Domestic Encyclopædia (1802)/Mineral Kingdom

2607106Domestic Encyclopædia (1802), Volume 3 — Mineral Kingdom

MINERAL KINGDOM, an expression comprising all bodies that are dug out of subterraneous places, or mines, being totally inanimate, and devoid of the power of vegetation.

From the preceding definition, it is obvious that minerals are inorganic substances which, like organized bodies, have a certain origin, progressively increase, and are subject to dissolution, or a decomposition of parts. But they arise merely by an accumulation of homogeneal, or similar particles from without, namely, either by substances combining in consequence of their attractive power, which process of Nature is called cohesion; or by the solid particles being separated from the fluid ones, when the former attract each other, according to certain laws, constituting together a solid body; and this is termed crystallization, a form of which only certain minerals are susceptible.—Most metals, however, are supposed to take their origin from the contact or accumulation of mineral or subterraneous fumes and vapours; because the latter, which float in mines and metallic veins, at length penetrate into the particular fossil exposed to their action, and produce ore; or, they combine, each according to their peculiar species, and afford native metal.

With respect to the origin of minerals, it is probable that, in some kinds of them, a gradual refinement and change takes place within the bowels of the earth. It is also remarkable that, in the southern hemisphere, there is a greater profusion of precious metals; and these are nearer the surface of the earth, than in the northern regions.

Minerals increase in bulk only while they remain undisturbed in their natural situation; but, by exposing them to the air for a sufficient length of time, they are decomposed, or crumble to pieces, without strictly decaying, such as is the case with organized bodies.

Mineralogists divide the mineral kingdom into four classes, namely,

I. Earths and stones.

II. Salts.

III. Inflammable bodies; such as sulphur, bitumens, amber, rock-oil, sea-coal, &c.

IV. Metals.

Of these, however, we cannot in this place attempt an analysis; as, according to our plan, we give concise accouins of the more useful mineral bodies, in their alphabetical order.