rapidly moving Electrified Particles. 471 



we find that for any gas at atmospheric pressure when the 

 particles have this velocity 



a; = (tt — 2) X roughly. 



7^.{2-(l-^).»} 



Becker found that cathode rays of about this velocity travel 

 through about '5 cm. of oxygen before the number moving 

 forwards is reduced to \. Putting a3 = | we get for Nq about 50, 

 if the number of corpuscles were equal to the atomic weight 

 Nq would be equal to 16. Thus these experiments show that the 

 number of corpuscles in the atom is of the same order as the 

 atomic weight ; we must, however, wait for experiments made on 

 different lines before we can determine the exact relation between 

 the number of corpuscles and the atomic weight. 



