528. Earth is thus the body, which is mutable neither in water, air, nor fire. Earth is a water-, air-, and fire-proof body. This is the brief, rigid, wholly exclusive, and significantly expressive definition, which a so-called empirical science could never, but philosophy alone, bestow.
529. The Ore is not soluble in water, nor mutable in air; on the contrary, it is fusible, oxydizable, or reducible in fire. Ore is a water-and air-, but not fire-proof body.
530. The Inflammable is immutable in water, but mutable in air and fire. The Inflammable is a water-proof, but not air-and fire-proof body.
531. The Salt is soluble in water, and decomposible in fire, but immutable in air. Salt is an air-, but not water-and fire-proof body. The legitimate series of gradations comprised in the above four definitions cannot escape the attentive reader, nor moreover that the properties of the earths are all affirmative. Nature has not employed such insignificant means of distinction as our mineralogy has done; has nowhere used an acid in order to distinguish the metals from the earths, nor savour to separate the salts from the earths; but she selects universal reagents which are the elements themselves. So simple is Nature, if we do not violate her by art.
DIVISION OF THE EARTHS.
532. There is not merely a single silicious mineral, but many such, just as in clay, talc, and calx. How, then, do differences occur in these earths? When we survey the science of Mineralogy we remark that most minerals are composed of several earths; with them also metals, coal, sulphur, alkalies and acids are frequently associated. It follows thereupon that the further distinctions are no longer of an internal kind, namely, alterations of substance; but proceed from combinations and thus indicate stöchiometric bodies. The next division of the orders I call Families.
Order 1. Silicious minerals. *
533. With how many bodies now can the silicious earth combine? It will first of all appear in a pure condition, as in quartz; then, in the next place, combine with the other earths, thus with clay, talc and calx. We have thus four families of Earth-silices.
| Fam. 1. | Pure-Silex | Quartz. |
| 2. | Argillaceo-Silex | Zircon. |
| 3. | Talco-Silex | Emerald. |
| 4. | Calcareo-Silex | Leucite. |
534. Thus the hardest minerals or the silicious precious stones are here placed. But these are obviously not exhausted with the above four combinations, but more of the latter must still be sought for. Those bodies which rank next to the earths, and can therefore enter into the following combinations are the other mineral classes, such as the salts, Inflammables, and metals; and we accordingly obtain the following silicious minerals, as constituting classes.