From J. S. Burdon Sanderson 25 June 1873
49 Queen Anne St.
June 25th. 1873
My dear Sir
It has been a great pleasure to me to receive your letter. I will at once proceed to make some notes on the Paper you have been so kind as to send to me & particularly on the marked passages.1
Ad 3. Sodium salts may be injected into the circulation of mammals in very large doses without effect. Very small doses of potassium salts produce death by suddenly arresting the contractions of the heart.2 This fact I have verified experimentally.
Ad 7. I can give you no explanation of the result obtained with Extract of Belladonna.3 I will write again on this subject
Ad 8. On the matter of Calabar bean I will write to Dr Fraser4
Ad 11 I believe that the citrate of Strychnine wd. be as good a salt as could be used.5
Ad 14 The negative result in the case of Curare is very interesting. It may I think be compared with the equally negative result obtained with Colchicine. Both are muscular poisons. I will send you some veratrine the alkaloid of Cevadilla which acts on muscle in the same way as Colchicine and does not act on nerve If it is found that veratrine does not act on the Sundew it would I think be of interest.6
Another agent (very accessible) which acts on nerve & is without action on muscle is glycerine. If a very weak solution of glycerine in water produces inflection, this wd. indicate that the excitability of Drosera is allied to that of nerve rather than to that of muscle.7
No doubt the most important fact of all is the one recorded in Par. 2. The action cannot be due to the presence of nitrogen—nor to the presence of nitrogenous compds. for these exist in vegetable liquids—in the very tissues and juices of the leaf itself— It must be dependent on the action of a ferment. To determine this it would be interesting to observe 1st. whether carbolic acid acts on the Drosera in ferment-destroying dose (say in per cent solution) & secondly whether the same agent when added to an animal liquid (e.g. Saliva) inhibits its action.8
The best expt. for this purpose would be first to give the leaf some carbolic acid (half per cent solution) and then follow it with the Saliva.
If it is not too late and I could do so without disturbing either you or your Droseras I should like extremely to witness some of the facts9
Believe me my dear Sir | very truly yours | J S B Sanderson
CD annotations
Footnotes
Bibliography
Fraser, Thomas Richard. 1867. On the physiological action of the Calabar bean. Transactions of the Royal Society of Edinburgh 24: 715–88.
Insectivorous plants. By Charles Darwin. London: John Murray. 1875.
Summary
Informs CD of the effects of certain salts and other chemicals on animals.
Comments on CD’s results with Drosera. Suggests some experiments.
Letter details
- Letter no.
- DCP-LETT-8949
- From
- John Scott Burdon Sanderson, 1st baronet
- To
- Charles Robert Darwin
- Sent from
- London, Queen Anne St, 49
- Source of text
- DAR 58.1: 116–19
- Physical description
- ALS 8pp †
Please cite as
Darwin Correspondence Project, “Letter no. 8949,” accessed on 26 September 2022, https://www.darwinproject.ac.uk/letter/?docId=letters/DCP-LETT-8949.xml
Also published in The Correspondence of Charles Darwin, vol. 21