lo Ramsay, The Newly Discovered Elements. 



apparently too high ; to agree with its position in the 

 Periodic Table, the atomic weight of cobalt, instead of 

 being 59, and exceeding that of nickel, 587, by 0*3, should 

 fall below the latter ; and the atomic weight of tellurium, 

 127-6, (Brauner, Chikashige, Staudenmaier and others), is 

 075 below that of iodine, I26"85, its neighbour in the Table. 



But the position of argon in the Periodic Table is thus 

 far vouched for only by the ratio of its specific heats. As 

 it has hitherto formed no compounds, and as its specific 

 heat in the solid state has not been determined, and indeed 

 would present many difficulties in experimental determi- 

 nation, some other clue must be found for the solution of 

 the problem. The problem has been solved, and it is 

 evident that its solution in the sense indicated must also 

 lend additional strength to the arguments in favour of the 

 justice of the kinetic view of the ratio between the specific 

 heats of mono-atomic gases ; arguments derived both from 

 a theoretical standpoint, as well as from the known ratio 

 between the specific heats of mercury gas. 



The discovery of argon in 1 894 was followed early in 

 1895 by the discovery of helium, an element closely 

 resembling argon in its indifference towards chemical 

 reagents, and also in the ratio between the specific heats ; 

 but differing in its density, which is almost exactly 2, and 

 in its spectrum. Other remarkable properties of helium 

 are its unusually low refractivity, and the ease with which 

 an electric discharge can pass through it, even at atmos- 

 pheric pressure. It appears, also, to diffuse through a 

 porous plug at a rate about 10 per cent, more rapid than 

 would correspond with its density. Moreover, it has the 

 lowest coefficient of solubility of any gas — 100 volumes 

 of water dissolve only 07 volume of helium. 



Arguing from the ratio between the specific heats of 

 helium, in a manner similar to that employed for argon 



