CYANIDE, in chemistry, a salt of prussic or hydrocyanic acid, the name being more usually restricted to inorganic salts, i.e. the salts of the metals, the organic salts (or esters) being termed nitriles. The preparation, properties, &c., of cyanides are treated in the article PRUSSIC ACID; reference should also be made to the articles on the particular metals. The most important cyanide commercially is potassium cyanide, which receives application in the " cyanide process " of gold extraction (see GOLD).