SCIENCE 



Pbidat, Decembee 26, 1919. 



CONTENTS 



The Building of Atoms: Professor William 



, D. Harkins 577 



The Disruption of Atoms by Alpha Hays: 



. Professor G. S. Fulcher 582 



The Festschrift of Svante Arrhenius 584 



The Death of Lady Allardyce 585 



Scientific Events : — 



Gift to the Museum of Vertebrate Zoology 

 of the University of California: Loss of 

 Geologists by the National Survey; Seduced 

 Bailway Fares to Meetings of Scientific and 



, Learned Societies; The St. Louis Meeting 

 of the American Association for the Ad- 



. vancement of Science 585 



Scientific Notes and News 588 



University and Educational News 590 



Discussion and Correspondence: — 

 , A Proposal of Two New Miocene Forma- 

 tional Names: Dr. Carlotta J. Maury. 

 Snow Doughnuts: Dr. W. Armstrong 

 Price. Variation of Fishes according to 

 Latitude: A. G. Huntsman. Constants and 

 Variables in Biology: J. E. de la Torre 

 BuENO 59 1 



Scientific BooTcs: — 



Chandler on Animal Parasites a}id Humaai 

 Disease: Professor Henrt B. Ward 593 



The Tennessee Academy of Science: Eoscoe 

 NuNsr 594 



The American Chemical Society: Dr. Charles 

 L. Parsons 595 



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

 review should be sent to The Editor of Science, Garriaon-on- 

 Hudson, N. Y. 



THE BUILDING OF ATOMS AND THE 

 NEW PERIODIC SYSTEMi 



What is usually known as the periodic. 

 system of the elements was developed largely 

 in the decade from 1860 to 1870, during the. 

 period of our civil war, by de Chancourtois, 

 JSTewlands, Mendeleefi and Meyer. Mendeleeff, 

 the third to develop the system, has been 

 given almost all of the credit for it, but this 

 is largely because he paid very much more 

 attention to its details than any of the three 

 others. It has now been found that the Men- 

 deleeff periodic relation is simply one method 

 of expressing the arrangement in space of the 

 electrons in the outer part of the various 

 kinds of atoms. 



Five years ago I discovered a new periodic 

 system of the elements, or more properly 

 speaking, of the atoms. This second system 

 is not at all directly related to the arrange- 

 ment of the electrons in the outer part of the 

 atom, hut has heen found to indicate how the 

 atoms are iuilt up, that is, it is related to the 

 structure of the nuclei of the different species 

 of atoms. 



In order to imderstand the meaning of this 

 new periodic system it is important to have a 

 good idea of the present theory as to the gen- 

 eral structure of the atom. According to 

 Rutherford the atom is similar to the solar 

 system in that it has a central sun called the 

 nucleus of the atom, and a system of planets, 

 each of which consists of one negative elec- 

 tron. The atom as a whole is electrically 

 neutral, and the electrons outside the nucleus, 

 which we may call the planetary electrons, are 

 held in the atom by a positive charge on the 

 nucleus. This positive charge is equal numer- 

 ically to the sum of the charges of all of the 

 planetary electrons. This is often expressed 



1 Abstract of a general address presented at the 

 Philadelphia meeting of the American Chemical 

 Society, September 3, 1919. 



