The foregoing might be considered a useless recommendation, which is not the case. Spiritists, whose experience in such matters is not to be disdained, insist on the necessity of harmony in the circle, which is, they say, an essential condition of success. My personal experience confirms their opinion on this point. I have often been present at sittings which promised well in the beginning, and became suddenly barren because of a futile discussion between the sitters. The harmony recommended by spiritists is a kind of equilibrium between the mental and emotional states of the sitters. Each sitter should be animated by the same spirit—I do not use this word in its spiritistic acceptation—and seek only the truth; for I take it for granted they will operate as I have done. This unity of views, this uniformity of desires, this harmony between brains and hearts ensures the synergy of the forces which each member of the circle develops. For there is no doubt that some kind of force is emitted, and that if the medium throws off more than the other experimenters, an equilibrium between him and the other sitters is nevertheless fairly quickly established. The medium takes back from the latter the force he has expended. The result is that after a successful seance, the sitters are generally tired. I have noticed that certain persons give out this force more readily than others, and this perhaps explains a medium’s preference for certain experimenters as neighbours during the seance. We must not attribute this choice to the greater facility, which some people might offer for the execution of fraudulent phenomena. I have frequently been thus chosen, and I beg my readers to believe that I have a horror of fraud and imposture. I am also accustomed to experimenting; I feel no emotion whatever; I keep cool and observe with care. I am well acquainted with fraudulent methods, and I take good care not to be imposed upon. I repeat, it is a mistake to attribute to fraudulent intentions the preference shown by the medium for such or such an experimenter. In reality, it seems as though the medium, possessing an organism much more sensitive than that of the majority, quickly recognises those persons who the more easily throw off the force which he requires to retrieve his losses. This more rapid emission may be the result of habit, or may even depend upon individual constitution. Eusapia quickly discerns people from whom she can easily draw the force she needs. In the course of my first experiments with this medium, I found out this vampirism to my cost. One evening, at the close of a sitting at l’Agnélas, she was raised from the floor and carried on to the table with her chair. I was not seated beside her, but, without releasing her neighbours’ hands, she caught hold of mine while the phenomenon was happening. I had a cramp in the stomach—I cannot better define my sensation—and was almost overcome by exhaustion.