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Darwin Correspondence Project

From Francis Darwin   [after March 1873]1

6 Q A

Dear Father

I thought that perhaps it might make a difference whether the extracts were made from leaves seeds or roots—

Ext Hyoscyami)

Belladonna) leaves



Dalton’s physiology calls legumine, which is the nitrogenous element in peas & beans, “vegetable caseine” but says it is different from casein. De Caisne & Le Maout calls it casein as if it were the same animal casein—3 So I thought that Extr Strammonii might contain some casein or legumin—as there is a good large cotyledonous embryo—but I forgot that it wd be precipited by the alchohol used in making Ex Stramonii at least as far as I can make out fr Lauder Brun4 all varieties o f albumin are ppd. by e-alcohol—

Yrs affec | F D

I think I told you Extr Stram was with proof spirit, that is what I got fr Garrod,5 but the B Pharmacopeia says Proof Spirit Ether & Water—6 I suppose Garrod only mentions the Proof Sp as being the most important


The date is established by the publication of Klein et al. 1873 in late March 1873 (Publishers’ Circular, 1 April 1873, p. 222; see n. 4, below).
See first letter from Francis Darwin, [after March 1873] and n. 2.
Francis Darwin refers to Dalton 1859, p. 69, and Le Maout and Decaisne 1868, p. 114.
Francis refers to Thomas Lauder Brunton, and Brunton’s contribution on ‘Digestion and secretion’ in Klein et al. 1873, p. 422.
Francis refers to Alfred Baring Garrod and Garrod 1866, pp. 295–6.
British pharmacopœia (1867), pp. 127–8.


Has investigated whether it makes a difference if extracts [of alkaloid poisons] are made from leaves, seeds, or roots.

Letter details

Letter no.
Francis Darwin
Charles Robert Darwin
Sent from
London, Queen Anne St, 6
Source of text
DAR 58.1: 133
Physical description

Please cite as

Darwin Correspondence Project, “Letter no. 9199,” accessed on 23 April 2018,

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