596

Alkalies and Neutral Salts.

part III.

Sulphates are discovered by saturating with muriatic acid, andadding muriate of barytes; and if lime be present, blowinginto the solution through a tube will render it turbid; butthese contaminations do not alter its effects as a remedy, noras a pharmaceutical agent. One pint of it should weigh sixteenounces.

Medical properties and uses. — This solution is diuretic, ant-acid, and lithrontriptic. The two first properties it certainlypossesses in a considerable degree: but its continued use, evenwhen much diluted, is said to debilitate, and otherwise injurethe stomach. As a solvent of calculus, both in the kidneysand bladder, this alkali has long been celebrated: it acts, how-ever, on calculi composed of uric acid, or of urate of ammonia,only; the presence of which in the habit is known by a reddeposit in the urine of the patient. But although the continueduse of solution of potass certainly renders the urine alkaline,yet there is reason to believe that its solvent effects on calculousmatter in the kidney or the bladder are not equivalent to theirritation it excites both in the stomach and the bladder ; andas a prophylactic, its place can be much better supplied bymagnesia and the alkaline carbonates. Dr. Willan says, hehas seen the most beneficial effects experienced from the in-ternal use of this solution in lepra ': and from my own expe-rience I can assert, that it may be almost regarded as a specificin the various species of psoriasis, which depends altogether onacidity of the primae viae, and a hasty and consequently imper-fect formation of the juices of the stomach. It is also usedas a local stimulant, much diluted, in the form of lotion, tothe joints, in rachitis and gouty swellings; and in its concen-trated state, as a caustic, to destroy the poison introduced bythe bite of rabid or venomous animals.

The dose of this solution may be from nix. to f^j. taken inchicken-broth, milk, or almond mixture; but in cases of pso-riasis, it should be gradually increased to f 5 ij. In cases ofacidity of the stomach, it may be administered in some bitterinfusion.

Officinal preparations. Potassa fusa, L. E. D. Potassa cumCalce, L. E. D. Liquor Sulphureti Kali, D. Antimonii Sulpku-retum prcecipitatum, L. E.

LIQUOR POTASS^ SUBCARBONATIS, Lond. So-lution of Subcarbonate of Potass. »

" Take of subcarbonate of potass, a pound ; distilled water,twelvejluid ounces. Dissolve the subcarbonate of potass in thewater, and filter the solution through paper."

AgUA Subcarbonatis Kali, Dub. Water of Subcarbonateof Kali.

1 Willan on Cutaneous Diseases, p. 141.3 Aa. Kali prcsparatum, P. L. 1787,