Use. Chiefly in chemistry, and as a source of the pure oxide and the subnitrate.
Bismuth Oxides:—
Bismuthous Oxide. Bi2O3. Syn. Teroxide of bismuth, Protoxide of bismuth. From either the neutral or the basic nitrate, by exposure, in a crucible, to gentle ignition. Pure. A straw-yellow powder, of rather difficult solubility.
Hy′drated:—By gradually dropping an acid solution of bismuthous nitrate into a concentrated solution of potassium hydrate perfectly free from carbonic acid, and washing and drying the resulting precipitate. Pure. A rich-looking white powder.
Prop., &c. Fuses at a high temperature, and then acts as a powerful flux on siliceous matter without itself imparting colour, a property of which the enameller and gilder has long availed himself. Like the basic nitrate, it has been used as an antispasmodic and as a cosmetic. Sp. gr. 8·211 to 8·355.
Bismuthic Oxide. Bi2O5. Syn. Bismuthic anhydride, Bismuthic acid. Suspend teroxide of bismuth in a strong solution of potassa, and pass chlorine through the mixture until decomposition is complete; treat the powder with dilute nitric acid (to remove any undecomposed teroxide), after which wash it in cold water, and dry it.
Prop., &c. A reddish powder, soluble in water. Its salts, of which little are known, are called BIS′MUTHATES. When heated it loses oxygen, and a bismuthate of bismuth is formed.
Bismuthous Sulphide. Bi2S3. This compound occurs native (BIS′MŬTHĬNE), and may be easily prepared artificially by either fusing its elements
together, or by passing sulphuretted hydrogen through a solution of nitrate of bismuth.
Bismuthous Valerianate. Syn. Bismu′thi valeria′nas, L. Prep. An acid solution of nitrate of bismuth is decomposed with a solution of valerianate of soda in water containing a little free valerianic acid; the precipitate is carefully washed in distilled water, and dried in the shade. Recommended as superior to the subnitrate in some forms of gastrodynia, dyspepsia, intermittents, &c.—Dose, 2 to 6 gr., or more.