THE 

 LONDON, EDINBURGH, and DUBLIN 



PHILOSOPHICAL MAGAZINE 



AND 



JOURNAL OF SCIENCE. 



[FIFTH SERIES.] 



JANUARY 1883. 



I. Researches on the Passage of Electricity through Rarefied 

 Air. By E. Edlund*. 



§1. 



IN a previous memoir! I brought together, in order to com- 

 pare them with each other, the researches made at dif- 

 ferent times by various physicists on the passage of electricity 

 through rarefied gases, and I endeavoured, inter alia, to de- 

 monstrate that vacuum is a conductor of electricity, or at least 

 opposes but an inconsiderable resistance to its propagation. 

 This result is in flagrant contradiction to the hitherto gene- 

 rally received opinion that vacuum is a perfect insulator. The 

 reason that an electric current cannot traverse the Torricellian 

 vacuum does not depend on vacuum itself being an insulator, 

 but on the fact that there exists at the point of passage between 

 the electrodes and the rarefied gas an obstacle to the propaga- 

 tion of electricity, and that this obstacle is augmented in pro- 

 portion as the air is rarefied. As soon as the gas has been 

 sufficiently rarefied, the obstacle in question has become so 

 powerful that the current is incapable of surmounting it, and, 

 consequently, of traversing the rarefied air. According to 



* Translated from a copy, communicated by the Author, of No. 1, 

 vol. xx. of the Kongliga Svenska Vetenskaps-Akademiens Handlingar. 



f Memoirs (Handlingar) of the Royal Academy of Sciences of Sweden, 

 xix. no. 2; Ann. de Chim. et de Phys. xxiv. p. 199 (1881) ; Phil. Masr. [5] 

 xiii. p. 1 (1882); Wied. Ann. xv. p. 514 (1882). 



Phil Mag. S. 5. Vol. 15. No. 91. Jan 1883. B 



