To J. S. Burdon Sanderson   19 November [1873]1

Down, | Beckenham, Kent.

Nov. 19th

My dear Dr. Sanderson

I grieve to find that I kept only a few particles of the globuline & of the so-called Hæmaglobine; but I shd think they could be tried on a small scale by the artificial gastric juice.—2 The case, however, interests me so much, (as well as that of the Mucin) that I daresay I could get some more Globuline from Dr. Moore, if the few particles sent do not suffice, & if you do not find the much larger parcel previously sent to you.—3 I shd be very glad to know what I ought to call the Hæmaglobine,—that is if you can tell by its appearance.—

Perhaps Dr Brunton knows about the digestion of Chlorophyll by animals.—4 Will you ask him when you ask about gelatin & Chondrin; though I daresay your explanation is correct that my chondrin was not as pure as the gelatin prepared by Hoffmann.—5

I hope & trust the trial of the proprionic, butyric & valeric acids will not be very troublesome:6 it ought, I shd think on mere physiological grounds to be ascertained how far these acids will replace Hydrochloric.—

You have been very very kind to aid me in so many ways.—

Yours most sincerely | Ch. Darwin

1
The year is established by the relationship between this letter and the letter to J. S. Burdon Sanderson, 15 November [1873].
2
Globuline (now known as globulin) is a type of serum protein found in animals. Haemoglobin is the iron-containing oxygen-transport protein found in the red blood cells of all vertebrates. Burdon Sanderson’s experiments with globulin are described in Insectivorous plants, pp. 120–1.
3
Mucins are a family of proteins produced by epithelial tissues in most animals. CD described his digestive experiments with mucin in Insectivorous plants, pp. 122–3. Samuel William Moore prepared animal substances for CD’s experiments on insectivorous plants (see letter from S. W. Moore, [1 October 1873] and n. 2), including globulin from the lens of the eye and mucin (see Insectivorous plants, pp. 120 and 122).
4
Thomas Lauder Brunton’s experiments with chlorophyll and gelatine are cited in Insectivorous plants, pp. 111 and 126.
5
In 1862, August Wilhelm von Hofmann had supplied thin sheets of gelatine uncontaminated by chlorine (see Correspondence vol. 10, letter from A. W. von Hofmann, 27 June 1862, and Insectivorous plants, pp. 110–11).

Manuscript Alterations and Comments

1.5 previously] interl
2.4 Hoffmann] before del ‘for me’

Please cite as “DCP-LETT-9155,” in Ɛpsilon: The Charles Darwin Collection accessed on 5 June 2025, https://epsilon.ac.uk/view/dcp-data/letters/DCP-LETT-9155