PROCEEDINGS 



OP THE 



NEW ZEALAND INSTITUTE 



PART II. 



1908-9 



AUCKLAND INSTITUTE. 



1908. 



First Meeting : ^th June, 1908. 



E. V. Miller, Esq., President, in the cbair. 



New Members.— hi. Aldis, A. Clark, M.B., A. J. Cottrell, W. G. Guinness, 

 M.D., S. E. Lamb, M.A., T. Simson, H. G. Stringer, A. Wyllie, C.E. 



The President delivered the anniversary address. 



The address was mainly devoted to an account of the scientific work which had 

 been done during the last two or three years in connection with the discharge of electricity 

 through gases, and of radio-activity ; and more especially as these two bear on the 

 nature of material atoms and of electricity. After a brief preliminary account of older 

 scientific work, in the course of which the nature of ionisation. of radio-activity, and of 

 the more important phenomena connected with the discharge of electricity through a 

 vacuum tube were touched on, the lecturer proceeded to refer to more recent work on 

 the same subject. An account was given of the metliod employed by J. J. Thomson 

 to measure the velocity and the electro -chemical equivalent of the particles constituting 

 the canal rays, and the remarkable nature of his results was pointed out. The work 

 of Rutherford in 1906 in measuring the velocity and electro-chemical eqiiivalent of the 

 a particles from different radio-active sources was then described, and it was noted 

 that the electro-chemical equivalent found by Rutherford for the a particles was identical 

 with one of the two values found by Thomson for the canal ray particles. This coin- 

 cidence, in conjunction with the already proved identity of the /3 rays with cathode 

 rays, 7 rays with Rontgen rays, brings the phenomena of the vacimm tube into the 

 domain of radio-activity. By means of the discharge in a vacuum tube various ordinary 

 materials, otherwise non-active, may be rendered strongly radio-active at Avill, and the 

 elements disintegrated and traiismuted. 



Existing views were discussed as to the share which the corpi'scles in an atom take 

 in making up its total mass. 



