THE 



LONDON, EDINBURGH, and DUBLIN 



PHILOSOPHICAL MAGAZINE 



AND 



JOURNAL OF SCIENCE. 



[FIFTH SERIES.] 



JANUARY 1882. 



I. On the Electrical Resistance of Vacuum. By E. Edlund, 

 Professor of Physics at the Swedish Royal Academy of 

 Sciences*. 



si. 



IT has been generally assumed that a vacuum presents a 

 total absence of electric conductivity; and there are 

 experiments dating from long ago which seem to favour 

 the truth of this opinion. A multitude of researches have 

 been made from time to time, with the view of discover- 

 ing the real state of the question. This last is, indeed, of the 

 greatest importance in several respects. The heavenly bodies 

 are separated from one another by space in which, as far as we 

 know, no other matter exists but the luminiferous aether. It 

 is a fact generally known at the present time that the solar 

 spots exert a sensible influence upon the aurora borealis and 

 the magnetic condition of the earth, or that all these pheno- 

 mena derive their origin from a common cosmic cause. Now, 

 if the space between the celestial bodies were perfectly non- 

 conducting, it would be difficult to conceive the possibility of 

 a direct correlation between those phenomena; indeed it would 

 hardly be possible that an appreciable action of electrical in- 

 duction should assert itself at so great a distance. And it is 

 quite as impossible to see, in the correlation observed, a secon- 

 dary action of the insignificant modification of the thermal 



* Translated from a copy, communicated by the Author, of a memoir 

 presented to the Swedish E,oyal Academy of Sciences on the 23rd of April 

 1881, Kongliga Svensha Vetenskaps-Akademiens HandUngar, Bandet xix. 

 no. 2. 



Phil. Mag. S. 5. Vol. 13. No. 78. Jan. 1882. B 



