ACTION AND USES: The ointment is used, especially on the eye, as an antiseptic and stimulant; also to some extent in impetiginous affections. DOSAGE: For the eye, 2 per cent.; for the skin, from 5 to 10 per cent. _Lotio Flava (Lot. Flav.), Yellow Lotion, N.F._ (Yellow Wash, Aqua Phagedaenica Flava).--A suspension of mercuric oxide produced by the action of lime water on mercuric chloride. USES: Mercurial antiseptic. _*Unguentum Hydrargyri Oxidi Flavi (Ung. Hydrarg. Oxid. Flav.), Ointment of Yellow Mercuric Oxide, U.S.P._--Yellow mercuric oxide (10%) in water, hydrous wool fat and petrolatum. =Hydrargyri Oxidum Rubrum (Hydrarg. Oxid. Rub.), Red Mercuric Oxide, U.S.P.= (Red Precipitate).--HgO. Heavy, orange-red scales or powder, odorless and with a somewhat metallic taste. Almost insoluble in water; insoluble in alcohol, readily dissolved by nitric acid. ACTION AND USES: Occasionally used externally in the form of an ointment and as a parasiticide. Without advantage over yellow oxide. _Unguentum Hydrargyri Oxidi Rubri (Ung. Hydrarg. Oxid. Rub.), Ointment of Red Mercuric Oxide, N.F._--Red mercuric oxide (10%) in water, hydrous wool fat and petrolatum. =*Hydrargyri Salicylas (Hydrarg. Salicyl.), Mercuric Salicylate, U.S.P.= (Mercuric Subsalicylate).--Contains Hg (about 57%). White or nearly white, odorless, tasteless powder. Nearly insoluble in water or alcohol. Dissolved by solutions of the fixed alkalies or their carbonates. ACTION AND USES: Used as antisyphilitic especially by intramuscular injection of oily suspensions; also as local antiseptic. DOSAGE: 0.004 Gm. or 1/15 grain (U.S.P.). By intramuscular injection, 0.6 Cc. or 10 minims of a 10 per cent. suspension in liquid petrolatum once in four days =*Hydrargyrum (Hydrarg.), Mercury, U.S.P.= (Quicksilver).--Hg. Shining, silver-white, odorless, tasteless metal, liquid at ordinary temperatures. Insoluble in the ordinary solvents. 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.