It strikes us that the title of this work might have very properly been, Geological Physics, or the Philosophy of Geology: for not more than one-half of it is occupied with geological details, and even these are subordinate to general inductions. The introduction is in reality an elaborate philosophical discourse, in which several important preliminary questions are discussed: such as the visionary spirit of cosmogonists, ancient and modern; the connexion of geology with Scripture history, and of science with revelation in general; the illogical procedure of geognostic theorists, exemplified particularly in the Huttonian and Wernerian systems, as expounded by Playfair and D'Aubuisson; the new era of practical geology, commencing with Mr. Smith's sections of English strata, and the foundation of the Geological Society of London; the importance and uses of organic remains, &c. One of the author's motives for publishing the present work will receive the unqualified approbation of all good members of society," a wish to lead popular students of philosophy to the moral and religious uses of their knowledge;" and, consequently, to expose the fallacies of our modern Pyrrhonists who ransack nature apparently with no other end than to call in question or vilify the wisdom and goodness of the Creator. Under this head, we find the limits of final causes well defined, and their temperate application ably vindicated. Among the champions who have figured in the arena of cosmogony few have been more extolled than Professor Playfair, the eloquent historian of physical science; yet in our humble apprehension, few have so frequently violated every rule of induction as he has done in his geological speculations. We feel, therefore, truly grateful to Dr. Üre for the moral courage with which he has dispelled this illusion of a great name, so injurious to the advancement of truth. "The theory of Hutton was passing fast into oblivion, like its visionary predecessors*, when it was re-embodied, for a season, by the eloquence of Playfair. Delighted with the imposing boldness of the Huttonian creed, the Professor undertook its exposition with the ardour of a mineralogical neophyte. Bringing to the task the joint resources of dialectics and geometry, he produced those Illustrations of the Huttonian Theory which have been so highly celebrated by his literary friends, though they will probably add nothing to his fame as a philosopher." *The cosmologies of Leibnitz, Whiston, Demaillet, Buffon, Dolomieu, Bertrand, &c. WOV After a few introductory remarks, Dr. Ure quotes a passage from the illustrations, on which he comments in the following terms: "Had the Professor regarded the hypothesis of his friend, whe Dr. Hutton, with equal impartiality as that of Werner, he would not have expended any refined analysis in its support. That the planets had at one time an actual figure infinitely more irregular than the present, is certainly a very strange proposition for a modern philosopher to make, one equally extravagant with any Epicurean fiction in Lucretius. After an indefinite period, it appears that one of them at least, the earth, became sufficiently regular for an abode of living beings. Their habitation has, however, a precarious existence. The progress of waste will eventually crumble down its mountains, and strew their detritus over the bottom of the sea, converting our imperfect spheroid into the perfect form of equilibrium. This geometrical symmetry which conspiring physical forces tend, by this creed, to produce, should some day cover the whole land with a winding-sheet of water, universally fatal to organic motion and life. This mortal consummation, however, they propose to obstruct from time to time, by fortuimountains tous explosions from the central fires, upheave, by fortui and plains, as they are wanted, to rescue the world from a watery grave. The probability of such a mode of salvation is rapidly diminishing; for it is admitted by the theoretic votaries both of Vulcan and Neptune, that these igneous eruptions are becoming vastly feebler and less frequent than they were in ancient times; that volcanic fires are fast expiring, and only a few smoking spiracles remain to attest their former activity. In this predicament, the Huttonians can hold forth to prose proselytes but slender hopes of the duration of their system. The casual convulsion of a dying power is a very precarious resource, and can be little relied on for resisting the steady pace of destruction. The earth of the Huttonians must become a finished spheroid, unfit for every useful purpose. "Mr. Playfair's two travellers, the celestial and terrestrial, would have found a better coincidence, and one more to their credit, as philosophers, by tracing at once the actual and only beneficial form of the earth, and its fellow planets, to that perfect Wisdom which created all things in conformity to their destined ends, and which provides, with unwearied beneficence, for the wants and well-being of every organic tribe. แส I have no desire to fatigue my readers with a detailed examination of the theory propounded by Hutton, and embellished by Playfair. Its defects and inconsistencies, and 'in די deed its whole hypothetical tenor are now so notorious, that no practical naturalist of eminence will venture to adopt its conclusions. My sole object, here, was to unveil its vain spirit of theoretic cosmogony; to exhibit its efforts to build a Babeltower that should make a name, and enfranchise it from the control of a creating and directing Providence. The world, according to Hutton, shows no trace of a beginning, or of an end; but has been the theatre of an indefinite series of transformations in time past, and will continue to be so in time to come. The mountains of a former earth were worn down and diffused over the bottom of a former ocean. There they were exposed to the agglutinating power of subjacent internal fires; and after due induration, were heaved up by the explosive violence of the same force, into the inclined or nearly vertical positions, in which the great mountain strata now stand.. "The mountains of gneiss and mica slate, allowed by every practical geologist to be primitive, are barren in animal exuvia. Now these most distinctly stratified rocks were formed, it is said, at the the bottom of the Huttonian sea, by the same process as the calcareous and other secondary strata that are replete with shells. Whence do these organic ruins come, and why are they absent in the former class of rocks, both of them formed in the same sea, and under similar circumstances? They cannot reply that the epoch of the gneiss and mica-slate formations was anterior to the existence of animals; for their theory affirms, that the present earth sprung up out of a preceding one, by a spontaneous growth or transition, without the intervention of a divine creative energy. They tell us, that in an indefinite series of ages, the mountain masses of the preexisting globe became submarine concentric layers of rock, which were thence elevated by catastrophe into the present dry lands. Their marine deposition was slow and tranquil, disturbing fo the general economy of nature no more than at present, and, consequently, not interfering with the production of marine testaceous animals, nor with the distribution of their shelly theirs exuviæ. Hence, should these beds be eventually indurated and heaved up by the subjacent fires into the nearly vertical mountain schists of a new earth, they must contain the organic witnesses of their submarine formation. But since our actual mountains of gneiss and mica-slate are destitute of these internal witnesses, as also of their basis, carbonate of lime, they cannot have been formed at the bottom of an ocean teeming an, with animal life. Devoid of organic remains, they indicate a sea devoid of vital energy. The first appearance of shelly strata is coincident with a specific exertion of creative power, Sas "This mortal chasm, in the succession of mineral formations, breaks the chain of the Huttonians. It is the death blow of their theory; demonstrating that the present earth has resulted from definite creative Fiats; and not from the progressive operations of any merely physical forces whatsoever. It is therefore to be regretted, that a mind so accomplished as that of Professor Playfair should have devoted so many studious years to the decoration of the phantoms described by him in the following paragraph. "How often these vicissitudes of decay and renovation have been repeated, is not for us to determine; they constitute a series, of which, as the author of this theory has remarked, we neither see the beginning nor the end; a circumstance that accords well with what is known concerning other parts of the economy of the world. In the continuation of the different species of animals and vegetables that inhabit the earth, we discern neither a beginning nor an end; and in the planetary motions, where geometry has carried the eye so far both into the future and past, we discover no mark either of the commencement or of the termination of the present order. It is unreasonable, indeed, to suppose that such marks should any where exist. The Author of Nature has not given laws to the universe, which, like the institutions of men, carry in themselves the elements of their own destruction. He has not permitted in his works any symptom of infancy or old age, or any sign by which we may estimate either their future or past duration. These phenomena, then, are all so many marks of the lapse of time, among which the principles of geology enable us to distinguish a certain order, so that we know some of them to be more, and others to be less distant, but without being able to ascertain, with any exactness, the proportion of the immense intervals which separate them. These intervals admit of no comparison with the astronomical measures of time; they cannot be expressed by the revolutions of the sun or the moon; nor is there any synchronism between the most recent epochas of the mineral kingdom, and the most ancient of our ordinary chronology.' "Our ordinary chronology comprehends the deluge, a great epocha of the mineral kingdom, the truth of which is obviously discarded by Mr. Playfair. In the third part of the present work, ample evidence will be adduced from Cuvier and other practical naturalists, of the reality of that recent epocha, and of its synchronism with our chronology. Moreover, it will be shown in our second part, that the mineral strata contain formations, which discover marks of the commencement' of the different species of vegetables and animals that peopled the earth. The astronomical comparison is a strange solecism for so acute a logician to commit. The cases are quite discrete, and destitute of any true analogy. The laws of the planetary motions are represented in a system of mechanical theorems, which relate solely to co-existing phenomena. The principles of their actual equilibrium apply equally to all past and future time. The appearances reveal nothing in the past, or the future, different from the present, except change of relative position among separate masses. The physical constitution of the planets, which could alone afford, in their anterior metamorphoses, kindred or parallel facts for geology, are beyond our cognisance. In the mineral structure of the earth, we shall find symptoms of infancy, as well as on its surface, considered as the dwelling-place of man." Our author gives the Wernerian theory fair play, in judging it by D'Aubuisson's temperate representation. On this, its most reasonable form, we find the following observations; in which we perfectly concur. "It would be superfluous, indeed, to offer an elaborate refutation of a world-building hypothesis, so extravagant, so visionary, and so inconsistent with every principal of mechanical and chemical science. Whence arose that immense chaotic ocean, within whose bosom the summits of the Himmalaya and the Andes were crystallised? Whither did it retire in measured stages of descent, to allow the primary and secondary rock formations, to lay their successive platforms, in the amphitheatre of the globe? The atmosphere has a finite extent, not expanding into space beyond a limited distance from the earth; and thus that world of waters could not escape into another sphere, in vaporous exhalations. The quantity of water requisite to cover the globe to the height of the Himmalaya, or 27,000 feet, would be as great as the whole mass of our actual ocean. Werner was too little of a philosopher to calculate that his crystallisation plan called on him to provide a receptacle for 1000 millions of cubic miles of water. The great density of the interior body of the earth precludes the possibility of that receptacle being subterranean. Since neither celestial nor terrestrial space will admit his retiring chaotic ocean, itself must be deemed an inadmissible supposition. Even granting its reality, and allowing moreover that this water was adequate to dissolve the now insoluble granitic mountains, so as to form a clear and tranquil fluid, we may ask, why the solvent that then exercised so marvellous an affinity for the siliceous and aluminous earths, came so soon to discard them |