place only on a small scale, he applies unlimitedly by simple multiplication, and infers thirty feet of strata in a day, and nine hundred in a month. But he takes no notice of the extremely slow rate of deposit, in those circumstances which constitute the general course of nature; and which is demonstrated by facts innumerable in estuaries, in deltas, or in fresh-water lakes. He exhibits the crude impertinence of a few foreign sophists, whose day in this respect is past, representing the succession of organized beings as becoming gradually more complete and perfect, so as to indicate an improvement by practice in the Creator's skill; and he notices not the fact that all the great geologists repudiate such a notion with abhorrence, and give physical evidence of its falsehood. With respect to this subject, it should not be forgotten that, on account of the perishable substance of their structure, many species of both animal and vegetable creatures must have failed to perpetuate any memorials of themselves, in all the periods of the earth's antiquity. The more profoundly anatomical investigations are carried on, the more abundantly is it evinced that, within the range of the animal remains presented even in the earliest fossiliferous strata, the remark will hold, as a general truth, which has been made by eminently qualified judges, in relation to the vegetable kingdom :-" The result of this investigation is well worthy of attention. It shows that, so far from 'a gradual perfection of organization having been going on from the remotest period, till the latest geological epoch,' [the words of an able adverse writer,] some of the most perfect forms of each of the three great classes of the vegetable kingdom were among the very first created; and that, either the more simple plants of each class did not appear till our own era, or that no trace of them at an earlier period has been preserved." Lindley and Hutton's Fossil Flora; vol. I. pref. p. xix. It would appear almost incredible that Dr. Y. should say, "Fishes, zoophytes, ammonites, belemnites, terebratulæ, &c. occur in almost every portion of them [the secondary strata]; but those in the inferior strata have as much similarity to the living races as those in the superior." P. 9. An assertion full of extreme inaccuracies! Can he, for example, push out of sight a most remarkable circumstance in the caudal prolongation of the back-bone, which distinguishes all the fish of the Magnesian Limestone and the earlier formations, from the subsequent; and from almost all existing species? This, and many other striking peculiarities in the fossil ichthyology, were discovered by the distinguished investigator, M. Agassiz. See Lyell's Elements, p. 417. SUPPLEMENTARY NOTES. 315 I thankfully avail myself of the authority (- -can there be a higher ?-) and testimony of Mr. Murchison. "The fossils of the Silurian System here represented, and amounting in all to about 350 species, are, with the exception of a very few (chiefly doubtful casts,) essentially distinct from any of the numerous and well-defined fossils of the Carboniferous System; and further, that the Old Red Sandstone which separates these two systems is also characterized by fossils peculiar to it.-Having for a series of years collected fossils from every stratum of the Silurian rocks, throughout a large region, in which the stratigraphical order is clear, I now present the results. Professor Phillips had previously completed a valuable monograph of the organic remains of the Carboniferous System; [in his Illustrations of the Geology of Yorkshire; vol. II. 1836.] If the naturalist will compare the figures in these, the only two works yet published upon the older fossiliferous rocks, which combine geological description with zoological proofs, he will at once see the truth of my position. 66 Beginning with the vertebrata; Are not the fishes of the Old Red Sandstone as distinct from the Carboniferous System on the one hand, as from those of the Silurian on the other? M. Agassiz has pronounced that they are so. "Are any of the crustaceans, so numerous and well-defined throughout the Silurian rocks, found also in the Carboniferous strata? I venture to reply, not one. "Are not the remarkable cephalopodous mollusca, the Phragmoceras, and certain forms of Lituites, peculiar to the older system? "Is there one species of the Crinoidea figured in this work, known in the Carboniferous strata? "Has the Serpuloides longissimum, or have those singular bodies the Graptolites, or in short any zoophytes of the Silurian System, been detected in the well-examined Carboniferous rocks? "And, in regard to the corals, which are so abundant that they absolutely form large reefs, is not Mr. Lonsdale, who has assiduously compared multitudes of specimens from both systems, of opinion that there is not more than one species common to the two epochs ?— "Such evidences are-additional supports of the important truth which Geology has already established; that each great period of change, during which the surface of the planet was essentially modified, was also marked by the successive production and obliteration of certain races.' Silur. Syst. pp. 581, 582. With astonishment I read in Dr. Y., "The general conformity of the strata and their undisturbed succession, indicate that they must have been deposited about the same era." P. 23. He admits indeed of some exceptions, but he confines them to the elevating force of "volcanic agency." One might almost fancy that the worthy author had never fixed his eyes upon any rocks but those of his own Yorkshire coast, and that he had explored even them but cursorily. That all strata were at their origin deposited horizontally or nearly so, is not the question. But, is it possible for him to be ignorant of the instances innumerable, in almost all parts of the world, where the formations of the secondary series, and many even of the third, follow with most remarkable disconformity? How often a deposit has been laid, long after the underlying one has been raised and bent and broken? The Sections published in the Geological Society's Transactions, and innumerable other works of unquestionable authority, furnish the most ample proofs of the contrary to Dr. Y.'s assertion. If possible, I am still more surprised to read, "The breaks, or faults, in the strata affect the whole mass of rocks, in almost every instance where they occur; instead of being limited by the boundaries of particular formations." P. 24. So far as, in a subject including many and various conditions, one can lay down general positions, I must say that what he affirms is not the fact, and what he denies, and builds largely upon his denial, is the fact. It is painful to me to remark thus upon the writing of a very estimable friend; and to be obliged to acknowledge that to me his book appears to abound in misconceptions of the sentiments of others and wrong imputations to them, in assertions positively made, but often hazardous or decidedly erroneous, in narrow investigation and defective induction, and in too rapid conclusions from imperfect premises. I should not however have brought forwards these observations, which might be considerably extended, but for this reason; Dr. Young's character as a Christian and a minister of the gospel, gives weight and currency to his opinions, and some persons have not failed to display his authority as if it were a sufficient refutation of the doctrines commonly maintained by geologists. [E.] Referred to at pages 74 (where by error it is called B) and 197. ON THE REASONS FOR ASSIGNING A VERY HIGH ANTIQUITY TO THE EARTH. THE evidence of geological phenomena constrains us to the belief that our earth has existed, has been the seat of life, and has under SUPPLEMENTARY NOTES. 317 gone many changes of its surface, through periods of time utterly beyond human power to assign. That evidence is of distinct and independent kinds, chiefly derived from the appearances of stratification and the remains of animal and vegetable life: and, to at least the most of those who have taken pains to become competently acquainted with its nature and variety, it produces the effect of an overpowering ocular and tangible demonstration. At the same time, there is extreme difficulty in communicating such a knowledge of the facts, to persons who have not the sensible perceptions upon which it rests. I have therefore felt it to be necessary, in the preceding lectures, to rest my repeated assertions in reference to this subject upon authority; pleading that the authority is of a kind sufficient to be the ground of certainty, on account of the moral and intellectual character of the witnesses, their scientific qualifications, their opportunities for investigation upon the largest scale, their original prepossessions against this conclusion, and finally their number and diversity as to country, party, religious denomination, and other circumstances which are rational gurantees against prejudice. But this is not sufficient to satisfy all. Some of our friends persist in rejecting the conclusion, resting chiefly upon the fact of its denial by persons, who, though a very few in number, possess some geological knowledge and opportunities for personal observation. The difficulty is perhaps increased, and advantage is given to the objector, from the fact that our most distinguished philosophers avowedly, and much to their honour, decline the task of laying down any common measure between geological time and our ordinary enumerations of years and centuries. The best writers abound in general expressions; such as, "immense periods of time,-undefined-yet countless-ages,-a duration to which we dare not assign a boundary,—a work infinitely slow, a space of time from the contemplation of which the mind shrinks; a long succession of monuments, each of which may have required a thousand ages for its elaboration;-successions of events, where the language of nature signifies millions of years:-it is evident that no greater folly can be committed, than to think to serve the cause of truth by contracting the long periods of Geology into the compass of a few thousand years.' -- Opponents have not been backward to take notice of this style of expression, and to make use of it for their own purposes. In so doing, * Mantell's Wonders of Geology, i. p. 6, ii. 247. Macculloch's Geol. i. 455, 473. Sedgwick on the Studies of Cambridge, p. 26. Lyell's Principles, i. 116. Phillips's Treatise in the Encycl. Brit. 293. Similar passages might be quoted indefinitely. they act a very uncandid and unreasonable part: but we can administer no remedy to them, so long as they persist in refusing to provide themselves with the requisite preliminary knowledge, and to examine the question with far more diligence and patience, and I may add Christian honour too, than they appear to have yet exercised. We readily acknowledge that the problem, to represent geological by astronomical time, is of the greatest difficulty; perhaps it is utterly beyond human power to resolve, in the present state of our being.* Some approximation is all that we venture to hope for. It is selfevident that the application of any continuous measure of time, analogous to our common periods of multiples and products, is utterly out of the question. It would be the height of absurdity to imagine it for each one of the phenomena whose aggregate forms the whole case, must have occupied its own particular portion of time destitute of any rule of conformity to others. In the formation of strata, each process (transportation, deposition, consolidation, elevation and subsidence; to be followed by a renewal of similar actions under new conditions; and that probably several times repeated) might occupy a duration different from that of the corresponding process in every other stratum or system of strata. Yet this does not set aside the reality of a prevailing analogy; nor does it destroy the evidence of a general conclusion from a multitude of particular facts, each one of which must have required, for its consummation, a very long period; we may in most cases say, immensely long. This will appear, if we consider a few of those facts. 1. The remains of human beings and of any vestiges of the arts and operations of man, are discovered only upon or in those surfaces and earthy masses which are demonstrably posterior to all regular geological deposits; and under circumstances indicating the human species to have been among the most recent products of the Creator's power. Disinterments of human bones have often occurred, with articles characteristic of an age, one third, and in the Egyptian relics one half, of the period since the creation of man; but these are all in * In 1834, the Council of the Royal Society announced the prize of one of the Royal Medals, the gift of the Sovereign, to the author of the best paper, to be entitled "Contributions towards a System of Geologi. cal Chronology, founded on the Examination of Fossil Remains and their attendant phenomena." The period for such communication was fixed to expire in June 1837. It did so expire, without producing the result desired. "The Geologists of England," remarks Prof. Phillips, "gave a fair proof that hypotheses were out of fashion, when they declined to compete for the medal." Treat. on Geol. (in Lardn. Cyclop.) vol I. p. 245. |