CANTON, JOHN English physicist, born at Stroud, Gloucestershire, on July 31, 1718, was a weaver's ap prentice, and became a schoolmaster in Spital square, London. In I 749 he read a paper before the Royal Society on a method of making artificial magnets, which procured him election as a fellow of the society and the award of the Copley medal. He was the first in England to verify Benjamin Franklin's hypothesis of the phenomenon of lightning, and invented an electroscope and an electrometer. In 1762 and 1764 he published experiments in refutation of the decision of the Florentine academy, at that time generally accepted, that water is incompressible; and in 1768 he described the preparation, by calcining oyster-shell with sulphur, of the phosphorescent material known as Canton's phos phorus. He died in London on March 22, 1772.