SHORT PAPERS 709 



In the domain of technical chemistry no American has ever achieved greater 

 results than Hamilton Young Castner (1858-99), and the opportunity of present- 

 ing a brief summary 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 inter- 

 est, and he then turned his attention to the study of an improved method for the 

 production of aluminium. To accomplish this it was necessary to produce sodium 

 economically, and this he succeeded in doing by using carbide of iron as a reducing 

 agent. When he began this now historic research the market price of aluminium 

 was $10 a pound, and when his process was completed he was able to manufacture 

 aluminium at about one dollar a pound. "This," says Dr. Chandler, "revolution- 

 ized the whole industry and aluminium 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 

 process constitutes one of the most interesting of recent illustrations of the progress 

 made in technical chemistry." 



But there were other uses for which sodium could be employed, and so he in- 

 vented a process for converting metallic sodium into sodium peroxide. Then came 

 the suggestion that with cheap sodium pure cyanides could be produced, and so he 

 modified his process so as to manufacture pure cyanides, especially the potassium 

 and sodium cyanides, enormous quantities of which were used for the extraction of 

 gold from low-grade ores. His active mind was ever busy with new solutions 

 of chemical problems, and subsequent to the invention of electrolytic processes for 

 the reduction of aluminium, Castner concentrated his attention on the original 

 methods used by Sir Humphry Davy, and overcoming the difficulties encountered 

 by that great chemist he soon devised an electric process of remarkable 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 electro- 

 lysis of common salt l with the production of caustic soda and bleaching powder. 

 Thus Castner invented " the first process which could be said to be a complete 

 success for accomplishing what French, German, English, and American chemists 

 had been working at for a hundred years." Again to quote Chandler: 2 " He never 

 worked on a chemical process that he did not invent a better one to accomplish 

 the same result." 



The silver metal and the white crystals, pure and beautiful, the results of his 

 many hours of study and research, will always preserve in the literature of chem- 

 istry the memory of him of whom 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 was studying the problem of preparing aluminium by chemical 

 methods Charles Martin Hall (1863- ), a student in Oberlin College, conceived the 

 plan of extracting aluminium by electrolysis and he found that a melted bath of 

 the double fluorides of aluminium and metals more electro-positive than alumin- 

 ium, such as sodium or calcium, was a perfect solvent for aluminia, and from such 

 a solution he was able to separate the aluminium by means of the electric current. 

 It is by this process that all of the aluminium of commerce is produced to-day. 



Moissan, whose extended researches with the electric furnace have made his 

 name justly famous, writes : " The discovery of crystalline carbon silicide belongs 



1 Charles J. Parsons (Journal of the American Chemical Society, vol. xx, p. 868, 

 1898) gives Ernest A. Le Sueur credit for " the distinction of having invented the 

 first electrolytic process for the commercial decomposition of sodium chloride, 

 which became a regular contributor to the markets of the world." 



2 See the Unveiling of a Bronze Tablet in Havemeycr Hall to the Memory of 

 Hamilton Young Castner, December 16, 1902, School of Mines Quarterly, vol. xxv, 

 p. 204, January, 1904. 



