is composed, and all the nuclei of mountains, were produced by the primitive fire. The waters have only formed the accessory strata, which surround the nuclei horizontally, and in which are the relics of shells, and other productions of the ocean. The whole surface of the earth, therefore, as we now behold it, was, at a period long subsequent to its separation from the sun, covered by an ocean; and the waters forming this ocean probably remained for a succession of ages on what are now inhabited continents. Hence the remains of marine plants and animals to be found in almost every part of the globe, on or near its surface. M. Buffon supposes, further, that, since the period when the primitive waters encircled the earth, there have been repeated partial inundations, in different places; and, in others, instances of land formerly covered with the ocean being elevated above it, and becoming inhabitable; and similar events, he seems to suppose, may in future occur. According to him, also, the earth, for many ages, too intensely heated to admit the existence of animal life on its surface, first acquired at the poles a more genial temperature. There, consequently, must we look for the first abodes of man. To Greenland or Iceland, to Spitzbergen or Nova-Zembla, we must have recourse for the verdant bowers of Eden. And, finally, he contends that all the other planets belonging to our system were stricken off from the sun in the same manner with that which we inhabit, and have probably undergone similar changes, so far as their respective circumstances admitted.

Such are the outlines of a theory bold and plau

sible, as might have been expected from the mind of its author, but unsubstantial and deceptive. Its manifest object is to exclude the agency of a Divine Architect, and to represent a world begun and perfected merely by the operation of natural undesigning causes. That it cannot be reconciled with the sacred history, will appear evident on the slightest inspection; and that it involves the grossest philosophical absurdities, has been clearly shown by succeeding geologists. It was embraced, however, by M. Bailly, of France, by the celebrated Hollmann, of Goettingen, and others; and continues to be respected and adopted by many to the present time.

Some modern philosophers have supposed every thing to have been originally fluid; that this universal fluid gave existence to animals of the simplest kind; that in process of time the races of these animals became complicated, and dying, supplied calcareous earth or lime; that aluminous earth or clay was supplied by the decay of vegetables. That these two earths were re-dissolved, and finally converted into silex; hence that the more antient mountains are siliceous. Thus the solid parts of our globe, according to these visionaries, owe their existence to animal or vegetable life, and without it would have continued entirely liquid.

Kepler, one of the greatest of astronomers, considered the globe to be possessed of living faculties and a circulating vital fluid; that all the particles of it are alive and possess instinct and volition, whence their attraction and repulsion: that the organs through. which the huge animal breathes are the mountains;

that mineral veins are abscesses, and metals the products of rottenness and disease.

These systems, and many more than these, have had their admirers, and have successively sunk into disrepute and neglect in proportion to the advance of chemical and physical science. It will be sufficient for our purpose to notice two other systems, those of Professor WERNER and Dr. HUTTON, which still continue to occupy the attention of geologists; the partisans of the former theory being denominated Neptunists or Wernerians, and of the latter, Plutonists, Volcanists or Huttonians, according as the particular agency of water or fire has been referred to.

The first principle of the Wernerian theory assumes that our globe was once covered with a sort of chaotic compost, holding either in solution or suspension the various rocks and strata which now present themselves as its exterior crust. From some unexplained cause, this fluid began first to deposit those bodies which it held in chemical solution, and thus a variety of crystallized rocks are formed. In these we find no vegetable or animal remains, nor even any rounded pebbles; but in the strata which lie upon the crystalline, or first deposits, shells and fragments occasionally occur: these, therefore, have been termed transition strata; and it is imagined that the peopling of the ocean commenced about this period. The waters upon the earth began now more rapidly to subside, and finely divided particles, chiefly resulting from disintegration of the first formations, were its chief contents; these were deposited upon the transition rocks

chiefly in horizontal layers. They abound in organic remains, and are termed by Werner, Floetz, or Secondary rocks.

It is now conceived that the exposure of the primitive, transition, and secondary rocks to the agencies of wind and weather, and to the turbulent state of the remaining ocean, produced inequalities of surface; and that the water retreated into lowlands and vallies, where a further deposition took place, constituting clay, gravel, and other alluvial formations.

There are also certain substances which, instead of being found in regularly alternating layers over the earth, are met with in very limited and occasional patches. Rock salt, coal, basalt, and some other bodies, are of this character, and Werner has called them subordinate formations. Lastly, subterraneous fires have sometimes given birth to peculiar and very limited products; and these are called volcanic rocks. Such is Werner's account of the production of rocks, which he arranges under the terms primary, transition, secondary, alluvial, subordinate, and volcanic formations.

Dr. HUTTON gives a very different account of the present order of things. Looking upon the face of nature, he observes every thing in a state of decay; and as she has obviously provided for the regeneration of animal and vegetable tribes, so the philosophic mind will descry, in this apparent destruction of the earth's surface, the real source of its renovation. The lofty mountains exposed to the action of the varying temperature of the atmosphere, and the waters,

of the clouds, are by slow degrees suffering constant diminution, their fragments are dislodged, masses are rolled into the valley, or carried by the rushing torrent into rivers, and thence transported to the sea. The lower and softer rocks are undergoing similar but more rapid destruction. The result of all this must be, the accumulation of much new matter in the ocean, which will be deposited in horizontal layers. Looking at the transition rocks of Werner, he perceives that, though not strictly crystalline, they appear made up of finely divided matter, more or less indurated, and sometimes very hard in texture, and of a vitreous fracture; and that this hardening is most perceptible when in contact with the primitive or inferior rock, which often pervades them in veins, or appears to have broken up or luxated the superincumbent masses. According then to Dr. Hutton, the transition or secondary rocks of Werner were deposited at the bottom of the ocean, in consequence of operations similar to those which are now active, and the primary rocks were formed beneath them by the operation of subterraneous fires: their crystalline texture, their hardness, their shape and fracture, and the alterations they have produced upon their neighbours, are the proofs of the correctness of these views. It is by the action of subterraneous fire, then, that rocks have been elevated, that strata have been hardened, and that those changes have resulted which an examination of the earth's surface unfolds. The production of soils and of alluvial land is considered as dependent upon causes the same as those referred to in the other theory.