.206 Geological Society : — 



in Geneva, verified experimentally the Lorentz-Einstein 

 formula for cathode-rays with speeds from 0'25 up to 0*48 

 of the velocity of light. They found it in excellent agree- 

 ment with their measurements of a great number (over two 

 thousand) of observed electric and magnetic deviations of 

 the rays. 



Of course one would wish a further verification for 

 velocities below 0'25 or beyond 0*7 that of light, but the 

 experimental evidence obtained so far in favour of the 

 incriminated formula leaves nothing to be desired. 



Yours sincerely, 

 University of Leiden, A. D FOKKER 



26th June, 1918. 



XVIII. Proceedings of Learned Societies. 



GEOLOGICAL SOCIETY. 



[Continued from vol. xxxv. p. 507.] 



February 15th, 1918.— Dr. Alfred Harker, F.R.S., President, 

 in the Chair. 



fTPHE President delivered his Anniversary Address, giving first 

 JL obituary notices of H. Emile Sauvage (elected Foreign 

 Correspondent, 1879), W. Bullock Clark (For. Corr. 1904), 

 T. McKenny Hughes (el. 1862), Edward Hull (1855), E. H. 

 Tiddeman (1869), G-. A. Lebour (1870), Arnold Hague (1880), 

 Robert Bell (1865), G. F. Franks (1890), G. C. Crick (1881), 

 H. P. Woodward (1883), Upfield Green (1889), C. O. Trechmann 

 (1882), A. N. Leeds (1893), R. Boyle (1911), A. M. Finlayson 

 (1909), and others. 



The President went on to discuss the present position and 

 outlook of the study of metamorphism. The rapid de- 

 velopment of physical chemistry and the successful application 

 of experimental methods to penological questions have greatly 

 changed the situation during recent years, and for the first time it 

 seems possible to approach the subject of metamorphism sys- 

 tematically from the genetic standpoint. For the geologist this 

 implies the critical study, not only of the great tracts of crystal- 

 line schists and gneisses, but equally of metamorphic aureoles, of 

 pneumatolysis and other contact-effects, and of the phenomena, 

 mechanical and mineralogical, related to faults and overthrusts. 

 It implies, moreover, the recognition that these are all parts of one 

 general problem, that of the reconstruction of rocks under varying 

 conditions of temperature and stress. In practice, this problem is 

 complicated by the fact that perfect adjustment of chemical 

 equilibrium cannot be assumed, either in the rocks prior to meta- 

 morphism. or during the process of metamorphism itself. 



