SCIENCE 



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Friday, November 10, 1916 



CONTENTS 

 The Nature of the Chemical Atom: Dr. Wil- 

 let L. Hardin 655 



On the Utility of Field Labels in Herbarium 

 Practise : Dr. E. D. Merrill 664 



The National Academy of Sciences 670 



Scientific Notes and News 671 



University and Educational News 674 



Discussion and Correspondence: — 



Scientific Appointments under the Govern- 

 ment: Professor Arthur Gordon Web- 

 ster. Preparation for Medicine: Dr. Cecil 

 K. Dbinker. The Auroral Display of Au- 

 gust 26: F. Alex. McDeemott, J. E. Hyde, 

 S. Stillman Berry, Wilheb G. Stovee, 

 John C. Hesslee, H. B. Latimer, B. B. 

 Hudelson, Gael Zapffe, Maecus I. Gold- 

 man, Aethue Bevan, W. L. Foster, B. H. 

 Chapman, M. H. Jacobs 675 



Scientific BooTcs: — 

 Needham and Lloyd on the Life of Inland 

 Waters: Peofessor E. A. Birge. Child on 

 Individuality in Organisms: Professor H. 

 V. Neal 683 



Proceedings of the National Academy of Sci- 

 ences 685 



The Auriferous Gravels of the Sierra Nevada. 686 



Special Articles: — 



On the Differential Effect of Certain Cal- 

 cium Salts upon the Bate of Growth of the 

 Two Sexes of the Domestic Fowl: Dr. Bay- 

 mond Pearl. The Present Status of the 

 Dolomite Problem: Dr. Francis M. Van 

 Tuyl 687 



MSS. Intended for publication and books, etc.. intended for 

 review should be sent to Professor J. McKeen Cattell, Garrison- 

 On-Hudson, N. Y. 



THE NATURE OF THE CHEMICAL 

 ATOMi 



There is probably no subject in physical 

 science that has received more attention or 

 produced a more profound influence on 

 the theories of chemistry and physics dur- 

 ing the last few years than that of the con- 

 stitution of the atom. The problem has 

 been attacked, not only by many of the 

 foremost chemists and physicists of the 

 world, but also by many eminent astron- 

 omers and mathematicians. It is one of the 

 most difficult as one of the most important 

 problems with which the chemist is con- 

 cerned. 



The conception of the atom became an 

 important factor in chemical science early 

 in the nineteenth century, when Dalton 

 discovered the laws of definite and multiple 

 proportions and announced his well-known 

 atomic theory. He found that when one 

 chemical element combines with another, it 

 combines in a definite proportion or some 

 integral multiple of that proportion. It 

 was only natural that Dalton should have 

 assumed this definite proportion, which he 

 called an atom, to be an indivisible ulti- 

 mate particle ; and it was only natural that 

 this theory should have prevailed through- 

 out most of the nineteenth century, for, 

 among the most prominent characteristics 

 of the atom are its individuality and its 

 permanency. It behaves in many respects 

 like an indivisible particle. 



Eecent investigations, however, into the 

 phenomena of the cathode rays, Lenard 



1 An address delivered at a meeting of the 

 Southern California Section of the American 

 Chemical Soeiety, Los Angeles, California, Friday 

 evening, October 22, 1915. 



