. I do not hear the
mosquito much as it flies about, but when it passes close by my ear
I hear a "ping," the suddenness of which is very striking. Mr. Dalby,
the aurist, to whom I gave one of these instruments, tells me he
uses it for diagnoses. When the power of hearing high notes is
wholly lost, the loss is commonly owing to failure in the nerves,
but when very deaf people are still able to hear high notes if they
are sounded with force, the nerves are usually all right, and the
fault lies in the lining of the auditory canal.

E.--QUESTIONS ON VISUALISING AND OTHER ALLIED FACULTIES.

The Questions that I circulated were as follows; there was an
earlier and uncomplete form, which I need not reproduce here.

The object of these Questions is to elicit the degree in which
different persons possess the power of seeing images in their mind's
eye, and of reviving past sensations.

From inquiries I have already made, it appears that remarkable
variations exist both in the strength and in the quality of these
faculties, and it is highly probable that a statistical inquiry into
them will throw light upon more than one psychological problem.

Before addressing yourself to any of the Questions on the opposite
page, think of some definite object--suppose it is your
breakfast-table as you sat down to it this morning--and consider
carefully the picture that rises before your mind's eye.

1. _Illumination_.--Is the image dim or fairly clear? Is its
brightness comparable to that of the actual scene?

2. _Definition_.--Are all the objects pretty well defined at the
same time, or is the place of sharpest definition at any one moment
more contracted than it is in a real scene?

3. _Colouring_.--Are the colours of the china, of the toast, bread
crust, mustard, meat, parsley, or whatever may have been on the table,
quite distinct and natural?

4. _Extent of field of view_.--Call up the image of some panoramic
view (the walls of your room might suffice), can you force yourself
to see mentally a wider range of it than could be taken in by any
single glance of the eyes? Can you mentally see more than three
faces of a die, or more than one hemisphere of a globe at the same
instant of time?

5. _Distance of images_.--Where do mental images appear to be
situated? within the head, within the eye-ball, just in front of the
eyes, or at a distance corresponding to reality? Can you project
an image upon a piece of paper?

6. _Command