216 PROFESSOR THOMAS GRAHAM's SCIENTIFIC WORK. 



to regard it as a true alloy of palladiuin with hydrogen, or rather hydro- 

 geiiium, in which the volatility of the latter metal was restrained by 

 the fixity of the former, and of which the metallic aspect was equally 

 due to both of its constituents. Although, indeed, the occlusion of up- 

 ward of 900 times its volume of hydrogen was found to lower the 

 tenacity and electric conductivity of palladium appreciably, still the 

 hydrogenized i)alladium remaiued possessed of a most characteristically 

 metallic tenacity and conductivity. Thus, the tenacity of the original 

 wire being taken as 100, the tenacity of the fully charged wire was 

 found to be 81.29 ; and the electric conductivity' of the original wire 

 being 8.10, that of the hydrogenized wire was found to be 5.99. In fur- 

 ther support of the conclusion arrived at by Mr. Graham, as to the me- 

 tallic condition of the hydrogen occluded in palladium, he adduced his 

 singular discovery of its being possessed of magnetic properties, more 

 decided than those of palladium itself, a metal which Mr. Faraday had 

 shown to be "feebly but truly magnetic." Operating with an electro- 

 magnet of very moderate strength, Mr. Graham found that while an ob- 

 loug fragment of electrolyticall}^ deposited palladium was deflected from 

 the equatorial by 10° only, the same fragment of metal, charged with 

 601.0 times its volume of hydrogen, was deflected through 48°. Thus 

 did 3Ir. Graham supplement the idea of hydrogen as an invisible incon- 

 densable gas, by the idea of hydrogen as an opaque, lustrous, white 

 metal, having a specific gravity between 0.7 and 0.8, a well-marked 

 tenacity and conductivity, and a very decided magnetism. 



