Note 1216 — BOOK XXXIV. THE NATURAL HISTORY OF METALS.

“Æris Metalla.” The word “Æs” does not entirely correspond to our word “brass;” the brass of the moderns being a compound of copper and zinc, while the “Æs” of the ancients was mostly composed of copper and tin, and therefore, would be more correctly designated by the word “bronze.” But this last term is now so generally appropriated to works of art, that it would seem preferable to employ in most cases the more general terms “copper” or “brass.” For an excellent account of the “Æs” of the ancients, see Smith’s Dict. Antiq. “Æs.”—B. Mr. Westmacott, in the above-mentioned article, says that the ancient “Æs” has been found, upon analysis, to contain no zinc, but in nearly every instance to be a mixture of copper and tin, like our bronze. Beckmann says, on the other hand, that the mixture of zinc and copper now called “brass,” first discovered by ores, abundant in zinc, was certainly known to the ancients. “In the course of time, an ore, which must have been calamine, was added to copper while melting, to give it a yellow colour.” Hist. Inv. Vol. II. pp. 32, 33. Bohn’s Edition. There can be little doubt that the native Cadmia of Chapter 22 of this Book was our Calamine, hydrosilicate of zinc, or carbonate of zinc, or else copper ore impregnated with calamine.