CH. v.] OF CATHODE RAYS 4T 



If the flying particles were really atoms, there was 

 no escape from the certainty that they were 

 extraordinarily highly charged atoms ; but if, as 

 seemed more likely to the instinct of most of those 

 who worked at the subject, the charge on the flying 

 particles was the same as the charge possessed by an 

 atom in electrolysis, then, assuming that the experi- 

 ments were correct and correctly interpreted, there 

 would be no escape from the conclusion that the 

 mass associated with the ionic charge in cathode rays 

 must be a thousand times smaller than the mass of a 

 hydrogen atom ; in which case the cathode projectiles 

 might conceivably be the detached and hitherto 

 hypothetical individual electrons or atoms of elec- 

 tricity themselves. It would be extremely rash, 

 however, to jump to such a far-reaching conclusion 

 on such comparatively scant evidence. The evidence 

 must be confirmed by other departments of Physics 

 or by other determinations based on a different 

 method ; and they must be further scrutinised in 

 the light of other and totally different phenomena. 

 We will first describe a determination made by 

 another method, and then some striking confirmatory 

 measurements applied to phenomena which belong 

 apparently to other departments of Physics. 



Further Measurements of Cathode Ray Velocity 



and m/e Ratio by Aid of Electrostatic 



Deflection. 



Another and perhaps simpler method of deter- 

 mining the two quantities u and m/e was also 

 employed by J. J. Thomson, was indeed the first 

 used by him, though it was not safe to draw a full 

 deduction from it alone viz., by deflecting the 

 same rays both electrostatically and magnetically ; 



