soluble in alcohol. Those made by the first two formulæ are of a pale yellow colour. It is transparent and totally soluble in water. The solution, on the addition of hydrochloric acid, evolves hydrocyanic acid, known by its smell; and a glass moistened with a solution of nitrate of silver, and held over it, gives a deposit soluble in boiling nitric acid. When heated it evolves cyanogen, and runs into globules of metallic mercury. It has been administered in some hepatic and skin diseases, and has been proposed as a substitute for corrosive sublimate. (Parent.) It has been said to act directly on the skin and bones, and to have proved useful in allaying the pain of nodes and in dispersing them. (Mendaga.) It is, however, principally used as a source of cyanogen and hydrocyanic acid.—Dose, 1⁄16 to 1⁄4 gr. (beginning with the smaller quantity), made into pills with crum of bread, or in alcoholic solution; as a gargle or lotion, 10 gr. to water, 1 pint; as an ointment, 10 or 12 gr., to lard, 1 oz.
Mercuric Iodide. HgI2. Syn. Protiodide of mercury, Red iodide of mercury, Iodide of mercury, Biniodide of mercury; Hydrargyri iodidum rubrum (B. P.), Hydrargyri iodidum, H. biniodidum (Ph. E.), H. iodidum rubrum (Ph. D.), L. Prep. 1. (B. P.) Mercuric chloride (corrosive sublimate), 4; potassium iodide, 5; boiling distilled water, 80. Dissolve the mercuric chloride in 60 of water, and the potassium iodide in the remainder, and mix the two solutions. Allow to stand, decant the supernatant liquor, and collect the precipitate on a filter, wash twice with cold water, and dry at 212° F.
2. (Ph. L. 1836.) Mercury, 1 oz.; iodine, 10 dr.; rectified spirit, q. s. (2 or 3 fl. dr.); triturate until the globules of mercury disappear, and the mixture assumes a scarlet colour, then dry it in the shade, and preserve it in a well-stoppered vessel.
3. (Ph. E.) Mercury, 2 oz.; iodine, 21⁄2 oz.; spirit, q. s.; triturate together as last, dissolve the product, by brisk ebullition, in concentrated solution of sodium chloride, 1 gall., filter whilst boiling hot, wash the crystals that are deposited as the solution cools, and dry them.
4. (Ph. D.) Mercuric chloride, 1 oz.; hot distilled water, 25 fl. oz.; dissolve potassium iodide, 11⁄2 oz.; water, 5 fl. oz.; dissolve; when the solutions are cold, mix them, collect the precipitate on a paper filter, drain it, wash it with distilled water, 10 fl. oz., and dry it at a heat not above that of boiling water.
Prop., &c. A bright scarlet powder, insoluble in water, but soluble in alcohol and ether, and in the solutions of several of the iodides and chlorides. It is also soluble in cod-liver oil, and in several other fixed oils. Readily sublimed.—Dose, 1⁄16 to 1⁄4 gr., dissolved in alcohol or made into a pill; in the same cases as the subiodides, from which it
differs chiefly in its greater energy and poisonous qualities.
Mercuric Oleate. See Ointment of Oleate of Mercury.
Mercuric and Potassium Iodide. HgI2.KI. Syn. Iodide of mercury and potassium, Iodo-hydrargyrate of potassium; Hydrargyri et potassii iodidum, L. Prep. 1. (M. Boullay.) Mercuric iodide, potassium iodide, and water, equal parts; dissolve by heat, and crystallise by evaporation or refrigeration, or gently evaporate to dryness.
2. (Puche.) From mercuric iodide and potassium iodide, equal parts, triturated together.—Dose, 1⁄16 to 1⁄8 gr., dissolved in water; in the same cases as the biniodide, and in chronic bronchitis, hooping-cough, inflammatory sore throat, &c.