June 9, 1905.] 



SCIENCE. 



881 



power of about five hundred times that of 

 cane sugar, although now manufactured 

 chiefly in Germany, was discovered in 

 1879 in the laboratory of the John Hop- 

 kins University by Constantin Fahlberg, a 

 student under Ira Remsen (1846- ) and 

 the Society of Chemical Industry in 1904 

 crowned Eemsen's work by conferring 

 upon him the medal of the society, rec- 

 ognizing thus for the first time in its 

 history the discoveries of an American 

 chemist. 



In the domain of technical chemistry no 

 American has ever achieved greater results 

 than Hamilton Young Castner (1858-99), 

 and the opportunity of presenting a brief 

 svimmary of his brilliant inventions is a 

 pleasure that I gladly welcome. 



His first invention was a continuous 

 process for the manufacture of bone char- 

 coal, but this failed of commercial success, 

 although scientifically of much interest, 

 and he then turned his attention to the 

 study of an improved method for the pro- 

 duction of ahiminum. To accomplish this 

 it Avas necessary to produce sodium eco- 

 nomically, and this he succeeded in doing 

 by using carbide of iron as a reducing 

 agent. ^AHien he began this now historic 

 research the market price of aluminum was 

 $10 a pound, and when his process was 

 completed he was able to manufacture 

 aluminum at about one dollar a pound. 

 "This," says Dr. Chandler, "j^evolution- 

 ized the whole industry and aluminum 

 could be now used for a hundred different 

 purposes." In his retiring address before 

 the British Association in 1890 Sir Fred- 

 erick A. Abel said : ' ' The success which has 

 culminated in the admirable Castner proc- 

 ess constitutes one of the most interesting 

 of recent illustrations of the progress made 

 in technical chemistiy. " 



But there Avere other uses for which so- 

 dium could be employed, and so he invented 

 a process for converting metallic sodium 



into sodium peroxide. Then came the sug- 

 gestion that with cheap sodium pure cyan- 

 ides could be produced, and so he modified 

 his process so as to manufacture pure cyan- 

 ides, especially the potassium and sodium 

 cyanides, enormous quantities of which 

 Avere used for the extraction of gold from 

 low-grade ores. His active mind was ever 

 busy with new solutions of chemical prob- 

 lems, and subsequent to the invention of 

 electrolytic processes for the reduction of 

 aluminum, Castner concentrated his at- 

 tention on the original methods used by Sir 

 Humphry Davy and overcoming the diffi- 

 culties encountered by that great chemist 

 he soon devised an electric process of re- 

 markable simplicity for obtaining metallic 

 sodium from caustic soda by electrolysis. 

 His ambition was not yet satisfied and he 

 added to his triumphs a beautiful method 

 for the electrolysis of common salt Avith the 

 production of caustic soda and bleaching 

 poAA'der. Thus Castner invented 'the first 

 process Avhich could be said to be a com- 

 plete success ; for accomplishing Avhat 

 French, German, English and American 

 chemists had been Avorking at for a huudi-ed 

 years. ' Again to quote Chandler :* ' He 

 never Avorked on a chemical process that 

 he did not invent a better one to accom- 

 plish the same result.' ■ 



The sih'er metal and the Avhite crystals, 

 pure and beautiful, the results of his many 

 hours of study and research, will always 

 preserve in the literature of chemistry the 

 memory of him of Avhom it is surely not 

 too much to say that he was the most 

 eminent of American inventors in chemical 

 technology in recent times. 



"While Castner Avas studying the prob- 

 lem of preparing aluminum by chemical 

 methods Charles Martin Hall (1863- ), 



* See tlie ' Unveiling of a Bronze Tablet in 

 Havemeyer Hall to the Memory of Hamilton 

 Young Castner, December 16, 1902,' School of 

 Mines Quarterly, XXV., January, 1904, p. 204. 



