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Darwin Correspondence Project

To J. S. Henslow   [26 March 1838]

My dear Henslow

I am ashamed to trouble you with an answer, simply to say I cannot come, but as the invitation to the Ray dinner1 is formal, I thought I ought to answer.—

I am much obliged to Mr Peacock for his “insinuation”2 & I should like to be with you very much, but I am tied firmly by the leg by the hundred & one details, I find I incur with my Editorship of the Zoolog. Beagle’s Voyage.—

I am moreover Goth enough to prefer paying you a quiet visit to meeting all the world at a great Dinner.—

Many thanks for your last letter, which delights me touching the Journal.— You & others are magnificent in presenting my work to the Cambridge. Phil. Soc.—

Will you tell Miller how much obliged I am to him for determining the minerals for me.3 But will you say, that the point I am most anxious about with regard to specimen (378 yellow) is whether in those cells where [diagram here] there are two kinds of minerals,—one opake, & one crystallized,—whether both are Chabasie4 as the point appears to me a cu〈rious〉 one with respect to the formation of the crystallized mineral, which I suppose is the Chabasie.—

Most truly ys. | Chas. Darwin

36 Grt Marlbro’ St—Monday.—

I am going out to dine with Lyell so am in a hurry.


The Ray Club was founded by Charles Cardale Babington and other Cambridge naturalists in March 1837, after Henslow had discontinued his Friday night soirées. Its stated purpose was ‘the cultivation of Natural Science by means of friendly intercourse and mutual instruction’ (see C. C. Babington 1857 and Jenyns 1862, pp. 66–7).
A play on ‘invitation’. See letter to Susan Darwin, [26 April 1838], n. 7.
CD had asked William Hallowes Miller to identify several geological specimens (see letter to J. S. Henslow, [4 November 1837]). The fragment from J. S. Henslow, [5 November 1837 – March 1838], is probably from the letter to which CD here refers.
According to CD’s code, this specimen is number 3378 from Tahiti. The catalogue listing specimens 2864–3742 has the following entry: ‘3378. Amygdaloid. half the cells, horizontally filled with Lime, half with Silex.’ In Volcanic islands, p. 27, where the specimen is described, the opaque substance in the lower half of the amygdaloid is identified as ‘a white, soft, earthy mesotypic mineral, which intumesced under the blow-pipe in a remarkable manner.’ The crystals are ‘apparently of chabasie’. This later description probably came from Miller, but apparently not until 1842 when CD again reminded him of the specimen and of his question about it (see letter to W. H. Miller, [16 October – 27 November 1842]).


Babington, Charles Cardale. 1857. The Cambridge Ray Club. Cambridge.

Jenyns, Leonard. 1862. Memoir of the Rev. John Stevens Henslow, late rector of Hitcham, and professor of botany in the University of Cambridge. London: John Van Voorst.


Declines Ray Club dinner; too busy with Zoology.

Thanks JSH for presenting his work to Cambridge Philosophical Society.

Asks him to get an answer from W. H. Miller on specimen of crystallised mineral.

Letter details

Letter no.
Charles Robert Darwin
John Stevens Henslow
Sent from
London, Gt Marlborough St, 36
Source of text
DAR 93: A1–2
Physical description

Please cite as

Darwin Correspondence Project, “Letter no. 406,” accessed on 13 May 2021,

Also published in The Correspondence of Charles Darwin, vol. 2