLAW
The line derived from specimen ED is of special interest, since within it
appeared the greatest diversities that were found during the entire investiga-
tion. The progeny of ED had a mean spine number of 9.91 and a mean diam-
eter of 23.51 units (fig. 1, E). At the same time the mean spine number of the
parent line (E) was 10.99 and the mean diameter was 27.05 units, giving a
difference in mean spine number of 1.08 and in mean diameter of 3.54 units.
Furthermore the differences persisted for many generations and until the line
was discontinued. Specimen ED therefore fulfilled the conditions usually
required of a mutation, i.e., it was a sudden large variation that was inherited.
From line ED there were derived three branches, EDA, EDB and EDC, that
quickly exceeded in diameter and spine number any other branches in the
entire family 58. The largest specimen appeared in branches EDB. It had
20 spines and a diameter of 40 units (fig. 1, F). These branches, however,
soon died out for some unknown reason, although they were cultivated as
carefully as possible.
The general conclusion reached is that within a large family of Arcella den-
tata produced by vegetative reproduction from a single specimen, there are
many heritably » diverse branches. These diversities are due both to very
slight variations and to sudden large variations ('mutations'). The formation
of such hereditarily diverse branches appears to be a true case of evolution
that has been observed in the laboratory and that occurs in a similar way in
nature.
1 Middleton, A. R. J. Exp. Zool., 19, 1915. (451-503.)
2 Jennings, H. S. Genetics, 1, 1916, (407-534.)
THE IMPORTANCE OF NIVATION AS AN EROSIVE FACTOR, AND
OF SOIL FLOW AS A TRANSPORTING AGENCY, IN
NORTHERN GREENLAND
By W. Elmer Ekblaw
Crocker Land Expedition, American Museum of Natural History, and University
of Illinois
Communicated by J. M. Clarke, July 12, 1918
Nivation and solifluctidfi, two closely related and important physiographic
processes of Arctic lands, are perhaps nowhere better illustrated than in
those coastal areas of northern Greenland not covered by the permanent
ice-cap. The climate and the topography are favorable to the high develop- •
ment of these processes; the rather heavy snowfall that melts gradually
during the short summer promotes the work of nivation; and the high relief,
with numerous small plateaus and generally steep slopes, affords opportunity
for the action of solifluction. The presence of an ' ice-table' everywhere, not
deep below the surface, is an added favorable condition. As a consequence
GEOLOGY: W. E. EKBLAW
289
nivation and solifluction attain a degree of importance in northern Greenland
not generally appreciated.
Nivation is the process by which quiescent neve effects the disintegration
of rocks, and the destruction of some land forms, and the formation of others.
In this process the snow itself produces very little, if any, effect; it is the
water from the gradual melting of the snow that does the work. The melting
must be so slow and gradual that the water does not escape by surface run-
off, but soaks into the layer of rock fragments or soil above the ice-table, and
then seeps slowly downward and outward from its source.
Nivation is assuredly most effective in regions of pronounced relief, and
strong and variable winds, conditions prevalent in Greenland. Under such
conditions, the snow does not lie as a mantle of uniform thickness, but is
piled up in drifts of various kinds. For the sake of clearness, I have classi-
fied these drifts into two, or three, rather distinct divisions, more or less
characteristic of the kinds of localities in which they are found. These divi-
sions are (1) dome-shaped drifts, formed on the more or less uneven tops of
plateaus, on the small plain areas, and on other relatively level surfaces;
(2) piedmont drifts, formed along the foot of extended cliffs, or series of cliffs;
and (3) wedge drifts, formed in gullies and small gorges near the top of cliffs.
The dome-shaped drifts vary in size with the size of the plateau or plain
surface upon which they lie, and with the strength and character of the winds
that blow over. On the small segments of a plateau surface dissected by
gullies or stream beds, these dome-shaped drifts may not be very large or
very thick; on larger segments, they may form one large dome, or several,
all, or some, very thick, — in cases even becoming small ice-caps. Thus there
may be every gradation from small dome-shaped drift to the great ice-cap of
Greenland. If the winds that blow over vary considerably and rather uni-
formly in direction, the domes are somewhat symmetrical; if not, they slope
gradually toward the windward side, and quite abruptly on the other. On
the plateaus north of Foulke Fjord, the winds blow from almost all points of
the compass, as often, almost, from one direction as another, and the drift
slopes almost uniformly from the center to the whole peripheral edge; on
Herbert Island, where the winds blow generally from the South, the dome
slopes gently in that direction, while on the north side, the slope is abruptly
precipitous. Very few of the tops of the plateaus are free from dome-shaped
drifts; and many terraced moraines, deltas, and plains are covered by the
same form.
The piedmont drifts are those that form along the cliffs on the windward
sides of valleys, fjords, and straits, on the lee sides of capes, peninsulas, and
islands. They are formed from the snow that comes drifting over the lands
back of the cliffs, and piles up on the talus slopes below, at the foot of the
cliffs. Thus, both sides of Foulke Fjord are bordered for almost nine months
of the year by these piedmont drifts, those on the north side from the snow
carried over by northerly winds, those on the south from the snow carried
290
GEOLOGY: W. E. EKBLAW
over by southerly winds. In Inglefield Gulf, only the south side is thus bor-
dered because the cliffs on that side are more continuous, and the winds carry
the snow from the plateaus over in great quantities; whereas on the north
side, more broken by rather large valleys, the winds are deflected down the
valleys, and little, if any, snow is carried over. Similar differences occur in
other fjords.
The wedge drifts which form in gullies and small gorges near the top of the
cliffs are genetically related to the piedmont cliffs, and consequently are dis-
tributed in much the same manner. They, however, are included within
limited areas, and though in places they may be considered continuous with,
and part of, the piedmont drifts, in other places they are the only drifts
formed, for all the snow is carried into the gorges and gullies by the winds
which are deflected into them The character of the drifts is so closely a
function of the topography, the direction of the wind, and the consistency of
the show, that as any one of these factors changes in character, the drifts
may also change In Grenville Bay, for instance, the south side is bordered
by piedmont and wedge drifts, while the north side is almost bare of snow;
and since the south side gradually changes its direction from northeast-south-
west at its mouth, to a nearly due east-west direction toward its head, and the
prevailing wind is a general south-by-westerly, a regular succession develops,
from tiny wedge drifts near the mouth, to a full-fledged glacier at the head, a
glacier heading in a cirque a mile from the coast.
As long a quiescent neve covers the ground, and protects it from changes
in temperature and from weathering, little disintegration or degradation can
take place. It is only when the snow melts that the work begins. The melt-
ing in North Greenland is not a rapid process. Even when the sun shines at
its highest, the temperature of the air does not rise much above 55° F.; it is
usually lower, though that of exposed soil and rocks may be considerably
higher. The snow drifts melt rather slowly, fastest at their edges.
Each of the kinds of drifts described produces different effects when melt-
ing. The dome-shaped drifts on the level surfaces melt first at their periph-
eral edges. The water formed is very near 32° F., and freezes at every drop
of temperature due to cloudiness or change of wind so that excessive frost
action takes place at the margin and just beyond, with consequent breaking
up and disintegration of the rock. Often, too, the water freezes on the side
of the drift away from the low sun, even at noondays, thus increasing the
freezing action. Just beyond the margin of the drift, the temperature of the
water is a little higher, and solifluction sets in. The disintegration of the
rock, and the movement of resulting material, progresses in toward the
center of the snow-drift covered area, as the drift melts back. Horizontal
solifluction and consequent applanation terraces so clearly defined by H.
M. Eakin,1 are the immediate effect, and these in time result in reducing the
plaeau top, or other plain surface, to a quite level surface, constantly being
extended in area, and lowered. The process has been so well described by
GEOLOGY: W. E. EKBLAW
291
Mr. Eakin that I merely call attention to this phase dependent upon the
melting of the dome-shaped drifts.
The piedmont drifts formed on the lee slopes, or at the foot of the lee
cliffs, act somewhat differently. The melting edges are at the top of the drift,
and at the bottom. At the top the process is a sapping one, cutting back the
cliff; at the bottom solhiuction is the dominant process, though generally
there is also some direct transportation by excess surface water that does not
seep through the soil. The drift melts down from the top, and back from the
foot. F. E. Mathes,2 in his discussion of the glacial sculpture of the Bighorn
Mountains, illustrates a cross section of such a drift, and the direction of the
erosive attack upon the cliff. From the lower edge of the cliff where soli-
fluction begins, the movement of the soil may continue to the foot of the slope,
in one continuous sheet, or it may progress in a series of steplike slopes, or
sloping terraces, with crescentic terminal margins, like festoons. Throughout
northern Greenland these piedmont drifts are numerous, and almost invari-
ably they give rise to similar solirluction slopes. When they occur on both
sides of a V-shaped valley they tend to grade the sides and build up the
bottom until it becomes U-shaped, as Mathes has described.
The wedge drifts formed in gullies and small gorges near the tops of cliffs,
while acting in the same way as the piedmont drifts, produce different re-
sults. When these wedge drifts melt, the sapping process mentioned in the
piedmont drifts cuts back the sides and the head of the gully or gorge in
such a way as gradually to give it the form of a segment of a circle, the depth
and extent of the segment depending upon the amount of snow blown into it.
In this way a typical cirque may be initiated. When the snowdrifts become
so large that they do not melt during the summer, ice gradually forms and a
glacier occupies the floor of the cirque; frequently, though, the snow all melts
away during the summer and no ice is formed, yet the cirque-form continues
and the process goes on. A cirque in which ice has played no part can usu-
ally be distinguished by its rough and uneven floor, not at all like the scoured
floor of a cirque once containing a glacier. The bergshrund in these high
latitudes does not play an important part in cirque formationas it
apparently does farther south, even in those cirques in which glaciers are
formed; in the cirques carved by nivation alone there is, of course, no
bergshrund at all.
Nivation is unquestionably of prime importance in the development of
some of the topographic forms of the Greenland coast, and plays no small
part in the degradation of the high cliffs, and the grading of the slopes.
Solirluction as defined by J. G. Andersson3 is the process by which masses
of the regolith saturated with water (which may come from melting snow or
rain), flow slowly from higher to lower ground. This saturated, semi-fluid
substance, not at all assorted as to size of fragments, moves along in much
the same way as a glacier. H. M. Eakin1 defined the process of solifluction
as the migration of detritus under the thrust and heave of frost action. He
292
GEOLOGY: W. E. EKBLAW
recognized and described several types of soil movement and resultant
topographic forms.
In northwest Greenland, solifluction is closely connected with nivation.
For it is under conditions best suited to nivation that soil flow is best de-
veloped as a transporting agency. If precipitation be in the form of rain,
most of the water flows away as surface runoff and its chief work is then the
characteristic ordinary stream action. But if precipitation be in the form of
snow — as it is in northern Greenland — which melts rather slowly and gradu-
ally, little of the water flows away on the surface. Most of it seeps into the
ground, saturates it, and forms a more or less pasty mass according to the
relative proportions of soil and water. The presence of an ice-table, in that
it effectually prevents the seepage of water below the depth of the ice, facili-
tates soil flow. Thus, perhaps, the principal conditions necessary to soli-
fluction are snowfall, with gradual melting of the snow, and an ice-table to
prevent, or at least retard, the seepage of water deep into the ground.
Several forms of solifluction occur in Greenland, including probably all
that have been observed elsewhere. Distinction should be made between
solifluction which causes progressive motion of surface material such as re-
sults in applanation terraces, solifluction slopes, and soil streams or soil
glaciers; and that which causes only circulatory movement such as may
result in 'polygon-boden.' It is the first of these forms of solifluction which
is one of the most important important transporting agencies in northern
Greenland, and which has produced there land forms similar to those de-
scribed by Eakin in Alaska, and by Andersson and others elsewhere. The
other of these forms is also generally prevalent in Greenland, but while it is
an active agent of movement contributory to the breaking up and degrada-
tion of the detritus, it is not so important as a transporting agent.
Throughout northern Greenland, every land area free of ice and snow during
the short summer, exhibits the solifluction slopes and applanation terraces
described by Eakin from Alaska. Both on the slopes and on the plateaus,
the terraces resulting from solifluction are every where conspicuous. In
northwestern Greenland, particularly, solifluction of these types is a most
important transporting agency; the removal of detritus resulting from niva-
tion, freezing and insolation, to the few torrential streams that bear it on-
ward to the sea, is quite dependent upon solifluction. In many valleys the
streams at the bottom of the valleys are not nearly large enough to remove
the detritus brought down by solifluction, and the valley fast fills up, with
lakes in the depressions, behind the dams of more abundant, or faster moving,
detritus. On the gentler slopes, the rate of movement is not high, but on
some of the steeper slopes the movement is rapid.
Though the type of solifluction resulting in solifluction slopes and alti-
plantation terraces is the dominant and most important type in northern
Greenland, other types are very well represented. From this important
type to rock slide on the one hand, and to circulatory movement that re-
MATHEMATICS: G. A. MILLER
293
suits in 'polygon-boden' on the other, every gradation of type of soil-flow
may be found, and the combined results of their activities is a transportation
of material as important as that of the streams and glaciers.
All the field evidence tends to show that nivation andsolifluction, charac-
teristic processes of disintegration and denudation under subarctic or arctic
conditions, are of prime importance in the reduction of the high relief of
northern Greenland.
iEakin, H. M., Washington, U. S. Geol. Survey, Bull. 631, p. 76, 1916.
2 Mathes, F. E., Washington, U. S. Geol. Survey, 21st Ann. Rep., p. 181, 1899-1900.
3 Andersson, J. G., Chicago, J. Geol., Univ. Chicago, 14, 1906, p. 91.
ON THE a-HOLOMORPHISMS OF A GROUP
By G. A. Miller
Department of Mathematics, University of Illinois
Communicated by E. H. Moore, July 18, 1918
The term a-holomorphism was introduced by J. W. Young to denote a
simple isomorphism of a group G with itself which is characterized by the fact
that each operator of G corresponds to its ath power.1 A necessary and suf-
ficient condition that an abelian group of order g admits an a-holomorphism
is that a is prime to g, and J. W. Young proved in the article to which we re-
ferred that when a non-abelian group admits an a-holomorphism the (a— \)th
power of each of its operators is invariant under the group and the group ad-
mits also an (a — l)-isomorphism. Moreover, these conditions are sufficient
for the existence of an a-holomorphism.
The object of the present note is to furnish a complete answer to the fol-
lowing question : For what values of a is it possible to construct non-abelian
groups which admit separately an a-holomorphism? It will be proved that no
such group is possible when a is either 2 or 3, but that for every other posi-
tive integral value of a there is an infinite system of non-abelian groups each
of which admits an a-holomorphism.
The fact that every group which admits a 2-holomorphism is abelian results
directly from a theorem noted in the first paragraph of this article. If a non-
abelian group G admits a 3-holomorphism we may represent two of its non-
commutative operators by Si, s2, and note that as a result of this holomorphism
the two dependent equations
SiW = O1S2)3, Si2S22 = O2S1)2
must be satisfied. Since $i2 and s22 are invariant under G it results directly
from the latter equation that SiS2 = s2Si, and hence the assumption that Si
and s2 are non-commutative led to a contradiction. That is, if a group admits
a 3-holomorphism it must be abelian.
294
MATHEMATICS: G. A. MILLER
We shall now prove that when p is any odd prime number it is possible to
construct a non-abelian group whose order is of the form pm and which admits
a (1 + &^)-holomorphism, k being an abitrary positive integer. Suppose that
k is divisible by pP~x but not by pP. Hence 1 + kp = 1 + hpP, where h is
prime to p. Let t be an operator of order p which transforms an operator s
of order pP+l into its (1 + hjP)th power. It will be proved that t transforms
each operator of the non-abelian group G of order p&+2 which is generated by s
and / into its (1 + hpP)th power.
This proof is an almost direct consequence of the two dependent equations2
{sty = /, (st)^ = y
In fact, from these equations it results that t transforms sPrfPx and sai into
the same powers. If we form the direct product of the group G just con-
structed and any abelian group of type (1,1,1, . . . ) we clearly obtain an-
other non-abelian group which is such that / transforms each of its operators
into a (1 + -holomorphism. The group G can therefore be used to con-
struct an infinite system of groups each of which admits such a holomorphism.
To prove the theorem under consideration it is desirable to note that it is
possible to construct a non-abelian group whose order is of the form 2m and
which admits a (1 + 27) -holomorphism whenever y > 2. In fact, if s is an
operator of order 2T+1 and if / is an operator of order 2 which transforms s
into its (1 + 27Yh power the non-abelian group of order 27+2 which is gener-
ated by s and / will clearly satisfy the required condition. Moreover, each one
of the infinite system of groups obtained by forming the direct product of the
group just constructed and an abelian group of order 2l and of type (1,1,1, ... )
must likewise satisfy this condition.
It is now easy to establish the general theorem noted in the second para-
graph. To construct a non-abelian group which admits an a-holomorphism,
a>3, it is only necessary to consider the factors of a — 1. When a — 1 is
of the form 2wany one of the groups described in the preceding paragraph satis-
fies the condition in question. When a — 1 is not of this form let p be any
one of its odd prime divisors and suppose that a — 1 is divisible by jr but not
by Hence a is of the form 1+ hpP considered above and it has been
proved that whenever a>3 it is possible to construct an infinite system of groups
such that each group of this system admits an a-holomorphism.
1 J. W. Young, New York; Trans. Amer. Math. Soc, 3, 1902, (186).
2 Miller, Blichfeldt and Dickson, Theory and Applications of Finite Groups, Wiley, New
York, 1916, p. 108.
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CONTENTS
Page
Geology. — Metaliferous Laterite in New Caledonia . . By W. M. Davis 275
Anatomy. — A Comparison of Growth Changes' in the Nervous System of the
Rat with Corresponding Changes in the Nervous System of Man . . .
By Henry H. Donaldson |280
Zoology. — Variation and Heredity During the Vegetative Reproduction of
Arcella dentata By R.W. Hegner 283
Geology. — The Importance of Nivation as an Erosive Factor, and of Son.
Flow as a Transporting Agency, in Northern Greenland
By W. Elmer Ekblaw 288
Mathematics. — On the «-Holomorphisms of a Group . . . By G. A. Miller 293
VOLUME 4
OCTOBER, 1918
NUMBER 10
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Montgomery, T. H., J. M or ph., Boston, 22, 1911, (731-815); or, Wheeler, W.
M., Konigsburg, Schr. physik, Ges., 55, 1914, (1-142).
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Copyright, 1918, by the National Academy of Sciences
PROCEEDINGS
OF THE
NATIONAL ACADEMY OF SCIENCES
Volume 4 OCTOBER 15, 1918 Number 10
MEASURING THE MENTAL STRENGTH OF AN ARMY
By Major Robert M. Yerkes
Sanitary Corps, N. A.
Communicated by R. Pearl. Read before the Academy, April 23, 1918
Committees of the American Psychological Association and the Psychology
Committee of the National Research Council prepared between April and
August, 1917, various psychological methods for the selection and classifica-
tion of recruits in the Army and Navy. In August, 1917, the Surgeon General
on recommendation of Majors Victor C. Vaughan and William H. Welch of the
National Research Council accepted for trial certain methods which had been
devised especially for the psychological examination of men enlisted in the
United States Army. Dr. Robert M. Yerkes, Chairman of the Psychology
Committee of the National Research Council was appointed on August 17,
Major in the Sanitary Corps, to organize and direct this new branch of the
service for the Medical Department.
During the initial development of this service, Major Yerkes worked under
the immediate administrative supervision of Major Pearce Bailey, Chief of
the Division of Neurology, Psychiatry and Psychology. Plans were speedily
prepared and the necessary authorization secured from the Secretary of War
for thorough trial of the proposed methods in four National Army canton-
ments. For this work sixteen psychologists were commissioned first lieuten-
ants in the Sanitary Corps, and twenty-four others were given civil appoint-
ment by special authorization of the Secretary of War. The psychological
staff of each camp consisted of ten men.
Between October 1 and December 1, 1917, nearly 100,000 drafted men,
students in Officers' Training Camps, and officers of camps or divisions were
examined. In December the work was officially inspected by an officer of
the Medical Corps. The reports of this inspectional officer supplemented im-
portantly the statistical data supplied during progress of work by Major Yerkes.
As the results of psychological examining indicated clearly the value of the
work for the elimination of men mentally defective, the balancing of organi-
295
296
PSYCHOLOGY: R. M. YERKES
sations in mental strength, the classification of men for the assistance of per-
sonnel officers in the camps, and the indication of men of exceptional intelli-
gence to be charged with special responsibility or sent to Officers' Training
Camps, and as all reports of the inspector were favorable, the Surgeon General
in December 1917 recommended to the Secretary of War the continuance
and the extension of psychological examining to the entire army. This
recommendation, after careful inquiry concerning the value of the work by
the Training Committee of the War College Division of the General Staff, was
approved by the Secretary of War who directed the Surgeon General to pre-
pare a plan for the proper conduct of the proposed work.
A comprehensive plan was promptly prepared by the Staff of the Section
of Psychology, Division of Neurology, Psychiatry and Psychology. This plan
provided for suitably trained personnel, special psychology building in each
camp, and necessary apparatus and printed materials. It was fully approved
by the Secretary of War, Jan. 19, 1918, and the Surgeon General was author-
ized to create a Division of Psychology in his office, and to put the plan of
psychological examining into effect.
A school for military psychology was immediately organized in connection
with the Medical Officers' Training Camp, Fort Oglethorpe, Georgia, in
which a maximum of 100 student officers and approximately 100 psycholo-
gists enlisted in the Medical Corps could be trained simultaneously during a
period of two months. This school was opened February 4 with Captain
William S. Foster, San. C, N.A. as senior instructor. Between this date
and July 1, 1918, approximately 70 officers of the Sanitary Corps and 250
men enlisted in the Medical Corps were given special training in military
psychology.
Plans for suitable psychology buildings were prepared and duly submitted
to the Quartermaster General. Subsequently the Equipment Committee
of the General Staff disapproved the expenditure for these buildings pending
Congressional appropriation for the purpose, and by special request of the
Secretary of War, existing buildings were assigned for psychological examining
in most of the divisional training camps.
The necessary apparatus and printed materials for the examining of 500,000
soldiers were speedily prepared, and during April and May, psychological
examining staffs were organized in twenty-five National Army and National
Guard camps. During the month of June additional apparatus and printed
materials were manufactured for the examining of 1,000,000 soldiers.
On July 1 1918, psychological examining was in progress in twenty-eight
army camps and in three General Hospitals. Seventy-nine officers of the
Sanitary Corps were on duty in these stations, and in the Division of Psy-
chology, Surgeon General's Office. Approximately 100 non-commissioned
officers and privates of the Medical Corps especially trained in military psy-
chology had been assigned to duty in examining stations, and somewhat
more than 100 were in training at the school of military psychology,
PHYSICS: E. H. HALL
297
Fort Oglethorpe. Up to April 27, 1918, when new methods were put into
use, approximately 140,000 soldiers had been examined. On July 1, 1918,
600,000 had been examined. Of this number, slightly more than 0.25%
had been recommended by psychological examiners to psychiatrists for dis-
charge because of mental deficiency, and about 0.5% had been recommended
for assignment to service organizations for development battalions because
of mental inferiority.
Psychological examinations which were originally conducted in wards of
Base Hospitals, are now made in a psychology building located usually in the
Depot Brigade. In this building, drafted men are examined promptly on
reporting to camp. Their intelligence ratings are immediately transmitted
to the Personnel Officer of the camp. All cases of mental deficiency, or those
for which psychiatric examination is indicated as desirable, are referred to
the psychiatrist.
The aim of the Division of Psychology, Surgeon General's Office, is to develop
a psychological center in each military training camp to which all psycho-
logical problems of military assignment, training, discipline, morale, and in-
telligence may be referred by officers of the line or staff. Such a center exists
in twenty-five camps, and the service is being extended as rapidly as available
personnel permits.
(Publication approved by the Board of Publications, Office of the Surgeon
General.)
THERMO-ELECTRIC ACTION WITH THERMAL EFFUSION IN
The last paragraph of my paper in these Proceedings for April, 1918,
dealt incorrecly with the effect of 'hypothesis (B)' the hypothesis that free
electrons in the interatomic spaces of an unequally heated metal bar have a
tendency like that which in ordinary gases produces the phenomena of ther-
mal effusion.
In a common gas the condition of equilibrium maintained by thermal
effusion is not p constant but p oc T% where T is the absolute temperature.
In dealing with the free electrons, for wjiich the R of the equation pv =
N RT may not be a constant, we have as the condition which thermal effusion
tends to create
METALS: A CORRECTION
By Edwin H. Hall
Jefferson Physical Laboratory, Harvard University
Communicated August 3, 1918
p* (RT)*
(1)
whence
(2)
298
PHYSICS: E. H. HALL
If we take one gram of electrons, each of mass m, we have
pv = -RT, (3)
m
and by substitution in (2) we get
dp, or (dp)s = --d (j>v). (4)
2v
This is the difference of pressure which the free electrons within a metal
could bear without drift and without the help of electrical force. It may
be called the static difference of pressure, (dp)s.
If, now, there exists within a metal a free-electron pressure dp>(dp)s, the
excess
dp - (dp)s- or dp-— -d (pv), (5)
2v
will be the true mechanical driving force operating to maintain a drift of the
electrons. Hence the introduction of 'hypothesis (B)' requires the substitu-
tion of dp — (1 -f- 2v) d(pv) for dp in the second member of equation (4),
of my paper referred to above, and makes the whole equation read
(?<-?„)+ [ki-dP,+ f|„ = ± C^(vdp-id(pv)), (6)
J k Jh k ue Jc k
where k has the same meaning as the (ka + &/) used in the original equation.
This is the expression for the Virtual e.m.f.' resident in a detached metal
bar having one end at and the other at Tc. In my previous discussion
of this matter, not written out in my April paper, I had proceeded as if the
factor (kf -7T k) could be put with the (pv) so as to give d [(kf -r- k)(pv)]. This
error led to my giving figure 4 of that paper as the graphical representation,
on the P-V plane, of the virtual e.m.f. in question.
The second member of equation (6) can be put into the form
If
Ge Jc
k
and the graphical representation of this expression is given in figure 1 . Here
A D is the pv line for one gram of free electrons in the metal; A' D' is ob-
tained from A D by applying the proper value of the factor (kf -r- k) to each
value of v; and A' D' is obtained for A D by applying the proper value of
the factor (kf ^ k) to each value of p. A" D" is obtained from A' D' by
taking one-half of each value of v, so that the area E A" D" G represents
-1 ■ vdp of (7). Ai D"i is obtained from A i Dx by taking one-half
pdv of (7).
PHYSICS: E. H. HALL 299
The sum of these two areas, multiplied by (1 -v- Ge), represents the virtual
e.m.f. in question.
If the line A D were of constant pv, as it might be if we were dealing with
an isothermal 'alloy bridge,' the two shaded areas would be equal and their
sum would equal EA'D'G. That is, there would be no tendency to 'ther-
mal effusion' in such a case, and the virtual e.m.f. would reduce to
Ge Jc k
the value it has under hypothesis (A).
The total effective e.m.f. for a closed circuit made up of two different
metals and two isothermal alloy bridges is represented by (1 -f- Ge) times the
sum of two areas like A" B" C" D" and A\b\ C'[ D'[ in figure 2, where the
path A BCD represents the pv changes of one gm. of free electrons through-
out the circuit.
CL o(
FIG. 1 FIG. 2
The total effective e.m.f. of the circuit is not, as I have previously believed
it to be, necessarily the same under hypothesis (B) as under hypothesis (A).
For the latter case it is represented in figure 2 by (1 -5- Ge) times the area
A' B' C' D', the boundary of which corresponds to the changes of pressure
and volume undergone by 1 gram of electrons, in part free electrons and in
part associated electrons, in going around the circuit as part of a current.
I had overlooked the interesting fact that, when we have to do with thermal
effusion, which overrides the tendency to equality of pressure throughout a
gaseous body, we can no longer calculate the work done by or on a body of gas
by means of a mere diagram of its pressure-volume changes. Thus, in a ver-
tical cylinder containing a column of air, kept warmer at the top than at the
bottom, a porous partition extending partly across the cylinder wou d con-
stantly transmit air upward through its interstices, to be returned down-
ward past the edge of the partition, and work could thus be done by means of
air acting in a pv cycle of no area.
300
MATHEMATICS: E. J. WILCZYNSKI
INVARIANTS AND CANONICAL FORMS
By E. J. WlLCZYNSKI
Department of Mathematics, University of Chicago
Communicated by E. H. Moore, August 7, 1918
Every student of the theory of invariants has observed the fact that the
coefficients of a unique canonical form are invariants. But a general a priori
proof of this fact, sufficiently general to cover all of the cases needed in the
applications, seems to be lacking. It is the purpose of this paper to furnish
such a proof, making use only of the abstract principles which are common to
all known invariant theories.
We begin by giving a brief outline of some of these invariant theories, so
that we may have these instances in mind when we formulate our general
theory. Consider first a binary n-ic,
n
(p) = 2 A***?"' (A>
2'= 0
This binary form is a function of po,pi,. . , pn and of Xi, x2. The p's are
called the coefficients, and the x's the variables of the form. We introduce
new variables by putting
Xi = an Xi + oii2 x2 ,(i = 1> 2),
where the quantities are arbitrary constants with a non-vanishing determi-
nant, thus transforming the form (p) into a new form (p). Those combina-
tions of the coefficients pk which are equal to the same functions of the co-
efficients pk are called invariants of the form. In the classical theory of in-
variants it is really the equation (p) = 0 which is the object of study rather
than the form or function (p). Consequently the additional transformations,
operating upon the coefficients only, pi = \pi} (i = 0, 1, 2, . . , n), where X
is an arbitrary constant, are introduced. An invariant of the equation must
remain unaltered by these transformations also.
A second invariant theory is concerned with the class of linear differential
expressions or forms
where p0,pi . . . , pn, and y are functions of x. The coefficients pk in this case are
functions of x, whereas in instance (A) they are numbers, real or complex.
In instance (A) the variables Xi,x2 are also numbers; in (B) the variables
y,dy/dx,. . ., dny/dxn are functions. In this case we may even think of y
as the only variable, since the variables dy/dx, etc., are determined when y
is given.
Let us now transform the variable y by putting y = \(x)y, where X(x) is
an arbitrary function. Then (B) goes over into a new differential form (B)
MATHEMATICS: E. J. WILCZYNSKI 301
#
whose coefficients pk depend upon po,ph. . . , pn and X. The corresponding
invariants are of considerable importance. Here also we must distinguish
between the theory of invariants of forms, and the theory of invariants of
equations.
As a third instance, let us consider the class of analytic functions
/(*) = pQ +pix + p2x2 + . . . + pnxn +...., (C)
where the coefficients po, pi ... ,pn,---, and the variable x are complex num-
bers. We introduce transformations of the form
aX+(3
x = , ao — py q= 0,
yx-\- 5
where a, ft 7, 5 are arbitrary constants, and attempt to find invariants of
f(x) under all such transformations. In this case we are dealing with a form
which has infinitely many coefficients, forming a denumerable set. »
We shall list one further instance of our general theory. Let K (x, £) be
a real continuous function of a: and £ in the region 0^x^l,0^£^l,
and let ], of [F], by imposing some property
upon the coefficients p which is not satisfied by all forms of [F]. It is assumed
that this property is well defined, so that we may be able to decide whether a
given form F, of [F], does or does not belong to the sub-class [<£]. Let us
assume that, for every form F of [F], there exists in G at least one transforma-
tion S which transforms F into an equivalent form of the sub-class [<£]. We
shall then say that <£ = S[F] is a canonical form of F. It may happen that such
a canonical form equivalent to F under the group G, and belonging to the
sub-class [] exists merely for those forms of F which do not belong to a well-
defined sub-class \&] of [F]. We shall speak of the forms of the sub-class [&]
as exceptional forms, and call all the other forrns of [F] generic forms. Of
course the term, general form of [F], includes both the exceptional and the
generic forms. Under these circumstances we shall still speak of $ as a canoni-
cal form of Fj but we shall add the qualifying phrase for the generic case when-
ever the distinction becomes necessary.
In general there will be many transformations of G which transform every
generic F into a canonical form of the sub-class [<£]. If all of these transforma-
tions transform every generic F into the same form of the sub-class [$>], we
shall say that the canonical form <£ is unique.
It remains to define the term invariant. A function /, of the coefficients
p of a form F, is an absolute invariant under the broup G, if it is equal to the
same function of the corresponding coefficients of any form F which is equiva-
lent to F, by means of a transformation of the group G.
This notion may be regarded as including also the notion covariant. For,
we may replace the given form F by another form, or system of forms, who
coefficients depend also upon the variables of F.
We are now ready to prove the following theorem.
Let [F] be a well-defined class of forms, and let [<£] be a proper sub-class of [F].
Let G be a group of transformations which transforms every form of [F] into a
form of the same class. By a generic form of [F] we mean one which is equiva'ent
to a form of [] under G. Then, there exists, for every generic form of [F] at
least one transformation in G which transforms F into a canonical form of the
sub-class [<£]. If this canonical form is unique, its coefficients are one-valued
absolute invariants of the form F for the group G.
Proof. — Let F be a generic form of [F], and let be its canonical form. Let
5 be the most general operation of G which transforms F into 3>. We shall
have symbolically
S(F)=$. (1)
The operation S will depend, in general, upon the coefficients p, of F, and
may contain, besides, arbitrary elements in great number. The canonical
form <£ belongs to the sub-class [<£] of [F]. Since this canonical form is, by hy-
pothesis, unique, its coefficients it are independent of the arbitrary elements
which may occur in S, and they are one-valued functions of the coefficients
304
MATHEMATICS: E. J. WILCZYNSKI
of F in the sense, that when F is given, the coefficients of are determined
uniquely. We may express this symbolically by the equation
* = U(p), (2)
where U (p) is the symbol for a one-valued function of the coefficients p.
Now let T be any transformation of G, and let
F = T (F)
be any form of [F] equivalent to F under G. Since we assumed that F was
generic, and since
F = T~\F),
we conclude that F is also generic. In fact we find
S(F) = ST~ 1 (F) =
so that ST~l is an operation of G which transforms F into a canonical form
of the sub-class [#].
Let 5 be the most general operation of G which transforms F into a canoni-
cal form of the sub-class [<£], so that
5 (?) = *,
and let ir denote the coefficients of i. These coefficients will depend on the
coefficients p of F, in exactly the same way as the coefficients ir of <£ depend
upon the coefficients p of F. That is, we shall have, in a manner analogous
to (2),
7T = U (P). (3)
We also know that
i =
for we have seen already that 5T_1 will transform F into <£, and we are
assuming that every generic form F of [F] has a unique canonical form of the
sub-class [$>].
But, if two forms of a class are equal, their corresponding coefficients are
equal. Therefore we have ir = t or, according to (2) and (3).
U(p)=U (p).
In other words the coefficients of $ are indeed absolute invariants of F under
the group G, and therefore our theorem is demonstrated.
If the forms of the class [F], which are generic forms from the point of view
of the canonical form chosen, do not constitute the whole of [F] there will
remain in [F] certain exceptional forms constituting a sub-class [H] of [F],
But the theorem may be applied to these exceptional forms as well, whenever
a unique canonical form exists for a generic one of the exceptional forms; but
of course, the canonical form in this case will not belong to the class [<£], but
PHYSICS: NICHOLS AND HOWES
305
to a certain sub-class [X], of [H]. If the forms of [H] are not all generic
from this new point of view, we may adopt a new canonical form for the
exceptional ones, and continue in this way.
We have observed that the coefficients of a unique canonical form are abso-
lute invariants, and moreover one-valued invariants, in the sense, that their
values are uniquely determined as soon as the coefficients of the form F are
given. In the ordinary theory of algebraic invariants, it is at once apparent
that these invariants are algebraic functions of the coefficients of F. Con-
sequently it follows from their one-valuedness that, in this case, these invari-
ants are rational functions of the coefficients. In the theory of invariants of
linear differential equations, the uniquenes of a canonical form gives rise to
invariants which are rational functions of the coefficients of the differential
equation and of their derivatives.
There are many cases in which a ^-valued canonical form is obtained rather
than a unique one. That is, if we resume our terminology, the sub-class []
contains not merely one, but exactly k forms 3>i, $2, . . . , $h eacn of which is
equivalent to F by a transformation of the group G. The coefficients of these
canonical forms will still be absolute invariants of F, but they will be k-valued
functions of its coefficients. It is obviously possible to find an equation of de-
gree k with one- valued invariants as coefficients, of which these ^-valued
invariants are the roots. In the theory of algebraic invariants we obtain in
this way irrational invariants, as roots of an equation whose coefficients are
rational invariants.
TYPES OF PHOSPHORESCENCE
By Edward L. Nichols and H. L. Howes
Department of Physics, Cornell University
Communicated, August 1, 1918
The existence of phosphorescence of exceedingly short duration was long
ago revealed by the phosphoroscope of Becquerel but, until very recently the
afterglow of luminescent bodies has been studied quantitatively, only where
it is of comparatively long duration. Curves of decay were supposed to be
all of the same character. It was assumed that the law of diminution of
brightness, as expressed by»the equation
Oi + M2 (a2 + b2t)2
was of general application and that the phosphorescence of various substances
differed only in color, brightness and duration.
The measurements of Waggoner1 and of Zeller2 on phosphorescence of short
duration tended to confirm this view. On the other hand the observations of
306
PHYSICS: NICHOLS AND HOWES
Ives and Luckiesh3 on the effect of temperature upon the curves of decay of
certain phosphorescent sulphides might seem to demand a modification of the
usual law in certain cases, while the studies of the phosphorescence of gases
by C. C. Trowbridge4 and of paraffine at liquid air temperatures by Kennard5
indicate that for the range covered by their measurements the law of decay
cannot be expressed by a summation of l/(a + bt)2 terms.
In a recent investigation6 we have found the exceedingly brief phosphor-
escence of the uranyl salts, which, although very brilliant lasts only for about
0.03 seconds, to be of an entirely different type. It decays very slowly at
first and later very rapidly, whereas in all cases previously studied the opposite
is true. Measurements just completed on the luminescence of calcite indi-
cate that this newly determined form of decay curve is not confined to the
uranyl salts.
PERSISTENT TYPE.
—
/ /
/
/
TIME.
FIG. 1
VANISHING TYPE.
TIME.
FIG. 2
We propose therefore to recognize two distinct types of phosphorescence
and to designate them as persistent phosphorescence and vanishing phosphor-
escence. They are sharply distinguished from one another by the following
characteristics.
Types of phosphorescence. — 1: (Characteristic of persistent phosphorescence.)
This type has a curve of decay made up of a succession of linear process, of
diminishing slope as we proceed from the origin of time (fig. 1). Three or
more such processes have been found in all cases which have been studied
through a sufficient range.
2: (Characteristic of vanishing phosphorescence.) This type has a curve of
decay made up of a succession of linear processes, of increasing slope as we
proceed from the origin of time (fig. 2).
PHYSICS: NICHOLS AND HOWES
307
It is understood that in these specifications and elsewhere, unless otherwise
stated, the curve of decay is plotted with time from the close of excitation as
abscissae and the reciprocal of the square root of intensity (7~2) as ordinates.
A linear process is any straight portion of the graph; as 1, 2 or 3 in figures 1
and 2. The inference is that the more or less abrupt changes of slope are re-
lated to and indicative of real changes in the processes by which the emission
of light from the phosphorescing body is being maintained.
A distinguishing criterion of type is found in the sign of the intercepts
of the various processes at the origin of time. In type 1 the intercepts are all
positive; in type 2 the intercepts of process 2 and 3 are negative.
I *
CALCITE.
ULTRA-VIOLET EXCITATIOM.
SEC.
FIG. 3
FIG. 4
The passage from one process to the next is presumably never actually dis-
continuous, as in the above diagrams, but it is sometimes very abrupt as in the
curves of figures 3 and 4 which are from our recent measurements of the phos-
phorescence of calcite. Sometimes the transition from slope to slope is very
gradual; so that the first and second processes tend to merge into a curved
line. We have shown,6 in the case of the uranyl salts that the location of
the knees depends on the intensity of the excitation and that distributed knees
— so to speak — occur when the exciting light penetrates the crystal and being
absorbed produces luminescence of decreasing intensity in successive layers;
also that where the conditions are such that excitation is confined chiefly to
the surface, the knees are well defined.
Similar modifications of the curve occur in kathodo-excitation, and distrib-
uted knees are then probably due to a kathodic discharge containing par-
ticles of varying velocity.
308
PHYSICS: NICHOLS AND HOWES
Both types may occur in a single substance. — Shortly after the completion of
our experiments on the vanishing phosphorescence of the uranyl compounds,
Misses Wick and McDowell7 found that some of the same salts, notably
K.U02(N03)3 and K2U02(N03)4 when exposed to the kathode discharge at
the temperature of liquid air glowed for many seconds after the close of exci-
tation with decay curves of the persistent type. At + 20° the effect is either
absent or excessively feeble. Not all the uranyl salts, even among those
that are reasonably stable in vacuo, respond to the action of the kathode dis-
charge to a measureable extent.
The Franklin Furnace calcites, as we discovered in our recent investigation,8
have the same remarkable property, i.e., vanishing phosphorescence under
photo-excitation and persistent phosphorescence under the kathode discharge.
Figures 3 and 4 exhibit the vastly different behavior of the same calcite after
the close of these two modes of excitation.
Both types of phosphorescence are obtainable with calcite at any tempera-
ture between -180° and +300°.
Independence of the two types. — Since the kathode discharge modifies the
surface layers of substances subjected to its action, it might be supposed that
calcite crystals after kathodo-bombardment would show persistent phosphor-
escence when photo-excited. To test this supposition we placed a crystal of
the Franklin Furnace calcite in the bottom of a V shaped vacuum tube having
a quartz window.
It could thus be excited either by the kathode discharge or from an iron
spark. Previous excitation by the kathode rays had no observable effect on
the photo-phosphorescence which was of the vanishing type and had approxi-
mately at least the normal color, brightness and duration. The photo-phos-
phorescence could be superimposed upon the persistent kathodo-lumines-
cence, as a fleeting effect, at any time during the life of the latter either after
or before the close of the kathodo-excitation. Apparently the two were en-
tirely independent of each other.
Misses Wick and McDowell had previously made a similar observation in
their study of the kathodo-phosphorescence of the uranyl salts; i.e. that the
kathode rays do not render them capable of persistent photo-phosphorescence.
Apparent occurrence of both types with a single source of excitation. — Wil-
lemite is one of the most brlliant of luminescent substances. The afterglow
is commonly fleeting, but masses are occasionally found which exhibit phos-
phorescence of long duration. Such specimens are persistent under photo-
excitation and kathodo-excitation alike. The phosphorescence of the other
variety, unlike that of calcite and of the uranyl salts, is of short duration under
both kinds of excitation.
The determination of the decay of phosphorescence of a specimen of the
latter variety, using the disk phosphoroscope, gave curves like that plotted in
figure 5. Processes 1 and 2 are of type 1 (vanishing) but these are followed
by a process 3 of lesser slope.
PHYSICS: NICHOLS AND HOWES
309
This is obviously a composite curve due to the superposition of phosphor-
escence of both types. It does not follow however that it is a true example of
a single substance brought to both types of phosphorescence by photo-excita-
tion. The evidence is to the contrary.
1. The two varieties of willemite are commonly associated. One of our
specimens contains parallel veins of the persistent form and of willemite of
short duration in the same matrix.
2. Willemite is associated with the Franklin Furnace calcite.
That the vanishing phosphorescence in the curve in figure 5 may be due to
an admixture of calcite is suggested by the following observations.
a. When the disk of the phosphoroscope, coated with the powdered will em-
ite and exposed to the light of the iron spark, was driven rapidly, the region
nearest the spark in the direction of revolution but shielded from the direct
light was a brilliant yellow-green, the regions approaching the spark but
601
WILLEMITE. U-V. EXC. DISK.
40
/%
20
1.
.10 .20 .30 SECONDS .40
FIG. 5
shielded, were of a dark blue-green. This is the effect which would be expected
were calcite present, since its red-yellow phosphorescence would give the yel-
lowish caste during the first process of decay but would vanish before the revo-
lution of the disk was completed.
b. When the collimator of a spectroscope was directed to the rapidly revolv-
ing disk the spectrum of the phosphorescent willemite appeared as a broad
continuous band extending from the extreme red to the blue. The crest was
approximately at 0.54 /x and there was suspicion of a weak region in the yellow.
At a somewhat lower speed, which allowed a longer interval of time between
excitation and observation the red end of the spectrum disappeared and at a
much lower speed the yellow and brightest part of the green vanished leaving
a much narrower band in what had been a comparatively feeble region, with
its crest in the blue green at about 0.52 /x.
The former brilliant crest at 0.54 fi was now very dim and lay near the edge
of the persistent band. This persistent crest coincides in position with that
of the fluorescence spectrum of a willemite of long duration determined spec-
trophotometrically some years ago.9
310
PHYSICS: NICHOLS AND HOWES
Obviously we have in this spectrum two, and perhaps three overlapping
bands. A very rapid red band, presumably due to calcite, the band of the
willemite of short duration and a persistent band of small intensity indica-
tive of the presence of willemite of long duration.
Not all specimens of willemite have the complicated curve of decay above
described. Waggoner,1 (1908) in his studies of phosphorescence of short dura-
tion, determined the beginnings of the curves of decay of two will emites; one
of the rapid and one of the persistent variety. He used the Merritt phos-
phoroscope having a range up to 0.06 seconds. His curves are of the persistent
type.
Not all phosphorescence of quick decay is of the vanishing type. — That the type
of phosphorescence is not altogether a question of duration we have abundant
i
CADMIUM PHOSPHATE.
U-V. EXC.
DISK.
0
40
20
•T
1.00 SECOND.
r
FIG.
6
evidence. The willemite of quick decay measured by Waggoner is of much
shorter measurable duration than the Franklin Furnace calcites, yet its curve
of decay is clearly of the opposite type. The same is true of various phos-
phorescent compounds prepared by Waggoner, i.e., ZnCl2, CdCl, CdS04, —
each with a trace of MnSCU added, which were heated to redness with a flux
of Na2S04. Although their phosphorescence is of brief duration they gave
decay curves of the persistent type.
There is this distinction between the luminescence of such substance and van-
ishing phosphorescence. The latter becomes completely extinct almost im-
mediately after it ceases to be of measurable intensity; as indicated by the
steepness of the second and third processes (fig. 2). In the persistent type
PHYSICS: NICHOLS AND HOWES
311
of short duration the loss of light during the initial process may go to the very
limit of visibility within a few hundredths of a second or less, but if the
threshold is not actually crossed the phosphorescence may remain, barely visible
in a completely dark room, for a considerable time. Waggoner remarks (on
page 216 of his paper) 11 It will be noted that in practically all the substances
studied, the measurable portion of the decay is over in 0.07 seconds. Some of
the substances may, however, be seen in a dark room for a very much longer time."
Phosphorescence of short duration, when not of the vanishing type, may be
considered simply as a case of the persistent type in which the rapid initial
process reduces the intensity nearly to or beyond the threshold of visibility.
The subsequent processes, though gradual are therefore too faint for observa-
tion or invisible. The brightness of the first process may be as great or greater
in cases of quick decay than where the phosphorescence continues of meas-
urable intensity for a long time. Zeller2 who has studied the beginnings of
decay of the phosphorescence of various persistent compounds has made note
H
EFFECT* OF INFRA-RED.
4
/ /
* y •
2
%f y^
1 .
*
. 4.° . 8.0SEC-
FIG. 7
of the fact that duration is not in any simple way related to initial brightness.
In a group of phosphorescent cadmium compounds, in particular, some that
were too dim for measurement with the phosphoroscope remained visible for
a long time while those of greatest initial intensity were of very short duration.
An interesting substance which came to our notice during these investiga-
tions through the kindness of Mr. W. L. Lemcke is a cadmium phosphate
prepared by Mr. W. S. Andrews. Under the iron spark it is excited to a fine
white phosphorescence having a measurable duration of about one second.
We determined its curve of decay with the disk phosphoroscope. As may be
seen from figure 6 it is of the persistent type and so far as the white afterglow
is concerned might be classed as of rather short duration; but a very faint
ruddy phosphorescence remains for a much longer time. This specimen, as
viewed on the rotating disk is remarkable for the succession of color effects
which it exhibits. Pink, very fleeting, is followed by nearly pure white, then
for an instant by blue which goes over into a very persistent pink, turning
ruddy as decay progresses.
312
PHYSICS: NICHOLS AND HOWES
Such color changes in other substances have been shown to be due to the
existence in the phosphorescence spectrum of overlapping bands having dif-
ferent rates of decay and the striking display would seem to indicate an unusual
complexity of composition. We were surprised, therefore, to learn from Mr.
Andrews that for the production of this brilliant white phosphorescence cad-
mium phosphate of exceptional purity is necessary, and that there is no ad-
mixture of other metallic salts, as in the preparation of the phosphorescent
sulphides.
Curves exhibiting the new vanishing type of decay, above described, resemble
nothing in the earlier work on phosphorescence so much as the curves ob-
tained as a result of the action of infra-red light on Sidot Blende.1 Fig-
ure 7 exhibits this phenomenon. Processes 1 and 2 together show the pure
decay curve, without infra-red, but if the infra-red is applied after 18 seconds
of decay the more rapid process 3-4 ensues. If, however, the infra-red is
removed at the end of 25 seconds the decay resumes a slower rate, as shown by
process 5. Processes 1, 3 and 4 taken together show a striking resemblance
to the vanishing type of decay. Attempts to hasten the decay of calcite or of
the phosphorescent uranyl salts by infra-red action however have yielded no
result. Here the successively steeper processes must be due to a change in
the rate of recombination of the ejected electrons with the active phosphores-
cing groups. It is commonly believed that only certain groups of particles
are active, the majority being considered to be inactive. It is evident that
these changes in rate of decay are inherent with the crystal and must be due
to a more or less sudden change in the internal conditions. The electric
fields within a crystal are so strong that it is perhaps not surprising that the
infra-red field, applied from the outside, cannot affect either the phosphores-
cent action in the active groups or increase the number of free electrons. The
sudden change in the rate of decay may be due to a change in the electric
field concomitant with the changed orientation of the charged particles, which
drives the ejected electrons in greater proportion to the non-active parts of
the molecule.
1 Waggoner, Physic. Rev., Ithaca, (Ser. 1), 27, 1908, (209).
2Zeller, Ibid., 31, 1910, (367).
3 Ives and Luckiesh, Astroph. J., Chicago, 36, 1912, (330).
4 Trowbridge, C. C, Physic. Rev., 32, 1911, (129).
6 Kennard, Ibid., (Ser. 2), 4, 1914, (278).
6 Nichols and Howes, Ibid., 9, 1917, (292).
7 Wick and McDowell, Ibid., 11, 1918, (421).
8 To be described in a forthcoming number of the Physical Review.
9 Nichols and Merritt, Ibid., (Ser. 1), 28, 1909, (349).
10 Nichols and Merritt, Studies in Luminescence, Carnegie Inst., Washington, Pub.. 152,
1912.
ASTRONOMY: C. G. ABBOT
313
THE SMITHSONIAN 1 SOLAR CONSTANT EXPEDITION TO
CALAMA, CHILE
By C. G. Abbot
Smithsonian Astrophysical Observatory
Communicated August 16, 1918
As early as 1903 the observations of the Smithsonian Astrophysical Ob-
servatory suggested the view that the solar radiation varies over a range of
several per cent within intervals as short as a few days or weeks. We were
measuring the radiation of the sun at the earth's surface. The measurements
comprised determinations of the heating effect of tbe solar rays on the black-
ened surface of the pyrheliometer, which measures all rays of the spectrum as
found in 'white light/ and also the heating effects at all parts of the solar
spectrum as detected by the bolometer, including ultra-violet, visible and
infra-red rays. We measured at intervals on every clear day as the sun
declined from high altitudes near the zenith to low altitudes near the horizon.
Thus the rays measured rjassed through longer and longer paths, according
to the obliquity with which they crossed the atmospheric layers, and con-
sequently they grew weaker and weaker as the sun declined lower and lower.
From the spectro-bolometric measurements, standardized to calories by aid
of the simultaneous pyrheliometer measurements and reduced to zero atmo-
spheric absorption by the method of Langley we thus determined the intensity
of solar radiation as it would be outside the atmosphere at mean solar dis-
tance. This has been called the solar constant of radiation. Its average
value is about 1.93 calories per square centimeter per minute.
As I have said the results of 1903 at Washington indicated variations of
this so-called constant over a range of nearly 10%. Owing to the prevalence
of clouds at Washington all too few observations were available. Neverthe-
less when we compared such as we had with the anomalies of temperature
of the North Temperate Zone as represented by meteorological observations
at 89 stations, all regions showed a variation of temperature nearly parallel
to, and of a proper magnitude to correspond with, the supposed variations of
the sun.
In 1905 we transferred the observing to Mount Wilson, California, and
with the exception of 1907 we have observed the 'solar constant,' in that
relatively favorable place, usually from June to October of each year. The
results have confirmed the apparent variability of the sun. It is impossible
to go outside the atmosphere to observe, and we feared that the apparent
variability of the sun might have been really due to defects in our estimation
of the losses in the atmosphere. To check our work as far as possible we
observed in 1908, 1909, and 1910 from the summit of Mount Whitney (4420
meters) the highest peak in the (older) United States. No error dependent
314 ASTRONOMY: C. G. ABBOT
on altitude appeared. In 1914 we sent an automatic recording pyrheliometer
by sounding balloon to 25,000 meters altitude. The result obtained was
trustworthy and agreed with what we expected. All these checks confirmed
the accuracy of our work and strengthened our belief in the solar variability.
Meanwhile in 1911 and 1912 I had observed in Algeria while my colleagues
observed in California. Unfortunately for the proof of solar variability 1911
was cloudy and 1912 was the year the air was charged with volcanic dust by
the great volcanic eruption of Mount Katmai, June 6, 1912. Nevertheless
despite this handicap the results left little reasonable doubt that the sun is
variable. High 'solar constant' values at Bassour, Algeria, coincided with
high values at Mount Wilson, California, and vice versa, and equal increments
of radiation were found at the two stations independently, notwithstanding
that they are separated by one-third the earth's circumference.
In 1913 and subsequently the proof of solar variability was rendered im-
pregnable. We investigated daily the distribution of radiation over the solar
image formed by our tower telescope on Mount Wilson. The sun's image is,
as you know, unequally bright at centre and edges, so that the curve of its
intensity along a diameter takes the form of the letter U inverted. The
steepness of the curves of the U varies with wave-length. But we found also
that it varies from day to day, and that the variations are such that a greater
contrast of brightness between center and edge occurs when the solar radia-
tion as a whole is found to be diminished and vice versa. I suppose the outer
layers of the sun vary in transparency. When more opaque they diminish
the 'solar constant' but as the effect is greatest near the limb of the sun where
the oblique path of the ray in the solar layers is greatest, the result is also to
increase the contrast. At all events we have found a true variation of the
sun, independent of the earth's atmosphere, which coincides in time of its
fluctuations with the observed changes of the 'solar constant.'
Professor Pickering had kindly undertaken pyrheliometer measurements
at Arequipa, Peru. These were carried on from 1912 to 1917. They tended
to confirm in the more outstanding features the variation of the sun observed
at Mount Wilson.
Dr. L. A. Bauer, whose remarkable campaign of magnetic observations
lends lustre to the science of our country, has investigated certain minute
disturbances of terrestrial magnetism for which no cause had been assigned.
He finds them to be closely correlated with the variations of solar radiation
we have observed.
Dr. H. H. Clayton, formerly of Blue Hill Meteorological Observatory, now
of the Argentine Meterological Service, has investigated the variations of
terrestrial atmospheric temperature and pressure for nearly fifty stations
in all parts of the earth. He finds a close correlation of these meteorological
variations with the irregular variations we have observed in solar radiation.
Equatorial stations show a direct correlation in temperature. That is high
solar radiation is followed by high temperature and vice versa. Many tern-
ASTRONOMY: C. G. ABBOT
315
perate zone stations show opposition of variation. Polar stations show
direction variation. If these results shall be confirmed and enlarged they bid
fair to aid in actual weather forecasting, for the changes are by no means
small.
In view of the scientific and utilitarian interest associated with the vari-
ability of the sun, I have long desired that several cloudless observing stations
might take up 'solar constant' work. In 1914 I made a trip to Australia
expecting that the Australian Government would take it up. This hope was
frustrated by the war.
In 1916 Secretary Walcott appropriated from the income of the Hodgkins
Fund to equip and maintain for several years such a station in South America,
but owing to the war it was temporarily located in the North Carolina moun-
tains in 1917. The station proved very cloudy, and now it has proved pos-
sible though very expensive to go to Chile.
After correspondence with the South African, Indian, Argentine and
Chilean meteorological services I became convinced that near the nitrate
desert of Chile is to be found the most cloudless region of the earth easily
available. Dr. Walter Knoche of Santiago has most kindly furnished two
years (1913 and 1914) of unpublished daily meteorological records for a
number of Chilean stations. In his judgment and mine the best is Calama
on the Loa River, Lat. S. 22° 28', Long. W. 68° 56', Altitude 2250 meters.
For the two years the average number of wholly cloudless days is at 7 a.m.
228; 2 p.m., 206; 9 p.m., 299; and of wholly cloudy days, none. The precipi-
tation is zero; wind seldom exceeds 3 on a scale of 12; temperature seldom
falls below 0° or above 25°C.
Our expedition, Director Alfred F. Moore, Assistant Leonard H. Abbot,
reached Calama June 25, 1918, equipped with a full spectro-bolometric, pyr-
heliometric, and meteorological outfit of apparatus, as well as with books,
tools, household supplies, and everything which we could furnish to make the
work successful and life bearable. We are under great obligations to the
Chilean Government for facilitating the expedition in many ways, and to the
Chile Exploration Company who have given the expedition quarters and
observing station at an abandoned mine near Calama. Many others in
Antofagasta, Chuquicamata and Calama have been of great assistance.
The apparatus is set up in an adobe building about 30 feet square, in which
the observers also have sleeping apartments. A 15-inch two-mirror coelostat
reflects the solar beam to the slit of the spectro-bolometer. We use a Jena
ultra-violet crown glass prism and speculum metal mirrors in the spectro-
scope. The linear bolometer is in vacuum, and constructed in accord with
complete theory for greatest efficiency. Its indications as measured by a
highly sensitive galvanometer are recorded photographically on a moving
plate which travels proportionally to the movement of the spectrum over the
bolometer. Successive bolometric energy spectrum curves each occupying
8 minutes of time are taken from early morning till the sun is high and are
316
GENETICS: C. B. BRIDGES
thus recorded on the plate. Their intensity indications at 40 spectrum posi-
tions are reduced by aid of a special slide rule plotting machine.
A pair of silver disk pyrheliometers is read simultaneously with each
spectro-bolographic determination. Measurements of humidity, temperature,
and barometric pressure accompany the bolometric observations. Also a
pyranometer is employed to determine the total sky radiation.
The young men find pleasant companions at the great copper mine at
Chuquicamata. At present they are boarding with a Chilean family at
Calama, but as both are good cooks they may wish to board themselves. The
railway and the river both pass the town of Calama, so that there is no such
desert isolation as might be feared. To the east are the Andes Mountains.
The peaks in that neighborhood rise to 16,000 or 17,000 feet. Some are vol-
canic but none of these are very near.
We hope the work will be continued for several years at least, and that
nearly daily observations may be obtained. The application of the results
to meteorology is something which may prove to have great possibilities.
To exploit them we must first possess a long and nearly unbroken series of
solar radiation observations.
MAROON— A RECURRENT MUTATION IN DROSOPHILA1
By Calvin B. Bridges
Marine Biological Laboratory, Woods Hole
Communicated August 23, 1918
The recessive eye-color 'maroon' was one of the early mutations in Drosophila
(found March 13, 1912). This eye-color was found in a stock culture of
wild flies, and was at first supposed to be a new appearance of the recessive
mutation 'purple' discovered about a month earlier. Genetic tests (crosses
between the two lines, etc.) showed that the new color was not the old purple,
but was a new mutation almost identical with purple in appearance but en-
tirely independent in origin and inheritance. This was the first of our now
numerous cases of eye-color 'mimics/ in which two distinct genes produce
practically the same somatic effect.
During the six months following the discovery of purple and maroon there
were thirteen recorded appearances or 'purple' eye colors, which constituted
our most striking 'mutating period' of 'epidemic of mutation.' Of these new
'purples,' tests showed that the first, fifth, sixth, and thirteenth were maroon,
while the rest were true purple. A study of the pedigrees showed that these
maroons had come from two independent occurrences of the maroon mutation,
while the true purples likewise came from at least two separate acts of muta-
tion. Maroon has reappeared independently on two subsequent occasions,
so that this particular mutative process has occurred at least four times. The
GENETICS: C. B. BRIDGES
317
same property of specific recurrent mutation has since been found to be char-
acteristic of several other loci, of which notch, vermilion, rudimentary, and cut
are the most striking examples.
At this time (April, 1912) pink was the only mutation known to be in the
third chromosome (by definition) so that the F2 results from the cross of ma-
roon to pink constituted the only test as to whether maroon also is in the third
chromosome. Maroon differs enough from pink in its characteristics so that
the separation of the two forms could be accurate for about 85% of the in-
dividuals. The Fi flies from the cross were wild- type (two non-allelomorphic
recessives), and the F2 flies were 485 wild- type: 215 maroon-like: 183 pink-
like : 0 maroon pink.
It was expected that the flies which were homozygous for both maroon and
pink would be as much lighter than pink as maroon is lighter than the wild-
type, since this was the usual type of relationship. No flies lighter than pink
were found, but it was uncertain whether this meant that the double recessive
was actually absent because of strong linkage (no crossing over), or that the
double form was present but indistinguishable from pink or from maroon.
That the double form should be present, but not lighter than pink, would mean
that maroon and pink are 'non-modifiers' of each other. Subsequent work has
shown that' 'non-modification' is the usual relation between the different pinks
that have arisen.
That the apparent absence of the maroon pink class was a real absence due
to linkage was soon proved: Tests, by means of F2 and back cross results, of
the linkage relations between maroon and the second chromosome mutant
"arc" showed that these two genes assort with complete independence. The
above tests showed that the locus of maroon was probably not in the second
chromosome, and was therefore probably in the third chromosome. Mean-
while the body color ebony had arisen and had been shown to be linked to
pink (Sturtevant, '13). 2 Since there could be no question of failure of identi-
fication of the double recessive maroon ebony the next step was to show that
maroon is linked to ebony. The F2 of the cross of maroon by ebony gave a
2:1 : 1 : 0 linkage ratio, which we had just learned to explain as the result of
'no crossing over in the male' (Morgan, '12). 3 The F2 from the maroon by
pink cross was thus proved to have been a 2 : 1 : 1 : 0 ratio, and was in fact
the first such linkage result obtained for the third chromosome.
The location within the third chromosome of the gene for maroon was made
easy and direct by the discovery and location of two excellent III chromosome
dominants, 'dichaete' and 'hairless.' The locus of dichaete is quite near the
left end of the third chromosome (at about 11.0) while that of hairless is near
the middle (at about 32.0). The back cross tests showed that the locus of
maroon is to the right of dichaete by about 4.2 units, or is at a position of 15.2
(11.0 + 4.2) when referred to the locus of sepia as the zero point. With hair-
less, maroon gave 21.2% of crossing over, which corresponds to the location
of maroon between dichaete and hairless.
318
GENETICS: C. B. BRIDGES
It was found that the chromosome in which the third independent mutation
to maroon had occurred was carrying two other mutant genes : One of these,
'dwarf/ is a recessive that reduces the size of flies to only about half that of
normal sibs; it also sterilizes females homozygous for it. The locus of dwarf
is within a unit to the right of that of maroon. The other gene causes no
observable somatic difference, but profoundly affects the process of crossing
over in third chromosome in definite regions and by definite amounts. A dis-
tinct new system of cross-over values corresponds to the heterozygous and still
another to the homozygous condition for the gene. A comparison of the be-
havior and effects of this gene with that of the already known genetic varition
called 'Cm' showed that they were probably identical mutations. There was
found to be 5.9% of crossing over between dichaete and maroon in femal s
heterozygous for Cm, and 6.6% when females were homozygous for Cm. In
the region near dichaete there is, as these values show, no great difference be-
tween the homozygous and heterozygous Cm conditions.
1 A full account of maroon with the detailed data on which the various statements of
this paper are based will appear as a section of a publicatian by the Carnegie Institution
of Washington.
2Sturtevant, Science, New York, N. S., 36, 1913, (990-992).
^Morgan, Ibid., 36, 1912, (718-720).
INFORMATION TO SUBSCRIBERS
Subscriptions at the rate of $5.00 per annum should be made payable
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CONTENTS
Page
Psychology.— Measuring the Mental Strength of an Army
By Major Robert M. Yerkes 295
Physics. — Thermo-Electric Action with Thermal Effusion in Metals: A
Correction By Edwin H. Hall 297
Mathematics.— Invariants and Canonical Forms . . . By E. J. Wilczynski 300
Physics. — Types of Phosphorescence . . By Edward L. Nichols and H. L. Howes 305
Astronomy.— The Smithsonian 'Solar Constant' Expedition to Calama, Chile
By C. G. Abbott 313
Genetics. — Maroon — A Recurrent Mutation in Drosophila
By Calvin B. Bridges 316
VOLUME 4
NOVEMBER, 1918
NUMBER 11
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