September 29, 1916] 



SCIENCE 



437 



has likewise advanced with giant strides, 

 mainly of course through the application 

 of the results of scientific research to indus- 

 trial purposes. An attempt to sketch in 

 the merest outline the recent development 

 of applied chemistry would, I fear, exhaust 

 your patience, but I may indicate in pass- 

 ing some of the main lines of advance. 

 Many of the more striking results in the 

 field of modern chemical industry have 

 been obtained by taking advantage of the 

 powers we now possess to carry out opera- 

 tions economically, both at very high and 

 at very low temperatures, and by the em- 

 ployment on the manufacturing scale of 

 electrolytic and catalytic methods of pro- 

 duction. Thanks largely to the invention 

 of the dynamo, the technologist is now able 

 to utilize electrical energy both for the pro- 

 duction of high temperatures in the differ- 

 ent types of electric furnace and for elec- 

 trolytic processes of the most varied 

 description. Among the operations car- 

 ried out with the help of the electric fur- 

 nace may be mentioned the manufacture of 

 graphite, silicon and phosphorus; of 

 chromium and other metals ; of carbides, 

 silicides and nitrides, and the smelting and 

 refining of iron and steel. Calcium carbide 

 claims a prominent place in the list, in the 

 first place because of the ease with which 

 it yields acetylene, which is not only used 

 as an illuminant, and, in the oxy-acetylene 

 burner, as a means of producing a temper- 

 ature so high that the cutting and welding 

 of steel is now a comparatively simple mat- 

 ter, but also promises to serve as the start- 

 ing-point for the industrial synthesis of 

 acetaldehyde and many other valuable or- 

 ganic compounds. Moreover, calcium car- 

 bide is readily converted in the electric 

 furnace into calcium cyanamide, which is 

 employed as an efficient fertilizer in place 

 of sodium nitrate or ammonium sulphate, 

 and as a source of ammonia and of alkali 

 cyanides. Among the silicides carborun- 



dum is increasingly used as an abrasive 

 and a refractory material, and calcium sili- 

 cide, which is now a commercial product, 

 forms a constituent of some blasting ex- 

 plosives. The Serpek process for the prep- 

 aration of alumina and ammonia, by the 

 formation of aluminium nitride from 

 beauxite in the electric furnace and its sub- 

 sequent decomposition by caustic soda, 

 should also be mentioned. Further, the 

 electric furnace has made possible the man- 

 ufacture of silica apparatus of all kinds, 

 both for the laboratory and the works, and 

 of alundum ware, also used for operations 

 at high temperature. Finally, the first 

 step in the manufacture of nitric acid and 

 of nitrites from air, now in operation on a 

 very large scale, is the combustion of nitro- 

 gen in the electric arc. 



In other industrial operations the high 

 temperature which is necessary is obtained 

 by the help of the oxy-hydrogen or the oxy- 

 acetylene flame, the former being used, 

 amongst other purposes, in a small but I 

 believe profitable industry, the manufac- 

 ture of synthetic rubies, sapphires and 

 spinels. Also, within a comparatively re- 

 cent period, advantage has been taken of 

 the characteristic properties of aluminium, 

 now obtainable at a moderate price, in the 

 various operations classed under the head- 

 ing alumino-thermy, the most important 

 being the reduction of refractory metallic 

 oxides, although, of course, thermite is use- 

 ful for the production of high temperatures 

 locally. 



The modern methods of liquefying gases, 

 which have been developed within the 

 period under review, have rendered pos- 

 sible research work of absorbing interest 

 on the effect of very low temperatures on 

 the properties and chemical activity of 

 many substances, and have been applied, 

 for instance, in separating from one 

 another the members of the argon family, 

 and in obtaining ozone in a state of prac- 



