I have quite often been absolutely deceived. When I took the precautions that were necessary to put the medium beyond the possibility of trickery, I obtained no result; if I pretended not to see anything I would perceive out of the corner of my eye attempts at deceit. And, in general, the phenomena which took place happened only in the moments of distraction in which my attention was for an instant relaxed. While I was pushing my investigation a little farther, I saw with my own eyes Buguet's prepared negatives; saw with my own eyes Slade writing under the table upon a concealed slate, and so forth. Apropos of this famous medium Slade, I may recall the fact that after his experiments with Zöllner, director of the observatory at Leipzig, he came to Paris, and for the purpose of experimentation, placed himself at my disposal (and that of all the astronomers at the Observatory to whom I should introduce him). He said he got direct writings from the spirits by a bit of pencil placed between two slates tied together, by oscillations of the magnetic needle, displacements of furniture, the automatic throwing about of objects, and the like. He was very willing to give me one séance a week, for six weeks (on Monday at 11 o'clock A. M., at 21 Beaujon Street). But I obtained nothing certain. In the cases that did succeed, there was a possible substitution of slates. Tired of so much loss of time, I agreed with Admiral Mouchez, director of the Observatory of Paris, to confide to Slade a double slate prepared by ourselves, with the precautions which were necessary in order that we should not be entrapped. The two slates were sealed in such a way with paper of the Observatory that if he took them apart he could not conceal the fraud. He accepted the conditions of the experiment. I carried the slates to his apartment. They remained under the influence of the medium, in this apartment, not a quarter of an hour, not a half-hour or an hour, but ten consecutive days, and when he sent them back to us there was not the least trace of writing inside; and yet specimens of this were always furnished by him when he had the opportunity of transposing slates prepared in advance.[42]
Without entering into other details, let it suffice me to say, that, too frequently deceived by dishonest and mendacious mediums, I brought to my experiments with Eusapia a mental reserve of scepticism, of doubt, and of suspicion.