Darwin Correspondence Project

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[in reply to various contributions and criticisms by Forbes, and with Darwin's request for information on a point he wanted to check for the new edition of Origin of Species, which was completed a few weeks later:^f2 `Your letter pleased me exceedingly.<sup>f3</sup> When I saw how much error you detected in d'Orbigny, I said to myself ``good heavens my turn will come next'' ';<sup>f4</sup> encouraging Forbes to submit his observations on Chile to the Geological Society and offering advice on publication;<sup>f5</sup> replying to various matters raised by Forbes including `I am sorry for my blunder about [Andesite]‘,^f6 asking Forbes if he had done any work on plutonic rocks, commenting on some observation of the Norwegian geologist B. M. Keilhau: `… it seems to me very mysterious & indicating some great unknown class of facts’;<sup>f7</sup> asking for help in sorting out a point in the first edition of Origin of Species: `I know how busy you are & must be: but it would be a great favour, if you would write literally one line to me to say whether the(?) great mound of detritus in Val del Jesu(?) has any connection with ice-action; because I am preparing new [sic] edition of Origin of Species, & if you say “no” I will strike out 3 lines: if you say “yes” I will leave them as they now stand’ [...],^f8 and commenting that features he saw near the hot springs of Cauquenes in the Cordillera (in 1834), he was now inclined to attribute to glacial (rather than fluvial), action;^f9 asking Forbes if he would undertake some observations on mules.]

[...] it trouble you to make a few observations on mules, as by enclosed paper, & some time write me the results?^f10 With every good wish for your success & prosperity, & with cordial thanks for your letter and kind expressions. Believe me | My dear Sir | yours very sincerely | C. Darwin

Footnotes

f1

The date is given in the sale catalogue; the year is confirmed by the relationship between this letter and the publication of the third edition of Origin (see n. 2, below).

f2

In his Journal, CD noted that he worked in December 1860 and January 1861 on the third edition of Origin, which was published in April 1861 (see Correspondence vol. 9, Appendix II). The new edition included information from Forbes about glacial action on the rocks of the Andes (see Correspondence vol. 8, letter from David Forbes, [November? 1860] (now dated [after 11 December 1860]; see n. 3, below), and Origin 3d ed., pp. 403–4).

f3

Forbes’s letter has not been found. The letter from David Forbes, [November? 1860] (Correspondence vol. 8), which should now be dated [after 11 December 1860], is a reply to this letter.

f4

CD refers to D. Forbes 1860, in which Forbes challenged many of Alcide Charles Victor Dessalines d’Orbigny’s findings on the geology of South America (Orbigny 1835–47; see Correspondence vol. 8, letter to Charles Lyell, 4 December [1860]). For a summary of the differences between Forbes and Orbigny, see Proceedings of the Geological Society of London 33 (1877): 44–6.

f5

D. Forbes 1860 was read to the Geological Society of London on 21 November 1860. It concerned the geology of Bolivia and southern Peru, and was intended as the first part of a memoir that would include two further parts on the geology of Chile and the Argentine (D. Forbes 1860, p. 62). However, Forbes read no further paper on the geology of South America to the Geological Society.

f6

CD refers to andesite, the plutonic rock that CD named having first found it in the vicinity of the Beagle Channel (South America, pp. 154–5 et seq.). Forbes had revised CD’s nomenclature, preferring diorite on account of its similarity to European diorites (D. Forbes 1860, p. 29).

f7

CD had earlier been impressed by Baltazar Mathias Keilhau’s theory of the origin of rocks by heat-induced crystallisation (see Keilhau 1838–40 and 1844, and Correspondence vol. 3, letter to Adolf von Morlot, 10 October [1844] and n. 7).

f8

CD described the geological features of the Yeso valley, in Chile, in South America, p. 178. This may have been the source for the passage about the `vast mound of detritus’ in an Andean valley in Origin, p. 373. After receiving Forbes’s reply (Correspondence vol. 8, letter from David Forbes [November? 1860], now redated [after 11 December 1860]), CD restated his conviction that the mound was due to glacial action (Origin 3d ed., pp. 403–4).

f9

See South America, pp. 64–7. While a small number of boulders near Cauquenes in Chile had previously been described by Adolphe Théodore Brongniart as erratics deposited by glaciers, CD argued that river action and uplift could have displaced them from their original strata (South America, p. 66 and n.).

f10

The enclosure listing questions for Forbes has not been found. By mules, CD probably means hybrids between goats and sheep. For Forbes’s reply, see Correspondence vol. 8, letter from David Forbes, [November? 1860], now redated [after 11 December 1860]. CD cited Forbes on the sheep of Chile in Variation 1: 95, and considered the question of the possible relatedness of sheep to goats in Variation 1: 94, 98–9, and 102.

f11

The original letter is complete and is described in the sale catalogue as being five pages long.