Let there be no other light than a taper in the room; then put on
a pair of dark green spectacles, and having closed one eye, view
the taper with the other. Suddenly remove the spectacles, and the
taper will assume a bright red appearance; but, if the spectacles be
instantly replaced, the eye will be unable to distinguish any thing
for a second or two. The order of colours will, therefore, be as
follows:—green, red, green, black.