Hence I carefully watched my own infants. One of them at the age of
forty-five days, and being at the time in a happy frame of mind,
smiled; that is, the corners of the mouth were retracted, and
simultaneously the eyes became decidedly bright. I observed the same
thing on the following day; but on the third day the child was not
quite well and there was no trace of a smile, and this renders it
probable that the previous smiles were real. Eight days subsequently
and during the next succeeding week, it was remarkable how his eyes
brightened whenever he smiled, and his nose became at the same time
transversely wrinkled. This was now accompanied by a little bleating
noise, which perhaps represented a laugh. At the age of 113 days these
little noises, which were always made during expiration, assumed a
slightly different character, and were more broken or interrupted, as
in sobbing; and this was certainly incipient laughter. The change in
tone seemed to me at the time to be connected with the greater lateral
extension of the mouth as the smiles became broader.
In a second infant the first real smile was observed at about the same
age, viz. forty-five days; and in a third, at a somewhat earlier age.
The second infant, when sixty-five days old, smiled much more broadly
and plainly than did the one first mentioned at the same age; and even
at this early age uttered noises very like laughter. In this gradual
acquirement, by infants, of the habit of laughing, we have a case in
some degree analogous to that of weeping. As practice is requisite with
the ordinary movements of the body, such as walking, so it seems to be
with laughing and weeping. The art of screaming, on the other hand,
from being of service to infants, has become finely developed from the
earliest days.
_High spirits, cheerfulness_. A man in high spirits, though he may not
actually smile, commonly exhibits some tendency to the retraction of
the corners of his mouth. From the excitement of pleasure, the
circulation becomes more rapid; the eyes are bright, and the colour of
the face rises. The brain, being stimulated by the increased flow of
blood, reacts on the mental powers; lively ideas pass still more
rapidly through the mind, and the affections are warmed. I heard a
child, a little under four years old, when asked what was meant by
being in good spirits, answer, It is laughing, talking, and kissing.
It would be difficult to give a truer and more practical definition. A
man in this state holds his body erect, his head upright, and his eyes
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