86 Prof. E. Wiedemann on the 



believe we may explain all the peculiarities of the kathode- 

 rays, in accordance with the views already expressed, by 

 assuming that the kathode-rays represent light rays of very 

 small oscillation-period *. 



(1) From experiments by E. Goldstein f, which have 

 been confirmed partly by myself J, partly by Spottiswoode 

 and Moulton § ; it may be shown that the motions in the 

 kathode-rays must certainly be supposed to be orientated in 

 a certain way to the rays themselves. The experiments 

 showed that the kathode-rays can traverse the positive light 

 without hindrance if their motion of direction coincides with 

 that of the positive light, and, further, that if a point of the wall 

 be connected with the ground, and thus a kathode be pro- 

 duced at that point, shadows of the positive stratifications are 

 thrown by the rays issuing from the wall. In this arrange- 

 ment of the experiment the kathode-rays traverse the positive 

 column of light at right angles. The experiments first men- 

 tioned show that we cannot, with Spottiswoode and Moulton, 

 explain the phenomenon by supposing that larger quantities 

 of matter are accumulated in the stratifications than in the 

 dark spaces between them. For when the kathode-rays 

 traverse the stratifications longitudinally, they must pass 

 through larger quantities of matter than when this takes 

 place transversely. 



Since, then, in the second case we have a mutual disturb- 

 ance and not in the first, we must conclude that the motions 

 of the kathode-rays and of the positive discharge are opposite 

 in direction. Since further disturbances occur, especially in 

 motions which take place parallel to each other, the motion in 

 the kathode-rays must be at right angles to that in the posi- 

 tive light. We may imagine the motion in the positive light 

 as produced by a dielectric polarization which issues from the 

 positive electrode, and which is then followed by a current of 

 positive electricity || . This motion is certainly longitudinal ; the 



* That the kathode-rays consist of waves in the sether, I have en- 

 deavoured to show in Wied. Ann. ix. p. 100, and Wied. Ann. x. p. 251. 

 Messrs. Goldstein and Hertz have signified their adherence to this view. 



In a recently published paper Herr Goldstein asserts that he was the 

 first who considered the electric discharge as a motion of aether. This is 

 not quite correct, as already in the year 1797 Gren had the same view for 

 the electric light in the vacuum of the barometer. As far as I can see 

 I was the first who tried to explain from that conception the several 

 phenomena. 



t Wien. JBer. lxxiv. p. 413 (1876). Herr Goldstein has drawn no 

 conclusion from his experiments. 



t Wied. Ann. x. p. 337 (1880). 



§ Beibl. vii. p. 725 (1883). 



|| E. Wiedemann, Wied. Ann. x. p. 250 (1880), and further on. 



