To sum up the indications I have just given in perhaps too complete a fashion, I will briefly recall to mind the conditions which have seemed the best to me: sufficient light first of all—the personification must not acquire the habit of operating in darkness, for the brighter the light, the more convincing the experiment; a small room; a light table with four legs, put together with wooden pegs rather than with nails; a cabinet of soft thin curtains; the experimenters not to exceed as a rule eight in number; the experimenters to agree to experiment seriously, without turning into ridicule the practices to which they submit themselves. It is a good plan to allow only one of their circle to direct the seance, to converse with the personification, to control the proceedings. They must try and keep up a spirit of good understanding, and refrain from reciprocally accusing each other of pushing the table—novices do this regularly. Discussion should be relegated to the end, and should never be provoked during the sitting. Finally, they should pay great attention to the susceptibility of the medium—whoever he may be. The greatest patience will be required; the circle should be modified with prudence, and only after a certain number of sterile experiments. IV. THE PERSONIFICATION I think it will be useful to indicate what has seemed to me the best way of treating the personification—for this point is important. I give the name of ‘personification’ to the manifesting intelligence, whatever this may be. As previously indicated, this intelligence, as a rule, claims to be the soul of a deceased person. This is not absolute, and the phenomena may personify God, the devil, angels, legendary personages, fairies, etc. I need not say how far I am from believing in the reality of the being thus manifesting, and I have, as I believe, excellent reasons for doubting. I have noticed that the rôle played by the personification varies with the composition of the circle. It will always be the spirit of a dead or living person with spiritists. But the rôles are more varied if the circle be composed of people who are not spiritists; it then sometimes happens that the communications claim to emanate from the sitters themselves. I am inclined to believe this is the real origin of the communications, and that a sort of collective consciousness is formed. I give my impression with the greatest reserve, for, I repeat, I have no decided opinion upon the subject; but the experiments I have made leave me that impression, in a general way. This forms part of an—as yet—undeciphered chapter on the psychology of crowds. I confess I have no explanation to give of the action which such a collective consciousness appears to have upon matter; but this difficulty seems to me less insurmountable than those attending the spirit hypothesis. If we attribute the phenomena to a being distinct from ourselves, having a will-power so much the more marked because