5. On an Oxycyanide, and a New Oxide, of Bismuth

Abstract

Bœdeker (Annalen, 123, 61), by the action of potassium cyanide on bismuth nitrate, obtained a reddish-brown salt, to which he assigned the formula Bi2O5.2H2O. In an examination of the oxides of bismuth in conjunction with Hoffmeister and Robbs (Chem. Soc. Jour., 1881; Proc., p. 21), I had occasion to prepare Bœdeker's salt; a slight study of its properties proved it to be a compound of no little interest. When a concentrated aqueous solution of potassium cyanide is added to a solution of metallic bismuth in excess of nitric acid, and the mixture is boiled, a brownish-red solid and a more or less dark red liquid are obtained, and quantities of hydrocyanic acid are evolved. When the excess of nitric acid is nearly neutralised by potash before addition of potassium cyanide, the colour of the solid is a much lighter brown, and the supernatant liquid is nearly or quite colourless.