From W. W. Baxter   4 December 1872

Bromley Kent

Dec 4. 72

Sir

There is no sort of animal matter used in preparing the Extract of Belladonna, it is prepared exactly in the same way as Ext Hyoscyamus & neither ought to contain albumen, tho’ albumen is present in the juices of both plants, but they should be heated before being evaporated to form an extract, so as to coagulate the albumen, which should be filtered out,—1

The process for both these extracts is identical namely—leaves bruised, juice slightly heated so as to separate chlorophyll, (which is set aside) heated nearly to boiling point to coagulate the albumen which is filtered out, the filtrate is then evaporated partly, the chlorophyll added & the evaporation continued to finish.

I shall be happy to get you some extract from Apoths. Hall, Morton’s or other special place if you desire it, as I cannot make any at this time of year—2 Might I presume to suggest the use of Atropia the active principle of the Belladonna plant, if that is the reason of its use, as it wd. be chemically pure in the form of Sulphate of Atropia   it is soluble in water.3

With respects | I remain | Yrs obedly. | Wm. W. Baxter

C. Darwin Esqre.

P.S. I do not find albumen in our Ext. Belladonna

CD annotations

Top of letter: ‘Belladonna juices with albumen removed.— says I ought to try Atropia.’ ink
1
See letter to W. W. Baxter, 2 [December 1872]. Atropa belladonna (deadly nightshade) and Hyoscyamus, a genus of plants of the nightshade family (Solanaceae), were used by CD in his experiments on the carnivorous plant genus Drosera. CD wanted to determine whether it was albumen, rather than the nightshade poison (atropine), that affected the leaves of Drosera (see Insectivorous plants, pp. 84, 206).
2
Atropa belladonna is a herbaceous plant that dies down in the winter. The Society of Apothecaries manufactured and sold medicinal and pharmaceutical products at the Apothecaries’ Hall, London. Morton’s may be a reference to Henry Morton, chemist, in Ramsgate, Kent (Post Office directory of the six home counties 1870).
3
CD, following Baxter’s suggestion, showed that atropine was ‘quite powerless’ when applied to the leaves of Drosera (see Insectivorous plants, p. 84). Sulphate of atropia was commonly used in opthalmic practice to dilate the pupil of the eye (see W. G. Smith 1869, pp. 197–8).

Please cite as “DCP-LETT-8659,” in Ɛpsilon: The Charles Darwin Collection accessed on 5 June 2025, https://epsilon.ac.uk/view/dcp-data/letters/DCP-LETT-8659