On the results of Robert Bunsen's journey to Iceland, which he compares in detail with his own research.
"I have for the present given up Geology, & am hard at work at pure Zoology & am dissecting various genera of cirripedes, & am extremely interested in the subject." "I always, however, keep on reading & observing on my favourite work on Variation or on Species, & shall in a year's time or so, commence & get my notes in order."
Down Farnborough Kent
My dear Sir
I have taken a long time to thank you for your long & most interesting letter
of the 5
I have never before heard of Pelagonite which you refer to as a hydrated tuff; I cannot but suspect it is the same, as the rock which I have described in some detail in my Volcanic Island volume (p 99, 100) at the Galapagos, which I thought new: I was induced to think that it was produced by the action of water on particles of Scoriæ. If Prof. Bunsen compares his Geolog. observations with those of others, I wish you would point out this page to him. In several parts of the Cordillera (<s>ee index to my S. American volume ) I found very thin & uneven layers of black pitchstone, often almost composed of angular concretionary masses, & which appeared to me to have certainly been in origin of a sedimentary nature; this has always appeared to me strange, seeing how clearly igneous, pitchstone generally is. What a grand mass of observations Bunsen seems to have made; I am glad he is entering on Amygdaloids; I believe I saw cases in the Uspallata range, where lavas flowing over tuffs had produced amygdaloids, which at the time suprised me much, as I had been accustomed to connect amygdaloids exclusively with true molten rock.
I am much obliged by your informing me that Von Dechen had not received his copy; I
have made enquiries, & am assured that it went through a safe channel, viz
Williams & Norgate & I hope it will yet arrive: I trust that you have
received your copy. You will have heard that a translation of Tschudi's travels
has appeared; I have sent for it & expect to enjoy it much.— I presume you see the Geolog. Journ of our Society, allow me to
call your attention to what appears to me an important step in the right direction on
the curious subject of cleavage; it is by M
with my best wishes, believe me, my dear Sir | Yours very sincerely | C. Darwin
- f1 1059.f1The cover of the letter is addressed: ‘D
r E. Dieffenbach | Giesen | Hesse Darmstadt’.
- f2 1059.f2Robert Wilhelm Eberhard Bunsen described volcanic phenomena in Iceland in Bunsen 1847a, 1847b, and 1847c. See also letter to A. W. H. Kolbe, 5 May .
- f3 1059.f3C. Lyell 1847.
- f4 1059.f4See Correspondence vol.5, letter to Charles Lyell, [November–December 1851], in which CD tells Lyell to include ‘Palagonite of Bunsen’ in his list of volcanic rocks in C. Lyell 1851.
- f5 1059.f5Volcanic islands.
- f6 1059.f6South America.
- f7 1059.f7South America, p. 200.
- f8 1059.f8Tschudi 1847. No copy of this work is in the Darwin Library, but CD listed it among his books read on 8 March 1847 (DAR 119; Correspondence vol. 4, Appendix IV).
- f9 1059.f9Sharpe 1847. See also letters to Daniel Sharpe, [19 January 1847] and [23 January 1847].
- f10 1059.f10CD did not begin this work until 9 September 1854, when the final volume of the monograph on the Cirripedia had been published (de Beer ed. 1959a, p. 13). At the time he wrote this letter, CD was planning only to prepare a paper on the anatomy of cirripedes in connection with describing his new barnacle, Arthrobalanus.
- f11 1059.f11The whereabouts of the original manuscript letter is unknown. The above transcription was made from a photographic copy in the possession of the editors.