covering; but, at the same time, it brought with it fresh elements for the constitution of future continents. The numerous substances which the water held in solution formed various combinations with the metals and soils of its bed; the currents and tempests which agitated it destroyed its shores only to form new ones; the sediment deposited at the bottom of the water commenced the series of rocks and strata which follow one another above the primitive crust. Henceforward the igneous planet was externally clothed with a triple covering, solid, liquid, and gaseous; it might therefore become the theatre of life. Vegetables and lowly forms of animals were called into existence in the water, and on the land which had emerged from it; and, finally, when the temperature of the surface of the globe had become less than 50°, allowing albumen to liquefy and blood to flow in the veins, the fauna and the flora would be developed, the remains of which are found in the earliest fossil strata. The era of chaos was succeeded by that of vital harmony; but in the immense series of ages we are dealing with, the life which appeared on the refrigerated planet was little else than the “mouldiness formed in a day.” According to the theory generally propounded, the solid crust was not very completely formed; it is, indeed, much thinner than the layer of air surrounding the globe; for, following the common estimate, which, however, is purely hypothetical, at 22 to 25, or, at most, 50 miles below the surface of the earth, the terrestrial heat would be sufficient to melt granite. Compared to the diameter of the earth, which is about 250 times greater, this crust is nothing more than a thin skin, a just idea of which may be given by a sheet of thin cardboard surrounding a liquid sphere a yard in diameter. In the case of the earth, this liquid is a sea of lava and molten rocks, having, like the ocean above it, its currents, its tides, and perhaps its storms. It is, in fact, very probable that a great part of the rocks which form the outer portion of our planet, especially the most ancient formations, existed in former times in a state of fusion like that of volcanic lava. As most geologists are of opinion, granite and other similar rocks, forming the principal building-blocks in the architecture of continents, existed once in a soft or semi-soft state.