Bismuth
a triad metallic element, with the ores of nickel, cobalt, copper and silver, in Saxony, Austria, Peru, Australia and Bolivia. Bismuth is usually found in a metallic state, and is readily obtained from the ores containing it on account of its low fusibility (266° C.). Bismuth forms a dioxide Bi2O2, a trioxide Bi2O3, and a pentoxide Bi₂Os. The so-called tetroxide Bi₂O, is said to be a compound of the last two oxides. Bismuth forms one chloride BiCl3, bismuthous chloride.
Bismuth is known by its reddish color and crystalline structure. On account of its brittleness it is unfit for use in the metallic state, by by itself, except in the construction of thermo-electric piles. The use of bismuth in alloys depends on its low melting point, and its property of expanding upon solidification. It is used in type metal and in several solders. Bismuth is used for pharmaceutical purposes in form of subnitrate of bismuth, carbonate of bismuth, and oxide of bismuth, which, taken internally, act as sedatives on the stomach, in dyspepsia and chronic vomiting. They have been also used in epilepsy and in diarrhœa attending phthisis. Preparations of bismuth are sometimes employed externally as cosmetics, but when a sulphuretted gas acts upon them they blacken the face.