114 Generating Economic Cycles 



of his critics, most of whom were scandaHzed by his 

 postulating a new form of matter, inferred from the 

 luminescent effect of the rays that they must be some 

 form of wave motion in the ether analogous to ultra- 

 violet light. 



The controversy as to the nature of the cathode rays 

 lasted nearly twenty years until Sir J. J. Thomson, in 

 1895, following the lead of Perrin, proved that they 

 are not ethereal waves but negatively electrified 

 particles with definite mass. The experiments of Pro- 

 fessor Thomson not only were conclusive with respect 

 to the nature of the cathode rays but were suggestive 

 of epoch-making views with regard to the theory of 

 electricity and the constitution of the atom. 



The characteristics of cathode rays w^hich, for our 

 purpose, should be specified are these: 



(1) Cathode rays originate at the cathode of the 



discharge tube and proceed in straight lines 

 perpendicular to the cathode. The rays will 

 take this direction, noiTnal from the cathode, 

 no matter where the anode may be placed. 



(2) They light up a fluorescent screen when they 



fail upon it. 



(3) They are composed of negatively electrified 



particles. 



(4) They may be deflected from their path by a 



magnetic or an electrostatic field. 



The experunental proof is suggested by 

 the preceding characteristics. As the cathode 

 rays light up a fluorescent screen the deflecti- 

 bility of the rays by a magnet or by an 



