Synonym. Antimonii Potassio-Tartras. Lond. Often termed Tartar Emetic.

Prep. By mixing five ounces of oxide of antimony with six ounces of acid tartrate of potash in line powder, and a little water so as to form a paste, and setting the mass aside for twenty-four hours; afterwards boiling it in water for a quarter of an hour, filtering the solution, and allowing the clear filtrate to crystallize. In this process one equivalent of oxide of antimony (Sb O3) replaces the equivalent of water in the acid tartrate of potash (HO, KO, C8 H4 O10).

Prop. & Comp. Colourless transparent crystals, exhibiting triangular facets (rhombic octahedra) with slight metallic taste. Composition (Sb O3, KO, C8 H4 O10 + 2 HO). The crystals effloresce slightly in dry air; are soluble in about 20 parts of boiling water; partially soluble in proof spirit and insoluble in alcohol: they decrepitate and blacken upon the application of heat. The watery solution decomposes readily with the formation of algae (Sirocrocis tartarica); is precipitated orange-red by sulphuretted hydrogen, not by ferrocyanide of potassium, chloride of barium, or nitrate of silver unless the solution is concentrated. Nitric acid gives a precipitate soluble in excess of the acid. The watery solution gives a white precipitate with hydrochloric acid, which is not formed if tartaric acid be previously added. Twenty grains dissolve without residue in a fluid ounce of distilled water at 60°, and the solution gives with sulphuretted hydrogen an orange precipitate, which when washed and dried at 212° weighs 9.91 grains.

Off. Prep. Vinum Antimoniale. Antimonial wine. (Tarta-rated antimony, forty grains; sherry wine, twenty ounces.) Two grains of the salt are contained in each ounce of the wine.

Unguentum Antimonii Tartarati. [Unguentum Antimonii, U. S.] Ointment of Tartarated Antimony. (Tartarated antimony, in fine powder, a quarter of an ounce; simple ointment, one ounce.) The ointment contains one part of antimonial salt in five parts of the preparation, and nearly twice as much tartarated antimony as unguentum antimonii tartarati. Dub.

Therapeutics. Internally, in small doses, tartar emetic acts on the skin and mucous membranes, and is diaphoretic, expectorant, and probably cholagogue. In larger doses it acts at first as an emetic, sometimes as a purgative; if continued, tolerance becomes established, and it then produces a powerful sedative effect upon the vascular system (not the heart especially) and upon all the muscles. Externally it is powerfully irritant, and produces pustules having the character of those in Variola; occasionally when thus applied it becomes absorbed, and hence may be dangerous in very young subjects. Tartar emetic is used in febrile affections to promote secretions; in severe inflammation, as in acute pneumonia and bronchitis, as a vascular depressant; also in the reduction of dislocations; not unfrequently as an addition to purgative medicines. It is frequently employed as an emetic, being adapted to cases in which depression of the circulation is not objectionable. Externally, in the form of ointment, or hot aqueous solution, it is used as a powerful counterirritant in head and abdominal affections, also over diseased joints, and other chronically inflamed parts.

Dose. Of tartar emetic; as a diaphoretic, expectorant, etc, 1/16 gr. to 1/6 gr.; as a vascular depressant or sedative, 1/6 gr. to 2 gr.; as an emetic, 1 gr. to 3 gr.

The wine is objectionable in cases where large doses of the salt are required for its depressant effect, but is a useful form for administration in doses of 15 min. to 40 min. in febrile affections, etc.

Incompatibles. Acids, alkalies, and their carbonates cause precipitates in the solutions of this salt; also some earthy and metallic preparations, as those of lime, lead, etc.; but caustic alkalies in excess redissolve the precipitate. Astringent vegetable infusions throw down an insoluble tannate of antimony.

Adulteration. Cream of tartar is the only adulteration likely to be met with; this can be detected by its being less soluble in water than tartar emetic, and by finding that upon the addition of a small quantity of carbonate of soda to a boiling solution of the suspected salt, the precipitated oxide of antimony, which is at first thrown down, becomes redissolved from the presence of the free acid of the acid tartrate of potash.