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III. The Influence of Molecular Constitution and Temperature on Magnetic 
By A. E. Oxley, B.A., M.Sc., Coutts Trotter Student, Trinity College, Cambridge. 
Communicated by Prof. Sir J. J. Thomson, O.M., F.R.S. 
Received December 17, 1913,—Read January 29, 1914. 
Contents. 
Introduction. Hypothesis of molecular distortion . . . 
Page 
109 
Part I. 
(1) The measurement of magnetic susceptibility at air temperature.Ill 
{2) Experiments at low temperatures.114 
(3) Experiments at high temperatures.115 
(4) Discussion of possible errors.‘.116 
(5) Method of experiment.118 
(6) Experimental.120 
A study of— 
(a) Benzene derivatives. 123 
(b) Naphthalene derivatives.130 
(e) Several other substances. 130 
(7) General discussion of the experimental results with reference to crystal structure .... 131 
Part II. 
(1) Theoretical interpretation of the experimental results in terms of the electron theory of 
magnetism and the hypothesis of molecular distortion.136 
(2) The mean molecular field of a diamagnetic crystalline substance.141 
Summary of conclusions.143 
Introduction. 
The present communication is a continuation, and in some respects a completion, of 
several preliminary researches which have been published from time to time during 
the past three years. 
On the hypothesis that a molecule may be distorted by the near approach of its 
neighbours, it has been shown* how the presence of molecular groups, which vary in 
* ‘Proc. Camb. Phil. Soc.,’ vol. XVI., p. 486, 1912. 
VOL. CCXI4 . A 511. Published separately, May 5, 1914. 
