POTASSÆ TARTRAS. L. Tartras Potassæ.
Olim, Tartarum Solubile. E. Tartras Kali. D.
Kali Tartarizatum. P.L. 1787.
Tartarum Solubile. P.L. 1745.
Qualities. Form; this salt, although ordered to be crystallized, is generally kept in its granular form. Taste, bitter and cool. Chemical Composition. It consists of one proportional of acid, and one proportional of base. Solubility. When in its crystalline form it is soluble in its own weight of water, but in its ordinary granular form, 4 parts are required for its solution; hence, compared with the insoluble super-tartrate, it has justly acquired the name of soluble tartar; when long kept in solution, its acid is decomposed, and its alkali remains in a state of a sub-carbonate. It is also readily soluble in alcohol. Incompatible Substances. Magnesia, baryta, and lime; acetate and sub-acetate of lead, and nitrate of silver decompose it. All acids, even the carbonic,[[616]] and acidulous salts, tamarinds, and other sub-acid vegetables, by neutralizing a proportion of the base, convert it into the state of super-tartrate; this fact offers another illustration of the chemical law of affinity, explained under the head of sulphate of potass. The practitioner should bear this in his recollection, for I have frequently seen a dose of soluble tartar directed in the acidulated infusion of roses; the result was of course very different from that which the author of the prescription intended to produce. Med. Uses. It is a mild and efficient purgative, and forms a very valuable adjunct to resinous purgatives or to senna, the griping properties of which it corrects by accelerating their operation. Form. 70. Dose, ʒj to ℥j, in solution.
PULVERES. L.E.D. Powders.
For the administration and advantages of this form of preparation, see page 190. The following Officinal Formulæ offer some valuable combinations.
Pulvis Aloes compositus. L. Pulvis Aloes cum Guaiaco. D. It consists of aloes three parts, guaiacum two (G), and compound powder of cinnamon one part (O). It combines sudorific and purgative effects. Dose, grs. x to ℈j. See Form. 80.
Pulvis Aloes cum Canella. D. and P.L. 1807. Aloes four parts, white canella (E) one part. It is known in the shops by the name of Hiera Picra. The compound is more adapted for the form of pills than that of powder. It is very generally used by the lower classes, infused in gin. Dose, grs. x to ℈j.
Pulvis Antimonialis. L.D. Oxidum Antimonii cum phosphate Calcis. E. This preparation was introduced into the Pharmacopœia, as the succedaneum of the celebrated fever powder of Dr. James, the composition of which was ascertained by Dr. George Pearson. (Phil. Trans. lxxxi. 317.) It consists of 43 parts of the phosphate of lime, mixed, or perhaps chemically combined, with 57 parts of oxide of antimony, of which a portion is vitrified; and it is probable, that the difference of the two remedies depends principally upon the quantity of oxide which is vitrified: the specification of the original medicine is worded with all the ambiguity of an ancient oracle, and cannot be prepared by the process as it is described.[[617]] Experience has established the fact, that James’s Powder is less active than its imitation; it affects the bowels and stomach very slightly, and passes off more readily by perspiration; in general however the difference is so inconsiderable, that we need not regret the want of the original receipt.[[618]] As it is quite insoluble in water, it should be given in powder, or made into pills. It is diaphoretic, alterative, emetic, or purgative, according to the extent of the dose and the state of the patient; in combination it offers several valuable resources to the intelligent practitioner. (See Form. 119, 121, 125, 129, 134.) But it may be fairly questioned whether this remedy has not been far too highly appreciated. Dr. James was certainly very successful in its use, but it must not be forgotten that he usually combined it with some mercurial, and always followed it up with large doses of bark.