ANTIMONIUM NIGRUM - BLACK ANTIMONY, Sb2S3, = 340.

Preparation

From the native ore stibnite, by fusing and then reducing to a fine powder.

Characters And Tests

A crystalline steel-gray metallic-looking powder, which dissolves in boiling hydrochloric acid, with evolution of sulphuretted hydrogen.

Antimonium Sulphuratum - Sulphurated Antimony, Sb2S3, Sb2O3.

(Golden or precipitated sulphuret, an oxy-sulphide).

Preparation

By dissolving the black sulphide in caustic soda with the aid of heat, and adding sulphuric acid; several complex reactions occur, and sulphurated antimony is precipitated.

Characters And Tests

An orange-red powder, inodorous, almost tasteless, insoluble in water, soluble in hydrochloric acid, also in solutions of caustic alkali, and of acid tartrate of potash: exposed to light and air it partially decomposes, with separation of sulphur.

There are several other reddish or brown oxy-sulphides of antimony, and all have been termed "kermes mineral," from some resemblance in color to the insect kermes (cochineal).

ANTIMONII CHLORIDI LIQUOR - SOLUTION OF CHLORIDE OF ANTIMONY, SbCl3, =228.5.

Preparation

By dissolving black antimony in hydrochloric acid.

Characters And Tests

A heavy, yellowish-red liquid, which, when poured into water, gives a dense white precipitate of oxy-chloride (SbOCl).

The pure chloride, which may be obtained by distillation, is volatile, but concretes, on cooling, into a soft, white solid, "butter of antimony;" and this term is sometimes given to the officinal solution.

ANTIMONII 0XIDUM - OXIDE OF ANTIMONY, Sb2O3,=292.

Preparation

By decomposing the oxy-chloride with sodic carbonate.

Characters And Tests

A grayish-white powder, inodorous, tasteless, and insoluble in water, soluble in hydrochloric acid: moderately heated, it turns yellow, at a red heat it burns, or sublimes in crystals.

ANTIMONIUM TARTARATUM - TARTARATED ANTIMONY - TARTRATE OF ANTIMONY AND POTASH-TARTAR EMETIC, KSbC4H1O7H1O, = 343.

Preparation

By mixing the oxide of antimony with acid tartrate of potash and water for twenty-four hours, afterward boiling in water, and crystallizing out.

Characters And Tests

Occurs in rhombic, octahedral, colorless crystals, transparent when fresh, but efflorescing on exposure to air; also, and more frequently, in the form of powder, which should be perfectly white, a yellowish tinge indicating the presence of iron. It is odorless, but has a sweetish, subacid taste, which quickly becomes metallic and nauseous, but may not be much noticed if the powder be largely diluted. The crystals are best obtained for microscopic examination by evaporating on a slide a drop of the hot solution: characteristic triangular facets are seen, and some modifications of the cube, and they are larger than arsenical crystals: branched crystalline forms also occur, as in many other saline solutions. The crystals of tartar emetic are isomorphous with those of the sulphate of potash, but the latter do not effloresce. Tartar emetic is soluble in two parts of boiling, and in fourteen parts of cold water; less soluble in proof spirit, or in wine, and insoluble in absolute alcohol. Acids, except tartaric acid, occasion a white precipitate, as also do alkalies, alkaline earths, and their carbonates, but excess of these agents will re-dissolve the precipitates.

The dried salt, like other tartrates, decrepitates and chars on the application of heat, and its solution in water readily becomes mouldy from the development of a fungus (a little added spirit will prevent this).

Infusion of galls, catechu, cinchona, strong tea, or tannin in any form, precipitate a tannate of antimony, which is so insoluble as to be practically inert. The following tests are applicable to any soluble antimonial salt: - (1) If it be boiled in water with one-sixth part of pure hydrochloric acid and a strip of metallic copper, antimony will be deposited on the metal, violet-red in color if the quantity be small, but iron-gray, or black, if in large amount. (2) A solution acidulated with the same acid (1/16 th) gives, in the cold, a black deposit on pure tin. (3) Sulphide of ammonium, or sulphuretted hydrogen, produces, in acid solutions, an orange-colored deposit soluble in hydrochloric acid (boiling), and, if this latter solution be poured into water, a white deposit of oxide occurs. (4) Evolution of nascent hydrogen (as from zinc and sulphuric acid) in the presence of antimony, leads to the formation of antimoniuretted hydrogen: this burns with a blue flame, and produces on porcelain a black stain which is insoluble in bleaching powder.