19. The first effect of the cooling process was to solidify the outermost surface of the melted mass, and to form there a resisting crust, which, thin at first, little by little thickened. This crust constitutes the stone called “granite,” of an extreme hardness, named thus by reason of its granulated appearance. The three principal substances found there are feldspar, quartz or crystal rock, and mica. This last has a brilliant metallic tint, although it is not a metal.
The granite-bed is then the first ever formed upon the globe, which it entirely envelops, and of which it constitutes in some sort the bony framework. It is the direct product of melted matter consolidated. Upon it and in the cavities that its violently agitated surface presented are successively deposited the beds of other rocks subsequently formed. That which distinguishes this from later formations is the absence of all stratification; that is to say, it is in its whole extent a compact and uniform mass, and not divided by different kinds of beds. The effervescence of incandescent substances must have produced numerous and profound crevasses through which this substance was expelled.
20. The second effect of the cooling process was to liquefy certain vaporous substances in the air, which were precipitated to the surface of the ground. There were then shower and lakes of sulphur and bitumen, veritable stream of iron, copper, lead, and other heated metals infiltrating themselves into the fissures which constitute today the metallic veins and arteries of the Earth.
Under the influence of these different agents the granite surface experienced successive decomposition. Combinations were formed which resulted in primitive rocks distinct from the granite rocks, but in confused masses, and without regular stratifications.
Then came the waters, which, falling upon a burning soil, vaporized anew, fell again and again in torrents until the temperature permitted them to rest upon the soil in a liquid state.
At the formation of the granite rocks the regular series of geologic periods commence. To the six principal periods it is proper to add that of the primitive incandescent state of the globe.
21. Such was the aspect of this first period, a veritable chaos of all the elements mingled together seeking their position where no living being could possibly exist, as one of its distinctive characters in geology at this time is the absence of all traces of vegetable and animal life.
It is impossible to decide upon the duration of this primary period: no more can we of the ones that follow. But, judging from the time necessary for a cannon-ball of given volume heated to the red-white heat to become sufficiently cool to allow of a drop of water resting upon it in a liquid state, it has been calculated, that, if this cannon-ball were of the magnitude of the Earth, more than one million years would be necessary.