5 3 2 THE POPULAR SCIENCE MONTHLY. 



tals of remarkable size " ; the liquefaction of air has been so conduct- 

 ed as to obtain two distinct liquids separated by a perfectly visible 

 meniscus (Wroblewski) ; and, finally, when hydrogen was subjected 

 to between 100 and 200 atmospheres pressure in small glass tubes sur- 

 rounded by oxygen boiling in vacuo, it condensed to colorless drops. 



These noteworthy results are triumphs of physics rather than of 

 chemistry, but no review of chemical progress can afford to omit them ; 

 their bearing on the molecular theory of matter justifies the space 

 given them. It seems probable, moreover, that every known sub- 

 stance on the face of the earth will be eventually obtained in solid 

 form by the mere withdrawal of heat. At these low temperatures 

 the chemical activity of bodies is greatly lessened or ceases, but ad- 

 ditional observations must be made on this point before attempting 

 generalizations. 



Experiments of the character described demand great resources and 

 are not devoid of danger ; those conducting them will be rewarded by 

 undying fame. 



The progress of chemistry, in its more material aspects, is charac- 

 terized by the improved and economic production of known sub- 

 stances, by the discovery and manufacture of entirely new ones, and by 

 novel applications of both these classes as well as of waste materials. 

 The necessity of utmost condensation precludes enumeration of even a 

 centesimal part of the processes and products, nor would the mere 

 catalogue be profitable. Omitting for the present the prolific depart- 

 ment of organic chemistry, brief mention may be made of improve- 

 ments in the metallurgy of nickel (now known to be malleable and 

 ductile), of attempts to cheapen the production of aluminium, of the 

 revival of the barium-dioxide process for manufacturing oxygen on a 

 large scale, of novelties in artistic keramics, of the industrial produc- 

 tion and application of the rare metal vanadium, of the successful 

 introduction of water-gas as an illuminating agent, and of constant 

 activity in the fascinating field of photography. 



No chemical manufactures are more important than those grouped 

 under the name " alkali industry," which comprises the production 

 of those adjuncts of civilization, carbonate of soda, caustic soda, bi- 

 carbonate of soda, and bleaching-powder. Conducted by the methods 

 originated by the ill-fated Nicolas Leblanc, they have, after a cent- 

 ury's successful career, begun to give way to a youthful rival. The 

 struggle to maintain the supremacy of Leblanc's process has been 

 severe, the problem being a purely financial one. At first, the profits 

 "were made exclusively on the soda ; then the decreasing profits, as well 

 as the necessity of condensing the torrents of hydrochloric acid, led 

 manufacturers to add to the production of alkali that of bleaching- 

 powder, and the latter then yielded the profits, while the soda became 

 a by-product. Sharp competition in England and France pushed 

 prices below profitable production, and capitalists with millions in- 



