Action and Uses: Its preparations are used to secure the systemic effects of mercury and locally against parasites.

*Hydrargyrum cum Creta (Hydrarg. cum Cret.), Mercury with Chalk, U.S.P. (Gray Powder).—Mercury (38%), with prepared chalk (57%), honey and water.

Light gray, odorless, rather damp powder, with a slightly sweet taste.

Action and Uses: A mild cathartic acting like calomel. Also used in the treatment of infantile and hereditary syphilis and of syphilis in aged patients.

Dosage: 0.25 Gm. or 4 grains (U.S.P.), as powder.

*Massa Hydrargyri (Mass. Hydrarg.), Mass of Mercury, U.S.P. (Blue Mass, Blue Pill).—Hg (about 33%) in pill mass.

Uses: Mainly as cathartic.

Dosage: 0.25 Gm. or 4 grains (U.S.P.).

Oleatum Hydrargyri (Oleat. Hydrarg.), Oleate of Mercury, U.S.P.—A mixture of mercury oleate and oleic acid equivalent to 25 per cent. of HgO.

Uses: Alterative, antisyphilitic; rarely used.