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Letter 1384

Darwin, C. R. to Lyell, Charles

[Nov–Dec 1851]

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    Detailed critique of CL's A manual of elementary geology [3d ed. (1851), used in editing 4th ed. (1852)].

Transcription

diag p. 36.pozzolana I actually found bolts of iron embedded with conglomerate at the C. Verds. p. 21 Volcanic Islds p. 40 is it correct that wood in the ground (not peat-bog) lasts longer than in water— this sounds very strange to me.— p. 66. The opening sentence makes me groan, viz your saying denudation is owing to “running water”, for breakers cannot be called running water— you seem to preclude beach or tidal action— I know it is only in expression.— p. 81. ought you not to add earthquakes to causes of formation of alluvium.— It strikes me that a very little more ought to be said about sand-dunes—coral-sand—Laterite Kunkaer. p. 85. “In some cases, the alluvium in which” &c— Surely is not the tendency of all researches to show that in most cases, the alluvium or superficial drift, (even so-called vegetable black mould in S. America) is of marine origin.—

Ought not a short account to be given of the Aralo-Caspian deposits of Murchison? p. 88. Even in shortest account of Glen Roy, notice ought to be taken of the intermediate shelf, of Tom Brahn which so clearly proves that the roads or beaches are not at all necessarily conterminous with the old expanses of water.— p. 113 At Coquimbo there is another case of (1) a bed with all recent shells in same proportion as on beach— (2) of a bed with recent shells, but in different proportion (3) of nearly all extinct species. p. 208. I think the S. American Tertiaries deserve a paragraph, if merely from area; where else can you travel uninterruptedly for at least 42o Lat: or 1620 over Tertiaries, without a sign of disturbance, fault or flexure: for 600 miles the formation contains only extinct shells— How grand is the superimposed contemporaneous basaltic lava, which has extended in a sheet 100 miles from source, & at end is 130 ft thick. In Chile it appears to me very interesting to find old, apparently Eocene, tertiaries, not indicating a hotter climate than that of Latitude in which they occur.— p. 217. The coral-mud is actually seen to be transported out of the opening, discoloring the sea, from the Maldivas atolls.— p. 228 “Cypris, an animal allied to the Crustacea”— you might as well say a seal or whale was allied to the mammalia. p. 282. Those who do not know you to be an Entomologist, would think fromap-position of words, that you fancied that “Carabus” was a “wood-eater”.— p. 273. I wish you had grappled with d'orbigny & others who speak of every species as distinct in the stages of the Chalk & Oolites p. 301 The Permian Chapter strikes me as rather short: one wants to hear a bit more about Russia p. 362. I will always protest against your distinction of Recent & Post-pliocence.— I declare, I think it wd be a good thing if your most useful Table had been printed at the beginning as well as at the end of the Chapters describing special Formations. p. 376. In the list, Palagonite of Bunsen ought to be introducedramme

If you intend your Manual to serve as an Introduction to a student going to a Volcanic district & as a guide to him what to observe, the Chapters strike me as very scanty & incomplete: (by incomplete I do not mean to say a word against all that is, which strikes me as excellent, only I think more is wanted.) surely particulars about “fluidity of lavas” inclination of streams—preexisting crystals—details on nature of amygdaloids—inclined strata within craters—obsidian—dolerite—Bombs—vaulted streams—ejected granitic fragments—tuff which has flowed as mud—blown up masses—subsided masses—state of surface of lava—effects of hot lava on underlying matter. &c &c.

In Cleavage discussion, it appears to me to be the gravest omission to leave out all allusion to Dan. Sharpes facts about change in shape in shells, with Mr Hopkins discussion on subject, which latter I presume you do not disbelieve in— I cannot doubt that Sharpes facts are most important with respect to origin of cleavage— Do you bring out prominently enough, the vast areas with uniform strike, but varying dip of cleavage; its parallelism to ranges of mountains & areas of elevation?.— I presume you do not believe in the Fan-like structure as held by Sharpe, & as stated to be case with foliated rocks by Studer.

With respect to foliated rocks, I wish you had read my few pages on subject which I see you have not; I do not at all suppose that all gneiss has actually flowed: the analogy from the obsidian layers is not by any means my chief argument.— In fact you seem at end of discussion willing to grant almost all I want, when you state that cleavage planes might be converted into the layers of various mineralscom-posing the metamorphic schists; for then these wd not be due to deposition.— p. 468. I am astonished at your comparing the undulations in these schists to ripple-marks: is not d'Aubuissons explanation of expansion by heat far more probable?— Does it not appear odd to you that the outline & diverse composition of pebbles not being preserved, when, on your view, millions of layers of sediment have been perfectly preserved?

You know that even Sedgwick admits a grain in Plutonic rocks; & such I most certainly have seen, where it was very difficult to make any clear distinction from gneiss.— But enough, & too much you will say.— I will only add that the fact, which I clearly saw in T. del Fuego, that in simple clay-slate there were slight mineralogical differences in the cleavage laminæ, seem to me important. p. 472.— The passage quoted from me had better be struck out: I told you so before, but I presume you forgot.— I am fearful I may have blundered.—

In your capital Mineral vein Chapter, might you not give some facts of the wide diffusion of the metals; some chemists have, I think, detected Copper in sea-water.— As illustrating the adhesion of metal to plutonic & hot volcanic districts; would it not be worth contrasting the entire ignorance of all metals in the inhabitants of the Pacific islands, with the aborigins of S. America.—

P.S. I earnestly beg you to read just 5 pages in my vol. on S. America, p. 162 et Seq. on Foliation, for I am interested on the subject.—

    Footnotes Add

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    f1 1384.f1
    The period during which Lyell was preparing the fourth edition of his Manual of elementary geology (C. Lyell 1852), which was published in February 1852 but was probably completed around 10 December 1851 (see C. Lyell 1852, preface). CD recorded having read the third edition (C. Lyell 1851a) on 5 April 1851 (see Correspondence vol. 4, Appendix IV, 119: 22a). CD's comments seem to have arrived too close to publication to have been fully incorporated into the fourth edition (see nn. 9, 10, and 12, below).
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    f2 1384.f2
    In this letter CD supplies comments on the third edition of Lyell's Manual of elementary geology (C. Lyell 1851a). The page references are to the third edition. CD's copy is in the Darwin Library–CUL. Lyell wrote comments on the letter, referred to in footnotes that follow.
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    f3 1384.f3
    On the letter Lyell inserted ‘x’ before ‘p. 36’, but no change was made in the fourth edition. The question concerned the hardness of strata consolidated under water, and CD's comments in Volcanic islands, pp. 21–2, confirmed Lyell's point. Pozzolana is an artificial stone, hardened in sea water, and formerly used by the Romans for building works. In his copy of C. Lyell 1851a, p. 36, CD underlined ‘may’ and ‘the artificial mixture’.
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    f4 1384.f4
    On the letter Lyell inserted ‘?’ before ‘p. 40’, but again made no change in the fourth edition.
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    f5 1384.f5
    In his copy of the third edition (C. Lyell 1851a), CD wrote opposite this passage (p. 66): ‘Think of the 32,000 ft of strata,—so much denuded’. On the letter, ‘x’ was inserted before ‘p. 66’, and a vertical line was drawn through the comment. Lyell changed the text of the fourth edition (C. Lyell 1852, p. 66) to read ‘by water in motion, whether of rivers or of the waves and currents of the sea’.
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    f6 1384.f6
    In his copy of the third edition (C. Lyell 1851a, p. 81), CD wrote ‘earth quakes’.
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    f7 1384.f7
    In his copy of the third edition (C. Lyell 1851a, p. 81), CD wrote ‘shell—sand sand-dunes’. On the letter Lyell bracketed CD's comments on p. 81, wrote ‘4th Ed’ before the page number, and drew a vertical line through the comment. However, CD's suggestions were not adopted.
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    f8 1384.f8
    In the fourth edition (C. Lyell 1852, p. 85), ‘some’ is changed to ‘many’.
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    f9 1384.f9
    On the letter Lyell bracketed this comment, inserting ‘4th Ed. or 5th’ before ‘Ought’. A vertical line was drawn through this and the following comment. A paragraph on the Aralo-Caspian deposits was added to the fifth edition (C. Lyell 1855, p. 176). The Aralo-Caspian deposits are described in Murchison, Verneuil, and Keyserling 1845, 1: 297–324.
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    f10 1384.f10
    On the letter Lyell inserted ‘5th Ed’ and a bracket in the left margin. No change was made in the fourth edition. However, a reference to Tombhran and CD's explanation of the non-extension of certain shelves appears in C. Lyell 1855, pp. 88–9. For CD's discussion of the intermediate shelf on Tombhran, see ‘Observations on the parallel roads of Glen Roy’ (Collected papers 1: 112–13).
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    f11 1384.f11
    Although Lyell marked this comment in the same manner as the preceding one, no mention of the Coquimbo shells was made in either the fourth or the fifth edition. For CD's description of the Coquimbo shells, see South America, pp. 36–7, 128–30.
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    f12 1384.f12
    Lyell made no use of this information, though on the letter he again bracketed the comment and marked it ‘5th Ed’. CD had discussed the climate in Chile during the Tertiary period in South America, pp. 134–5, and supported Lyell's view that the tropical climate during the Tertiary period in Europe was a local, not global, phenomenon.
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    f13 1384.f13
    No use was made of this comment in either the fourth edition or the fifth, although on the letter it was marked ‘5th’ by Lyell.
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    f14 1384.f14
    In the fourth edition Lyell changed the wording to ‘an animal belonging to the Crustacea’ (C. Lyell 1852, p. 228), and in the fifth, to ‘a genus of Crustaceans’ (C. Lyell 1855, p. 262).
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    f15 1384.f15
    Lyell had written ‘insects from the lias … comprise both wood-eating and herb-devouring beetles of the Linnean genera Carabus, Elater, &c.’ (C. Lyell 1851a, p. 282). In both the fourth and fifth editions (C. Lyell 1852, 1855) he altered the wording to read: ‘Elater, Carabus, &c.’
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    f16 1384.f16
    Although this comment was marked ‘5th Ed.’ by Lyell on the letter, no reference to the views of Alcide Charles Victor Dessalines d'Orbigny or of any other naturalist was incorporated in this section of the fourth edition.
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    f17 1384.f17
    In the fifth edition (C. Lyell 1855, p. 358), Lyell added references to Murchison, Verneuil, and Keyserling 1845 and Murchison 1854 but did not add to his description of the Permian rocks in Russia.
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    f18 1384.f18
    The distinction was made in a ‘Tabular view of fossiliferous strata’ in the third edition (C. Lyell 1851a, p. 361). It was preserved in both the fourth and fifth editions.
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    f19 1384.f19
    In the fifth edition (C. Lyell 1855), Lyell placed the table before the chapters describing the particular formations rather than following them.
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    f20 1384.f20
    A list of volcanic rocks with their compositions appears in C. Lyell 1851a, pp. 375–7. Palagonite was included in the list in the fifth edition (C. Lyell 1855, p. 478), and a description of palagonite-tuff was added (p. 474). See Correspondence vol. 4, letter to Ernst Dieffenbach, 9 February 1847, in which CD first learned of palagonite. CD refers to Robert Wilhelm Eberhard Bunsen.
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    f21 1384.f21
    Lyell did not adopt CD's suggestion that he enlarge the discussions of volcanic rocks to improve it as a guide to students. In the fifth edition (C. Lyell 1855), however, he added much new material as a result of observations he made during a visit to Madeira in the winter of 1854 (Ch. XXIX).
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    f22 1384.f22
    Daniel Sharpe's conclusions about the distorted shells (Sharpe 1847) were added to the fourth edition (C. Lyell 1852, p. 471). No mention, however, was made of William Hopkins on the subject of cleavage (Hopkins 1849). In the fifth edition (C. Lyell 1855, p. 615), Lyell referred to Sharpe 1852 and 1855.
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    f23 1384.f23
    CD's observations of uniform strike over vast regions of South America were referred to in the fourth edition (C. Lyell 1852, pp. 471–2) and again, at greater length, in the fifth edition (C. Lyell 1855, p. 613).
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    f24 1384.f24
    Lyell added to the fifth edition Sharpe's view (Sharpe 1852, 1855) that cleavage and foliation planes in certain regions ‘are parts of great curves or anticlinal axes’ (C. Lyell 1855, p. 615). Sharpe 1852, p. 448, made the point that the fan-like structure resulted from combining portions of two arches. No reference to Studer 1851–3 was made, but CD's observations on the same point in South America, p. 155, were added.
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    f25 1384.f25
    It was CD's contention that cleavage in slaty rocks and foliation in metamorphic schists were caused by mechanical processes and were unrelated to the original sedimentary depositions. For CD and Lyell's earlier differences on this question, see Correspondence vol. 4, letter to Charles Lyell, [on or before 20 January 1847], n. 2. See also n. 30, below.
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    f26 1384.f26
    Lyell made no change in his use of the term ‘ripple-mark’ to describe the undulations in schists. Annotated copies of Aubuisson de Voisins 1814 and 1819 are in the Darwin Library–CUL, but the exact reference has not been located.
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    f27 1384.f27
    CD's reference is to Adam Sedgwick. The description of these mineralogical differences in the clay-slate of Tierra del Fuego is in South America, pp. 155, 163.
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    f28 1384.f28
    The passage concerned CD's observations on the structural changes that take place in the mud-slag from the gold mines of Yaquil, Chile. Lyell's paraphrase (C. Lyell 1851a, p. 472) was taken from the first edition of Journal of researches, pp. 324–5 (not, as Lyell has it, p. 234). In Journal of researches 2d ed., p. 266, CD had deleted the sentence describing fragments in the heap as having a ‘well-defined slaty structure; but the laminæ were not inclined at any uniform angle’. Lyell deleted the passage as requested in the fourth edition (C. Lyell 1852, p. 472).
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    f29 1384.f29
    Lyell made no use of these observations.
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    f30 1384.f30
    Lyell, with most other geologists, believed that ‘the constituent parts of each layer were separately deposited as sediment, and then metamorphosed’ (South America, p. 165). CD's conclusion was that ‘planes of cleavage and foliation are intimately connected with the planes of different tension, to which the area was long subjected, after the main fissures or axes of upheavement had been formed, but before the final consolidation of the mass and the total cessation of all molecular movement’ (South America, p. 168).
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