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Darwin Correspondence Project

To Daniel Oliver   3 November [1860]1

15 Marine Parade | Eastbourne

Nov. 3d

My dear Mr Oliver

My daughter has escaped the imminent danger she was in for a week & our minds are now tolerably at ease; & we hope to get home in a week or 10 days, if she progresses favourably.—2

I shall be anxious to hear the result of the election for the Professorship.—3

I presume your time will have been fully occupied in this important matter, & you will not have had time for any experiments on Dionæa with the C. of Ammonia; nor had time to look at the moving red matter in the Hairs of Drosera.—4 I am so greatly obliged to you for taking so much trouble to copy the extract from Bot. Zeitung.5 I presume there is a paper in extenso.—   Is this so? The author has missed the point which seems to me most interesting, viz that though the Hairs close equally (or nearly so) over animal, vegetable & inorganic dry substances; they remain closed much longer over animal than over other substances. This fact led me to try the nitrogenous & non-nitrogenous fluids; for somehow the plant knows well when it has caught good food.—   You were right in anticipating (as I believe you did) that C. of Ammonia acts on the fluid in cells of other plants, as in case of Drosera; I find it so with Lemna & almost as quickly with the roots of a little Euphorbia, as with the hairs of Drosera.6 I have asked Daubeny whether the action of C. of Amm. on the sap of plants was known; & he says he does not remember having heard of it.7

Yours very sincerely | C. Darwin

P.S.8 There is something which looks odd to me in the roots of the Duck-weed;9 a new root seems formed within the old one; at least an old outer cylinder is cast off in pieces; but it is out of my line.



The year is given by the reference to Henrietta Emma Darwin’s illness.
CD and his family returned to Down on 10 November 1860 (‘Journal’; Appendix II).
Oliver was a candidate for the chair of botany at University College London. See letters to William Sharpey, 28 October [1860], and to Daniel Oliver, 7 November [1860].
See letter from Daniel Oliver, [before 23 October 1860]. The extract that Oliver copied from Milde 1852 has been found, but not Oliver’s accompanying letter. See also letter to Daniel Oliver, 23 [October 1860].
CD described the effect of a weak solution of carbonate of ammonia on the root cells of various plants in Insectivorous plants, pp. 63–5. He stated that he ‘dug up in the latter part of October the first weed which I met with, viz. Euphorbia peplus’ (ibid., p. 63).
The correspondence on this subject between CD and Charles Giles Bridle Daubeny has not been found. Daubeny, professor of botany at Oxford University, was renowned for his studies on the chemistry of plants.
The postscript is on a separate slip of paper, which from the content appears to belong with this letter.
CD refers to the roots of Lemna, the common duckweed, which he was studying in relation to the effect of carbonate of ammonia on plants. He had been led to experiment on the roots of plants from the analogy between their nutritive processes and those of the leaves of insectivorous plants. There are notes on such experiments, carried out by CD in December 1860 and January 1861, in DAR 54: 8–9.


Insectivorous plants. By Charles Darwin. London: John Murray. 1875.

Milde, Karl August Julius. 1852. Ueber die Reizbarkeit der Blätter von Drosera rotundifolia. Botanische Zeitung 10: 540. [Vols. 8,10]


DO’s candidacy for Professorship of Botany [at University College, London].

Henrietta’s health is better.

Paper in Botanische Zeitung [T. Nitschke, "Über die Reizbarkeit der Blätter von Drosera rotundifolia", 18: 229–34, 237–45, 245–50] missed leading point that plants close longer over animal substances. Carbonate of ammonia works on Lemna and Euphorbia roots.

Letter details

Letter no.
Charles Robert Darwin
Daniel Oliver
Sent from
Source of text
DAR 261.10: 24 (EH 88206008)
Physical description
ALS 5pp

Please cite as

Darwin Correspondence Project, “Letter no. 2975,” accessed on 20 March 2023,

Also published in The Correspondence of Charles Darwin, vol. 8