This is where things stood when, of late years, the mediums, the spiritualists, or, rather, it appears, the spirits themselves, for one cannot tell exactly with whom we have to do, perhaps dissatisfied at not being more definitely recognized and understood, invented, for a more effectual proof of their existence, what has been called “cross-correspondence.” Here the position is reversed: it is no longer a question of various and more or less numerous spirits revealing themselves through the agency of one and the same medium, but of a single spirit manifesting itself almost simultaneously through several mediums often at great distances from one another and without any preliminary understanding among themselves. Each of these messages, taken alone, is usually unintelligible, and yields a meaning only when laboriously combined with all the others. As Sir Oliver Lodge says: The object of this ingenious and complicated effort clearly is to prove that there is some definite intelligence underlying the phenomena, distinct from that of any of the automatists, by sending fragments of a message or literary reference which shall be unintelligible to each separately--so that no effective telepathy is possible between them,--thus eliminating or trying to eliminate what had long been recognized by all members of the Society for Psychical Research as the most troublesome and indestructible of the semi-normal hypotheses. And the further object is evidently to prove as far as possible, by the substance and quality of the message, that it is characteristic of the one particular personality who is ostensibly communicating, and of no other.[2]