To Edward Frankland 12 July 1873
Down, | Beckenham, Kent.
July 12. 1873
My dear Sir
I am going to beg a great favour of you, if you can by means of any trustworthy assistant aid me. If you cannot, perhaps you can inform me whether there is any professional chemist on whom I cd rely to test a small quantity of fluid, not quantitively, but qualitively. The glands of Drosera secrete a very viscid slightly acid fluid, which dissolves animal matter out of the bodies of insects. I have lately proved this power by giving the leaves little measured cubes of the hardened white of eggs & of gelatine; keeping similar cubes damp on moss, as a standard of comparison.1
Now what I want to know is, what agent, apparently an acid, can dissolve in abt 2 days hardened albumen & gelatine at an ordinary temperature. I suppose that it is not probable that the fluid contains muriatic acid like our gastric juice.2 Several years ago when I was at work at this plant, I consulted Hoffman, who offered to test the fluid, & gave me some pure carbonate of ammonia, to dissolve in distilled water, & then to wash a large number of glands in it.3 Do you think this a good plan? And if so, whether or not you can aid me by getting the fluid tested, will you give me a few grains of pure C. of Ammonia? I know how valuable your time is, & I shd not have thought of troubling you, had I not felt convinced that Drosera is a very remarkable plant under a physiological point of view—
I say this with some confidence as Huxley & Burdon Sanderson have thought it worth while to come here to verify some of my statements.4
My Dear Sir | yours sincerely | Ch. Darwin
Footnotes
Bibliography
Correspondence: The correspondence of Charles Darwin. Edited by Frederick Burkhardt et al. 29 vols to date. Cambridge: Cambridge University Press. 1985–.
Insectivorous plants. By Charles Darwin. London: John Murray. 1875.
Summary
Seeks the assistance of a professional chemist in securing a qualitative analysis of the fluid secreted by the glands of Drosera which have the power of dissolving animal matter out of the bodies of insects. [See 8979.]
Letter details
- Letter no.
- DCP-LETT-8977A
- From
- Charles Robert Darwin
- To
- Edward Frankland
- Sent from
- Down
- Source of text
- The John Rylands Library, The University of Manchester
- Physical description
- LS(A) 4pp
Please cite as
Darwin Correspondence Project, “Letter no. 8977A,” accessed on 26 September 2022, https://www.darwinproject.ac.uk/letter/?docId=letters/DCP-LETT-8977A.xml
Also published in The Correspondence of Charles Darwin, vol. 21