Consequently, those who think that the frauds of the mediums give the death blow to mediumship are deceived. Mediumship exists, as well as hysteria, as well as hypnotism, as well as somnambulism. Trickery also exists. I will not say, with certain theologians, "There are _false_ prophets, _therefore_ there are _true_ ones," for that is a sophism of the worst kind. The existence of the false does not hinder the existence of the true. I knew a kleptomaniac, who got herself arrested more than once in the great shops of Paris for stealing various articles. That does not prove that she never bought anything, and only obtained by theft all the articles she needed. On the contrary, the objects stolen must have represented but a small part of the materials of her toilet. But the fact that she stole is incontestable. In the experiments which we are considering in these pages, deception is a co-efficient which cannot be neglected. It is my duty to point out here some examples of this failing. Before doing so, I ought to recall the fact that for a period of forty years I have examined all the mediums whose achievements have had the widest celebrity,--including Daniel D. Home, gifted with the most astounding powers, who gave at the Tuileries, before the Emperor Napoleon III, his family, and his friends, such extraordinary seances, and who was later employed by William Crookes in the accurate scientific researches made by that gentleman; Mme. Rodiere, a remarkable typtologic medium; C. Bredif, who produced strange apparitions; Eglington, with the enchanted slates; Henry Slade, who made with the astronomer Zoellner those incredible experiments from which geometry only saved itself by admitting the possibility of a fourth dimension of space; Buguet whose photographic plates caught and held the shadows of the dead, and who, having allowed me to experiment with him, let me conduct my researches for five weeks before I detected his fraudulent methods and mechanisms; Lacroix, to whom spirits of all ages seemed to troop in crowds; and many others who inspire deep interest in Spiritualists and scientific investigators by manifestations more or less strange and marvelous.