BISMUTH, (Fr. bismuth, Ger. Bis Wismuth, of unknown origin). A metallic element, probably known to the ancients. but first described in 1450. In the native state it is found widely distributed in small quantities, generally with ores of copper, lead. etc. It is further found in combination with oxygen as bisinite, with sulphur as bismathinite, with car bonic acid as bismutite, and as an alloy with tellurium, called trtrudymite. These various minerals are widely distributed ; but the princi pal commercial source is the metallic bismuth which is found in association with other ores, in the mines of Saxony and Bohemia, and at \lonroe, Conn., in the United States. The com mercial metal is obtained chiefly from the reduc tion-works in Saxony, although a small quantity is smelted in England. The process by which the metal is obtained consists in first carefully hand-pieking the ore, after which the selected pieces are roasted and the metal run off from the gangue into pots. By remelting at as low a temperature as possible. with one-tenth of its weight of nitre. a solid slag is formed by the nitre on the surface, with practically pure metal beneath. Bismuth (symbol, Bi; atomic weight. 208.5) is a brittle, grayish - white, crystalline metal of a distinctly red tinge, with a specific gravity of 9.8. It melts at 268.3° C., and boils between 1090° and 1450° C. It is a poor con ductor of heat and electricity. The metal itself is used chiefly as a constituent of alloys and amalgams. lYith lead, tin, and cadmium it forms a fusible metal, which melts at from 10° C. to C., according to the proportion of its constituents. These alloys, besides having a re markably low melting-point, expand in the act of solidification, thus giving a perfect east. Sniall
quantities have been used in the manufacture of bell-metal. Bismuth combines with radieak to form dial, triad, and pentad salts, of which the trivalent compounds are the most stable. Its principal compound with oxygen is the trioxide, which is found native as the mineral bismite, and may be prepared artificially by igniting the bis muth subnitrate until red fumes cease to come off. It is a pale-yellow amorphous compound. used for glass and porcelain staining, as an addition to certain Mixes to prevent the produe lion of color, and in gilding porcelain. Its most important compound is the nitrate, which may he made by dissolving metallic bismuth, or its oxide, or carbonate, in nitric acid, yielding a pearly-white powder consisting of minute scales.
which is used as a flux for certain enamels, owing to the fact that it increases their fusibility, 11:4 colorless iridescent glaze on porcelain, and as a cosmetic for softening the skin, under the names of blanc de ford and blanc d'Espagne. It is an officinal medicine, and was formerly termed majcstery of bismuth, being largely used in chronic diarrluea and cholera. Bismuth oxy chloride. prepared by treating a solution of the normal nitrate with a dilute solution of common salt, yields a precipitate which is a white pearly powder that is used as a cosmetic under the name of pearl-white, and also as a pigment. Bis muth citrate, bismuth carbonate, and bismuth and ammonium citrate are officinal medicines, and are used chiefly as astringents.