MacArthur, John Stewart

SUBJECT AREA: Chemical technology, Metallurgy

[br]

b. December 1856 Hutchesontown, Glasgow, Scotland

d. 16 March 1920 Pollokshields, Glasgow, Scotland

[br]

Scottish industrial chemist who introduced the "cyanide process" for the commercial extraction of gold from its ores.

[br]

MacArthur served his apprenticeship in the laboratory of Tennant's Tharsis Sulphur and Copper Company in Glasgow. In 1886 he was appointed Technical Manager of the Tennant-run Cassel Gold Extracting Company. By 1888 he was advocating a treatment scheme in which gold was dissolved from crushed rock by a dilute solution of alkali cyanide and then precipitated onto finely divided zinc. During the next few years, with several assistants, he was extremely active in promoting the new gold-extraction technique in various parts of the world. In 1894 significant sums in royalty payments were received, but by 1897 the patents had been successfully contested; henceforth the Cassel Company concentrated on the production and marketing of the essential sodium cyanide reagent.

MacArthur was Managing Director of the Cassel Company from 1892 to 1897; he resigned as a director in December 1905. In 1907 he created the Antimony Recovery Syndicate, and in 1911 he set up a small plant at Runcorn, Cheshire, to produce radium salts. In 1915 this radium-extraction activity was transferred to Balloch, south of Loch Lomond, where it was used until some years after his death.

[br]

Principal Honours and Distinctions

Institution of Mining and Metallurgy Gold Medal 1902.

Bibliography

10 August 1888, jointly with R.W.Forrest and W.Forrest, British patent no. 14,174. 13 July 1889, jointly with R.W.Forrest and W. Forrest, British patent no. 10,223. 1905, "Gold extraction by cyanide: a retrospect", Journal of the Society of Chemical

Industry (15 April):311–15.

Further Reading

D.I.Harvie, 1989, "John Stewart MacArthur: pioneer gold and radium refiner", Endeavour (NS) 13(4):179–84 (draws on family documents not previously published).

JKA