The same vicariousness occurs when perception is attributed to one sense while it properly belongs to another. This happens particularly at such times when one has not been present during the event or when the perception was made while only half awake, or a long time ago, and finally, when a group of other impressions have accompanied the event, so that there was not time enough, if I may say so, properly to register the sense impression. So, e.g., some person, especially a close friend, may have been merely heard and later quite convincingly supposed to have been seen. Sensitive people, who generally have an acuter olfactory sense than others, attach to any perceived odor all the other appropriate phenomena. The vicariousnesses of visual sensations are the most numerous and the most important. Anybody who has been pushed or beaten, and has felt the blows, will, if other circumstances permit and the impulse is strong enough, be convinced that he has seen his assaulter and the manner of the assault. Sometimes people who are shot at will claim to have seen the flight of the ball. And so again they will have seen in a dark night a comparatively distant wagon, although they have only heard the noise it made and felt the vibration. It is fortunate that, as a rule, such people try to be just in answering to questions which concern this substitution of one sense-perception for another. And such questions ought to be urgently put. That a false testimony can cause significant errors is as obvious as the fact that such substitutions are most frequent with nervous and imaginative persons.
Still more significant is that characteristic phenomenon, to us of considerable importance, which might be called retrospective illumination of perception. It consists in the appearance of a sense-perception under conditions of some noticeable interruption, when the stimulus does not, as a rule, give rise to that perception. I cite a simple example in which I first observed this fact. Since I was a child there had been in my bed-room a clock, the loud ticking of which habit of many years prevented my hearing. Once, as I lay awake in bed, I heard it tick suddenly three times, then fall silent and stop. The occurrence interested me, I quickly got a light and examined the clock closely. The pendulum still swung, but without a sound; the time was right. I inferred that the clock must have stopped going just a few minutes before. And I soon found out why: the clock is not encased and the weight of the pendulum hangs free. Now under the clock there always stood a chair which this time had been so placed as to be inclined further backward. The weight followed that inclination and so the silence came about.