Ɛpsilon

To William Ogle   18 March [1871]

Down. | Beckenham | Kent. S.E.

March 18th

My dear Dr Ogle

There is not the most remote danger of my finding any letter of yours too long. Many thanks for the last.1 Since writing I have found old notes of my own, on the jaw falling from concentrated attention, & I agree that this may apply to the Deaf— I suspect various causes come into play.2 I am convinced that in startled surprise the mouth is opened suddenly & the chest filled with air.3 It is odd that so simple a movement as opening the mouth under surprise, & this holds good in all parts of the world, shd. be so perplexing to understand. I shall consider all that you say with my best attention.

Believe me | Yours very sincerely | Ch. Darwin

Postmark: MR 19 71

1
Ogle’s letter has not been found, but was evidently a reply to the letter to William Ogle, 12 March [1871].
2
See letter to William Ogle, 12 March [1871]. In Expression, pp. 283–4, CD noted that when attention is concentrated for a length of time many facial muscles relax and the jaw drops.
3
In Expression, p. 284, CD observed that the mouth opened when one was astonished or startled.

Manuscript Alterations and Comments

0.1 Beckenham] before del ‘Bromley.’
1.5 that] interl

Please cite as “DCP-LETT-7596,” in Ɛpsilon: The Charles Darwin Collection accessed on 5 June 2025, https://epsilon.ac.uk/view/dcp-data/letters/DCP-LETT-7596