Litharge was the basis of most of the popular plasters, and a century or two ago there were about a hundred of these either official or in demand. Litharge was called lithargyrum auri or lithargyrum argenti, according to its colour; but the deeper tint was only the result of a stronger fire in preparing the oxide. White lead was an ingredient in several well-known old ointments, the unguentum tripharmacum of Mesuë, which was the ceratum lithargyri of Galen, the unguentum nutritum, the unguentum diapomphologos, in which it was associated with pompholyx or oxide of zinc, and others. To a large extent these ointments were superseded after Goulard’s time by the unguentum Saturninum which he introduced. The ointment of Rhazes was composed of white lead, wax, and camphor dissolved in oil of roses. He also ordered the addition of the white of an egg to every half-pound, but this came to be omitted as it caused the ointment to become odorous. The Mother’s Ointment (onguent de la Mère) has long been a favourite ointment in France for promoting suppuration, and it is included in the Codex. It was made empirically by a nun at the Hotel Dieu, named La Mère Thecle, and as it became much sought after she furnished the formula. It is made by heating together mutton suet, lard, and butter, and when vapours are being exhaled, finely powdered litharge is sifted into the fats, causing a violent effervescence. Some wax and pure black pitch are afterwards added. The process has been studied by several pharmacists, and the conclusion come to is that the fats are decomposed and a number of fatty acids with some acroleine are produced. The operation is a rather dangerous one, especially if there is any naked light in the vicinity. Magistery of Saturn was a white lead precipitated from a solution of the acetate by carbonate of potash. This was the principal ingredient in the Powder of Saturn devised by Mynsicht. The other components of this powder, which was recommended in phthisis and asthma especially, were magistery of sulphur (lac sulphuris), squine root, flowers of sulphur, pearls, coral, oatmeal, Armenian bole, flowers of benzoin, olibanum, sugar candy, saffron, and cassia. The chief apostle of lead in medical practice was Goulard, whose name has become inseparably associated with the solution of the acetate. Some account of the bearer of this familiar name, and of his medicinal preparations of lead will be found in the section on Masters in Pharmacy. QUICKSILVER