process repeated four or five times. It might be given in white wine, or made into a syrup, or into pills, electuary, or lozenges. Dr. Willis preferred the crude tartar because the cream of tartar sold by the druggists was generally a cheat, often combined with alum. The crude could be bought at 6d. to 8d. per lb. In the apothecaries' shops cream of tartar was sold at 3s. to 3s. 6d. per lb.
Quincy (1724), who frequently offers explanations of the exact way in which medicines exercise their remedial power, thus scientifically describes the action of iron in removing obstructions:—"Mechanics teach nothing more plainly than that the momenta of all percussions are as the rectangles under the gravities and celerities of the moving bodies. By how much more gravity then a metalline particle has more than any other particle in the Blood, if their celerities are equal, by so much the greater will the stroke of the metalline particle be against everything that stands in its way than of any other not so heavy; and therefore will any Obstruction in the Glands and Capillaries be sooner removed by such particles than by those which are lighter. This is a way of reasoning that is plain to the meanest Capacity."
Tartarised iron has always been a favourite form for its administration. The Balls of Mars (boules de Mars, or boules de Nancy), still a popular medicine in France, are a tartarised iron prepared by a complicated process. First, a decoction of vulnerary species is made from 12 parts of water and 2 of the species. This is strained and poured on 12 parts of pure iron filings in powder. The mixture is evaporated to dryness and powdered. On this powder another decoction, 18 of water and 3 of species, is poured, and 12 parts
