1896.] 



19 



perimenting now. Dr. Oliver Lodge, of Liverpool, tried two years ago 

 to repeat this very experiment, with a tube of rather thick glass, 

 "Failing," to use his own words, "simply by reason of insufficient 

 pertinacity. ' ' This is doubtless the case, since Lodge has lately repeated 

 Rbntgen's experiment with that same tube, obtaining results "through 

 a quarter inch of wood and a sheet of aluminum, provided something 

 like a half an hour's exposure is allowed" {Electrician, Vol. xxxvi, 

 p. 438). 



Opinions differ as to whether the rays used by Lenard were the same 

 as those producing the Rontgen phenomena. As has been said, 

 cathode rays are deflected by a magnet, while the Rontgen rays seem 

 not to be. The Lenard rays, also, were shown to be capable of deflec- 

 tion by a magnet under certain conditions. Roiitgen, himself, is of the 

 opinion that the new energy is some form of ether wave motion per- 

 haps longitudinal, and Lord Kelvin, I think, maintains the same views. 

 Other English authorities seem to be divided between the ultra-violet 

 theory and the longitudinal wave theory. 



Dr. Lodge in ajecture before the Liverpool Physical Society, January 

 27, 1896, expressed himself as rather favoring the opinion that the 

 Rontgen rays are highly electrified material particles, traveling with 

 very great velocity. In a recent article {Electrician, Vol. xxxvi, p. 

 430), Lodge says, that "He permits himself to doubt and inclines to a 

 sort of electrolytic impulsive propagation, through and by means of 

 ordinary matter ; in spite of the immensely important fact that Prof. 

 Rontgen can detect in his rays no magnetic deflectibility whatever." 

 In concluding the article referred to, Lodge says, "Meanwhile, the 

 possibility, even the probability, that in these rays we have a new kind 

 of radiation, even though it be only ultra-violet, so high up as to be 

 comparable to the size of molecules, lends to these experiments a 

 prodigious interest in the eyes of physicists, far surpassing the obvious 

 practical applications which have gained the ear of the general public." 



Since writing the above. Lodge has himself repeated the magnetic 

 experiment with very great care, finding no deflection {Electrician, 

 Vol. xxxvi, p. 471), and expresses himself as follows : "Consequently, 

 the hypothesis of a stream of electrified particles is definitely dis- 

 proved, as no doubt had already been done in reality by Prof. Rontgen 

 himself." 



It seems that Lenard had arrived at the conclusion that he was deal- 

 ing with two classes of rays, as regards their deflectibility by a magnet. 

 The question may still arise then. May not the Rontgen rays be the un- 

 deflectible Lenard rays ? 



The ultra-violet theory is said to be favored by Professors Schuster 

 and Fitzgerald. One difficulty is, that some electrical conductors are 

 practically transparent to the new radiation. To waves of light of 

 every kind they ought to be opaque according to Maxwell's theory. 

 However, the fact that gold and some other metals, when excessively 



