Red Lead

Red-Lead is an oxide of lead represented by the formula Pb304. It has been known from early times, and was formerly known as minium, but was only partially distinguished from cinnabar and realgar. It is prepared by carefully heating litharge [Lead] in reverberatory furnaces with air-supply until the oxidation of the litharge has gone on sufficiently; but its brilliancy, and hence its value as a pigment, can be much diminished by insufficient care during this oxidation. It forms a bright red or scarlet powder which is largely employed as a pigment, also in the manufacture of flint glass.