1. By water—Transition-rocks, or
2. By air—Trappean-rocks.
3. By fire—Volcanic-rocks.
There are properly four kinds of rock formations—
1. Earth-formation, masses that have originated through the crystallizing
force of the earth-element itself—Primary-rocks.
2. Aqueous-formation—Transition-rocks.
3. Aerial-formation—Trappean-rocks.
4. Igneous-formation—Volcanic-rocks.
The stratified rocks, having originated for the most part mechanically, are only the object of Physio-philosophy, in so far as chemical precipitations partly occur amongst them.
573. The earth-formation is represented by the crystallized primary rocks.
a. Earth-Formation.
574. The earths can only be precipitations from the element that immediately precedes them, and thus from water. They have been enveloped in the water, as this has been in the air, and the latter again in the æther, but not mechanically, as we at present dissolve clay in water, nor chemically either, as lime dissolves by corrosion in water, but dynamically. The water did not exist from the beginning as water in the air, but only its principles, which became for the first time water, when they had combined by electricity.
575. Even so was it the case with the earths. The primary water, which was present prior to the solid nucleus of the earth, is not the water, with which we are at present acquainted; it had still the earthy principles, the basic in itself, which being separated by a differencing act from the oxygenous of the water, was deposited as carbon specially produced. No calcareous, argillaceous, and silicious earth was imbedded in the primary water. How then could they have been dissolved in it? Some say, by a great quantity of acids which prevailed at that time; but from whence then did these acids come? The largest quantity of them resides in lime, gypsum, and common salt; but how could this quantity, which has not so much as acidified all the calcareous earth, have held the rest of the earths in solution? And then again are all the earths soluble by the process of acidification? We cannot reason in geogeny, as we would of a common chemical precipitation, where we precipitate earths that have been dissolved by elective affinities.
576. The earths originated for the first time, when they were separated from the primary water. The instant of their precipitation was also the instant of their generation, even as rain is, or rather was, a production of the water. It is easy to say that the earths had been dissolved in the water, and were then precipitated by elective affinities. But it is absurd to rest content with such an assertion. The chief question still remains; how did the earthy originate, before the earth was? Every one can say how that which had already originated, and was only suspended in water, was precipitated. But we are in the habit of distinguishing the several earths, before having taken a survey of matters and inquired if earths then existed.
577. It must not, however, be thought, that all had happened in a gradual manner; that air was first converted into water, and lastly, after a lapse of some thousand years, the latter again into earth, without with the one element the principles conducting to the others being already and necessarily imparted. No, everything has been granted and determined at one stroke, even as with the impregnation of the ovum all the organs of the future embryo are determined, although they first develop themselves gradually. The same agent, which creates the air solicits also its two principles unto combustion in the water; and the same act, which separates the oxygen gas out of the air as water, separates also the carbon from it to constitute earth. Not one can be posited, without the other being codetermined.