SCIENCE 



Friday, September 21, 1917 



CONTENTS 

 The Magnetic Field of an Atom: Dr. "W. J. 

 Humphreys 273 



Kentucky as an Oil State: James H. Gardner. 279 



Overwintering of the Apple-scab Fung^is: Dr. 

 W. P. Fraser 280 



Scientific Events: — 



Baron DoArohu KiTcuchi; The Production of 

 Potash in the United States; The Museum 

 of the Soyal College of Surgeons of Eng- 

 land; The Mayo Foundation and the Uni- 

 versity of Minnesota 28^ 



Scientific Notes and News 284 



University and Educational News 287 



Discussion and Correspondence: — 



On the Bawness of Subsoils: Dr. Chas. B. 

 LiPMAN. Northern Lights: Thomas Btkd 

 Magath. The New Moon: Dr. Otto Klotz. 

 Erasmus Varum, and Benjamin Franldin: 

 Professor Lorande Loss Woodruff 288 



Scientific Books: — 

 MacNutt on the Modern Milk Problem: 

 Professor Leo F. Eettqer 292 



Special Articles: — 

 Gravitational Repulsion : Professor Francis 

 F. Nipher. The Catalase Content of Lumi- 

 nous and Non-luminous Insects compared: 

 Dr. W. E. Burge. The Effect of Smelter 

 Gas on Insects : R. W. Doane 293 



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

 re-riew should be sent to Professor J. McKeen Cattell, Ganison- 

 On-nudsau, X. V 



THE MAGNETIC FIELD OF AN ATOMi 



The substance and structure of the atom, 

 the movements of its parts, and its proper- 

 ties, are, perhaps, the most fundamental 

 subjects of modern physical investigation. 

 And although the structure and even the 

 substance of the atom can as yet only be 

 inferred, nevertheless its numerous and 

 varied phenomena not only challenge the 

 theorist, but also, through their manifold 

 checks, afford him at every turn the very 

 best guidance to an approximately correct 

 inference. Among the more important of 

 these phenomena are the actions of atoms 

 in respect to absorption and emission of 

 radiation under various conditions of tem- 

 perature, pressure, magnetic and electric 

 fields. Crystal forms, chemical reactions 

 and magnetic properties offer additional 

 suggestions and valuable tests. 



One of the most interesting inferences 

 concerning the atom is this: that it has a 

 very powerful magnetic field. This infer- 

 ence is supported by a number of investiga- 

 tions of entirely different character which 

 'it is proposed in what follows to outline 

 briefly and in approximately their chrono- 

 logical order. 



1. The electromagnetic theory of ether 

 vibrations so satisfactorily accounted for 

 many known phenomena "and so success- 

 fully predicted others, including wireless 

 telegraphy, that it was long ago generally 

 believed that all radiation, including light, 



1 Presented at the symposium on ' ' The Struc- 

 ture of Matter" at a joint meeting of the Sections 

 of Physics and Chemistry of the American Asso- 

 ciation for the Advancement of Science, The Amer- 

 ican Physical Society and the American Chemical 

 Society, New York, December 27, 1916. 



