CANTON, JOHN, was born at Stroud, July 31, 171S. Some advances made by him in mathematics and experimental philosophy induced his father to send him to London in 1737. Ile then articled himself for five years to the master of a school, with whom he after wards went into partnership, and iu this profession he spent his life.
On the invention of the Leyden phial lie turned his attention particularly to electricity, and various discoveries of his not suffi ciently marked to require biographical notice, though evincing great ingenuity, will be fouud in the referenoes at the end of this article. He was the first who in England verified Dr. Frankliu'e idea of the similarity of lightning and electric fluid (July 1752). lie was then a member of the Council of the Royal Society, of which, in 1751, he received the gold medal for hierinethod of making artificial magnets. In a paper communicated in 1753 he announced the discovery (which Franklin made about the same time) of clouds being in different states of electricity. In the following year he found that the quality of the electrical excitement made by rubbing any given substance depended on the rubber, as well as on the other substance. The
common pith-ball electrometer, and the amalgam of tin and mercury used for the increase of the action of the rubber, are due to him. In 1762 he demonstrated the compressibility of water, iu opposition to the well-known Florentine experiment. His experiment was repeated in the presence of a committee of the Royal Society, and a second gold medal was awarded to him in 1765. In 1769 he communicated expe riments in proof that the luminous appearance of the sea arises from the presence of decomposed animal matter. He died March 22, 1772. There is a life of him by his sou in Kippis'e Biographia Britannica,' abridged in Hutton's mathematical dictionary. His papers are in the ' Philosophical Transactions,' and he communicated some new experi ments for Priestiey's 'Histories of Electrical and Optical Discoveries.'