*Hydrargyri Chloridum Mite (Hydrarg. Chlor. Mit.), Mild Mercurous Chloride, U.S.P. (Mercurous Chloride, Calomel, Protochloride of Mercury, Subchloride of Mercury).—HgCl.
White or nearly white, odorless, tasteless powder. Insoluble in water, alcohol or ether. Incompatible with alkalies, with oxidizing acids like nitric acid, and with soluble bromides and iodides.
Action and Uses: A slow cathartic, fairly powerful and relatively non-irritant. Should usually be followed by a saline laxative. Should not be taken continuously as it may salivate. Also employed as a diuretic in cardiac dropsies. Intramuscular injections are very efficiently antisyphilitic, but painful.
Dosage: Laxative, 0.15 Gm. or 2-1/2 grains (U.S.P.); alterative, 0.015 Gm. or 1/4 grain (U.S.P.). From 0.005 to 0.02 Gm., or from 1/12 to 1/3 grain, may be given every half hour or hour until from 0.1 to 0.2 Gm., or from 1-1/2 to 3 grains have been given. In the treatment of syphilis 0.1 Gm. or 1-1/2 grain in oily suspension is injected about once a week.
Lotio Nigra (Lot. Nigr.), Black Lotion, N.F. (Black Wash, Aqua Phagedaenica Nigra).—A suspension of mercurous oxide, Hg2O, produced by the action of lime water on mild mercurous chloride.
Uses: Mercurial antiseptic.
Pulvis Hydrargyri Chloridi Mitis et Jalapae (Pulv. Hydrarg. Chlor. Mit. et Jalap.), Powder of Mild Mercurous Chloride and Jalap, N.F. (Calomel and Jalap).—Mild mercurous chloride (34%) and jalap (66%).
Uses: Drastic purgative.
Dosage: 0.65 Gm. or 10 grains (N.F.).
*Hydrargyri Iodidum Flavum (Hydrarg. Iod. Flav.), Yellow Mercurous Iodide, U.S.P. (Mercurous Iodide, Protoiodide of Mercury, Yellow Iodide of Mercury).—HgI.