Gilbert, William

Gilbert, William, 1544–1603, English scientist and physician. He studied medicine at Cambridge Univ. (M.D., 1569), where he was elected a Fellow of St. John's College, and set up practice in London, becoming president of the College of Physicians (1599) and court physician to Queen Elizabeth I (1600) and later also to James I. He is best known, however, for his studies of electricity and magnetism. He coined the word electricity (from the Greek for "amber"), was the first to distinguish clearly between electric and magnetic phenomena, and published (1600) De Magnete, the most important work on magnetism until the early 19th cent. In it he described his methods for strengthening natural magnets (lodestones) and for using them to magnetize steel rods by stroking; he also outlined his investigations of the earth's magnetic field, from which he concluded that the earth as a whole behaves like a giant magnet with its poles near the geographic poles. He found that an iron bar that is left in alignment with the earth's magnetic field will slowly become magnetized, and that sufficient heating will cause a magnet to lose its magnetism.

Bibliography

See translations of his De Magnete by P. F. Mottelay (1893, repr. 1958) and S. P. Thompson (1901, repr. 1958).