TALBOT, WILLIAM HENRY Fox (1800-77). An English photographer and philologist, well known as one of the inventors of photography. He was educated at Cambridge, received the junior chancellor's medal in 1821, and subse quently became member of Parliament for Chip penham. But soon afterwards he gave up poll tics, and devoted himself entirely to scientific investigation. The first problem to attract his attention was that of fixing shadows, and by patient research he was gradually led to the dis covery of a process of obtaining and fixing sun pictures. On the dissemination of a report as to Daguerre's successes in the same field, Talbot secured his just rights by publishing a paper (Phil. Nag., March, 1839), in which the suc cessive steps of his investigation and their result were detailed. This process was subsequently improved by his invention (1841) of time calotype process. His discoveries and inventions in photog raphy are described in his Pencil of Nature (1844-46). Latterly he devoted himself to the study of philology and archaeology, and was one of the first to read the cuneiform inscriptions of Nineveh. Among his works are: Hermes, or
Classical and Antiquarian Researches (1828-39) ; Illustrations of the Antiquity of the Book of Genesis (1839) ; and a work on English Etymol ogies (1S46). See PHOTOGRAPHY.
TALC (Fr. talc, Sp. talco, talque, from Ar. talq, talc). A mineral hydrated magnesium sili cate crystallized in the orthorhombic system. It has a pearly or semi-metallic lustre, is soft, and is silvery-white to gray or green in color. Tale seldom occurs in crystals, but is usually found in foliated or granular masses. It is an exceedingly common mineral and in some regions is found in large beds. The granular massive varieties are commonly known as soapstone and find extensive use in commerce as slabs for hearthstones, man tels, sinks, etc., and when powdered, as a pigment, in paper-making, as a lubricator, for dressing skins and leather, etc. The fine granular or erypto-crystalline varieties are used for mark ing purposes under the name of French chalk. In 1900 27,943 tons, valued at $383,541, were mined in the United States.