Dr. Gilbert is known primarily for his original experiments in the nature of electricity and magnetism. He was born in Colchester, England and educated at Saint John's College, University of Cambridge. He began to practice medicine in London in 1573 and in 1601 was appointed physician to Elizabeth I, queen of England. Gilbert found that many substances had the power to attract light objects when rubbed, and he applied the term electric to the force these substances exert after being rubbed. He was the first to use the terms electric force, electric attraction, and magnetic pole. Perhaps Gilbert's most important contribution was the experimental demonstration of the magnetic nature of the earth. The unit of magnetomotive force, the gilbert, was named after him. He was also the first exponent in England of the Copernican system of celestial mechanics, and he postulated that fixed stars were not all at the same distance from the earth. His most important work was Of Magnets, Magnetic Bodies, and the Great Magnet of the Earth (1600; trans. 1890), probably the first great scientific work written in England.