ed by Darwin--viz. that
the contraction of the muscles round the eyes counteracts the gorging of
the parts during screaming, etc. The essay of Donders is, no doubt,
"On the Action of the Eyelids in Determination of Blood from Expiratory
Effort" in Beale's "Archives of Medicine," Volume V., 1870, page 20,
which is a translation of the original in Dutch.), as I shall now
proceed with some confidence; but I am intensely curious to read your
essay in full when translated and published, as I hope, in the "Dublin
Journal," as you speak of the weak point in the case--viz., that
injuries are not known to follow from the gorging of the eye with blood.
I may mention that my son and his friend at a military academy tell me
that when they perform certain feats with their heads downwards their
faces become purple and veins distended, and that they then feel an
uncomfortable sensation in their eyes; but that as it is necessary for
them to see, they cannot protect their eyes by closing the eyelids. The
companions of one young man, who naturally has very prominent eyes, used
to laugh at him when performing such feats, and declare that some day
both eyes would start out of his head.

Your essay on the physiological and anatomical relations between the
contraction of the orbicular muscles and the secretion of tears is
wonderfully clear, and has interested me greatly. I had not thought
about irritating substances getting into the nose during vomiting; but
my clear impression is that mere retching causes tears. I will, however,
try to get this point ascertained. When I reflect that in vomiting
(subject to the above doubt), in violent coughing from choking, in
yawning, violent laughter, in the violent downward action of the
abdominal muscle...and in your very curious case of the spasms (465/3.
In some cases a slight touch to the eye causes spasms of the orbicularis
muscle, which may continue for so long as an hour, being accompanied by
a flow of tears. See "Expression of the Emotions," page 166.)--that in
all these cases the orbicular muscles are strongly and unconsciously
contracted, and that at the same time tears often certainly flow, I must
think that there is a connection of some kind between these phenomena;
but you have clearly shown me that the nature of the relation is at
present quite obscure.

LETTER 466. TO A.D. BARTLETT. 6, Queen Anne Street, W., December 19th
[1870?].

I was with Mr. Wood this morning, and he expressed hi