^ LEAD ACETATE 161 



Properties. — A heavy, yellowish or reddish-yellow pown 

 der, or minute scales, without odor or taste. On exposure 

 to the air it slowly absorbs moisture and carbon dioxide. 

 Almost insoluble in water ; insoluble in alcohol. Reaction 

 faintly alkaline. Lead oxide is only valuable for its prepa- 

 rations. 



PREPARATION. 



Emplastrum Plumbi. Lead Plaster. (U. S. & B. P.) 

 (Diachylon Plaster.) 

 Lead oxide, 32; olive oil, 60; water, a sufficient quantity. Basis of 

 other preparations. 



Plumbi Acetas. Lead Acetate. Pb {C^^JJ^)^ + 3 HgO. 

 (U. S. & B. P.) 



Synonym, — Sugar of lead, E.; sel (sucre) de saturne, Fr.; 

 essigsaures bleioxyd, bleizucker, G. 



Derivation.— 'H.esit lead oxide in acetic acid and water. 



PbO + 2 HC^HaO, + 2 H,0 = Pb(C,H30,), -h 3H,0. 

 Lead acetate crystallizes on cooling. 



Properties. — Colorless, shining, transparent, monoclinic^ 

 prisms or plates, or heavy, white crystalline masses, or 

 granular crystals, having a faintly acetous odor and a 

 sweetish, astringent, afterwards metallic, taste. Efflorescent 

 and absorbing carbon dioxide on exposure to the air. 

 Soluble in 2.3 parts of water and in 21 parts of alcohol. 

 Reaction slightly acid. 



Incompatibles. — Hard water, alkalies, mineral acids and 

 salts, potassium iodide, opium, vegetable astringents and 

 albuminous liquids. 



Bose.—'EL. & C, 3i. (4.);Sh. & Sw., gr.xv.-xx. {1.-1.3); D., 

 gr.i.-ii. (.06-.12). 



PREPARATIONS. 



Made from lead acetate in which lead exists as the subacetate, 



PbaO (CaHaOa)^. 



Liquor Plumbi Suhacetatis. Solution of Lead Subacetate. 

 (U. S. & B. P.) 

 Synonym. — Goulard's extract, acetum plumbicum, acetum Satumi, 

 plumbum hydrico-aceticum solutum, subacetas plumbicus liquidus, E.; 



