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