Thomas Graham, a Scottish chemist, born in Glasgow, Dec. 20, 1805, died in London, Sept. 15, 1869. He studied at the universities of Glasgow and Edinburgh, and after graduating opened a laboratory in Glasgow and lectured on chemistry at the mechanics1 institute. He was professor at the Andersonian university in Glasgow from 1830 to 1837, and at the university college in London from 1837 to 1855. Having, as a non-resident assayer, submitted all the specie in the mint to a uniform scientific standard, he became, in February, 1855, Sir John Herschel's successor as master of the mint, and held this office till his death. He was one of the founders and the first president of the chemical society of London, for many years president of the Cavendish society, and a fellow and twice vice president of the royal society, which gave him many medals. He conducted many physical and chemical investigations for the government, including one of especial interest on the effect of hail storms in the Newcastle coal mines, reporting on the ventilation of the houses of parliament, and in 1851, with Professors Miller and Hoffmann, on the quality of the metropolitan water supply.

He discovered the law of diffusion of gases and the polybasic character of phosphoric acid; demonstrated the existence of a diffusive power in liquids resembling that in gases, to which he applied the name of omosis, and determined its relation to endosmosis and exosmosis; expounded new theories on the composition of salts, and extended his researches to the tran-spirability of gases. His discoveries and other labors are embraced in his "Elements of Chemistry" (London, 1842), edited with notes and additions by Dr. Robert Bridges (Philadelphia, 1852; new eds., 2 vols., London, 1856-8, and 1865; German translation by Otto, 3d ed., Brunswick, 1857). He contributed important papers to the "Philosophical Transactions," and the annals of the chemical and other scientific societies. His genius is highly appreciated in Germany, and A. W. Hoffmann published in Berlin (1870) his Ge-dachtnissrede auf Thomas Graham. A bronze statue of Graham was placed in George square, Glasgow, in 1872.