Gilbert, William
Gilbert, William (1544 - 1603) was a pioneer in the modern study of magnetism and electricity. He wrote a famous and groundbreaking book, De Magnete, Magneticisque Corporibus, et de Magno Magnete Tellure (Concerning Magnetism, Magnetic Bodies, and the Great Magnet Earth), in 1600. The work was originally published in Latin in six volumes. It was concerned with existing knowledge about the magnet, with the names of the mineral loadstone and their etymology, and with the properties of the magnet.
Gilbert discovered many important facts about magnetism, such as the laws of attraction and repulsion, magnetic dip (the manner in which a compass needle dips toward the earth when the needle is freely suspended to allow vertical movement and the properties of loadstones. Gilbert based his findings on extensive observation and practical experiments. This practice differed greatly from that of most of the scientists of his time, who developed only abstract theories, unsupported by experiments. Gilbert funded his research himself. Some estimates say he spent up to 5,000 pounds on his work. He was able to afford this because his position as court physician paid him a stipend, or salary.
In Gilbert's time, loadstone was believed to cure headaches and insanity, rejuvenate the body, and draw poisons and pain out of the body. Gilbert dismissed all these notions. He also disproved the belief that garlic could destroy magnetism.
The hundreds of experiments he performed dispelled many misconceptions. He maintained that stronger reasons are obtained from sure experiments and demonstrated arguments than from probable conjecture and the opinions of philosophical speculators of the common sort.
Gilbert's theories about astronomy were remarkably advanced for the time in which he lived. He was the first English scientist to accept Nicolaus Copernicus's view that the sun was the center of the universe. He believed that the stars were at various distances from the earth, all of them very far, and that the stars might have habitable planets circling them. These beliefs are still held as true more than four centuries later.
The importance of Gilbert's work was recognized by many of his contemporaries, including the writer John Dryden, the playwright and poet Ben Jonson, and the astronomer and physicist Galileo. Galileo wrote of Gilbert: I extremely praise, admire and envy this author, for that a conception so stupendous could come into his mind. I think him moreover worthy of extraordinary applause for the many new and true observations he made. Galileo also considered Gilbert to be the principal founder of the experimental method. Gilbert's advances in the understanding of magnetism were so significant that it would be more than 200 years before any major new knowledge was added to the science. The next major advances were made by Michael Faraday and William Sturgeon.
Gilbert was born in Colchester, England, in 1544. He was the oldest of five children of Jerome Gilbert, a free burgess and recorder, and Elizabeth Coggeshall. Nothing is known of Gilbert's early life and education. He received his bachelor's degree (1561), master's degree (1564), and medical degree (1569) from St. John's College in Cambridge, England. He settled in London in the mid-1570's, where he practiced medicine. He was a prominent physician, and his services were sought by many, including members of the English nobility. He became a member of the Royal College of Physicians, advancing to censor in 1582 and subsequently serving as treasurer and then president of the college. In 1588, he was one of the four college physicians chosen to care for the health of the men in the Royal Navy. He was a contributor to the work Pharmacopoeia, a drug reference book published by the Royal College of Physicians. His famous De Magnete, the culmination of years of investigations, was published in 1600. Gilbert died in London in 1603, possibly from a plague that was sweeping the city at the time.
Gilbert coined the term electrics to describe substances, such as amber, which, when rubbed with silk, were able to attract light objects. He also invented the term magnetic pole and was the first to use the terms electric force and electric attraction. The unit of measure of magnetomotive force is called the gilbert, in his honor.
Gilbert was knighted for his service to the queen. After his death, his half-brother collected Gilbert's papers and arranged for them to be published. They appeared under the title De mundo nostro sublunari philosophia nova.