LETTER XI. New Formation or Adjustment of the Burface, after the Deluge, so as to produce the Soils fit for Human Residence and Cultivation-And for the present system of Vegetable and Animal Nature. MY DEAR SYDNEY, THAT the present surface of the earth on which we are living was not, in all its regions, that primeval surface on which the first plants vegetated, the organic remains in several of the subterraneous rocks satisfactorily evince. The exterior masses of our globe, to the lowest depth that we have been able to explore, appear to consist of a succession of rocks, which have been traced and named, and of which you had a summary notice in the seventh and eighteenth of my former Letters, with a brief intimation of the vegetable and animal fossils which had been found among them. It would be too great a digression from the main and chosen subject of the present correspondence to enter into a review of the geological construction of our earth, although it is an important compartment of its sacred history. But my other topics, and the limits which I have fixed for these pages, compel me to abstain from it, and only to desire you to bear of real knowledge. By confining our inquiries to more legitimate objects, we shall avoid the delusion into which one of the disciples of this transcendental school appears to have fallen, when he announces with exultation, that the simple laws he has discovered have now explained the universe: nor shall we be disposed to lend a more patient ear to the more presumptuous reveries of another system-builder, who, by assuming that there exists in organized matter an inherent tendency to perfectibility, fancies that he can supersede the operations of divine agency." Dr. Roget closes his gratifying task with this admirable paragraph. "Happily there has been vouchsafed to us from a higher source, a pure and heavenly light to guide our faltering steps, and animate our fainting spirit, in this dark and dreary search, revealing those truths which it imports us most of all to know; giving to morality higher sanctions; elevating our hopes and affections to nobler objects than belong to earth, and inspiring more exalted themes of thanksgiving and of praise."Rogel, An. & Veg. Phy. vol. ii. p. 639-41. in mind that the rocks and strata which we have attained to know are distinguishable by a natural separation into two great divisions. Those which, containing no organic remains, give thereby evidence that they were formed and laid down before plants and animals were created; and those which, containing in several of their series and localities fossil remains of organic life, must have been made and deposited at a subsequent period. The first are called the primordial or primary rocks, of which the chief members are granite, gneiss, and mica slate; to which some minor and subordinate ones are in several places attached. These primordial rocks constitute the greatest bulk of our surface masses. The granite formation appearing everywhere, and often uncovered by others, presents to us many indications that it is the foundation rock, on which all the others have been placed; and that it encompasses the whole circuit of the globe. Not só universal as this, but the next to it in extent and lying upon it, are the gneiss rocks, which, in several countries, predominate on the visible surface; and still less general, yet more so than any other, the mica slate formation appears resting upon the gneiss, where that has preceded it, or on the granite, where no gneiss has been deposited. Upon these have been placed those which have been called transition and intermediate in their lower masses; and secondary in the upper ones; but to all of which we may apply the term secondary, to distinguish them from a later series, which have been termed tertiary and diluvial. They comprise principally the slate formations, the grauwacke, and old and new red sandstones; the mountain and magnesian limestones; the oolites and lias, up to the great chalk beds, with some others less remarkable. On these the tertiary and diluvial strata have been deposited, which are more immediately connected with the deluge, as it is in some of these, always nearest the present surface, that the fossil remains of quadrupeds and land animals have been found; which may be presumed to have been those which perished in that overwhelming catastrophe which we have been recently considering. These recollections will be sufficient for my present subject, which is to lead your attention to the fact, that one great operation and intended result of the deluge was, to lay a new surface on many parts of the antideluvian one, and to form that peculiar configuration and kind of habitable ground which the human race and our accompanying plants and animals have ever since been occupying and subsisting on. In forming the new surface of the earth, it was peculiarly important to the future subsistence of the renewed human race, that the convulsions and agitations of the deluge should be so directed, that such earthy masses should be on the uppermost superficies, and in such a fragmentary and comminuted state, as would afterward suit and produce that vegetation, those herbs, shrubs, roots, and trees, from which our subsistence, conveniences, and comforts were afterward to arise. This event never could be a matter of course, because any rock, any sort of ground will not do. The steril granite, the sandy desert, the flinty rock, the watery marsh, the hard limestone, the mere clay, the gravel, the unbroken lava, or the stony ground, will not furnish mankind with what they need for their food and welfare. The earth is suffered in many parts to exhibit all these appearances, in some portions, as if to show us that undirected sequences of things, and what are called chance-formations, would not provide for the human race those supplies, without which they could not increase their numbers, or would do so, but to drag on a miserable life, and to remain in a destitution like that of the Australian savages.* Nor will every species of soil produce every kind of vegetation. Animals may need only grass; but it was intended that man should feed on corn, rice, and many other nutritious plants and roots that will only grow or flourish on the soil which is adapted respectively to them. The trees also that were to exist for his benefit, and for that of the bird classes, and of the brute animals that live in the shade and forests, equally require suitable ground. It was therefore expedient that Dr. Prout very appositely says, that "it is the business of the geologist to point out the changes which our earth has evidently undergone, before it arrived at its present condition :-and to show that all these changes have not resulted from chance; but from the agency of an intelligent Being, operating with some ulterior purpose, and according to certain laws, to which he had chosen to restrict himself."-Dr. Prout's Brid. Treat. p. 178-9. "Plants and trees, the roots of which are fibrous and hard, and capable of penetrating deep into the earth, will vegetate to advantage in the plan should be settled, what the subsistence of man, after the deluge, should consist of, and that the preceding surface should be so broken up or adapted, and its ruins so modified and intermingled, that the new deposites from those commotions and changes should be such as would everywhere nourish and yield to the human race those species and diversities of plants of all sorts, which their intended subsistence would require.* Let us see, from a few facts, what was necessary to be done and provided for in this respect. The antediluvian vegetation was very different from the present. This is the statement of the most eminent of the modern geologists; and the phenomena in the fossil matters of the earth have suggested, and justify the supposition. The difference was of two kinds; it was that of a tropical character, implying a temperature like that of the torrid zone or equatorial regions, and displaying that largeness of size which is only now found in regions where that degree of heat prevails; and it was also not of the leguminous species; not the corn plants, or the vegetables which now constitute the food of man,-but it was of the reedy, fern-like, grassy, more aquatic and puny kinds, such as are adapted for the nutrition of brute animals; and obviously by its nature indicating that these were then living or predominating in those regions where the imbedded remains of this character appear.‡ Mankind were then in some small parts of the globe which have not yet been explored; and the rest of its surface was almost all common'soils that are moderately dry, and that do not contain a very great excess of vegetable matter. I found the soil taken from a field at Sheffield-place, in Sussex, remarkable for producing flourishing oaks, to consist of six parts of sand and one part of clay and finely di vided matter-100 parts of the whole sort produced, silex 54, alumine 28, carbonate of lime 3, oxyde of iron 5, water 3, decomposing vegetable matter 4."-Sir II. Davy's Analysis of Soils, p. 15. * Dr. Prout adds, "that the geologist should also demonstrate that to these very convulsions and changes we owe all that boundless variety of sea and land, of mountain and plain, of hill and valley; all that endless admixture of rocks, of strata, and of soils, so essential to the existence of the present order of things; without which the world would be a mass of crystals; or one dreary monotonous void, totally unfit for the present race of organized beings, and particularly as a residence for man."-Brid. Tr. p. 180. See the first vol. of this History, p. 179 et seq. occupied by seas, lakes, vegetation, and the various orders of the animated creation, among which the human race had not spread. This being the state of the antediluvian superficies of the earth, it was essential, if man was to be its general resident, and to place his settlements and colonies in all parts of the surface, instead of forming only one or more dense population, in a few particular sites, that the general surface should be altered; that it should be taken out of its antediluvian form and condition, and be put into that state which would everywhere be fitted for the growth and fertility of the various articles of food which mankind were to subsist on and to derive pleasure from. Both these results were intended, and were therefore to be provided for. It was not only meant that the new earth should produce what would efficiently nourish the human race;-one single plant, a root, oats only, or potatoes alone, would have been sufficient for that, as grass is for the sheep and cattle ;--it was also a part of the divine plan, that the aliment of man should become a large part of his daily enjoyment; and therefore, in order that the pleasures from it might be more multiplied, that a great variety of nutritious vegetation should be provided for him, so that he should have both abundance and diversity to choose from, and to intermingle or alternate, as he might choose to raise, cultivate, and use. For the accomplishment of this benign purpose, a peculiar formation and adaptation would be necessary of the upper surface of the ground he was to cultivate, and of the soil and rocks underneath that, because the growth and productiveness of vegetation depend not only on the nature of the earth in which the seed or root is deposited, but also on the subsoil; on the species of the strata, which lie immediately below the matter in which the plant begins to shoot. This subsoil is next in importance to the main upper soil, in order to provide and continue the fertility of the cultivated ground.* These recollections will show you how much thought and "The productiveness of soil must be influenced by the nature of the subsoil. Thus a sandy soil may sometimes owe its fertility to the power of the subsoil to retain water; and an absorbent clayey soil may occasionally be prevented from being barren, in a moist climate, by the influence of a substratum of sand and gravel."--Sir H. Davy, Anal. p. 11. Many fields contain, beneath the surface, a subsoil well adapted to make the upper stratum for ever fertile."-Lance's Golden Farmer, p. 58. |