BLACK

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BLACK, Joseph, a distinguished chemist, born at Bordeaux, of Scottish parents, in 1728, studied medicine at Glasgow. Doctor Cullen, his instructor, inspired him with a taste for chemical studies. In 1754, he was made doctor of medicine, at Edinburgh, and delivered an inaugural dissertation, De Humore acido a Cibis orto et Magnesia alba, which exhibits the outline of his discoveries relative to carbonic acid and the alkalies. In 1756, he published his Experiments on White Magnesia, Quicklime, and several other AlkaMne Substances, in the 2d volume of the Essays, Physical and Literary, of the Edinburgh Society. He demonstrates the existence of an aerial fluid in these substances, which he calls fixed air, the presence of which diminishes the corro sive power of the alkalies and the calca rious earths. This discovery may be considered as the basis of all those which have immortalized the names of Cavendish, Priestley, Lavoisier, &c, and given a new form to chemistry. In 1757, B. enriched this science with his doctrine of latent heat, which has led to such important results. In 1756, he was appointed professor of medicine and lecturer on chemistry in the university at Glasgow, in the place of doctor Cullen, and, in 1765, when Cullen left the professor's chair in Edinburgh, he was there, also, succeeded by B. No teacher inspired his disciples with such a zeal for study ; his lectures, therefore, contributed much to make the taste for chemical science general in England. He died in 1799, at the age of 71. Upon Lavoisier's proposal, the academy of sciences, in Paris, had appointed him one of its eight foreign members. His habits were simple, his character cold and reserved. Though of eminent ability as a chemist, he injured himself by his long opposition to the reception of the new chemical theory. At length, however, he was convinced of its superior accuracy, and did justice to its merits. There is a paper of his in the Philosophical Transactions of 1774, and another in the Transactions of the Royal Society of Edinburgh, in 1791. Two of his letters on chemical subjects were published by Crell and Lavoisier, and his Lectures on Chemistry, in 1803, in 2 vols, by Robison.