Expression of the Emotions" Darwin remarks
that this muscle is sometimes said not to be under voluntary control,
and he shows that this is not universally true.) Nor can I remember how
I was misled. I find I can act on this muscle myself, now that I know
the corners of the mouth have to be drawn back. I know of the case of a
man who can act on this muscle on one side, but not on the other; yet
he asserts positively that both contract when he is startled. And this
leads me to ask you to be so kind as to observe, if any opportunity
should occur, whether the platysma contracts during extreme terror,
as before an operation; and secondly, whether it contracts during a
shivering fit. Several persons are observing for me, but I receive most
discordant results.

I beg you to present my most respectful and kind compliments to your
honoured father [Sir G.B. Airy].

LETTER 474. TO FRANCIS GALTON.

(474/1. Mr. Galton had written on November 7th, 1872, offering to send
to various parts of Africa Darwin's printed list of questions intended
to guide observers on expression. Mr. Galton goes on: "You do not,
I think, mention in "Expression" what I thought was universal among
blubbering children (when not trying to see if harm or help was coming
out of the corner of one eye) of pressing the knuckles against the
eyeballs, thereby reinforcing the orbicularis.")

Down, November 8th [1872].

Many thanks for your note and offer to send out the queries; but my
career is so nearly closed that I do not think it worth while. What
little more I can do shall be chiefly new work. I ought to have thought
of crying children rubbing their eyes with their knuckles, but I did not
think of it, and cannot explain it. As far as my memory serves, they do
not do so whilst roaring, in which case compression would be of use. I
think it is at the close of the crying fit, as if they wished to stop
their eyes crying, or possibly to relieve the irritation from the salt
tears. I wish I knew more about the knuckles and crying.

What a tremendous stir-up your excellent article on prayer has made in
England and America! (474/2. The article entitled "Statistical Inquiries
into the Efficacy of Prayer" appeared in the "Fortnightly Review," 1872.
In Mr. Francis Galton's book on "Enquiries into Human Faculty and its
Development," London, 1883, a section (pages 277-94) is devoted to a
discussion on the "Objective Efficacy of Prayer.")

LETTER 475. TO F.C. DONDERS