To John Tyndall 1 March 1
Down. | Beckenham | Kent. S.E. [6 Queen Anne Street]
My dear Tyndall
I saw Dr. Ogle, who is a most acute observer, & told him of your suggestion, & he will keep it in mind, in reference to the less hairy races of man & the lower animals—2
He is very anxious for information on one point, & as it is closely connected with your work, I have thought you could forgive me for troubling you.—
Does your glycerine &c respirator deprive odorous substances of their smell.—3 I neglected to ask what sort of substance, but I think from the tenour of his remarks, solid substances, such as camphor, musk, rubbed brass wd be most useful to him; but I daresay he wd. care about volatile oils or any odorous matter.
He is much perplexed with some physiological results,—as for instance the relation of colour to the tissues supplied with olfactory nerves, & of differently coloured substances absorbing with different degrees of power odours.4
A brief note, which I cd. communicate to Dr Ogle, wd. greatly oblige me.—
Yours very sincerely | Ch. Darwin
(I return home tomorrow morning)5
Ogle will keep JT’s suggestion in mind in observing less hairy races of man and the lower animals.
Asks JT whether he can help Ogle on a troublesome point on the colour of tissues with olfactory nerves, and the relation of colour to the absorption of odours. Does JT’s respirator deprive odorous substances of their smell?
Please cite as
Darwin Correspondence Project, “Letter no. 7524,” accessed on 31 August 2016, http://www.darwinproject.ac.uk/DCP-LETT-7524