_Vinum Pruni Virginianae Ferratum (Vin. Prun. Virg. Ferr.), Ferrated Wine of Wild Cherry, N.F._--Tincture of ferric citrochloride (8%) in wine of wild cherry. Absolute alcohol content about 21 per cent. USES: Superfluous "tonic." DOSAGE: 4 Cc. or 1 fluidrachm (N.F.). =Pulsatilla (Pulsatil.), Pulsatilla, N.F.= (Pasque Flower, Meadow Anemone).--The plant. ACTION AND USES: Has been recommended as an alterative, sedative and antispasmodic. Has been used in syphilis with undoubted harmful results because of its inefficiency. Its use is fortunately decreasing. DOSAGE: 0.3 Gm. or 5 grains (N.F.). _Tinctura Pulsatillae (Tr. Pulsatil.), Tincture of Pulsatilla, N.F._--Pulsatilla (10%) in alcohol and water. Absolute alcohol content about 65 per cent. DOSAGE: 2 Cc. or 30 minims (N.F.). =PULVERES, POWDERS.=--The official powders are mixtures of several substances in powdered form. For the preparations now official see under the names of the principal constituents. For Pulvis Antimonialis, see under =Antimonii Oxidum=; for Pulvis Antisepticus, see under =Zinci Sulphas=; for Pulvis Aromaticus and Pulvis Cretae Aromaticus, under =Cinnamomum Saigonicum=; for Pulvis Aromaticus Rubefaciens, under =Caryophyllus=; Pulvis Cretae Aromaticus et Opii, under =Opium=; for Pulvis Effervescens Compositus, under =Potassii et Sodii Tartras=; for Pulvis Glycyrrhizae Compositus, under =Senna=; for Pulvis Ipecacuanhae et Opii, under =Opium=, and for Pulvis Talci Compositus, under =Acidum Salicylicum=. =Pumex (Pumex), Pumice, N.F.=--Consists chiefly of complex silicates of volcanic origin. ACTION AND USES: Used as an abrasive material, and in pharmacy as an absorbent. =Pyrethrum (Pyreth.), Pyrethrum, U.S.P.= (Pellitory Root). ACTION AND USES: Obsolete, irritant sialagogue and local irritant. DOSAGE: 2 Gm. or 30 grains (U.S.P.). _Tinctura Pyrethri (Tr. Pyreth.), Tincture of Pyrethrum, U.S.P._ (Tincture of Pellitory).--Pyrethrum (20%) in alcohol. Absolute alcohol content about 90 per cent. USES: External. =Pyrogallol (Pyrogall.), Pyrogallol, U.S.P.= (Pyrogallic Acid).--Trihydroxybenzene. Light, white or nearly white, odorless, bitter laminae, fine needles or powder. Freely soluble in water (1:1.7) and in alcohol (1:1.3). ACTION AND USES: Irritant antiseptic in chronic skin diseases. Internally highly toxic. DOSAGE: 5 per cent. ointment. =Pyroxylinum (Pyroxylin.), Pyroxylin, U.S.P.= (Soluble Gun Cotton).--Chiefly cellulose tetranitrate. A yellowish-white matted mass of filaments, resembling raw cotton in appearance; very inflammable. Slowly but completely soluble in a mixture of three volumes of ether and one volume of alcohol. Also soluble in acetone and in glacial acetic acid. Practically insoluble in alcohol or water. ACTION AND USES: Basis for collodions. _*Collodium (Collod.), Collodion, U.S.P._--Pyroxylin (4%) in a mixture of ether and alcohol.