DOSAGE: Internally, 0.5 Gm. or 8 grains (U.S.P.) as syrup. Externally, in ointment, at first from 2 to 4 per cent., later in higher strength. _Glyceritum Picis Liquidae (Glycer. Pic. Liq.), Glycerite of Tar, N.F._--Tar (6.3%) in glycerin, alcohol and water. Absolute alcohol content about 12 per cent. DOSAGE: 4 Cc. or 1 fluidrachm (N.F.). _Liquor Picis Alkalinus (Liq. Pic. Alk.), Alkaline Solution of Tar, N.F._--Tar (25%), in potassium hydroxide (12.5%), and water. _Syrupus Picis Liquidae (Syr. Pic. Liq.), Syrup of Tar, U.S.P._--Tar (0.5%) in alcohol, mixed with syrup. Absolute alcohol content about 5 per cent. DOSAGE: 4 Cc. or 1 fluidrachm (U.S.P.). _*Unguentum Picis Liquidae (Ung. Pic. Liq.), Tar Ointment, U.S.P._--Tar (50%), yellow wax and lard. _Vinum Picis (Vin. Pic.), Wine of Tar, N.F._--Tar (10%) in alcohol and sherry wine. Absolute alcohol content about 29 per cent. DOSAGE: 8 Cc. or 2 fluidrachms (N.F.). =Pix Lithanthracis (Pix Lith.), Coal Tar, N.F.= (Pix Carbonis).--Obtained by the destructive distillation of coal. Nearly black semisolid, with a characteristic naphthalene-like odor and a sharp, burning taste. Only slightly soluble in water; partially dissolved by alcohol. ACTION AND USES: Antiseptic and irritant; used in skin diseases in the form of: _Liquor Picis Carbonis (Liq. Pic. Carbon.), Coal Tar Solution, N.F._--Coal tar (20%), quillaja and alcohol. Absolute alcohol content about 75 per cent. =*Plumbi Acetas (Plumb. Acet.), Lead Acetate, U.S.P.= (Sugar of Lead).--Pb(CH{3}COO){2} + 3H{2}O. Colorless, shining transparent crystals or heavy white crystalline masses, efflorescent, with a faint vinegar odor and a sweetish, astringent, afterward metallic taste. Freely soluble in water (1:1.4) and soluble in alcohol (1:38). ACTION AND USES: Seldom used internally for fear of lead poisoning. Externally, used as astringent lotion. DOSAGE: 0.06 Gm. or 1 grain (U.S.P.). _Lotio Plumbi et Opii (Lot. Plumb. et Opii), Lotion of Lead and Opium, N.F._ (Lead and Opium Wash).--A mixture of lead acetate (1.75%) and tincture of opium (3.5%) in water. USES: A popular but irrational application, astringent and protective, but not a true anesthetic. The opium alkaloids are not absorbed to any appreciable extent through the unbroken skin. =Plumbi Carbonas (Plumb. Carb.), Lead Carbonate, N.F.= (White Lead).--A mixture of lead carbonate and hydroxide. Heavy, white, odorless, tasteless powder. Insoluble in alcohol or water. ACTION AND USES: External protective and astringent, without marked advantage over zinc oxide or the bismuth preparations, but involving some danger of lead poisoning. =Plumbi Iodidum (Plumb. Iod.), Lead Iodide, N.F.=--PbI{2}. Heavy, bright yellow, odorless, tasteless powder. Very slightly soluble in water (1:1,300), and in alcohol.