452

Alkalies and Neutral Salts.

part III.

nic acid flies off - in the form of gas, exciting effervescence. Inour experiments, distilled vinegar of a specific gravity of 1007required 320 grains of the subcarbonate to saturate a pint;hence the proportion ordered by the London and DublinColleges is just sufficient for saturating three pints. 1 Owing,however, to the variable proportion of acid in distilled vine-gar, this preparation cannot be obtained of an uniform strength;and provided it be- accurately neutralized it is of little import-ance. If it be not accurately saturated, some of the metallic&alts, particularly those of antimony, which are often orderedin conjunction with it, are decomposed. *

Qjialities. — This solution is inodorous ; has a slightly nau-seous taste; and, when made with pure materials, is limpidand colourless. It is decomposed by the fixed alkalies, thestrong acids, oxymuriate of mercury, and nitrate of silver,which are consequently incompatible in formulae with it.

Medical properties and uses. —As a diaphoretic it is in com-mon use in febrile diseases; and may be combined with opium,camphor, antimonials, or nitrate of potash. It is necessaryto assist its determination to the skin with plentiful dilution,and a moderate degree of external heat: for by free exposureto cool air it excites the kidneys, instead of opening the skin.Externally it is employed as a discutient; as a lotion to in-flamed surfaces ; and when diluted with rose-water holding insolution a small portion of opium, it is an excellent collyriumin chronic ophthalmia; and still more largely diluted, isoccasionally used as an injection in the commencement ofgonorrhoea. The ordinary dose is from f^ij to %xvj, given everythree or four hours.

LI'QUOR AMMONIA SUBCARBO'NATIS. J Lond.Solution of Subcarbonate of Ammonia. 4

" Take of subcarbonate of ammonia, four ounces; distilled"water, a pint. Dissolve the subcarbonate of ammonia in thewater, and filter through paper."

Solutio Subcarbonatis AmmonijE. Edin. Solution ofCarbonate of Ammonia.

" Take of subcarbonate of ammonia, one part; distilled

' The mercury of a thermometer, the bulb of which was immersed in trie solutionwkile effervescing, sunk five degrees.

* M. ue La^sone obtained the salt crystallized by sublimation, in long slender flattedcrystals, terminating in sharp points, an inch in length, and of a pearl-white colour.They are very deliquescent, impress on the tongue a sense of coldness aud sweetness ;melt at 170°, and sublime at about 350°. According to Richter, they consist of 68 - 7 7acid,and 31"23. base. Thomson's Chemistry, 4th ed. vii. 62.

3 Soucarbonate d'ammoniaque (F.) Kohlensaures Amonium liquor (G.) LiquoreSotto-carbonato di ammoniaco (L)

4 Remarks on the Editio Altera of the Pharm. Lond. p. 16.