ELECTRONS 69 



that an evolution of complex from simple forms 

 of matter accompanied the development of planets 

 from the nebulae. Evolution could look for no 

 grander triumph." 



At that point, indeed, the doctrine of unity of 

 matter could neither be discarded as false nor 

 accepted as true. 



A few years later, however. Sir William Crookes 

 brought forward convincing evidence of Radiant 

 Matter — of matter neither solid, nor liquid, nor 

 gaseous, but apparently in the fourth state which 

 Faraday had foreseen. This was the first step 

 towards the demonstration of a materia prima. 



It came about thus. Hittorf had been investi- 

 gating the result of passing an electric current 

 through a glass bulb almost exhausted of air, and 

 Sir William Crookes continued the same experi- 

 ments. We have already explained that the 

 molecules of the air dart about with tremendous 

 rapidity ; but that, owing to collisions with each 

 other — thousands of millions in a second — their 

 progress is very interrupted. When, however, 

 a bulb is exhausted of air, the remaining particles 

 have much more room to rush about, and do not 

 jostle each other so much. 



By ingenious technique. Sir William Crookes 

 succeeded in producing a more complete vacuum 

 than had ever been produced before ; and on 



