of common sense, will wait in the expectation of such a monitor. Short of the term of the vivacious Varro, every reflecting person will be sensible of a period, in which it is prudent to begin sarcinas colligere. This motive has induced me, to allow treatises, upon subjects so widely different, to follow each other so soon; and I request, that the same may be favourably received as a general apology, should the present tract not be the last thus adventurously put forward.

With respect to the argument of the present work, it is my wish, not to anticipate it in a preface; but, to leave it to unfold itself to the reader in the perusal. I shall, therefore, only briefly and summarily state; that the First and Second Parts consider, severally, the doctrines of the Mineral and the Mosaical Geologies, concerning the MODE of the first formations of this terrestrial globe; and, that

the Third Part compares the doctrines of both Geologies, relative to the MODE of the revolutions which this globe has undergone. The results of these investigations, will be found combined in the Conclusion, with which the treatise is terminated.

I have endeavoured, by keeping the argument simple and compressed, to avoid all superfluous dilatation and digression; in which endeavour, I hope I shall be found to have succeeded. It was originally designed, and it has been solely prepared, with a view to such earnest and sincere inquirers, as may be anxious to relieve their minds from perplexity, or to disengage them from error, concerning the important subjects of which it treats; and to advance, in the prosecution of the truth respecting them, as far as its principles, actively pursued, are capable of conducting them. Such advance, is frustrated by the practice which, in similar discussions, has too frequently

CHAP. I.

THE characters which unfold themselves to PART I. our view, in examining the substances of this globe, point out to us some period, or periods, in which the order of its structure sustained violent agitation and alteration. In every part of the earth we encounter unequivocal evidence of disruption, subsidence, and subversion of its hardest and most solid materials; and we discover remains, equally unequivocal, of organic matter, both animal and vegetable, involved and deeply imbedded in other of its materials, which are soft, or which must have been so at the time when those foreign substances were imbedded within them. Monuments, so wonderful and so important, have

B

PART I. naturally stimulated the curiosity of man to inquire, and to endeavour to ascertain, how and when those amazing effects were wrought in the substance of our globe.

CHAP. I.

An extended investigation of the same characters has led to a further observation: that those foreign organic substances are not found indiscriminately in all the materials of which our earth consists; that they are found only in one order of them, while in another order they are never found at all. This remarkable fact, well established, has given occasion to a division of the materials of the earth into two general classes, distinguished chiefly by the presence and the absence of organic fragments; and, since it has been observed, that the materials in which those fragments occur, bear, in general, the appearance of sediment deposited in water; whereas, those in which they never occur wear a crystalline, appearance; their respective formations have been reasonably ascribed to different immediate causes. And because those which appear to be sedimentary are observed to be deposited upon those which appear to be crystalline, the latter, which sustain the former, are with equal reason assumed to be of a more ancient date: and from hence all the mineral matter of this globe has been distributed scientifically into two principal