letals under Influence of Alpha Rays. 

 Fig. 1. 



405 



CENT1METER5 



that the number escaping would he more or less nearly propor- 

 tional to the number of atoms ionized. Accordingly measure- 

 ments were made of the number of electrons escaping from a 

 thin metal foil when struck by a-rays at different points in the 

 range. 



