skip to content

Darwin Correspondence Project

To W. W. Baxter   8 September [1873]1

Down, | Beckenham, Kent.

Septr 8th

Dear Sir

I thank you sincerely for your kind & prompt assistance. I see that the Chloride of Antimony does not dissolve at all well & the Chloride of Tin imperfectly. Could you make or procure for me any soluble salts—(nitrates or acetates wd be best) of these 2 metals?2

The ammonio-citrate of Bismuth wd be of no use, as ammonia in all states acts with extraordinary energy on my plant, viz Drosera.—3 Will any of your Books tell you what percentage of the Chlorides of Antimony or Tin are dissolved?—

I have got, or tried, the following acids4

1 Hydrocyanic

2 Hodrychloric

3 Sulphuric

4 Nitric

5 Acetic

6 Boracic

7 Citric

8 Oxalic

9 Tartaric

10 Arsenious

11 Chromic

12 Phosphoric5

Have you any other acid, pure, which is soluble; if so, could you send me, one, two or three or four more.

Vegetable acids wd. perhaps be best.

Perhaps Iodic acid wd be worth trying

Yours faithfully & | obliged | Ch. Darwin


The year is established by the relationship between this letter and the letter to W. W. Baxter, 5 September [1873].
CD’s experiments on the effects of salts on Drosera (sundew) leaves included antimony tartrate and tin chloride (see Insectivorous plants, pp. 175, 185).
CD made no experiments using bismuth compounds, probably because of their very low solubility.
For CD’s observations on the effects of acids on Drosera leaves, see Insectivorous plants, pp. 189–98.
12 Phosphoric’ was written in pencil and appears to be in Francis Darwin’s hand.


Insectivorous plants. By Charles Darwin. London: John Murray. 1875.


Requests chemicals for Drosera experiments. Lists 12 acids tried so far.

Letter details

Letter no.
Charles Robert Darwin
William Walmisley Baxter
Sent from
Source of text
DAR 261.11: 6 (EH 88206058)
Physical description

Please cite as

Darwin Correspondence Project, “Letter no. 9046,” accessed on 21 January 2022,

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