Playfair, John

Hutton s theory of heat was very important to his theory of the Earth but was given little prominence in the accounts of Hutton s theory developed by his followers, notably John Playfair and Sir James Hall,24 who reinterpreted and reshaped it. For them the chemical theory of heat was an excisable irrelevance, a diversion from the centrally important features of Hutton s theory of the Earth.25... 

Miles, W.D. (1957a). Admiral Cochrane s plans for chemical warfare. Armed F orcei C/zemical Toumal 11(6) 22. Miles, W.D. (1957b). The chemical shells of Lyon Playfair. Armed Forces Chemical Journal 11(6) 23. Miles, W.D. (1958a). The velvet-lined gas mask of John Stenhouse. Armed Forces Chemical Journal 12(3) 25. Miles, W.D. (1958b). Chemical warfare in the civil war. Armed Forces Chemical Journal 12(2) 26-27, 33. Miles, W.D. (1959). Suffocating smoke at Petersburg. Armed Forced Chemical Journal 13(4) 35. 

Hutton, Jam s (1726-97) British geologist, born in Scotland. He studied law, medicine, and industrial chemistry before returning to Edinburgh in 1768 to devote himself to geology. He advocated the theory that contemporary geological processes are the same as those that have always prevailed. This theory was not generally accepted until popularized by John Playfair (1748-1819) and championed by Charles Lyell. 

This close relationship between maker and customer was fostered in Manchester by a relatively open scientific community. Joule and Dancer undoubtedly met socially at the Lit and Phil as well as at lectures or conversaziones at the Royal Manchester Institution. Dancer also made several of the instruments Joule required for the long series of experiments on atomic volume he carried out in conjunction with Lyon Playfair. (46) Both Playfair and Dancer were close friends of John Mercer, (47) a manufacturing chemist from Oakenshaw, Lancashire, who was responsible for inventing the process of treating cotton with strong alkali to ensure a good uptake of dye, which continues to bear his name. 

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