PORCELAIN, a fictile material inter mediate between glass and pottery, be ing formed of two substances, fusible and infusible, the latter enabling it to with stand the heat necessary to vitrify the former, thus producing its peculiar semi translucency. The infusible material is alumina, called kaolin; the fusible sub stance is feldspar, and is called pe-tun tse, both Chinese terms. There are two kinds, hard and soft (pate dure and pate tendre) ; the hard body has more alumina and less silex and lime. Orien tal porcelain is of two kinds, ancient and modern; the latter class includes imitations and reproductions. The man ufacture began in China between 185 B. C. and A. D. 87, and reached its per fection during the Ming dynasty (1368 1644). The rarest Chinese wares are of the Tsin dynasty (A. D. 265-419), the Soui (581-618), and the Thang (618 907)—forms virtually extinct except as copies. The Tcheou porcelain (954-959) is so valued that fragments are worn as personal ornaments. Ware of the Song dynasty (960-1279) is also highly prized. Porcelain came by trade into Persia and Egypt, and was known in Syria in the 12th century. First imported into Eu rope by the Portuguese in 1520. In Japan the porcelain manufacture began before 27 B. C., with a whiter body and more brilliant glaze than that of the Chinese. It is doubtful if it was ever made in Persia. In Europe, Boettcher, a Saxon chemist, found kaolin while seeking the philosopher's stone; and Augustus II., Elector of Saxony and King of Poland, established and placed under his control the famous Meissen factory at the castle of Albrechtsburg in 1710; 40 years later 700 men were em ployed. In Vienna, Stolzel, who escaped
from Meissen in 1720, began the Aus trian factory, which in 1785 employed 500 men; another was established in Berlin by Frederick the Great. During the 18th century, works were begun in Russia, Holland, Denmark, Spain, Portu gal, Switzerland and Italy. In France, soft porcelain was made at St. Cloud in 1695. Comte de Brancas-Lauraguan. in 1758, found kaolin near Alencon, and porcelain was made at St. Yrieix, near Limoges. The Sevres manufactory was first established at Vincennes in 1740, and moved to Sevres in 1756. In France, the manufacture of soft porcelain ex tends from 1695 to 1770, after which date the hard body of Sevres takes its place. In England, William Cook worthy, a chemist of Plymouth, found kaolin at Tregonning, near Helstone, in Cornwall, and his patent of 1768 was worked at Plymouth for two or three years, when the works were removed to Bristol. At Chelsea and Bow soft porce lain had been made. These two were transferred to Derby in 1770 and 1776. Bristol had a soft body works in 1753; its best period was from 1774 to 1778. Worcester porcelain dates from 1751; its best period ended witth 1783. Large quantities of porcelain are produced in the United States. Trenton, N. J., is a center for the manufacture. See POT TERY.