when the abdominal muscles act with unusual force in a downward
direction on the intestinal canal.



[18] Mr. Hensleigh Wedgwood (Dict. of English Etymology,
1859, vol. i. p. 410) says, "the verb to weep comes from
Anglo-Saxon _wop_, the primary meaning of which is simply outcry."

Yawning commences with a deep inspiration, followed by a long
and forcible expiration; and at the same time almost all the muscles
of the body are strongly contracted, including those round the eyes.
During this act tears are often secreted, and I have seen them
even rolling down the cheeks.

I have frequently observed that when persons scratch some point which
itches intolerably, they forcibly close their eyelids; but they do not,
as I believe, first draw a deep breath and then expel it with force;
and I have never noticed that the eyes then become filled with tears;
but I am not prepared to assert that this does not occur.
The forcible closure of the eyelids is, perhaps, merely a part of that
general action by which almost all the muscles of the body are at
the same time rendered rigid. It is quite different from the gentle
closure of the eyes which often accompanies, as Gratiolet remarks,[19]
the smelling a delicious odour, or the tasting a delicious morsel,
and which probably originates in the desire to shut out any disturbing
impression through the eyes.


[19] `De la Physionomie,' 1865, p. 217.