Note 1598 — BOOK XXXIV. THE NATURAL HISTORY OF METALS.

It is obvious that the “cadmia” here described must be an essentially different substance from the “cadmia” mentioned in the second Chapter of this Book, that being a natural production, possibly calamine or hydrosilicate or carbonate of zinc; while the “cadmia” of this Chapter is a furnace-calamine, a product of the fusion of the ore of copper, or zinc.—B. It is evident, too, that copper ores, impregnated with zinc or calamine, also passed under this name. See Beckmann, Hist. Inv. Vol. II. pp. 33-35, Bohn’s Edition, where this subject is discussed at considerable length: also the treatise by Delafosse, in Lemaire’s Edition of Pliny.