194 ELECTRIC THEORY OF MATTER [CH. xx. 



The other lines of experimental argument seem to 

 be confirmatory. The second one deduces, from the 

 energy of the Kontgen radiation which is scattered by 

 gases, as measured by Barkla of Liverpool, that mole- 

 cules of air each contain approximately 25 or 28 

 corpuscles ; which again corresponds to the molecular 

 weight of the chief ingredient. 



The third argument is based on the absorption of 

 beta rays by metals ; wherefrom it is deduced that 

 the number of corpuscles liable to be encountered in 

 each atom is nearly equal to the conventional atomic 

 weight of the metal on the hydrogen scale. 



This remarkable paper is the most serious blow yet 

 dealt at the electric theory of matter, at least in its 

 simpler and cruder form ; but modes of getting round 

 it are fore- shadowed in Chaps. XV. and XVII. 



