The truth is that the phenomenon known as "clairvoyance" rests just as plainly on trickery as the physical phenomena we have studied. Margaretta Fox explained decades ago how they used to watch minutely the faces of sitters and find their way by changes of expression. "I see a young man," says the medium dreamily, with half-closed but _very_ watchful eyes. There is no response on the face of the sitter. "I see the form of a young woman--a child," the medium goes on. At the right shot the sitter's face lights up with joy and eagerness, and the fishing goes on. Probably in the end, or after a time, the sitter will tell people how the clairvoyant saw the form of her darling child "at once." In some cases the medium is prepared in advance. Carrington tells us that he was one day strongly urged to give a man, who thought that he had abnormal powers, a sitting. He decided at least to give him a lesson, and made an appointment. The man came with friends at the appointed hour, and they were astonished and awed when Carrington, as a clairvoyant, told them their names and other details. He had simply sent a man to track his visitor to his hotel and learn all about him and his friends. Other cases are just as easy. When Sir O. Lodge and Sir A. C. Doyle lost their sons, the whole mediumistic world knew it and was ready. But mediums gather information about far less important sitters, because it is precisely these cases that are most impressive. It is quite easy to get information quietly about a certain man's dead relatives, and then find an intermediary who will casually recommend him to see Mrs. ----. I do not suggest that the intermediary knows the plot, though that may often be the case. In other cases the medium tells very little at the first visit. The "spirit" is dazed in its new surroundings. It takes time to get adjusted and learn how to talk through a medium. And so on. You go again, and the details increase. You have, of course, left your name and address in making a fresh appointment. Some clever people go anonymously. Lady Lodge went thus and heard remarkable things; but Sir O. Lodge admits that her companion greatly helped the medium by forgetting herself and addressing her as "Lady Lodge." You may leave your coat in the hall, and it is searched. When Truesdell consulted Slade in New York, he wickedly left in his overcoat pocket a letter which gave the impression that his name was "Samuel Johnson." The first ghost that turned up was, of course, "Mary Johnson."