Incompatibility, soluble salts of magnesium in strong solutions are precipitated by the hydrates of the alkalies and the alkaline earths; alkali carbonates, phosphates, arsenates; sulphides, oxalates, tartrates.

2Magnesia Levis. Light Magnesia. (Light Calcined Magnesia, Light Magnesium Oxide.) Dose, if repeated, 5 - 30 grs.; 3 - 20 dgms.: for a single administration, 30 - 60 grs.; 2 - 4 gms. A bulky white powder. Insoluble in water.

2Magnesia Ponderosa. Heavy Magnesia. (Heavy Calcined Magnesia, Heavy Magnesium Oxide.) Dose, as above for the Light Magnesia.

A white powder insoluble in water. Differs in weight only from the Light Magnesia, the same weight having only 2/7 of the volume of that of the Light.

1Magnesii Carbonas Levis. Light Magnesium Carbonate. Dose as for Light Magnesia. A very light powder. Insoluble in water.

1Magnesii Carbonas Ponderosus. Dose, as for Light Magnesia. A heavy white powder. Insoluble in water.

1Magnesii Sulphas (Epsom Salt). Dose, if repeated, 30-120 grs.; 2 - 8 gms.: for a single administration 1/4 - 1/2 oz.; 8 - 15 gms. Small, colourless crystals, with a bitter taste. Soluble, 10 in 13 of wafer, insoluble in alcohol.

2Magnesii Sulphas Eflervescens. Dose, if repeated, 60-240 grs.; 4 - 16 gms.: for a single administration, 1/2 - 1 oz.; 15 - 30 gms. - 50; Sodium Bicarbonate, 36; Tartaric Acid,19; Citric Acid, 12.5; Sugar, 10.5.

3Liquor Magnesii Carbonatis. Dose, 1 - 2 fl. oz.; 30 - 60 c.c. Magnesium Sulphate, 10; Sodium Carbonate, 12.5; Water to 100.

Mel Depuratum. Clarified Honey. The honey of commerce melted and strained through flannel.

2Oxymel. Oxymel. Dose, 1 - 2 fl. dr.; 4 - 8 c.c. - 80; Acetic Acid, 10; Water to 100.

Mellita (see Boron p. 42).

Menthol. Menthol. Dose, 1/2 - 2 grs.; 3 - 12 cgms. C6H9.OHCH3.C3H7. A saturated secondary alcohol obtained from various species of Mentha. Colourless, brittle crystals, with a strong odour of peppermint, and a warm aromatic taste followed by a sensation of cold on drawing air into the mouth. Almost insoluble in water and glycerin, soluble 5 in 1 of alcohol, 8 in 3 of ether, 4 in 1 of chloroform, 1 in 4 of olive oil, and in other oils.

Incompatibility, when triturated gives a liquid or soft mass with but-ylchloral, camphor, phenol, chloral, resin, resorcin, thymol.

Emplastrum Menthol

15; Yellow Wax, 10; Resin, 75.