Page:Edward Thorpe — History of Chemistry, Volume I (1909).pdf/28

12 by them as medicines and as pigments. The oxides of copper, known as flos œris, and scoria œris, obtained by heating copper bars to redness and exposing them to air, were used as escharotics. Verdigris, or œrugo, was made by the same methods as now. Blue vitriol, or chalcantum, is described by Pliny, who says that the blue transparent crystals are formed on strings suspended in its solution.

Chrysocolla, malachite, or copper carbonate, was used as a green pigment. The blue κύανος of the Greeks, or cœruleum of the Romans, was obtained by fritting together alkali, sand, and oxide of copper. Botryitis, placitis, onychitis, ostracitis, were varieties of cadmia or oxide of zinc, obtained by calcining calamine, and were used in the treatment of ulcers, etc. Molybdena, which was the Latin name for litharge, was employed externally as an astringent and in the manufacture of plaster. The lead plaster employed by Roman surgeons was practically identical in character and mode of preparation with that in use to-day. Cerussa, or white lead, was made as now by exposing sheets of lead to the fumes of vinegar. It was used in medicine, as a pigment, and in the preparation of cosmetics. Cerussa usia was probably red lead. Its present name of minium was originally applied to cinnabar, the red sulphide of mercury, which was frequently adulterated with red lead.