The Evolution of the Sciences 



were compelled by their inability to obtain per- 

 manent high and low temperatures, to confine 

 their attention to compounds which remain 

 stable at laboratory temperatures. 



To-day we can maintain as long as necessary, 

 in a space of several cubic decimetres, tempera- 

 tures ranging from two hundred degrees below 

 zero to three thousand five hundred degrees 

 centigrade above it; the use of liquid gases and 

 of the electric furnace has rendered this service 

 to science ; and our day has seen the rise of the 

 chemistry of intense cold and of intense heat. 

 The names of Ramsay and Dewar are associated 

 with the former by their discovery and separa- 

 tion of the constituents of the air, argon, neon, 

 krypton, xenon and helium, while the latter 

 has rendered famous one of the great names 

 whose loss French chemistry and science are 

 mourning to-day Moissan, one of the most 

 skilful experimenters known to chemistry, a 

 true representative of classical chemistry; his 

 isolation of fluorine, his studies on the diamond, 

 but chiefly the marvellous series of carbides and 

 nitrides obtained by means of the electric furnace, 



have made his name justly famous. But for 



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