PROCEEDINGS OF THE ACADEMY AND AFFILIATED 



SOCIETIES 



PHILOSOPHICAL SOCIETY 



S37TH MEETING 



The S37th meeting was held at the Cosmos Club, May 22, 1920, with 

 President Sosman in the chair and 50 persons present. 



The first two papers of the program were devoted to the general subject 

 Foreign laboratories and societies, the speakers being C. E. Mendenhall and 

 H. L. Curtis. Mr. Mendenhall confined his remarks to his observations 

 and experiences in England referring especially to the Royal Society, the 

 Royal Institution and the Physical vSociety of London. Mr. Curtis spoke 

 of the French societies and laboratories and of the National Physical Lab- 

 oratory of England. 



Discussion: Messrs. Sosman, Crittenden, Humphreys, Bowie, and 

 Williamson took part in the discussion. 



The last paper was by W. P. White on Three methods of promoting precision 

 in thermostats. Preliminary publication of this paper appeared in this 

 Journal.^ The paper was discussed by Messrs. Mendenhall, Dickinson, 

 Mueller, and T. S. Sligh. 



S38TH meeting 



The 83Sth meeting was held at the Cosmos Club, October 9, 1920. Presi- 

 dent Sosman presided and about 50 members and guests were present. The 

 program was as follows: 



S. J. Barnett: Further experiments on magnetization by rotation. 



This paper is a report of progress in the first part of a general investigation 

 of the relations between magnetization and rotation designed to extend the 

 earlier work in this field, to obtain more precise results, and especially to find 

 out whether negative electricity with the known value of m/e is alone re- 

 sponsible for magnetisfn. 



In earlier papers it has been shown that, if the slowly moving electron, 

 with the value of m/e known from other experiments, is alone involved in 

 the Ampereian vortices, the rotation of a magnetic substance at an angular 

 velocity of one revolution per second is equivalent to placing it in a magnetic 

 field of strength —7.1 X 10"'' gauss directed along the axis of rotation. 

 Two series of experiments made in 1914 and 1915, by a method of electro- 

 magnetic induction, gave 3.6 and 3.1, respectively, instead of 7.1, apparently 

 indicating that negative electricity is chiefly responsible, but that positive 

 electricity also is involved. Another alternative, on the assumption of the 

 correctness of the experimental results, is that negative electricity alone is 

 involved, but that it has, for the motions responsible for magnetism, a smaller 

 value of m/e than that determined in known experiments. 



Another series of experiments made in 1916 and 1917 by a magnetometer 

 method gave the same sign as before, but gave numbers approximately 5 and 

 6 in place of 8.1. A few experiments made more than two years ago at the 

 Ohio State University, where the earlier work was done, with copper sub- 



1 This Journal, 10: 429-432. 1920. 



162 



