592. Upon the whole the silicious character predominates in granite, as the primary formation of the planet, and must do so, for silicious earth is the primary earth, the principal earth of this precipitation, and one from which clay and talc subsequently proceed, being higher heterogynisms produced by light. Properly speaking only two perfectly different characters of earth exist, the silicious earth as the pure separation of the Earthy, and the calcareous earth, as the last separation of the water from the Earthy. It may also be said that in the calcareous earth fire, in the talcose earths the air, in the argillaceous earth water has exercised its influence and displaced the Earthy. Not only quartz is silicious earth, but feldspar and mica consist in a great measure of the same. Still, however, these last two constituent forms are wholly different from quartz, and very far removed from the nature of silex; the feldspar obviously forming the transition to clay by its resolution into porcellanic earths, but the mica passing over into talc. 593. There does not exist in nature an order of silex, clay, or talc, so soon as we take up these earths in a simply chemical manner. Nature instead of silex produces quartz, instead of clay feldspar, instead of talc mica; and these must be the earths, that determine this part of the mineral system; they are the characters of orders; there is thus properly no order of silex but of quartz, none of clay but of feldspar, none of talc but of mica, at least according to their signification. 594. The points of origin for this division of the mineral system or that formed by the fundamental earths are the three fundamental crystallizations, and upon these _everything_ that does not belong to the calcareous earth must and does naturally arrange itself. The mineral system is only the developed and separated granite. The fact cannot rest unobserved, that mica has only one laminar cleavage, feldspar two, quartz three, this being for the first time a perfect crystal, a double tetrahedron with one column. 595. With granite and with it alone the solidity, the body and form of the earth has been given; it is the homogeneous fundamental mass of the planet, and is therefore crystallized throughout to the finest degree in its three constituent forms. GNEISS AND MICA-SCHIST. 596. If, in addition to granite, several formations are displayed which bear traces of the same mode of origin, of the same component parts and the same aggregation, it may be inferred that they are only metamorphoses of the same precipitate. Granite is the basis of geogeny. 597. Granite is a totality for the earth, it is a representation of the three terrestrial elements under the form of identical earth; it is the earth represented in silex, water in clay, and air in talc; it is an universe represented individually in the earth-elements.