actually unremitting—since it would seem that nature itself forbids that,—is at least alive to its own lapses. And a power of observation of this kind is not demanded and is not exercised in the laboratory, and cannot be acquired except by training of a very special kind.
But in dealing with the phenomena presented by Spiritualist mediums, even errors of perception are often of less importance than errors of memory. The record of any event, or series of events, preserved in our memory is in no case comparable to a photograph. It is more like a picture or even a map. It is a selection, a work of art; and unfortunately in the present case the principle of selection, the aesthetic guidance, are supplied by the medium. In Dr. Hodgson's words:
The source of error which I desire in particular to press upon the reader's notice is the perishability, the exceeding transience, the fading feebleness, the evanescence beyond recall, of certain impressions which nevertheless did enter the domain of consciousness, and did in their place form part of the stream of impetuous waking thought.
It is, moreover, not simply and merely that many events, which did obtain at the sitting some share of perception, thus lapse completely from the realm of ordinary recollection. The consequence may indeed be that we meet with a. blank or a chaos in traversing the particular field of remembrance from which the events have lapsed; but this will often be filled with some conjectured events which rapidly become attached to the adjacent parts, and form, in conjunction with them, a consolidated but fallacious fragment in memory. On the other hand, the consequence may be that the edges of the lacuna close up—events originally separated by a considerable inter-