Definition. - Bismuth subsalicylate should yield not less than 62 per cent. nor more than 64 per cent. of pure bismuth oxide.

Official under the names of Bismutum subsalicylicum (P. G.), Bismutum salicylicum (Swiss), Bismuthi salicylas (Br. P.). The composition varies somewhat, but is approximately C6H4(OH)CO2BiO.

Description and Properties. - A white, or nearly white, amorphous or crystalline powder, odorless, tasteless, and permanent in the air. It is almost insoluble in water; on prolonged boiling with water, a more basic salt is formed through the splitting off of free salicylic acid. Alcohol or ether extracts salicylic acid, with decomposition of the salt. Acids decompose it, with separation of a white, flocculent precipitate of salicylic acid.

Dose. - Average dose: 4 grains (0.250 Gm = 250 milligrammes), U. S. P.