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 . 28, 1861.] vague and inconclusive. He would find plenty of speculation, and much ingenious theorising, but no reliable answer to his questions. Neither bold surmise, nor fanciful theory, however, could prepare his mind to receive without astonishment the startling solution which science has recently offered to the geological enigma,—What is flint?

Without going so far as to say that the explanation to which we allude meets all the difficulties of the case, it still undoubtedly accounts for several puzzling phenomena connected with flint formation in a much more complete and satisfactory manner than any previously published theory; and is withal of so singular and interesting a character, that we confidently count on our readers’ amusement, if not attention, while we state in a more detailed and popular form the substance of Dr. Wallich’s researches and conclusions.

It seems, then, we have all been wrong; we have ransacked our brains, our experience, and our fancy to no purpose; we have fathered the flint on earth and sea, chemical action, elective affinity, and metamorphic agencies, never dreaming that the legitimate parent was an old familiar friend.

It is positively pleasant to anticipate the incredulous laughter with which many readers will probably receive our statement of the fact, that every flint in the chalk, and consequently every pebble in our garden walks, owes its origin to the long-continued labours of those great silex producers—the whales. Of course every well-regulated mind will ridicule the idea forthwith, and pooh-pooh the whole thing as absurd; and it certainly does seem at first sight presumptuous to claim for Jonah the honour of having been the first and only visitor to the genuine birthplace of London gravel, and to exalt that Hebrew gentleman’s opportunities for investigation in this field of inquiry above those of such men as Lyell, Murchison, or Buckland; yet such is the conclusion towards which the latest dicta of science, uttered in sober earnest, and supported by a great array of facts, seems likely to compel the student. When the laugh has subsided, perhaps curiosity enough may survive to insure us a hearing, while we attempt to unravel this mystery step by step. Its clear elucidation to the general reader must necessarily take us over extensive ground. Several collateral branches of inquiry will claim our attention, so that if we shall presently seem to wander into paths apparently far from parallel with our main line of investigation, let us bespeak a little patience till each of these devious excursions is shown to tend towards the true end of our discourse.

To begin, we must take a hasty glance at a portion of the chalk formation of England, where the flints from which our pebbles were manufactured most abound. There are few Londoners whose summer trip to the sea-side does not take them at least across the North Downs, and perhaps even as far as the South Downs of Brighton and its neighbourhood. These great chalk escarpments form two sides of an enormous basin, roughly elliptical in form, and including within its area the whole of Sussex, parts of Surrey, Kent, and Hampshire, a strip of the English Channel, and a small tract of country known as the Bas Boulonnais, in France.

The accompanying map exhibits the outlines of this ring of chalk, and will help to illustrate our exposition. Within its white margin lies a district comprising several strata, chiefly clays and sand, and known to the geologist under the general name of the Wealden Valley. A glance at the map, or an excursion over the ground, will make it abundantly clear that there was once a time when the space enclosed in this ellipsis was covered with the chalk which now fringes its borders only. At that period the gault and clays of the Weald were deeply buried beneath a thick white pall of carbonate of lime, and the whole lay fathoms down under a cold sea.

We explained in a former paper, that recent discoveries have proved the cretaceous formation to be itself the result of the life, death, and accumulation of minute marine animals, similar in genera, though not in species, with the