To John Tyndall   [27 February 1871]¹

My dear Tyndall

I called yesterday for the improbable good luck of finding you at home on a Sunday at the R. Institution, to thank you for your note.—² What a very interesting & practical discovery you have made in saving the poor firemen from being choked by noxious fumes.— By an odd chance I was wondering some months ago about the hairs within our nostrils, & it w^d. be fine if you have explained it. At present, however, I can hardly think, except in a few anomalous individuals, that the hairs are thick enough together. It w^d be very adviseable to ascertain how far the character is present in the hairless races of man.— Also under a different point of view with animals which have great powers of scent.—

I hope to see tomorrow D^r. Ogle³ who has been attending to powers of smelling, & I will tell him your idea, & he may have opportunity, as a Doctor, of observing different races of man in Hospitals.

Many thanks for your note.

Yours very sincerely | Ch Darwin