THE EXTRACTION OF GOLD AND THE 

 CYANIDE PROCESS. 



PROGRESS in the metallurgy of gold has of late 

 undergone a complete change. The empirical stage 

 of the art persisted long after the importance of the 

 scientific foundation underlying most other industries had 

 been fully recognised. The victory of common sense over 

 ignorance or prejudice has been a slow one, and for many 

 years the "practical" man continued to scorn his "theo- 

 retical " contemporary, until at length the two became 

 united in the scientific metallurgists who are to-day en- 

 gaged in all parts of the world in the production and 

 purification of the precious metals. Research work, under 

 conditions likely to lead to useful results, and conducted by 

 men who are familiar with the problems to be solved, has 

 been rendered possible by the huge scale on which opera- 

 tions are now conducted in many parts of the world. 

 Parties cf diggers working surface deposits have no time 

 or money to investigate knotty points in the metallurgy of 

 gold, but it is otherwise with the great companies which 

 deal with the South African reefs, and the rate of progress 

 in scientific metallurgy has been greatly increased by the 

 means which these wealthy corporations have been able to 

 provide. Moreover when chemistry makes a present of 

 some useful fact to her technical sister, a whole army of 

 workers now fall upon it, dissect it, amplify it, and soon 

 enrich pure science with many return gifts. 



The way in which scientific discoveries and their tech- 

 nical applications may react on each other is well exemplified 

 in the history of the work which has been done on 

 the solvent action of potassium cyanide on gold. Dr. 

 Wright of Birmingham discovered this action in 1840, and 

 it was mentioned in a patent specification relating to 

 electroplating taken out by Elkington in the same year. 

 But though Bagration 1 in 1843, Eisner 2 in 1846, and 



1 Bull, de FAcad. des Sciences de St. Petersbourg (1843), vol. ii., p. 136. 



2 Erdm. Journ. Prak. Chem., vol. xxxvii. (1846), pp. 441-446. 



