Gilbert, WILLIAM, author of a celebrated treatise on magnetism, was born in 1540 at Colchester. A member, and subsequently fellow of St John's College, Cambridge, he graduated in 1560, and in 1573 settled in London to practise as a physician. Eventually Elizabeth made him her court physician, and the same office was confirmed to him by James I. on his accession to the throne of England. After holding various offices in the College of Physicians, he was finally elected its president in 1600. He died a bachelor, 30th November 1603, either at Colchester or at London; he was buried at Colchester in the church of the Holy Trinity. His leisure time was largely given to the study of magnetism and chemistry. In the former subject he carried on some notable researches, principally contained in De Magnete,
Magneticisque Corporibus, et Magno Magnete Tellure (1600), and the posthumously published De Mundo nostro Sublunari Philosophia Nova (1651). In the former he established the magnetic nature of the earth, which he regarded as one great magnet; and he conjectured that terrestrial magnetism and electricity were two allied emanations of a single force—a view which was only demonstrated with scientific strictness more than two centuries afterwards by Oersted and Faraday. Gilbert was the first to use the terms 'electricity,' 'electric force,' and 'electric attraction,' and to point out that amber is not the only substance which when rubbed attracts light objects, but that the same faculty belongs to the resins, sealing-wax, sulphur, glass, &c.; and he describes how to measure the excited electricity by means of an iron needle moving freely on a point. He also invented two instruments for finding latitude with the help of astronomical observations. See memoir prefixed to P. F. Mottelay's translation of De Magnete (1893).