GILBERT (or GYLBERDE), WILLIAM the most distinguished man of science in England during the reign of Queen Elizabeth, was a member of an ancient Suffolk family, long resident in Clare, and was born on May at Colchester, where his father, Hierome Gilbert, became recorder. Educated at Colchester school, he entered St. John's college, Cambridge, in 1558, and after taking the degrees of B.A. and M.A. in due course, graduated M.D. in 1569, in which year he was elected a senior fellow of his college. He travelled in Europe, and in 1573 settled in London, where he practised as a physician. He was ad mitted to the College of Physicians probably about 1576, and he held several important offices. In 1589 he was one of the commit tee appointed to superintend the preparation of the Pharmacopoeia Londinensis which the college in that year decided to issue, but which did not actually appear till 1618. In 160I Gilbert was ap pointed physician to Queen Elizabeth, with the usual emolument of f loo a year. On the death of the queen in 1603 he was reap pointed by her successor; but he did not long enjoy the honour, for he died on Nov. 3o (Dec. 1o, N.S.), 1603, either in London or in Colchester. He was buried in the latter town, in the chancel of Holy Trinity church, where a monument was erected to his mem ory. To the College of Physicians he left his books, globes, instru ments and minerals, but they were destroyed in the great fire of London.
Gilbert's principal work is his treatise on magnetism (q.v.; see also ELECTRICITY), entitled De magnete, inagneticisque corpori bus, et de magno magnete tellure (London, 1600 ; later editions Stettin, 1628, 1633; Frankfort, 1629, 1638) . This work, which embodied the results of many years' research, was distinguished by its strict adherence to the scientific method of investigation by experiment, and by the originality of its matter. It contains an account of the author's experiments on magnets and magnetic bodies and on electrical attractions, and also his great conception that the earth is nothing but a large magnet, and that it is this which explains, not only the direction of the magnetic needle north and south, but also the dipping or inclination of the needle. A posthumous work of Gilbert's was edited by his brother from two mss. ; its title is De mundo nostro sublunari philosopliia nova (Amsterdam, . He was also the first advocate of Coper nican views in England, and he concluded that the fixed stars are not all at the same distance from the earth.
An English translation of the De magnete was published by P. F. Mottelay in 1893, and another, with notes by S. P. Thompson, was issued by the Gilbert club of London in 190o.