Origin - Obtained by dissolving purified bismuth in nitric acid and water, decanting and filtering, mixing with ammonia water, washing the precipitate, and dissolving in nitric acid. The solution is then mixed with a solution of sodium carbonate, and the resulting precipitate collected and washed. It should yield not less than 90 per cent. of pure bismuth oxide.

Description and Properties.A white or pale yellowish-white powder, of - somewhat varying chemical composition, odorless and tasteless, permanent in the air. Insoluble in water or alcohol, but completely soluble in nitric or hydrochloric acid, with copious effervescence.

Dose. - 5-20 grains (0.3-1.2 Gm.) [71/2 grains (0.5 Gm.), U. S. P.].