becomes, the complexity being more that of the senses than of intellect.
It may be said there is always some appeal to both, but not in any equal
proportions, and there is manifestly a great difference between the
humour of a plough-boy grinning through a horse-collar, and of a sage
observing that "when the poor man makes the rich a present, he is
unkind to him." Caricature drawings produce little effect upon educated
people, unless assisted by a description on which the humour largely
depends. We can see in a picture that a man has a grotesque figure, or
is made to represent some other animal; by gesticulation we can
understand when a person is angry or pleased, or hungry or thirsty; but
what we gain merely through the senses is not so very far superior to
that which is obtained by savages or even the lower animals, except
where there has been special education.

Next to optical humour may be placed acoustic--that of sound--another
inferior kind. The ear gives less information than the eye. In music
there is not so much conveyed to the mind as in painting, and although
it may be lively, it cannot in itself be humorous. We cannot judge of
the range of hearing by the vast store of information brought by words
written or spoken, because these are conventional signs, and have no
optical or acoustic connection with the thing signified. We can
understand this when we listen to a foreign language.

Hipponax seems to have been the first man who introduced acoustic humour
by the abrupt variation in his metre. Exclamations and strange sounds
were found very effective on the stage, and were now frequently
introduced, especially emanating from slaves to amuse the audience.
Aristophanes commences the knights with a howling duet between two
slaves who have been flogged,