Incompatibility, most salts of mercury are insoluble and hence the range of incompatibility of the soluble salts is a wide one: amongst the substances producing precipitation in solution of mercuric salts are alkali hydrates or carbonates including ammonium, lime-water, borax, soluble iodides and bromides (precipitate soluble in excess), phosphates, hypophosphites, and sulphites, arsenites, ferrous salts, tartarated antimony, tannic acid, albumin, gelatin, some bitter principles, and gluco-sides. With mercurous salts the reactions are similar with the addition that iodides lead to the formation of metallic mercury and mercuric iodide, the same is true of chlorides; oxidising reagents lead to the formation of mercuric salts; cane-sugar, milk-sugar, acacia and tragacanth reduce mercurous salts.

1Hydrargyrum. A silvery white metal. Volatilises with heat.

1Hydrargyrum cum Creta. (Grey Powder.) Dose, 1 - 5 grs.; 1/2 - 3 dgms. - 33; Prepared Chalk, 66.

3Emplastrum Hydrargyri. Mercurial Plaster.-32.8; Olive Oil, 1.4; Sublimed Sulphur, 0.2; Lead Plaster, 65.6

1Pilula Hydrargyri. (Blue Pill.) Dose, 4 - 8 grs.; 2 1/2 - 5 dgms. (in 1 or 2 pills).

- 33; Confection of Roses, 49.5; Liquorice Root, 16.5. 1 gr. mercury in 3 grs.

3Emplastrum Ammoniaci cum Hydrargyro - 41. Ammoniacum 164, Olive Oil 1.75, Sublimed Sulphur 0.25.

Iunguentum Hydrargyri

48; Lard, 48; Prepared Suet, 3. 3Linimentum Hydrargyri. - 33; Strong Solution of Ammonia, 11; Liniment of Camphor q.s. (about 55).

3Unguentum Hydrargyri Compositum. (Scott's Dressing.) - 40: Yellow Beeswax, 24; Olive Oil (by weight), 24; Camphor, 12.

hydrargyri Iodidum Rubrum. Dose, 1/32 - 1/16 gr.; 2 - 4 mgms. Mercuric iodide (biniodide). A vermillion crystalline powder. Almost insoluble in water, sparingly in alcohol, freely in ether, and in solutions of potassium iodide.

3unguentum Hydrargyri Iodidi Rubri

4; Benzoated Lard, 96.

3Hydrargyri Oleas. Mercuric Oleate. An unctuous substance of a light greyish yellow colour, liable to darken on keeping.

3unguentum Hydrargyri Oleatis

25; Benzoated Lard, 75

2Hydrargyri Oxidum Flavum. Yellow Mercuric Oxide. A yellow non-crystalline powder, insoluble in water.

2unguentum Hydrargyri Oxidi Flavi

2; Soft Paraffin, yellow, 98.

hydrargyri Oxidum. Red Mercuric Oxide. Orange-red crystalline scales or powder.

1unguentum Hydrargyri Oxidi Rubri

10;Paraffin Ointment, yellow, 90.

1Hydrargyri Perchloridum. Mercuric Chloride. (Bichloride, Perchloride, Corrosive Sublimate.) Dose, 1/32 - 1/16 gr.; 2 - 4 mgms. HgCl2. Heavy colourless crystalline masses, with a highly acrid metallic taste. Soluble 1 in 19 of cold, 1 in 2 of boiling water; 1 in 5 of alcohol; 1 in 4 of ether; 1 in 2 of glycerin with trituration.

1Liquor Hydrargyri Perchloridi. Dose, 30 - 60 min.; 2 - 4 c.c. - 0.114; Water, 100.

1Hydrargyri Subchloridum. Mercurous Chloride. (Subchlor-ide, Calomel.) Dose, 1/2 - 5 grs.; 1/4 - 3 dgms.

Hg2Cl2. A dull white, heavy, nearly tasteless powder. Insoluble in water, alcohol or ether.

2Pilula Hydrargyri Subchloridi Composita. (Compound Calomel Pill, Plummer's Pill.) Dose, 4 - 8 grs.; 2 1/2 - 4 dgms. (In 1 or 2 pills). - 22.5; Sulphurated Antimony, 22.5; Guaiacum Resin, 45. Castor Oil (by weight), 9.27; Alcohol, q.s. Almost 1 gr. calomel in 4 grs.

2unguentum Hydrargyri Subchloridi

10; Benzoated Lard, 90.

2Hydrargyrum Ammoniatum. Ammoniated Mercury. A white powder, but little acted upon by water.

2unguentum Hydrargyri Ammoniati

10; White Paraffin Ointment, 90

3Liquor Hydrargyri Nitratis Acidus. Mercuric nitrate in solution in nitric acid.

1Unguentum Hydrargyri Nitratis. (Citrine Ointment.) Mercury, 4; in Nitric Acid, 12. Cooled and added to a mixture of Lard, 16 in Olive Oil, 28.

2unguentum Hydrargyri Nitratis Dilutum

25; Soft Paraffin, 75.

1Lotio Hydrargyri Nigra. Black Mercurial Solution. (Black Wash.) Mercurous Chloride, 0.685; Glycerin, 5; Mucilage of Traga-canth. 12.5; Solution of Lime, to 100. The Black oxide is formed Hg2Cl2 + Ca(OH)2 = Hg2O + CaCl2 + H20.

1Lotio Hydrargyri Flava. Yellow Mercurial Lotion. (Yellow Wash.) Mercuric Chloride, 0.46; Solution of Lime to 100. The yellow oxide is formed. HgCl2 + Ca (OH)2 = HgO + CaCl2 + H20.

Liquor Arsenii et Hydrargyri Iodidi. Dose, 5 - 20 min.; 0.3 - 1.2 c.c. 1 of Arsenious Iodide and 1 of Mercuric Iodide in 100 of Water.