196 Professor Sir J. J. Thomson [April 10, 



doublet consisting of a negatively electrified corpuscle in rapid 

 rotation round a much more massive particle with a positive charge, 

 and that these doublets may be the same from whatever molecule 

 they may be ejected. The secondary cathode rays are due to the 

 subsequent breaking up of this doublet, their energy being the 

 kinetic energy possessed by the corpuscle when rotating round the 

 positive charge. This hypothesis would also explain the constancy 

 of e/m in the Canalstrahlen produced from different gases. 



There are many ways in which the doublet might get broken up 

 after it had escaped from the molecule. Thus, for example, if 

 another corpuscle, which we shall call for brevity a comet, were 

 under the attraction of the positive particle to describe an orbit 

 such as that shown in Fiff. 7, then when the comet was in the 





p ® \ 



.«^.^' 



/ 



/ 



/ 



/ 



Fig. 7. 



immediate neighbourhood of the positive particle, it would neutralize 

 the attraction of this particle on the corpuscle in the doublet ; thus 

 this will move off with undiminished velocity along a straight line, 

 and when the comet has left the system, will, if not free, be at any 

 rate further from the positive particle than it was before, and still 

 possessed of its original kinetic energy : if it did not get free under 

 the influence of the first comet, a repetition of the process by other 

 comets might liberate it from the doublet. The same effect might 

 be produced if the positive part of the doublet came close to a 

 gaseous molecule, which behaved like a conductor of electricity ; the 

 negative charges induced on the conductor would balance the attrac- 

 tion of the positive particle on the corpuscle in the doublet, and just 

 as in the previous case, the corpuscle would be able to get off with 

 undiminished velocity. 



