﻿730 



Mr. ft. W. Varder on the 



In discussing this question with Dr. Bohr, he informed me 

 that he had deduced from theoretical considerations that the 



Fig. 5. 



1-4 



CM- 



2 1-2 



< 



= 8 



— r "T ! i | 



2000 



4000 

 HP 



6000 8000 

 IN GAUSS CM. 



i0,000 12,000 



loss of energy (<ZT) of a /3 particle in going through a 

 thickness of matter (dx) should be given by 



dj 



dx 



K 

 /3" 



where 



T = m c 2 ((l-/3 2 r*-l) 



is the kinetic energy of the particle. 



j3 = ratio of velocity of /3 particle to the velocity of light. 



K is a function of the velocity which increases slowly 

 with increasing velocity. If we assume K is constant, and 



