BLACK, Joseph (1728–1799), chemist and physician. Polychrome relief portrait in wax, with the inscription on the truncation "JOSEPH BLACK MD. 1788". On black glass 70 x 95mm in a 19th or 20th century gilt frame. There is a horizontal crack running from just below is lower lip right across to the back of his tied hair, and another less obvious crack running under his chin line to meet the horizontal crack.
Black is importantly known for his discoveries of latent heat, specific heat, and carbon dioxide. He was a founder of thermochemistry who developed many pre-thermodynamics concepts, such as heat capacity, and was the mentor for James Watt, with whom he forged a lifelong friendship. He developed other close friendships amongst the Edinburgh elite, including Cullen, Hutton, Hume, Smith, and Ferguson. He was an enormously popular lecturer, and the chemistry buildings at both the University of Edinburgh and the University of Glasgow are named after him.
This relief portrait is taken from James Tassie's sulphide portrait taken in 1788, which was also produced as a portrait medallion by Wedgwood.