Prep. By dissolving litharge in dilute acetic acid, and subsequent evaporation and crystallization.

Prop. & Comp. Generally in white spongy-looking masses, composed of interlaced acicular crystals; it may be obtained in large, flat four-sided prisms; acetate of lead has a sweetish, acetous odour, and sweet, metallic taste; effloresces slightly in the air; is soluble in water; the solution slightly reddens litmus; and is precipitated white by carbonate of soda, yellow by iodide of potassium, and black by sulphuretted hydrogen; treated with sulphuric acid, acetic vapours are given off. The solution in distilled water is clear, or has only a slight muddiness, which disappears on the addition of acetic acid: 38 grains dissolved in water require for complete precipitation 20 measures of the volumetric solution of oxalic acid, corresponding to 22.3 grains of oxide of lead. Composition (Pb O, C4 H3 O3 + 3 HO).

Off. Prep. Pilula Plumbi cum Opio. Pill of Lead and Opium. [Not officinal in U. S. P.] (Acetate of lead, in fine powder, thirty-six grains; opium, in fine powder, six grains; confection of roses, six grains.) One grain of opium is contained in eight grains of the pill mass.

Therapeutics. Acetate of lead in small doses acts as a sedative and astringent, lessening morbid mucous discharges and haemorrhages, and even diminishing the natural secretions; hence producing constipation, thirst, and a species of colic named Painters' or lead colic, accompanied by a peculiar blue line on the gums (a valuable diagnostic sign): when continued for some time, it renders the pulse smaller, and induces wasting of the body; it also produces an influence on the nervous system, shown by loss of power of the extensors of the hand', sometimes complete paralysis and apoplexy. The serious symptoms above described are, for the most part, brought on by contact with lead in various occupations, and not often by its employment as a medicine. Acetate of lead is much used in haemorrhages from various organs, also in chronic diarrhoea and dysentery; in phthisis to check expectoration and excessive sweating. Externally it is sedative and astringent, and is sometimes used in skin affections and over inflamed parts.

Dose. 1/2 gr. to 3 gr., or more; of Pilula Plumbi cum Opio, 4 gr. to 8 gr.

Liquor Plumbi Subacetatis. Solution of Subacetate of Lead. Prep. (Acetate of lead, five ounces; litharge, in powder, three ounces and a half; distilled water, twenty fluid ounces, or a sufficiency. Boil them together for half an hour, frequently stirring, 9 then filter; and when the liquor is cold, add of distilled water as much as may be necessary, that it may accurately measure twenty fluid ounces. Let it be kept in well-closed vessels.) By the action of the litharge on acetate of lead, a sub-salt is formed, an additional amount of the oxide of lead entering into the composition of the salt.

Prop. & Comp. A clear colourless liquid, sp. gr. 1.26, with an alkaline reaction, and sweet, astringent, metallic taste; it agrees with the acetate in most of its properties, except that it precipitates gum as well as mucilage from solution, forming an opaque white jelly. Sulphuric acid in excess gives a white precipitate of sulphate of lead, acetic acid being set free. Two fluid drachms require for perfect precipitation 27 measures of the volumetric solution of oxalic acid, corresponding to about 30 grains of oxide of lead. The composition of the salt contained in liquor plumbi subacetatis may be represented by the formula, 2 Pb 0, C4 H3 O3.

Off. Prep. Liquor Plumbi Subacetatis Dilutus. Dilute Solution of Subacetate of Lead. (Solution of subacetate of lead, two fluid drachms; rectified spirit, two fluid drachms; distilled water, nineteen fluid ounces and a half.) [Solution of subacetate of lead, three fluid drachms; distilled water, a pint. U. S.]

Unguentum Plumbi Subacetatis. Ointment of Subacetate of Lead. [Not officinal in U. S. P.] (Solution of subacetate of lead, six fluid ounces; camphor, sixty grains; white wax, eight ounces; olive oil, twenty fluid ounces.)

Therapeutics. Subacetate of lead acts as an astringent and sedative; it is only used externally; and in the form of the dilute solution, is most commonly employed when the topical action of lead is desired. The ointment is used for a similar purpose.