dumb-bell, where an
eye-movement commenced as voluntary would end as a reflex following of
the pendulum. In the present experiment, until the subject is well
trained, the stopping of the eye must be watched by a second person
who looks directly at the eye-ball of the subject during each
movement. The appearances are very varied when the eye stops, but the
typical one is shown in Fig. 8:1. The red strip _AB_ is seldom longer
and often shorter than in the figure. That part of it which is
superposed on the green seldom shows the orange phase, being almost
always of a pure straw-yellow. The localization of these images is
variable. All observations made during movements in which the eye
stops, are of course to be excluded.
If now the eye does not stop midway, and the image is not localized in
the center, the appearance is like either 2, 4, or 5, and is localized
over the final fixation-point. 2 is in all probability the case of the
eye moving very much faster than the pendulum, so that if the movement
is from left to right, the right-hand side of the image is the part
first exposed (by the uncovering of the left-hand side of _T_), which
is carried ahead by the too swift eye-movement and projected in
perception on the right of the later portion. 3 is the case of the eye
moving at very nearly but not quite the rate of the pendulum. The
image which should appear 2 cm. wide (like the opening _i_) appears
about 3 cm. wide. The middle band is regularly straw-yellow, extremely
seldom reddish, and if we could be sure that the eye moves more slowly
than the pendulum, so that the succession of the stimuli is even
slower than in the control, and the red phase is surely given, this
appearance (3) would be good evidence of anaesthesia during which the
reddish-orange phase elapses. It is more likely, however, that the eye
is moving faster than the pendulum, but whether or not so
inconsiderably faster as still to let the disappearance of the reddish
phase be significant of anaesthesia, is not certain until one shall
have made some possible but tedious measurements of the apparent width
of the after-image. Both here and in the following case the _feeling
of succession_, noticeable between the two phases when the eye is at
rest, has _disappeared with the sensation of redness_.
The cases in which 5 is seen are, however, indisputably significant.
The image is apparently of just the height and width of _i_, and there
is not the slightest
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