an illusion, but the sensation of this illusory finger was as definite
as that of any of his real fingers. In such cases the subject seemed
to perceive the relation of the points to each other, but failed to
connect them with the right fingers. For instance, if contacts were
made on the first, second and third fingers, the first might be
located on the first finger, the third on the second finger, and then
the second would be located in between.

So far my attention had been given almost entirely to fusion, but the
tendency on the part of all subjects to report more contacts than were
actually given was so noticeable that I concluded that diffusion was
nearly as common as fusion and about as easy to produce. It also
seemed that the element of weight might play some part, but just what
effect it had I was uncertain. I felt, too, that knowledge of the
apparatus gained through sight was giving the subjects too much help.
The subjects saw the apparatus every day and knew partly what to
expect, even though the eyes were closed when the contacts were made.
A more efficient apparatus seemed necessary, and, therefore, before
taking up the work again in 1900, I made a new apparatus.

Not wishing the subjects to know anything about the nature of the
machine or what could be done with it, I enclosed it in a box with an
opening in one end large enough to allow the subject's hand to pass
through, and a door in the other end through which I could operate. On
the inside were movable wooden levers, adjustable to hands of
different width. These were fastened by pivotal connection at the
proximal end. At the outer end of each of these was an upright strip
with a slot, through which was passed another strip which extended
back over the hand. This latter strip could be raised or lowered by
means of adjusting screws in the upright strip. On the horizontal