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Darwin Correspondence Project

To J. S. Burdon Sanderson   27 August 1873

Down, | Beckenham, Kent.

Aug 27. 1873

My dear Dr Sanderson

I have returned home & have been very unwell, otherwise I shd have written sooner to tell you that there are, or very soon will be, some good leaves on Dionæa, in case you are still inclined to investigate electric currents in them.1

It seems to me a point well worth investigating, but you can judge far better than I can. If you determine to make the trial, I think that I can send the plants to you safely carried by hand.

I presume that the apparatus is cumbrous & that it wd waste more of your time to come here, otherwise I should be delighted to see you at Down.2

I shall not try many more experiments on Drosera or Dionæa, for I have not knowledge enough; but I must tell you that minute drops of Sol. of Carb. of Soda entirely stops the action of the viscid & acid secretion of Drosera on cubes of Albumen; but afterwards, by putting a little weak Hydrochloric acid on the same leaves, the albumen is dissolved, so that the action seems like one of true digestion.3

Believe me | yours very sincerely | Ch. Darwin


See letter to J. S. Burdon Sanderson, 15 August 1873. The reference is to Dionaea muscipula (Venus fly trap).
CD described the experiment with carbonate of soda (sodium carbonate) followed by hydrochloric acid in Insectivorous plants, p. 95.


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


CD can provide leaves of Dionaea if JSBS wishes to investigate electric currents in them.

His experiments show that the digestive action of Drosera seems like that of true digestion.

Letter details

Letter no.
Charles Robert Darwin
John Scott Burdon Sanderson, baronet
Sent from
Source of text
National Library of Scotland (MS.6103 ff.101)
Physical description

Please cite as

Darwin Correspondence Project, “Letter no. 9029,” accessed on 22 October 2021,

Also published in The Correspondence of Charles Darwin, vol. 21