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Darwin Correspondence Project

To William Bowman   25 January 1872

Down Beckenham

Jan 25 1872

My dear Bowman

I do not know how to thank you enough for having taken so much trouble. Your letter is of the greatest value to me, & it is astonishing how much you have compressed in it.1 I will now gladly say what I am driving at.

I do not know why I did not do so before, as it wd have been much the best course; but I shd have hesitated to have troubled you with so long a letter, & now without giving full details, my ideas will appear weaker than I hope they are in reality.

(1) Donders has shewn that during violent expiration, the arterial pressure within the eye-ball is increased, & the return of the blood in the veins is impeded; also that the contraction of the orbicular muscles lessens this tendency to distention in the vessels.2

(2) I have such a number of cases under no emotion, & under different emotions, when the strong contraction of the orbiculars is accompanied by the secretion of tears, that I at one time, thought that the strong pressure of the eyelids on the surface of the eye, must lead to this secretion.3

(3) But I find that the strongest, prolonged, voluntary contraction of the orbiculars by children leaves their eyes dry, or only in a very slight degree moistened.

(4) Therefore it occurred to me that the distention of the vessels within the eye, during violent expiration, might have a double effect, viz through habit on the contraction of the orbiculars, & through reflex action on the secretion of tears. But I was so ignorant I did not know how far the internal parts of the eye stood in any reflex relation with the lacrymal glands. Now, by your letter I see that this does sometimes hold good, & I further see how difficult the whole subject is. What you say about the hardness of the eye from too much fluid not causing lacrymation, whilst the opposite condition does act in this manner, is greatly opposed to my notion. There may however be some difference in the effects of distention of the eye from distended blood vessels & from diffused fluids. If you wd turn this point in yr mind, viz whether judging from abnormal states &c of the eye, it appears at all probable to you that increased arterial pressure & distended veins throughout the eye, would give through reflex action some slight tendency to the secretion of tears, & let me hear yr opinion, it wd aid me most essentially in drawing up the concluding & theoretical part of my chapter on the expression of suffering; & I will lay aside my M.S. until I hear from you.4 It wd be a quite unreasonable request, but it wd be an immense advantage to me, if you wd have the patience to read over this chapter (I suppose 40 to 50 p.s. long) when, in a month or two it is copied out by a first-rate copyist; but I know how wearisome it is to read M.S5

I was very sorry I was not able to call on you when at Albury, but my head was very bad the whole time & I left the place a week before we had intended.6 I have lost this summer several months & been able to do absolutely nothing.—

Accept my hearty thanks for your great kindness & believe me | Yours very sincerely | Ch. Darwin

The eyes of a strangled man are said to start from his head,—I suppose from return of the veinous blood being prevented— do you imagine this would cause any lacrymation.— You will now see why I asked whether a tumour in the orbit from pressing on eye cd cause lacrymation—7


CD refers to Frans Cornelis Donders. See Correspondence vol. 18, letter from F. C. Donders, 27 May 1870, and Donders 1870a and 1870b.
CD refers to Expression, chapter 6.
No further correspondence with Bowman on the subject of CD’s manuscript has been found; however, see the letter to F. C. Donders, 17 June 1872.
The Darwins stayed at Albury in Surrey from 28 July to 25 August 1871 (see Correspondence vol. 19, Appendix II). Bowman had a country house, Joldwynds, nearby.
This postscript may not belong with this letter: it is on a different sort of paper to the rest of the letter. No letter by CD asking this question has been found.


Correspondence: The correspondence of Charles Darwin. Edited by Frederick Burkhardt et al. 29 vols to date. Cambridge: Cambridge University Press. 1985–.

Expression: The expression of the emotions in man and animals. By Charles Darwin. London: John Murray. 1872.


Discusses role of orbicular muscle and distended veins in eye in secretion of tears. Asks WB’s opinion.

Letter details

Letter no.
Charles Robert Darwin
William Bowman, 1st baronet
Sent from
Source of text
American Philosophical Society (Mss.B.D25.)
Physical description
LS(A) 8pp

Please cite as

Darwin Correspondence Project, “Letter no. 8179,” accessed on 27 February 2024,

Also published in The Correspondence of Charles Darwin, vol. 20