Contractions. - Ant. Tart. Tar.

Synonyms. - Antimonii Potassio-tartras, Tartarus Eme-ticus.

Present name. - Potassio-antimonic Oxytartrate. KSb C4H4O7H1O.

For. name: German, Brechweinstein.

The British Pharmacopoeia gives the following process for making this: -

Take of

Oxide of Antimony ....

5 ounces;

Acid Tartrate of Potash, in fine powder .

6 ounces;

Distilled Water .....

2 pints.

Mix the Oxide of Antimony and Acid Tartrate of Potash with sufficient distilled water to form a paste, and set aside for twenty-four hours. Then add the remainder of the water, and boil for a quarter of an hour, stirring frequently. Filter, and set aside the clear filtrate to crystallize. Pour off the mother liquor, evaporate to one-third, and set aside, that more crystals may form. Dry the crystals on filtering paper at the temperature of the air.

Characters and Tests. - In colourless transparent crystals, exhibiting triangular facets, soluble in water, and less so in proof spirit. It decrepitates and blackens upon the application of heat. Its solution in water gives with Hydrochloric Acid a white precipitate, soluble in excess, and which is not formed if Tartaric Acid be previously added. 20 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. 10 grains dissolved in a fluid ounce of Hydrochloric Acid give no precipitate when the solution is saturated with Sulphuretted Hydrogen. The gas delivery tube should be moistened with Hydrochloric Acid before dipping it into the liquid.

Preparation. - The lx, when required, must be a trituration; 1, solution in distilled water to which 5 per cent. of rectified spirit has been added. Dilute alcohol may be used after 2, and rectified spirit for 3 and upwards.

Reference to Horn. Proving. - Arch., iii.

Proper forms for dispensing. - lx, Trituration only. 1 to 5x, Solution only. 3 and upwards, Tincture, Pilules, or Globules.