Чарльз Дарвин
More Letters of Charles Darwin — Volume 2
I beg you to present my most respectful and kind compliments to your honoured father {Sir G.B. Airy}.
LETTER 474. TO FRANCIS GALTON.
(474/1. Mr. Galton had written on November 7th, 1872, offering to send to various parts of Africa Darwin's printed list of questions intended to guide observers on expression. Mr. Galton goes on: "You do not, I think, mention in "Expression" what I thought was universal among blubbering children (when not trying to see if harm or help was coming out of the corner of one eye) of pressing the knuckles against the eyeballs, thereby reinforcing the orbicularis.")
Down, November 8th {1872}.
Many thanks for your note and offer to send out the queries; but my career is so nearly closed that I do not think it worth while. What little more I can do shall be chiefly new work. I ought to have thought of crying children rubbing their eyes with their knuckles, but I did not think of it, and cannot explain it. As far as my memory serves, they do not do so whilst roaring, in which case compression would be of use. I think it is at the close of the crying fit, as if they wished to stop their eyes crying, or possibly to relieve the irritation from the salt tears. I wish I knew more about the knuckles and crying.
What a tremendous stir-up your excellent article on prayer has made in England and America! (474/2. The article entitled "Statistical Inquiries into the Efficacy of Prayer" appeared in the "Fortnightly Review," 1872. In Mr. Francis Galton's book on "Enquiries into Human Faculty and its Development," London, 1883, a section (pages 277-94) is devoted to a discussion on the "Objective Efficacy of Prayer.")
LETTER 475. TO F.C. DONDERS.
(475/1. We have no means of knowing whether the observations suggested in the following letter were made — if not, the suggestion is worthy of record.)
Down, December 21st, 1872.
You will have received some little time ago my book on Expression, in writing which I was so deeply indebted to your kindness. I want now to beg a favour of you, if you have the means to grant it. A clergyman, the head of an institution for the blind in England (475/2. The Rev. R.H. Blair, Principal of the Worcester College: "Expression of the Emotions," Edition II., page 237.), has been observing the expression of those born blind, and he informs me that they never or very rarely frown. He kept a record of several cases, but at last observed a frown on two of the children who he thought never frowned; and then in a foolish manner tore up his notes, and did not write to me until my book was published. He may be a bad observer and altogether mistaken, but I think it would be worth while to ascertain whether those born blind, when young, and whilst screaming violently, contract the muscles round the eyes like ordinary infants. And secondly, whether in after years they rarely or never frown. If it should prove true that infants born blind do not contract their orbicular muscles whilst screaming (though I can hardly believe it) it would be interesting to know whether they shed tears as copiously as other children. The nature of the affection which causes blindness may possibly influence the contraction of the muscles, but on all such points you will judge infinitely better than I can. Perhaps you could get some trustworthy superintendent of an asylum for the blind to attend to this subject. I am sure that you will forgive me asking this favour.
LETTER 476. TO D. HACK TUKE. Down, December 22nd, 1872.
I have now finished your book, and have read it with great interest. (476/1. "Influence of the Mind upon the Body. Designed to elucidate the Power of the Imagination." 1872.)
Many of your cases are very striking. As I felt sure would be the case, I have learnt much from it; and I should have modified several passages in my book on Expression, if I had had the advantage of reading your work before my publication. I always felt, and said so a year ago to Professor Donders, that I had not sufficient knowledge of Physiology to treat my subject in a proper way.
With many thanks for the interest which I have felt in reading your work...
LETTER 477. TO A.R. WALLACE. Down, January 10th {1873}.
I have read your Review with much interest, and I thank you sincerely for the very kind spirit in which it is written. I cannot say that I am convinced by your criticisms. (477/1. "Quarterly Journal of Science," January, 1873, page 116: "I can hardly believe that when a cat, lying on a shawl or other soft material, pats or pounds it with its feet, or sometimes sucks a piece of it, it is the persistence of the habit of pressing the mammary glands and sucking during kittenhood." Mr. Wallace goes on to say that infantine habits are generally completely lost in adult life, and that it seems unlikely that they should persist in a few isolated instances.) If you have ever actually observed a kitten sucking and pounding, with extended toes, its mother, and then seen the same kitten when a little older doing the same thing on a soft shawl, and ultimately an old cat (as I have seen), and do not admit that it is identically the same action, I am astonished. With respect to the decapitated frog, I have always heard of Pfluger as a most trustworthy observer. (477/2. Mr. Wallace speaks of "a readiness to accept the most marvellous conclusions or interpretations of physiologists on what seem very insufficient grounds," and he goes on to assert that the frog experiment is either incorrectly recorded or else that it "demonstrates volition, and not reflex action.") If, indeed, any one knows a frog's habits so well as to say that it never rubs off a bit of leaf or other object which may stick to its thigh, in the same manner as it did the acid, your objection would be valid. Some of Flourens' experiments, in which he removed the cerebral hemispheres from a pigeon, indicate that acts apparently performed consciously can be done without consciousness. I presume through the force of habit, in which case it would appear that intellectual power is not brought into play. Several persons have made suggestions and objections as yours about the hands being held up in astonishment; if there was any straining of the muscles, as with protruded arms under fright, I would agree; as it is I must keep to my old opinion, and I dare say you will say that I am an obstinate old blockhead. (477/3. The raising of the hands in surprise is explained ("Expression of Emotions," Edition I., page 287) on the doctrine of antithesis as being the opposite of listlessness. Mr. Wallace's view (given in the 2nd edition of "Expression of the Emotions," page 300) is that the gesture is appropriate to sudden defence or to the giving of aid to another person.)
The book has sold wonderfully; 9,000 copies have now been printed.
LETTER 478. TO CHAUNCEY WRIGHT. Down, September 21st, 1874.
I have read your long letter with the greatest interest, and it was extremely kind of you to take such great trouble. Now that you call my attention to the fact, I well know the appearance of persons moving the head from side to side when critically viewing any object; and I am almost sure that I have seen the same gesture in an affected person when speaking in exaggerated terms of some beautiful object not present. I should think your explanation of this gesture was the true one. But there seems to me a rather wide difference between inclining or moving the head laterally, and moving it in the same plane, as we do in negation, and, as you truly add, in disapprobation. It may, however, be that these two movements of the head have been confounded by travellers when speaking of the Turks. Perhaps Prof. Lowell would remember whether the movement was identically the same. Your remarks on the effects of viewing a sunset, etc., with the head inverted are very curious. (478/1. The letter dated September 3rd, 1874, is published in Mr. Thayer's "Letters" of Chauncey Wright, privately printed, Cambridge, Mass., 1878. Wright quotes Mr. Sophocles, a native of Greece, at the time Professor of Modern and Ancient Greek at Harvard University, to the effect that the Turks do not express affirmation by a shake of the head, but by a bow or grave nod, negation being expressed by a backward nod. From the striking effect produced by looking at a landscape with the head inverted, or by looking at its reflection, Chauncey Wright was led to the lateral movement of the head, which is characteristic of critical inspection — eg. of a picture. He thinks that in this way a gesture of deliberative assent arose which may have been confused with our ordinary sign of negation. He thus attempts to account for the contradictions between Lieber's statement that a Turk or Greek expresses "yes" by a shake of the head, and the opposite opinion of Prof. Sophocles, and lastly, Mr. Lowell's assertion that in Italy our negative shake of the head is used in affirmation (see "Expression of the Emotions," Edition II., page 289).) We have a looking-glass in the drawing-room opposite the flower-garden, and I have often been struck how extremely pretty and strange the flower garden and surrounding bushes appear when thus viewed. Your letter will be very useful to me for a new edition of my Expression book; but this will not be for a long time, if ever, as the publisher was misled by the very large sale at first, and printed far too many copies.
I daresay you intend to publish your views in some essay, and I think you ought to do so, for you might make an interesting and instructive discussion.
I have been half killing myself of late with microscopical work on plants. I begin to think that they are more wonderful than animals.
P.S., January 29th, 1875. — You will see that by a stupid mistake in the address this letter has just been returned to me. It is by no means worth forwarding, but I cannot bear that you should think me so ungracious and ungrateful as not to have thanked you for your long letter.
As I forget whether "Cambridge" is sufficient address, I will send this through Asa Gray.
(PLATE: CHARLES LYELL. Engraved by G.I. (J). Stodart from a photograph.)
CHAPTER 2.IX. GEOLOGY, 1840-1882
I. Vulcanicity and Earth-movements. — II. Ice-action. — III. The Parallel Roads of Glen Roy. — IV. Coral Reefs, Fossil and Recent. — V. Cleavage and Foliation. — VI. Age of the World. — VII. Geological Action of Earthworms. — VIII. Miscellaneous.
2. IX.I. VULCANICITY AND EARTH-MOVEMENTS, 1840-1881.
LETTER 479. TO DAVID MILNE. 12, Upper Gower Street, Thursday {March} 20th {1840}.
I much regret that I am unable to give you any information of the kind you desire. You must have misunderstood Mr. Lyell concerning the object of my paper. (479/1. "On the Connexion of certain Volcanic Phenomena, and on the Formation of Mountain-chains and the Effects of Continental Elevations." "Trans. Geol. Soc." Volume V., 1840, pages 601-32 {March 7th, 1838}.) It is an account of the shock of February, 1835, in Chile, which is particularly interesting, as it ties most closely together volcanic eruptions and continental elevations. In that paper I notice a very remarkable coincidence in volcanic eruptions in S. America at very distant places. I have also drawn up some short tables showing, as it appears to me, that there are periods of unusually great volcanic activity affecting large portions of S. America. I have no record of any coincidences between shocks there and in Europe. Humboldt, by his table in the "Pers. Narrative" (Volume IV., page 36, English Translation), seems to consider the elevation of Sabrina off the Azores as connected with S. American subterranean activity: this connection appears to be exceedingly vague. I have during the past year seen it stated that a severe shock in the northern parts of S. America coincided with one in Kamstchatka. Believing, then, that such coincidences are purely accidental, I neglected to take a note of the reference; but I believe the statement was somewhere in "L'Institut" for 1839. (479/2. "L'Institut, Journal General des Societes et Travaux Scientifiques de la France et de l'Etranger," Tome VIII. page 412, Paris, 1840. In a note on some earthquakes in the province Maurienne it is stated that they occurred during a change in the weather, and at times when a south wind followed a north wind, etc.) I was myself anxious to see the list of the 1200 shocks alluded to by you, but I have not been able to find out that the list has been published. With respect to any coincidences you may discover between shocks in S. America and Europe, let me venture to suggest to you that it is probably a quite accurate statement that scarcely one hour in the year elapses in S. America without an accompanying shock in some part of that large continent. There are many regions in which earthquakes take place every three and four days; and after the severer shocks the ground trembles almost half-hourly for months. If, therefore, you had a list of the earthquakes of two or three of these districts, it is almost certain that some of them would coincide with those in Scotland, without any other connection than mere chance.
My paper will be published immediately in the "Geological Transactions," and I will do myself the pleasure of sending you a copy in the course of (as I hope) a week or ten days. A large part of it is theoretical, and will be of little interest to you; but the account of the Concepcion shock of 1835 will, I think, be worth your perusal. I have understood from Mr. Lyell that you believe in some connection between the state of the weather and earthquakes. Under the very peculiar climate of Northern Chile, the belief of the inhabitants in such connection can hardly, in my opinion, be founded in error. It must possibly be worth your while to turn to pages 430-433 in my "Journal of Researches during the Voyage of the 'Beagle'," where I have stated this circumstance. (479/3. "Journal of Researches into the Natural History and Geology of the Countries visited during the Voyage of H.M.S. 'Beagle' round the World." London, 1870, page 351.) On the hypothesis of the crust of the earth resting on fluid matter, would the influence of the moon (as indexed by the tides) affect the periods of the shocks, when the force which causes them is just balanced by the resistance of the solid crust? The fact you mention of the coincidence between the earthquakes of Calabria and Scotland appears most curious. Your paper will possess a high degree of interest to all geologists. I fancied that such uniformity of action, as seems here indicated, was probably confined to large continents, such as the Americas. How interesting a record of volcanic phenomena in Iceland would be, now that you are collecting accounts of every slight trembling in Scotland. I am astonished at their frequency in that quiet country, as any one would have called it. I wish it had been in my power to have contributed in any way to your researches on this most interesting subject.
LETTER 480. TO L. HORNER. Down, August 29th {1844}.
I am greatly obliged for your kind note, and much pleased with its contents. If one-third of what you say be really true, and not the verdict of a partial judge (as from pleasant experience I much suspect), then should I be thoroughly well contented with my small volume which, small as it is, cost me much time. (480/1. "Geological Observations on the Volcanic Islands visited during the Voyage of H.M.S. 'Beagle'": London, 1844. A French translation has been made by Professor Renard of Ghent, and published by Reinwald of Paris in 1902.) The pleasure of observation amply repays itself: not so that of composition; and it requires the hope of some small degree of utility in the end to make up for the drudgery of altering bad English into sometimes a little better and sometimes worse. With respect to craters of elevation (480/2. "Geological Observations," pages 93-6.), I had no sooner printed off the few pages on that subject than I wished the whole erased. I utterly disbelieve in Von Buch and de Beaumont's views; but on the other hand, in the case of the Mauritius and St. Jago, I cannot, perhaps unphilosophically, persuade myself that they are merely the basal fragments of ordinary volcanoes; and therefore I thought I would suggest the notion of a slow circumferential elevation, the central part being left unelevated, owing to the force from below being spent and {relieved?} in eruptions. On this view, I do not consider these so-called craters of elevation as formed by the ejection of ashes, lava, etc., etc., but by a peculiar kind of elevation acting round and modified by a volcanic orifice. I wish I had left it all out; I trust that there are in other parts of the volume more facts and less theory. The more I reflect on volcanoes, the more I appreciate the importance of E. de Beaumont's measurements (480/3. Elie de Beaumont's views are discussed by Sir Charles Lyell both in the "Principles of Geology" (Edition X., 1867, Volume I. pages 633 et seq.) and in the "Elements of Geology" (Edition III., 1878, pages 495, 496). See also Darwin's "Geological Observations," Edition II., 1876, page 107.) (even if one does not believe them implicitly) of the natural inclination of lava-streams, and even more the importance of his view of the dikes, or unfilled fissures, in every volcanic mountain, being the proofs and measures of the stretching and consequent elevation which all such mountains must have undergone. I believe he thus unintentionally explains most of his cases of lava-streams being inclined at a greater angle than that at which they could have flowed.
But excuse this lengthy note, and once more let me thank you for the pleasure and encouragement you have given me — which, together with Lyell's never-failing kindness, will help me on with South America, and, as my books will not sell, I sometimes want such aid. I have been lately reading with care A. d'Orbigny's work on South America (480/4. "Voyage dans l'Amerique Meridionale — execute pendant les annees 1826-33": six volumes, Paris, 1835-43.), and I cannot say how forcibly impressed I am with the infinite superiority of the Lyellian school of Geology over the continental. I always feel as if my books came half out of Lyell's brain, and that I never acknowledge this sufficiently; nor do I know how I can without saying so in so many words — for I have always thought that the great merit of the "Principles" was that it altered the whole tone of one's mind, and therefore that, when seeing a thing never seen by Lyell, one yet saw it partially through his eyes — it would have been in some respects better if I had done this less: but again excuse my long, and perhaps you will think presumptuous, discussion. Enclosed is a note from Emma to Mrs. Horner, to beg you, if you can, to give us the great pleasure of seeing you here. We are necessarily dull here, and can offer no amusements; but the weather is delightful, and if you could see how brightly the sun now shines you would be tempted to come. Pray remember me most kindly to all your family, and beg of them to accept our proposal, and give us the pleasure of seeing them.
LETTER 481. TO C. LYELL. Down, {September, 1844}.
I was glad to get your note, and wanted to hear about your work. I have been looking to see it advertised; it has been a long task. I had, before your return from Scotland, determined to come up and see you; but as I had nothing else to do in town, my courage has gradually eased off, more especially as I have not been very well lately. We get so many invitations here that we are grown quite dissipated, but my stomach has stood it so ill that we are going to have a month's holidays, and go nowhere.
The subject which I was most anxious to talk over with you I have settled, and having written sixty pages of my "S. American Geology," I am in pretty good heart, and am determined to have very little theory and only short descriptions. The two first chapters will, I think, be pretty good, on the great gravel terraces and plains of Patagonia and Chili and Peru.
I am astonished and grieved over D'Orbigny's nonsense of sudden elevations. (481/1. D'Orbigny's views are referred to by Lyell in chapter vii. of the "Principles," Volume I. page 131. "This mud {i.e. the Pampean mud} contains in it recent species of shells, some of them proper to brackish water, and is believed by Mr. Darwin to be an estuary or delta deposit. M.A. D'Orbigny, however, has advanced an hypothesis...that the agitation and displacement of the waters of the ocean, caused by the elevation of the Andes, gave rise to a deluge, of which this Pampean mud, which reaches sometimes the height of 12,000 feet, is the result and monument.") I must give you one of his cases: He finds an old beach 600 feet above sea. He finds STILL ATTACHED to the rocks at 300 feet six species of truly littoral shells. He finds at 20 to 30 feet above sea an immense accumulation of chiefly littoral shells. He argues the whole 600 feet uplifted at one blow, because the attached shells at 300 feet have not been displaced. Therefore when the sea formed a beach at 600 feet the present littoral shells were attached to rocks at 300 feet depth, and these same shells were accumulating by thousands at 600 feet.
Hear this, oh Forbes. Is it not monstrous for a professed conchologist? This is a fair specimen of his reasoning.
One of his arguments against the Pampas being a slow deposit, is that mammifers are very seldom washed by rivers into the sea!
Because at 12,000 feet he finds the same kind of clay with that of the Pampas he never doubts that it is contemporaneous with the Pampas {debacle?} which accompanied the right royal salute of every volcano in the Cordillera. What a pity these Frenchmen do not catch hold of a comet, and return to the good old geological dramas of Burnett and Whiston. I shall keep out of controversy, and just give my own facts. It is enough to disgust one with Geology; though I have been much pleased with the frank, decided, though courteous manner with which D'Orbigny disputes my conclusions, given, unfortunately, without facts, and sometimes rashly, in my journal.
Enough of S. America. I wish you would ask Mr. Horner (for I forgot to do so, and am unwilling to trouble him again) whether he thinks there is too much detail (quite independent of the merits of the book) in my volcanic volume; as to know this would be of some real use to me. You could tell me when we meet after York, when I will come to town. I had intended being at York, but my courage has failed. I should much like to hear your lecture, but still more to read it, as I think reading is always better than hearing.
I am very glad you talk of a visit to us in the autumn if you can spare the time. I shall be truly glad to see Mrs. Lyell and yourself here; but I have scruples in asking any one — you know how dull we are here. Young Hooker (481/2. Sir J.D. Hooker.) talks of coming; I wish he might meet you, — he appears to me a most engaging young man.
I have been delighted with Prescott, of which I have read Volume I. at your recommendation; I have just been a good deal interested with W. Taylor's (of Norwich) "Life and Correspondence."
On your return from York I shall expect a great supply of Geological gossip.
LETTER 482. TO C. LYELL. {October 3rd, 1846.}
I have been much interested with Ramsay, but have no particular suggestions to offer (482/1. "On the Denudation of South Wales and the Adjacent Counties of England." A.C. Ramsay, "Mem. Geol. Survey Great Britain," Volume I., London, 1846.); I agree with all your remarks made the other day. My final impression is that the only argument against him is to tell him to read and re-read the "Principles," and if not then convinced to send him to Pluto. Not but what he has well read the "Principles!" and largely profited thereby. I know not how carefully you have read this paper, but I think you did not mention to me that he does (page 327) (482/2. Ramsay refers the great outlines of the country to the action of the sea in Tertiary times. In speaking of the denudation of the coast, he says: "Taking UNLIMITED time into account, we can conceive that any extent of land might be so destroyed...If to this be added an EXCEEDINGLY SLOW DEPRESSION of the land and sea bottom, the wasting process would be materially assisted by this depression" (loc. cit., page 327).) believe that the main part of his great denudation was effected during a vast (almost gratuitously assumed) slow Tertiary subsidence and subsequent Tertiary oscillating slow elevation. So our high cliff argument is inapplicable. He seems to think his great subsidence only FAVOURABLE for great denudation. I believe from the general nature of the off-shore sea's bottoms that it is almost necessary; do look at two pages — page 25 of my S. American volume — on this subject. (482/3. "Geological Observations on S. America," 1846, page 25. "When viewing the sea-worn cliffs of Patagonia, in some parts between 800 and 900 feet in height, and formed of horizontal Tertiary strata, which must once have extended far seaward...a difficulty often occurred to me, namely, how the strata could possibly have been removed by the action of the sea at a considerable depth beneath its surface." The cliffs of St. Helena are referred to in illustration of the same problem; speaking of these, Darwin adds: "Now, if we had any reason to suppose that St. Helena had, during a long period, gone on slowly subsiding, every difficulty would be removed...I am much inclined to suspect that we shall hereafter find in all such cases that the land with the adjoining bed of the sea has in truth subsided..." (loc. cit., pages 25-6).)
The foundation of his views, viz., of one great sudden upheaval, strikes me as threefold. First, to account for the great dislocations. This strikes me as the odder, as he admits that a little northwards there were many and some violent dislocations at many periods during the accumulation of the Palaeozoic series. If you argue against him, allude to the cool assumption that petty forces are conflicting: look at volcanoes; look at recurrent similar earthquakes at same spots; look at repeatedly injected intrusive masses. In my paper on Volcanic Phenomena in the "Geol. Transactions." (482/4. "On the Connection of certain Volcanic Phenomena, and on the Formation of Mountain-chains and the Effects of Continental Elevations." "Geol. Soc. Proc." Volume II., pages 654-60, 1838; "Trans. Geol. Soc." Volume V., pages 601-32, 1842. {Read March 7th, 1838.}) I have argued (and Lonsdale thought well of the argument, in favour, as he remarked, of your original doctrine) that if Hopkins' views are correct, viz., that mountain chains are subordinate consequences to changes of level in mass, then, as we have evidence of such horizontal movements in mass having been slow, the foundation of mountain chains (differing from volcanoes only in matter being injected instead of ejected) must have been slow.
Secondly, Ramsay has been influenced, I think, by his Alpine insects; but he is wrong in thinking that there is any necessary connection of tropics and large insects — videlicet — Galapagos Arch., under the equator. Small insects swarm in all parts of tropics, though accompanied generally with large ones.
Thirdly, he appears influenced by the absence of newer deposits on the old area, blinded by the supposed necessity of sediment accumulating somewhere near (as no doubt is true) and being PRESERVED — an example, as I think, of the common error which I wrote to you about. The preservation of sedimentary deposits being, as I do not doubt, the exception when they are accumulated during periods of elevation or of stationary level, and therefore the preservation of newer deposits would not be probable, according to your view that Ramsay's great Palaeozoic masses were denuded, whilst slowly rising. Do pray look at end of Chapter II., at what little I have said on this subject in my S. American volume. (482/5. The second chapter of the "Geological Observations" concludes with a Summary on the Recent Elevations of the West Coast of South America, (page 53).)
I do not think you can safely argue that the whole surface was probably denuded at same time to the level of the lateral patches of Magnesian conglomerate.
The latter part of the paper strikes me as good, but obvious.
I shall send him my S. American volume for it is curious on how many similar points we enter, and I modestly hope it may be a half-oz. weight towards his conversion to better views. If he would but reject his great sudden elevations, how sound and good he would be. I doubt whether this letter will be worth the reading.
LETTER 483. TO C. LYELL. Down {September 4th, 1849}.
It was very good of you to write me so long a letter, which has interested me much. I should have answered it sooner, but I have not been very well for the few last days. Your letter has also flattered me much in many points. I am very glad you have been thinking over the relation of subsidence and the accumulation of deposits; it has to me removed many great difficulties; please to observe that I have carefully abstained from saying that sediment is not deposited during periods of elevation, but only that it is not accumulated to sufficient thickness to withstand subsequent beach action; on both coasts of S. America the amount of sediment deposited, worn away, and redeposited, oftentimes must have been enormous, but still there have been no wide formations produced: just read my discussion (page 135 of my S. American book (483/1. See Letter 556, note. The discussion referred to ("Geological Observations on South America," 1846) deals with the causes of the absence of recent conchiferous deposits on the coasts of South America.)) again with this in your mind. I never thought of your difficulty (i.e. in relation to this discussion) of where was the land whence the three miles of S. Wales strata were derived! (483/2. In his classical paper "On the Denudation of South Wales and the Adjacent Counties of England" ("Mem. Geol. Survey," Volume I., page 297, 1846), Ramsay estimates the thickness of certain Palaeozoic formations in South Wales, and calculates the cubic contents of the strata in the area they now occupy together with the amount removed by denudation; and he goes on to say that it is evident that the quantity of matter employed to form these strata was many times greater than the entire amount of solid land they now represent above the waves. "To form, therefore, so great a thickness, a mass of matter of nearly equal cubic contents must have been worn by the waves and the outpourings of rivers from neighbouring lands, of which perhaps no original trace now remains" (page 334.)) Do you not think that it may be explained by a form of elevation which I have always suspected to have been very common (and, indeed, had once intended getting all facts together), viz. thus? —
