THE INFLUENCE OF THE IMAGINATION.
The above facts show plainly that optical illusions
find their source in the very mechanism of the organs
of sight, and that without going farther than the eye
itself we may discover numberless examples of these
phenomena. We shall presently bring before our readers
the innumerable means devised by art for deceiving
the sense of sight and impressing us with sensations that
are purely imaginary. But before describing these numerous
pieces of apparatus we must still remain for a
short time within the domain of man's faculties, and describe
some of the illusions that we are subjected to by
those powers of the imagination that are supposed to
hold in check the five senses of the body. Our imagination,
however, plays us as many tricks as our eyes,
and, like them, is alternately false and true. Touch,
taste, smell, hearing, and sight, are all supposed to be
under its powerful influence for good or evil; but they
are all deceived by it in turn, more especially the sense
of sight, which we generally boast of as being the most
trustworthy of them all. Were we to describe all the
labyrinths into which our imagination is continually
leading us, we might easily extend this little volume to
one of treble the size. But our purpose is not so much
to write a history of all the hallucinations to which the
imagination is subject, but to cull from those already
