# From J. S. Burdon Sanderson   26 June [1874]1

49 Queen Anne St

June 26

My dear Mr Darwin,

Again I have to apologize for delay. I am on the point of starting on a short tour in Germany and have been much pressed during the last few days in making preparations for my absence.

I am delighted to learn that Pinguicula & Drosera both digest fibrin readily   I do not think it would be correct to infer that the fibrin previously used was impure—but rather that it had undergone change to a certain extent consequent on the way in which it was prepared.2

I think that it would be fairest & best to experiment on gluten already subjected to the action of very dilute Hydrochloric acid ($\frac{1}{2}$ per cent)   It would thus be deprived entirely of its starch, which would be dissolved out in the form of Dextrine3   I have ask my assistant Mr. Page4 to send you some already so treated   He will send at the same time some bone treated in the same way. I have no doubt that the reason that the other did not digest completely was that the acid was insufficient to dissolve out the inorganic constituents of the bone

I mentioned in my last that I had put some enamel to digest. It was nearly digested by next morning.5

I am very sorry that I made a misstatement about the “aggregation”6 I said so little about it & expressed myself so indefinitely that I hope that no one would be seriously misled. I felt that I was dealing with a matter about which I had no adequate knowledge.

I hope that it may be possible to do something with Pinguicula about separating the digestive ferment. I should like very much to try after my return.

I am, my dear Mr Darwin | very sincerely yours | J B Sanderson

## CD annotations

1.1 Again … absence. 1.3] crossed pencil
2.1 I am … prepared. 2.4] crossed red crayon
3.3 I have … bone 3.7] crossed blue crayon
5.1 I am … knowledge. 5.4] crossed pencil
Top of letter: ‘enamel digested p 2 | on Fibrin not being impure | Gluten & Bone prepapred with $\frac{1}{2}$ pc Hydrochloric A’ pencil

## Footnotes

The year is established by the relationship between this letter and the letter to J. S. Burdon Sanderson, 21 June [1874].
Drosera is the sundew; Pinguicula is butterwort. See letter to J. S. Burdon Sanderson, 21 June [1874] and n. 2.
See letter to J. S. Burdon Sanderson, 21 June [1874] and n. 4. Gluten is a protein compound derived from wheat and other grains. Dextrine (now usually spelled dextrin) is a starch that is found together with gluten in the endosperm of the grain.
Frederic James Montague Page.

## Summary

Is delighted to hear that Pinguicula and Drosera digest fibrin. Suggests diluting gluten in weak hydrochloric acid to remove starch. Enamel was nearly digested [by Drosera] overnight. Would like to try separating the digestive ferment of Pinguicula.

## Letter details

Letter no.
DCP-LETT-9517
From
John Scott Burdon Sanderson, baronet
To
Charles Robert Darwin
Sent from
London, Queen Anne St, 49
Source of text
DAR 58.1: 144–5, 153–4
Physical description
7pp †