ANTIMONIC ACID. The peroxide of antimony. (See ANTIMONY.) A brittle metal of a silver white color ; specific gravity, 6'7. Fuses at 810°, or just at a red heat. The principal properties of this metal were first described in the " Currus Trium phalis Antimonii" of Basil Valentine, published towards the end of the 13th century. When heated in an open vessel, it combines with oxygen, and evaporates in a white vapor. There are three oxides of antimony. The protoxide consists of 65 antimony + 12 oxygen ; it is a grayish white powder eminently purgative, suaorific, and emetic ; and as such, of much importance in medicine. It is the active base of emetic tartar and of James's powder. The other oxides of antimony, from combining with certain bases, have been called antimonious and antimonie acid ; they consist respective ly of 65 antimony 16 oxygen, and 65 20. The combination of chlorine and antimony was known to the old chemists under the name of butter of an timony. The principal ore of antimony is the oicWuret : it is met with in com merce, melted into conical ingots, under the name of crude antimony. It is of a bluish gray color, metallic lustre, and a striated texture ; specific gravity 4.62; it
is much more easily fusible than the pure metal. Antimony forms brittle alloys with some of the most malleable metals : when gold is alloyed with a two-hun dredth part of antimony, the compound is brittle; and even the fumes of anti mony in the vicinity of melted gold are sufficient to render it brittle. Alloyed with lead in the proportion of 1 to 16, and a small addition of copper, it forms the metal used for printer's types : with lead only, a white and rather brittle com pound is formed, used for the plates upon which music is engraved. With iron it forms a hard whitish alloy, formerly called martial reguLue: 12 parts of tin and 1 of antimony form hard pewter. The white metal spoons and teapots are form ed of an alloy of 100 tin, 8 antimony, 2 bismuth, and 2 copper.
Antimony is the stimmi, or stibium, of the old chemists. The protoxide of anti mony has beep used in France and Eng land lately as a white paint in substita tion for carbonate of lead.