It was my intention to have prefixed to this edition of the Essay on the Theory of the Earth, a general discourse on Geognosy, with the view of explaining its various relations to the other branches of Natural History, and of examining some of the criticisms that have appeared on the work itself, and the notes and preface accompanying it, but want of leisure has prevented me at present from carrying into effect this plan. I have however enlarged the Notes, and added a series of observations on a very interesting topic; the distribution of fossil organic remains throughout the crust of the Earth, and also as intimately connected with the discussions contained in the Essay of Cuvier; an account of the Mineralogy of the country round Paris; and of some remarkable mineral formations that occur in the South of England.

On the Subsidence of Strata.

M . cuvier is of opinion, that all the older strata of which the crust of the earth is composed, were originally in an horizontal situation, and have been raised into their present highly-inclined position, by subsidences that have taken place over the whole surface of the earth.

It cannot be doubted, that subsidences, to a considerable extent, have taken place; yet we are not of opinion, that these have been so general as maintained by the illustrious author of this Essay We are rather inclined to believe, that the present inclined position of strata is in general their original one;–an opinion which is countenanced by the known mode of connection of strata, the phenomena of veins, particularly cotemporaneous veins, the crystalline nature of every species of older rock, and the great regularity in the direction of strata throughout the globe.

The transition and floetz-rocks also are much more of a chemical or crystalline nature than has been generally imagined. Even sandstone, one of the most abundant of the floetz-rocks, occasionally occurs in masses, many yards in extent, which individually have a tabular or stratified structure; but when viewed on the great scale, appear to be great massive distinct concretions.

Preliminary Observations.

It is my object, in the following work, to travel over ground which has as yet been little explored, and to make my reader acquainted with a species of Remains which, though absolutely necessary for understanding the history of the globe, have been hitherto almost uniformly neglected.

As an antiquary of a new order, I have been obliged to learn the art of decyphering and restoring these remains, of discovering and bringing together, in their primitive arrangement, the scattered and mutilated fragments of which they are composed, of reproducing, in all their original proportions and characters, the animals to which these fragments formerly belonged, and then of comparing them with those animals which still live on the surface of the earth ; an art which is almost unknown, and which presupposes, what had scarcely been obtained before, an acquaintance with those laws which regulate the coexistence of the forms by which the different parts of organized beings are distinguished, I had next to prepare myself for these enquiries by others of a far more extensive kind, respecting the animals which still exist.

Although the Mosaic account of the creation of the world is an inspired writing, and consequently rests on evidence totally independent of human observation and experience, still it is interesting, and in many respects important, to know that it coincides with the various phenomena observable in the mineral kingdom. The structure of the earth, and the mode of distribution of extraneous fossils or petrifactions, are so many direct evidences of the truth of the scripture account of the formation of the earth; and they might be used as proofs of its author having been inspired, because the mineralogical facts discovered by modern naturalists were unknown to the sacred historian. Even the periods of time, the six days of the Mosaic description, are not inconsistent with our theories of the earth. There are, indeed, many physical considerations which render it probable that the motions of the earth may have been slower during the time of its formation than after it was formed, and consequently that the day, or period between morning and evening, may have then been indefinitely longer than it is at present. If such a hypothesis is at all admissible, it will go far in supporting the opinion which has long been maintained on this subject by many of the ablest and most learned scripture critics.

That portion of the shore of the Adriatic which lies between the lake, or rather lagune, of Commachio and the lagunes of Venice, has undergone considerable alterations since ancient times, as is attested by authors worthy of entire credit, and as is still evidenced by the actual state of the soil in the districts near the coast; but it is impossible now to give any exact detail of the successive progress of these changes, and more especially of their precise measures, during the ages which preceded the twelfth century of our, era.

We are however certain, that the city of Hatria, now called Adria, was formerly situated on the edge of the coast; and by this we attain a known fixed point upon the primitive shore, whence the nearest part of the present coast, at the mouth of the Adige, is at the distance of 25,000 metres ; and it will be seen in the sequel, that the extreme point of the alluvial promontory, formed by the Po, is farther advanced into the sea than the mouth of the Adige by nearly 10,000 metres.