436

TEA

that invented by Mr. Hume of Long-acre, and which he publishedin the Philosophical Magazine, vol. xlv., p. 301. The London Col-lege of Physicians, after trying other formulae, preferred this, andadmitted it into their Pharmacopoeia of 1815 ; but, through some un-accountable mistake or negligence, the original directions are thereso mutilated, that probably very few chemists have been induced toadopt the process.Mr. Humes Formula, as given by himself, is literally the following:" Two parts of the black sulphuret of antimony in fine powder andone part of nitrate of potass are to be mixed and added to two partsof sulphuric acid, previously mixed with eight parts of water, andsuffered to cool. By a due application of heat, a proper oxide ofantimony will be the result, which, when thoroughly washed, is tobe boiled, while yet moist, with two parts of supertartarte of potass,and a proper quantity of water. The solution is then to be filtered,evaporated, and treated after the usual manner for crystallization."The formula in the present Pharmacopoeia directs glass of antimony to-be mixed with the supertartrate of potass, instead of the oxide pro-posed by Mr. Hume.

Tartaric Acid. See Acidum Tartaricum.

Tartarum. L. Tartar. Tartari cryslalli. D. An impure supertar-trate of potass, which may be used for making the purified article.It is called Argol, or Tartarum album, when procured from whitewines, and Tartarum rubrum when derived from red wines.

Tartarum Vitriolatum. See Potassje Sulphas.

Tartras Acidulus Potass* Solubilis. P. Cream of Tartar.

Tartras Acidulus Potass* Solubilis admixto Acido Boracico. P.Heat together in a silver vessel 30 parts of boracic acid, and 20 partsof distilled water. Then add in divided portions 120 parts of super-tartrate of potass, shaking it constantly till the whole melt, and con-tinuing the heat till a pulverulent mass is formed.Medicinally it is used in the same cases as cream of tartar, but is weaker.It is very deliquescent in the air.

Tartrates are combinations of tartaric acid, with alkaline, or metallicbases. Thus we have tartrate of potass, tartrate of ammonia, tar-tarized antimony, tartarized iron, &c. See Sod* Tartar, Anti-mon. Tartar, Ferr. Tartar., Potass. Tartar., and Supertar-trate.

Taxus Baccata. Yew Tree. The berries were formerly supposed tobe poisonous, but are not so, though the leaves are when, fresh.Three children were killed by a spoonful of the green leaves. Thedried leaves are innoxious. (Percival's Essays, III.)

Tea. See Thea. P.