566. The first and most important of these is the elevation of temperature. We cannot think otherwise than at the first precipitation of the earthy a number of huge cavities remained in the interior of the earth, which were filled with water. This being heated, was converted into steam, which thrust up the superincumbent rock, and converted it into new mountains or mountain-chains. These agencies of heat may be called primary volcanoes, although they are not to be confounded with volcanoes proper.
567. The igneous cavities were probably placed in a certain order, according with the original edges and angles of the earth's body. They may have therefore thrown up mountain tops and chains.
568. But the cavities, besides raising mountain chains, could just as well depress or allow them to sink in, and thus produce valleys. By these means the seas have probably been formed. Like the seas so also have the inland seas or lakes originated.
569. Lastly, a similar origin must be ascribed to the world-sea or ocean. Many earthquakes arose, with all their concomitant phenomena, by partial and sudden falling in of the deep descending cavities of the earth. Frequently that which fell in was again driven out by the expansive force of the suddenly compressed air.
570. The principal mass or body of the planet is formed by the earths proper, as being the typical or genuine representatives of the earth-element. The other classes, as the metallic minerals or ores, the Inflammables, and salts, are to be regarded only as viscera of this body. If we take a circumspective glance at the planet, we cannot fail to recognize this remarkable relation, that it is properly the elemental families only of the earths that form the mountain masses, while the other families are only scattered within them, like the glands in an animal body. Let us again place the Families in tabular contrast with each other.
SILICIOUS, ARGILLACEOUS, TALCOSE and CALCAREOUS-EARTHS.
A. Earth-silices. Earth-clays. Earth-talcs. Earth-calces.
Fam. 1. Quartz. 1. Felspar. 1. Mica. 1. Lapis-lazuli. 2. Zircon. 2. Sapphire. 2. Sappharine. 2. Mesotype. 3. Emerald. 3. Ruby. 3. Talc. 3. Stellite. 4. Leucite. 4. Epidote. 4. Angite. 4. Tabular-spar. 5. Topaz. 5. Schorl. 5. Hornblende. 5. Boracite. 6. Diamond. 6. Azurite. 6. Asbestus. 6. Phosphorite. 7. Garnet. 7. Harmotone. 7. Olivine. 7. Titanite.