December 17, 1920] 



SCIENCE 



581 



UNIVERSITY AND EDUCATIONAL 

 NEWS 



It is stated in Nature that the first list of 

 donations in response to the appeal of the Uni- 

 versity of Birmingham for £500,000 shows 

 gifts or promises to the amount of more than 

 £250,000. Nearly half of this amount is given 

 to the Petroleum Mining Endowment Fund. 

 The largest single gift is an anonymous one of 

 £50,000 for the general fund. A sum of £5,000 

 is for a chair of Italian, and an equal amount 

 is given by the James Watt Memorial Fund 

 for a James Watt research chair in engineer- 

 ing. 



Assistant Professor Eugene Taylor, of the 

 University of Wisconsin, has been appointed 

 professor and head of the department of mathe- 

 matics at the University of Idaho. 



Dr. J. C. Witt, assistant professor of analyt- 

 ical chemistry in the University of Pittsburgh, 

 has resigned, to become chief research chemist 

 for the Portland Cement Association with 

 headquarters in Chicago. Dr. C. J. Engelder, 

 of Hornell, !N'. Y., has been appointed to the 

 position at the University of Pittsburgh. 



. Mr. William B. Brown, associate physicist 

 of the aeronautic power plants section of the 

 Bureau of Standards, has been appointed in- 

 structor in physics at the Ohio State Univer- 

 sity. 



Dr. Eodney B. Harvey has resigned as plant 

 physiologist, bureau of plant industry, Wash- 

 ington, D. C, to accept the position of assist- 

 ant professor in plant physiology at the Uni- 

 versity of Minnesota and assistant plant physi- 

 ologist in the Minnesota experiment station. 



Dr. Benjamin Schwartz, assistant zoologist 

 in the Bureau of Animal Industry, has been 

 appointed professor of protozoology and para- 

 sitology ill the University of the Philippines 

 and will sail for Manila late in December. 



DISCUSSION AND CORRESPONDENCE 



HELIUM AND HYDROGEN MODELS 



To the Editor of Science: In a communi- 

 cation to the Science issue of June 18 Dr. 

 Irving Langmuir proposed a model of the 



helium atom consisting of a nucleus of charge 

 2e accompanied by a pair of electrons which 

 execute symmetrical oscillations about two 

 nearly circular arcs on opposite sides of the 

 nucleus. In the issue of November 5 he has 

 proposed a similar model for the hydrogen 

 molecule, and another, of a somewhat differ- 

 ent type, for the positively charged H„ ion. 

 The writer was particularly interested in these 

 models, for in each case the resultant angular 

 momentum is zero, a circumstance which 

 seemed to offer an explanation of the diamag- 

 netic behavior of helium and hydrogen, and 

 of the failure of the theories of the specific 

 heat of hydrogen based on the assumption 

 that the molecule is gyroscopic. 



Unfortunately, Dr. Langmuir did not see 

 how to apply the Wilson- Sommerf eld quantum 

 conditions to the determination of the ener- 

 gies of these models, and therefore was not 

 able to fix the theoretical energies and ioniza- 

 tion potentials defixiitely. These quantum 

 conditions are 





(1) 



where T is the kinetic energy of the atom or 

 molecule, g^, q„, . . . are a properly chosen set 

 of coordinates, p^, p„ . . . , are the correspond- 

 ing momenta, and n^, ?i,, . . . are any integers. 

 Each integral is to be extended over a com- 

 plete cycle of values of the corresponding co- 

 ordinate. Dr. Langmuir states that he is un- 

 able to apply these equations to his models^^ 

 because he does not know what systems of 

 coordinates to use. The choice of a proper 

 coordinate system is not essential, however, to 

 the application of these conditions to the type 

 of problem under consideration. For what- 

 ever coordinates are used, they will have a 

 common period t, which makes possible a con- 



1 Witli the exception of the positive H, ion. He 

 does apply the conditions to this model, and cor- 

 rectly, but expresses doubt concerning the validity 

 of the somewhat unsatisfactory result on account 

 of his uneertaiuty regarding the coordinate system. 



