UNSUSPECTED KADIATIUNS. 375 



mean liy our atom.s "carrving negative or positive electricit3%" we may 

 imagine that this means carrying a certain vibratory or, perhaps, spiral 

 movement, or any other sort of motion which we prefer not to specify 

 in order to avoid spreading conceptions which may prove to be erro- 

 neous. But we know for certain that gases, which usually are no con- 

 ductors of electricity, become conductors under the influence of electric 

 discharges, as also of the ultraviolet light, or even after having passed 

 through flames. In such cases they become able to transport electric- 

 ity — that is, some motion or some state unknown,. which we name elec- 

 tricity —from one spot of space to another, A stream of dissociated 

 and electritied particles of matter rushing in the kathode stream is thus 

 a ^'er3^ probable explanation — the more so as similar streams are already 

 admitted in order to explain the electro-chemical decomposition of 

 salts and many properties of solutions.^ The kathode rays would then 

 be ''an electric dance of atoms along the lines of force," as Villariand 

 Righi have expressed it. 



One question only must be asked: Is it necessary to suppose that the 

 molecules are so dissociated as to set free the "primary matter" out of 

 which the atoms of all elements are composed? Theoretically, there is 

 no objection to this view. Modern science knows that the atoms — or 

 the "chemical individuals." as Mendeleeff would prefer to name them- — 

 are onlv treated as indivisible in the chemical processes in the same 

 sense as molecules are (or rather were) treated as indivisible in ph3'sical 

 processes. The modern physicist does not consider the atoms indivisi- 

 ble in the sense Democritus taught it. but in the sense in which the sun 

 is an individual amid the boundless interstellar space. He is even 

 inclined to admit that the atoms have a complicated structure and are 

 vortex rings similar to rings of smoke (Lord Kelvin and Helmholtz), 

 or minute systems similar to planetary systems (Mendeleefi).~ The 

 "dissociation of atoms" would therefore be admissible; but before 

 admitting the ultimate dissociation advocated by J. J. Thomson, can 

 w^e not find a simpler explanation? Several explorers are inclined to 

 think so, and Dr. Villard points out one possible issue. The kathode 

 rays are, in his opinion, mere streams of hydrogen atoms or molecules — 

 the presence of this gas in all tubes, even the best exhausted, l)eing 

 explained by the particles of water sticking to the glass, or by the 

 decomposition of the alkalies of the glass. One fact certainly speaks 

 in favor of Villard's view: A small copper oxide plate, l)eing so placed 

 as to receive the kathode rays, parts with its oxygen (is reduced) just 

 as if it had been struck by a jet' of hot hydrogen. Besides, the spots 

 where the rays fall upon the glass of the tube are blackened, and these 



J See Recent Science, in Nineteenth Century, August, 1892, and January, 1894. 



2 Let me mention in connection with this a brilliant article by Mendeleeff on 

 "Matter," in the new Eussian Encyclopedic Dictionary, published by Brockhaus & 

 Efron, Vol. VI, ]>. 151. 



