617. The principal valleys of gneiss and mica-schist have not originated by themselves, but have been modelled according to the form of the granitic valleys. The valleys of those earth-precipitates are properly only subsequent valleys.
618. The lamination is not everywhere a mechanical phenomenon, but without doubt also a polar. It is exactly the same law, which determines the lamination of crystals, that does that of the strata of the earth, and operates also in producing their lamination.
619. The earths must be viewed as _one_ mass, the component parts of which observe a mutual relation. Now, after the silex, clay and talc had been precipitated, a proportionate abundance of lime became free, which was then thrown down at the end of this period of precipitation, as _Primary limestone_.
620. The calcareous mass may be viewed as corrosive earth, from which a certain quantity of carbon has been set free. As such, and combined with the oxygen developed out of the water by the influence of light to form carbonic acid, the lime was insoluble and was precipitated.
621. The primary limestone has also not been mechanically deposited. It has a crystalline texture, is a calcareous granite, and generally succeeds the mica-schist formation.
METAMORPHOSIS OF THE PRIMARY PRECIPITATIONS.
622. The metamorphosis of the granite did not terminate with these precipitations. They are only the starting points for the metamorphosis, in which the effort was first manifested to free themselves from the primary combination. In the metamorphosis of earths, the fundamental earths, or the constituent parts of granite, strove to become each for itself a particular rock. They were all identified in quartz; in granite they for the first time parted company with each other, yet still formed a common sphere; lastly, in gneiss and mica-schist they all separated into three spheres, but which still did not differ in mass from granite.
623. Individualization had not yet been attained. The gneiss had still all the constituent parts of the granite, as well as the mica-schist; both are only a more peripheric, slaty granite, the one having a preponderance of the Argillaceous, the other of the Talcose. With these formations, however, Geogeny cannot remain stationary; for verily the law of the development of the world is individualization. Instead of granite, simply quartz, instead of gneiss simply clay, instead of mica-schist simply talc must be separated; and then the termination of this period is attained, the trinity of the simple earths has been completely represented.