From G. G. Stokes 20 December 1875
Lensfield Cottage Cambridge
20th Decr 1875
My dear Sir,
You may remember that some years ago you asked my opinion as to the cause of the colours in peacocks’ feathers.1 I made some experiments, or rather observations hardly deserving the name of experiments, about it. I felt however that it was a matter hardly to be attacked without a thoroughly good microscope which I did not then possess. I expressed a leaning to the opinion that the colours were reflection-colours connected with intense absorption, and similar accordingly to the reflection-colours seen when some of the aniline colouring matters are poured in solution on glass, and the solvent allowed to evaporate. I felt at the time I think misgivings as to whether so much play of colour as is observed could thus be accounted for—2
As I have helped to lead you wrong if you followed my guidance, it is but just that I should direct you to a right solution. Some little while ago I was with Mr. Sorby, who wished to show me some other experiments, and I found that he has been studying birds’ feathers, as to their colours, and had arrived at the solution of the cause of the play of colours in the feathers of peacocks, humming birds &c. I am not sure whether he has yet published his results If he has, I have no doubt he will be happy to send you copies of his papers if he has not done so already.3 If not, I dare say he would explain to you in a few words their general nature. Though I feel confident of his permission, I refrain as a matter of principle from communicating to a third person what has been told me by a friend of his unpublished researches. Besides it is due to him not to spoil the pleasure he would feel in communicating to you for the first time his own results.
I am dear Sir | Yours sincerely | G. G. Stokes
Chs. Darwin Esq F.R.S.
Footnotes
Bibliography
Correspondence: The correspondence of Charles Darwin. Edited by Frederick Burkhardt et al. 29 vols to date. Cambridge: Cambridge University Press. 1985–.
Tyndall, John. 1875. Six lectures on light delivered in America 1872–1873. 2d edition. London: Longmans, Green, and Co.
Summary
Notifies CD that information he [GGS] gave before on colours of peacock’s feathers was wrong [see 5891 et seq.] and refers CD to H. C. Sorby, who has worked on the subject.
Letter details
- Letter no.
- DCP-LETT-10310
- From
- George Gabriel Stokes, 1st baronet
- To
- Charles Robert Darwin
- Sent from
- Cambridge
- Source of text
- CUL Manuscripts Department Add 7656: D71
- Physical description
- ALS 6pp
Please cite as
Darwin Correspondence Project, “Letter no. 10310,” accessed on 20 April 2024, https://www.darwinproject.ac.uk/letter/?docId=letters/DCP-LETT-10310.xml
Also published in The Correspondence of Charles Darwin, vol. 23