"The first two divisions, which will at once be understood as natural, are the aqueous and volcanic, or the products of water and those of igneous action at or near the surface.... The aqueous rocks, sometimes called sedimentary or fossiliferous, cover a larger part of the earth's surface than any other. These rocks are stratified, or divided into distinct layers or strata; these strata have been generally spread out by the action of water, like what we daily see taking place near the mouth of rivers or on the land during a temporary inundation. "The remains of animals, especially of aquatic species, are found almost everywhere, imbedded in stratified rocks; and sometimes, in the case of limestone, they are in such abundance as to constitute the entire mass of rock itself. Shells and corals are the most frequent, and with them are often associated the bones and teeth of fishes, fragments of wood, impressions of leaves, and other organic substances. "When geology was first cultivated, it was a general belief that those marine shells and other fossils were the effects and proofs of the deluge of Noah; but all those who have carefully investigated the phenomena have rejected this doctrine. A transient flood might be supposed to leave behind it, here and there upon the surface, scattered heaps of mud and sand and shingle, with shells confusedly intermixed; but the strata containing fossils are not superficial deposits, and do not simply cover the earth, but constitute the entire mass of mountains. Ample proof of these reiterated revelations is given, and it will be seen that many distinct sets of sedimentary strata, each several hundreds or thousands of feet thick, are piled one upon the other in the earth's crust, each containing peculiar fossil animals and plants, which are distinguishable, with few exceptions, from species now living. The mass of some of these strata consists almost entirely of corals, others are made up of shells, others of plants turned into coal, while some are without fossil. "Volcanic rocks are those which have been produced at or near the surface, whether in ancient or modern times, not by water, but by the action of fire or subterranean heat. These rocks are for the most part unstratified, and are devoid of fossils. "There are two other divisions of rock, called Plutonic rocks, granite, etc., and Metamorphic, or stratified crystalline rocks. The members of both these divisions of rocks agree in being highly crystalline and destitute of organic remains. "The composition of the aqueous rocks, mineral composition of strata: These may be said to belong principally to three divisions, as follows: