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Darwin Correspondence Project

To J. S. Henslow   [24 January 1840]

Friday Morning

My dear Henslow

I have just received your letter. as the waggon goes tomorrow, I pack up the specimens at once.— I believe you may keep them all.— They all come from the Maldeeve & Chagos lagoon-islands or atolls in the Indian Ocean,—islands precisely like Keeling Island.—

I hope they may be of any use to you.—

I send a couple copy of abstract of my worm Paper useless to me.—

Of course you have thought of Drummonds light.—1 Also of the use put to burn coral, shells, & limestone in the East Indian Archipelago to give a relish to the chewing of Betel.— In S. America, I believe potash is used, in analogous manner in chewing the Cocos leaves—2

I am in a hurry so goods Bye | C. Darwin

Do you recollect our discussion about varieties of same plants not having three primary—3 Surely I have seen pale yellow hyacinth, & certainly blue & pink ones.— pray tell me is it not so.—


‘Drummond light. The lime-light, or oxy-hydrogen light (invented by Capt. T. Drummond, R.E., c 1825), wherein a blow-pipe flame … impinges on a piece of pure lime, and renders it incandescent.’ (OED).
Coca leaves, chewed by South American Indians, contain various alkaloids, including cocaine. In Peru the Indians add unslaked lime or a preparation made from the ashes of the quinoa plant (EB, article on ‘Coca’).
Primary colours. CD was questioning a generalisation Henslow had made in Henslow 1837b, p. 201. Other conversations with Henslow on empirical laws of variation are recorded in CD’s transmutation notes, e.g., Notebook C: 192.


Notebook C. See de Beer 1960; de Beer and Rowlands 1961; de Beer, Rowlands, and Skramovsky 1967; Notebooks.

OED: The Oxford English dictionary. Being a corrected re-issue with an introduction, supplement and bibliography of a new English dictionary. Edited by James A. H. Murray, et al. 12 vols. and supplement. Oxford: Clarendon Press. 1970. A supplement to the Oxford English dictionary. 4 vols. Edited by R. W. Burchfield. Oxford: Clarendon Press. 1972–86. The Oxford English dictionary. 2d edition. 20 vols. Prepared by J. A. Simpson and E. S. C. Weiner. Oxford: Clarendon Press. 1989. Oxford English dictionary additional series. 3 vols. Edited by John Simpson et al. Oxford: Clarendon Press. 1993–7.


Sends specimens from Indian Ocean atolls.

Letter details

Letter no.
Charles Robert Darwin
John Stevens Henslow
Sent from
London, Upper Gower St, 12
Source of text
DAR 93: A3–4
Physical description

Please cite as

Darwin Correspondence Project, “Letter no. 552,” accessed on 16 September 2021,

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