(From bismut, German). Bismuth; also called wismuthum, marcasita, Galaena inanis, plum-bum cinereum Argricolae, blende Germanis, marcasite of silver, and tin glass.

It seems not to have been known to the Arabians, for their marcasite was the lapis pyrites; and the first traces of it occur in Basil Valentine. It is a brittle metal of a silvery whiteness; of the specific gravity 9.8217, melting at 460° of heat, smoking, and in a more intense fire rising in fumes. If calcined in close vessels the calx is in part volatile: if agitated it grows yellow, next red, and soon becomes a glass, vitrifying with it some of the less perfect metals. It may be easily powdered. The nitrous acid dissolves it, from which it is precipitated in the form of a bright white powder by dilution with water, The marine acid does not readily affect it, and the vitriolic scarcely at all. It impregnates the vegetable acid with a nauseous taste, and from all the acids may be separated by water alone in the form of a milky calx. By zinc and iron it may be precipitated in a metallic form. The chief of it brought into England is from Saxony. Dr. Alston denies that the ores of bismuth contain any arsenic; it is true that the bismuth, when brought to us, is without such particles.

It mixes easily with several metals, but destroys their ductility. It promotes the fusion of other metallic bodies. Mixed with lead and tin it forms a compound that melts with a very small heat; the following proportion is so fusible that it hath been proposed for anatomical injections, two parts of lead, three of tin, and five of bismuth. If bismuth is mixed with lead, a larger portion of the latter can be combined with quicksilver than without this method; and the quicksilver cannot be by the common methods.

The magistery of bismuth is a precipitation of the calx from nitrous acid by means of water, and with the addition of powdered pearls. It is styled pearl white, and chiefly used as a cosmetic. Internally, it has been said to occasion great anxiety. Dr. Odier has, however, recommended it in hysteric colics, diarrhoeas, and all diseases owing to too great irritability, particularly in the violent pains arising from a scirrhus of the pylorus. Carminati of Pavia, and Bonnat in France, have also experienced its good effects in similar diseases. Dr. Odier found it serviceable in the toothach. The dose is one or two grains suspended by mucilage, gradually increased to six, and by Odier to twelve, four or five times in a day.

The Spanish white is a magistery of bumuth, made by dissolving it in spirit of nitre, and precipitating it with salt and water. The calx further calcined has been commended by Jacobi, but not employed by any of his successors for more than a hundred years.