METAL, signifies a ponderous, opaque body, which, in general, is fusible by fire; but, when cold, coagulates and concretes into a solid mass, that is capable of being distended under the hammer.—Metals are distinguished by their peculiar brightness, perfect opacity, and great weight: the lightest of them being seven, and the heaviest upwards of nineteen times more ponderous than an equal bulk of water.
Naturalists have discovered twenty-one metallic substances, which essentially differ from each other: they are generally divided into perfect or entire, and into imperfect or semi-metals. A more accurate classification, however, is that of ductile or malleable, the parts of which may be displaced by compression, without being divested of their cohesion; and of fragile, or brittle, namely, such as do not admit of being stretched or extended. To the former class belong, gold, silver, platina, lead, copper, mercury, iron, and tin: of the latter are, zinc, bismuth, arsenic, cobalt, antimony, nickel, molybdæna, tellurium, manganese, wolfram, chrome, titanium, and uranium.—Consistently with the plan of our work, we shall describe only the native, and the more important foreign metals, of which the reader will find a concise account in their alphabetical series, interspersed with such facts, as may tend more fully to display their useful properties.