Prop. Pure acetate of lead forms colourless, transparent, prismatic crystals, slightly efflorescent in dry air; it is soluble in 8 parts of alcohol and in 11⁄4 part of cold water; the aqueous solution has a sweet astringent taste, and feebly reddens litmus, but turns turmeric and the juice of violets green; when gently heated, it melts in its water of crystallisation; by continuing the heat, the whole of the water is expelled, and the dry acetate obtained; at a higher temperature the salt suffers decomposition, and acetic acid, acetone, &c., is given off. Commercial acetate of lead is in general a confused crystalline mass, somewhat resembling broken lump sugar. It is powerfully astringent and poisonous.
When pure it is completely soluble in distilled water acidulated with acetic acid forming
a transparent colourless solution, “38 grains dissolved in water require for complete precipitation 200 grains measures of the volumetric solution of oxalic acid.” (B. P.)
Uses, &c. Acetate of lead is extensively employed in dyeing and calico-printing. In medicine it is used as an astringent, styptic, and hæmostatic; in pulmonary, uterine, and intestinal hæmorrhage, colliquative diarrhœa, phthisical sweats, &c. It is usually combined with morphia or opium, and with acetic acid to prevent it passing into the state of the poisonous carbonate in the stomach.—Dose, 1⁄2 gr. to 2 gr. (Collier); 1 to 2 gr. to 8 or 10 gr., twice or thrice a day (Pereira); 3 gr. to 10 gr., every 6 or 8 hours (A. T. Thomson). Externally, as a collyrium, 10 gr. to water, 8 fl. oz. (A. T. Thomson); as a lotion, 20 gr. (A. T. Thomson), 1 dr. (Collier) to water, 8 or 10 fl. oz.; as an injection, 40 gr. to rose water, 1⁄2 pint. The lotion is cooling and sedative, and is commonly used in excoriations, local inflammations, &c.
Basic Acetates. There are several of these salts, but only one is of any importance.
Tribasic Lead Acetate or Double Plumbic Acetate, and Dioxide. Pb(C2H3O2)2 2PbO. Syn. Subacetate of lead; Basic lead citrate; Goulard’s acetate of lead; Plumbi subacetas (B. P.). Prep. Litharge, 7; acetate of lead, 10; and distilled water, 40; are boiled half an hour, and evaporated down, and allowed to crystallise out of contact with air.
Used under the form of “Plumbi subacetas liquor” v. (B. P.)
Lead, Arse′′niate of. Pb3(AsO4)2. Syn. Arsenate of l.; Plumbi arsenias, L. Prep. Gradually add a solution of acetate of lead to another of arseniate of sodium. A white, insoluble powder. Proposed as an external application in certain forms of cancer.
Lead, Bro′mide of. PbBr2. Syn. Plumbi bromidum, L. Prep. By precipitating a solution of neutral acetate or nitrate of lead with a solution of bromide of potassium. A white, crystalline powder, sparingly soluble in water. It fuses by heat into a red liquid, which turns yellow when cold. It has been used in the same cases as iodide of lead.
Lead, Car′bonate of. PbCO3. Syn. Plumbi carbonas, L. Prep. By precipitating a cold solution of either acetate or nitrate of lead with a solution of an alkaline carbonate, observing to well wash the precipitate and dry it in the shade. This preparation is seldom employed, the commercial carbonate (WHITE LEAD) being substituted for it. See White pigments.