ACETUM COLCHICI. L. Vinegar of Meadow Saffron.

Vinegar appears to be a solvent of the acrid and medicinal principle which resides in the bulb of this plant. Dose fʒss to fʒij. in any bland fluid. See Colchici Radix.

ACETUM SCILLÆ. L.E.D. Vinegar of Squill.

This preparation is an acetic solution of the acrid matter of the Squill, upon which its medicinal efficacy depends.[[330]] Dose fʒss to fʒij. in cinnamon or mint water. See Scillæ Radix. Form. 107, 114. Alkalies and their carbonates are chemically incompatible with these Vinegars. This preparation, as well as the Oxymel, deposites when long kept a precipitate consisting of citrate of lime and tannin, but its medicinal efficacy is not on that account impaired.

ACIDUM ACETICUM DILUTUM. L. Acidum Acetosum Distillatum. E. Acetum Distillatum. D.

Common Distilled Vinegar.

Qualities. Odour, fainter and less agreeable than common vinegar (Acetum): Taste, less acid; Colour, none. Specific Gravity; Mr. Phillips states, that when prepared according to the directions of the Pharmacopœia, it varies from 1·007 to 1·009; and that 1000 grains of the latter require for their saturation, 145 grains of crystallized sub-carbonate of soda. I apprehend, however, that it will be found quite impossible to obtain a dilute acetic acid equal in strength or specific gravity, to that last mentioned, by the process of the London College;[[331]] it may even be doubted whether it can be produced of the specific gravity 1·007. The general run of distilled vinegar as found in the shop of the druggist, varies from 1·005 to 1·006, and contains from 2·80 to 2·826 per cent. of real acid; when of the specific gravity of 1·009 it would contain about 4·73 per cent. Dr. Powell states (Translation of the Pharmacop: of London, 1815) that “one fluid-ounce ought to dissolve at least thirteen grains of white marble;” or, what is equivalent to it, 39·67 grains of crystallized Sub-carbonate of Soda; acid of this strength corresponds very nearly with six degrees of the Revenue Acetometer, the proportions being as follow, 100 grains of Pharmacopœia strength will saturate 8·68 grains of crystallized Sub-carbonate of Soda; 100 grains of acid of 6° of the Acetometer will saturate 8·70 grains of the salt. Chemical Composition. Acetic Acid more largely diluted than that in vinegar, with very minute portions of uncombined mucilage and extractive. Solvent Powers. It is capable of dissolving all those vegetable principles which are soluble in water, and in some cases, as in Squill, Colchicum, and in several Aromatics and Narcotics, its acid appears to extend its solvent powers; at the same time it often modifies or diminishes the medicinal virtues of the substances, as for instance those of Narcotics; this circumstance considerably limits its pharmaceutical application; when however it is employed, a portion of spirit should be always added, in order to counteract the spontaneous decomposition to which it is liable, and the acetic compound should be preserved in stopped bottles. Acetic acid does not dissolve true resins, but it has some action on gum resins. Medicinal Uses. It is refrigerant, and may be advantageously administered in hemorrhage; especially in cases where the acetate of lead has been given, since the solubility of this latter substance is increased by it. See Form. 57; externally, it may be a convenient adjunct to lotions containing lead. See Form. 147. In consequence of its chemical action upon osseous matter, it has been much employed at the Gloucester Infirmary to hasten exfoliation of carious bone. Adulterations. Sulphuric Acid may be detected by a precipitate being produced on the addition of acetate of baryta: this test however will not answer for its detection in common vinegar, for the reason stated under that article. See Acetum. Sulphurous Acid may be recognised by drawing a little of the vapour into the lungs. The presence of Nitric Acid may be discovered by saturating the suspected sample with pure potass, evaporating to dryness, and then treating the product with a highly concentrated alcohol, the acetate of potass will be thus dissolved, but as it exerts no action on the Nitrate it will be found in the residuum, and may be recognised by its deflagration, when thrown upon burning charcoal;[[332]] Copper may be detected by the acid assuming a blue colour, when supersaturated with ammonia; and Lead, by a solution of sulphuretted hydrogen, producing a dark coloured precipitate. Tin however is the metal with which distilled vinegar is more usually contaminated, for no vegetable acid will act upon lead while any tin is present in the mixture, since the latter, being more oxidable than the former, is exclusively dissolved.

ACIDUM ACETICUM FORTIUS. L.

(Acidum Aceticum.)

(e Ligno Destillatum.)