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Darwin Correspondence Project

To T. L. Brunton   3 December 1873

Down, | Beckenham, Kent.

Dec 3 1873

My dear Sir

I am very much obliged for your kind note & offers of assistance.1 With respect to Chondrin, Dr B. Sanderson has rather mistaken my question; it was whether Chondrin is known to be more nutritious to animals than is Gelatin. Drosera digests the one as well as the other, but Chrondrin seems to excite the plant more than does Gelatin, tho’ neither do so to at all an equal degree as does Albumen—2

Dr Sanderson suggested to me that my Chondrin may not have been quite pure, whereas the gelatin was pure, having been prepared for me by Hoffman. The Chrondrin was prepared for me by Dr C. Moore of Brixton Road; but whether it was absolutely pure, I cannot of course say.3

If any thing is known of the relative powers of nourishment of Chondrin & Gelatin, I shd be grateful for the information.

It occurred to me as just possible, after seeing their different action on Drosera, that the many disputes about the value for nourishment to man of Gelatin might be due to different forms having been used.

I much wish to know whether Chlorophyl is digested by animals, as it was so very imperfectly or hardly at all by Drosera. Unfortunately Dr Sanderson has mislaid the bottle: if it is not found within a month or two, I wd ask Dr Moore to prepare a little more in the same manner as he did before, & then I wd beg your or Dr S. to test its digestibility. Or perhaps I cd. get some one else to prepare some.4

Your remarks on 2 shades of expression being combined on opposite sides of the same painted face is quite new & surprized me much. I will keep the subject in mind, but I hardly expect to see any such case on a living countenance.5

With very sincere thanks | yours very faithfully | Ch. Darwin


See letter from T. L. Brunton, 2 December 1873 and n. 1. Albumen is the clear part of an egg (egg white), and contains albumins and other proteins. John Scott Burdon Sanderson was assisting CD with his experiments on insectivorous plants.
Both gelatine and chondrin are hydrolysed forms of collagen (found in cartilage, bone, skin, etc.). CD refers to August Wilhelm von Hofmann and Samuel William Moore (C. Moore was evidently written in error). In 1862, Hofmann had supplied CD with gelatine uncontaminated by chlorine (see Correspondence vol. 10, letter from A. W. von Hofmann, 27 June 1862).
CD described his experiments with chlorophyll and Moore’s preparation of it in Insectivorous plants, pp. 125–6.


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.


Is interested in comparative nutritive values of chondrin and gelatin. The former seems to excite Drosera more, though albumen does so to a higher degree than either. Also asks if chlorophyll is digested by animals; Drosera digests it hardly at all.

Letter details

Letter no.
Charles Robert Darwin
Thomas Lauder Brunton, 1st baronet
Sent from
Source of text
American Philosophical Society (Mss.B.D25.)
Physical description
LS(A) 4pp

Please cite as

Darwin Correspondence Project, “Letter no. 9168,” accessed on 4 June 2023,

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