1919] on Atomic Projectiles and their Collisions 575 



the "central nucleus, and under favourable conditions the H atom 

 would acquire a high velocity and be shot for\Yard like a free 

 hydrogen atom. Taking into account the great energy of the 

 particle, the close colhsion of an a-particle with a light atom seems 

 to be the most likely agency to promote its disruption. Considering 

 the enormous intensity of the forces brought into play in such 

 collisions, it is not so much a matter of remark that the nitrogen 

 atom should suffer disintegration as that the a-particle itself escapes 

 disruption. The results, as a whole, suggest that if a-particles or 

 similar projectiles of still greater energy were available for experi- 

 ment, we might expect to break down the nucleus structure of many 

 of the lighter atoms. 



[E. E.] 



