382 Rollins — Cathode Stream and X-Light. 



Art. XXXYIII. — The Cathode Stream and X-Light / 

 by William Rollins. 



The Cathode Stream. 



There are two opinions about cathode rays. 



1. The rays are some phenomenon in the ether. Lenard 

 considered them smaller transverse waves than those of light. 

 Michelson thought they were ether vortices. 



2. They are flights of material particles. Varley, who 

 published his results in 1871, considered the cathode stream 

 composed of molecules of the residual gas in the vacuum 

 tube, charged with negative electricity. He deflected the 

 stream by a magnet : showed the force of its impact on a 

 pivoted mica vane. Crookes, who illustrated the earlier work 

 of Yarley and Hittorf by beautiful experiments, agreed with 

 Varley as to the nature of the stream. He said the cathode 

 stream particles left the cathode normal to its surface, moved 

 in straight lines, coming to a focus in the center of its curva- 

 ture. My experiments showed that neither theory of the 

 cathode stream could explain all the facts. If it was possible 

 to remove all the ether from an X-light tube, there would be 

 no X-light, for no cathode stream could form, because a strain 

 in the ether is essential. 



The Ether Theory. — One characteristic of the Yarley or 

 cathode stream has not been explained by this theory : the 

 stream can be deflected by a magnet, X-light arising where the 

 deflected stream strikes. As there are also other objections, 

 the pure ether theory will not be further considered. The 

 experiments supposed to support it apply as well to the 

 material particle theory. 



The Material Particle Theory. — Since Yarley's experi- 

 ments the opinion has slowly grown that the particles in the 

 cathode stream are not as large as molecules. The facts of 

 physics and chemistry appear to prove that electricity breaks 

 molecules into ions. Schuster therefore said the particles were 

 the same Faraday ions as appear in electrolysis. Other phys- 

 icists have further reduced the size, Weichert giving it as 

 1/3000 of a hydrogen atom, and the speed as one-third that of 

 light. In regard to this speed, Rowland, in a remarkable 

 paper before the American Physical Society in 1899, said there 

 was no way of producing this velocity in a body though it fell 

 from infinite distance on the largest aggregation of matter in 

 the universe. 



Weichert made the first determination of the relation 

 between the charge and the mass of a cathode stream particle. 



