Mercury, Precipitates of. 1. Black precipitate, Hahnemann’s soluble mercury (basic mercurous and ammonium nitrate). 2. Green p. (MERCURIUS PRÆCIPITATUS VIRIDIS, LACERTA VIRIDIS), from equal parts of mercury and copper, separately dissolved in nitric acid, the solutions mixed, evaporated to dryness, and then calcined until red fumes cease to arise. Caustic. 3. Red p., mercuric oxide. 4. White p., ammonio-chloride of mercury.
Mercury, Ward’s. Syn. Ammonio-nitrate of mercury; Hydrargyri ammoniæ nitras, L. To nitric acid, 4 parts, contained in a spacious bolt-head or matrass, add, gradually, ammonium sesquicarbonate, 2 parts; afterwards add of mercury, 1 part, and digest in a gentle heat, until the solution is complete.
Mercury with Chalk. Syn. Hydrargyrum cum Cretâ. Grey powder (B. P.) Prep. Rub 1 oz. (by weight) of mercury, and prepared chalk, 2 oz., in a porcelain mortar, until metallic globules cease to be visible to the naked eye and the mixture acquires a uniform grey colour.—Dose. From 3 to 8 gr.
A little water is said to aid in the extinction of the mercury. Mr Bottle suggests a slight departure from the Grey modus operandi followed by the British Pharmacopœia in the above preparation. He proposes to substitute for the tedious process of trituration in a porcelain mortar the agitation of the mercury with the chalk in a wide-mouthed glass bottle; by which means the metal may be minutely subdivided, at a considerably less expenditure of time and labour.
Mercury with Magnesia. (Ph. D.) Syn. Hydrargyrum cum magnesiâ. Pure mercury, 1 oz., carbonate of magnesia, 2 oz. Rub together in a porcelain mortar until the globules
cease to be visible and the mixture acquires a uniform, grey colour.—Dose, 3 to 8 grains.
Mercury, Yellow Oxide of. (Ph. B.) Syn. Hydrargyri oxydum flavum. Prep. Perchloride of mercury, 4 oz.; solution of soda (Ph. B.), 2 pints; distilled water, q. s. Dissolve the perchloride in 4 pints of distilled water, adding the solution by the application of heat, and add this to the solution of soda. Stir them together, allow the yellow precipitate to subside, remove the supernatant liquor by decantation, thoroughly wash the precipitated oxide on a calico filter with distilled water, and finally dry it by the heat of a water bath.
MES′LIN. A mixture of various kinds of grain. (Brande.)
METAGAL′LIC ACID. Obtained by heating dry gallic acid, by a quick fire, to about 480° Fahr., or until it froths, melts, and becomes black and solid, then dissolving the residuum in an alkali, filtering, and precipitating by an acid. An insoluble, black powder.
ME′TAL. Syn. Metallum, L. See Metals.