COMPOUNDS OF LEATL The two most impor tant among the compounds of h•ad with oxygen are litharge and minium. Litharge is obtained when molten lead is heated at a moderate tem perature in the air with constant stirring. It is used in the arts in the manufacture of flint glass, as a glaze for earthenware, for the prep aration of lead salts, as a paint. and for dry ing oils. Minium, which has been known since the time of Pliny. is a scarlet crystalline granu lar powder. usually prepared by carefully heat ing very finely divided pure litharge or white lead. It finds extensive use in the arts as a pig ment, also in the manufacture of flint glass, as a cement for making steam-tight joints, and in the manufacture of secondary batteries. (See Mixtum.) Lead combines with carbon dioxide to form the carbonate, which is found native as eerusite (q.v.). White lead. or basic car bonate of lead, is a White heavy powder. It is extensively used in the
arts as a pigment and as a body for other colors in the manufacture of paints. It is produeed artificially by the decomposition of basic acetates of lead by means of carbon di oxide. (See I'mxTs.) Lead acetate, or sugar of lead, is made by adding lead oxide to acetic acid and gently heating the mix ture. It is used in medicine. in the arts, as a clarifying agent in the relining of sugar, and to a certain extent in chemical analysis. Lead sulphate, which is found native as anglesite, may be obtained artificially by precipitating a lead salt with sulphuric acid, yielding a heavy white powder which is sometimes used as a substitute for white lead. The various lead ehromat es are colored yellow: they are used as pigments and in calico-printing.