I had the good fortune to be able to study these curious rappings at close range, and I believe I have reached certain conclusions. The first, and the best attested, is that the raps are closely connected with the muscular movements of the sitters. I will sum up my observations on this point as follows: 1. Every muscular movement, even a feeble one, is generally followed by a rap. 2. The intensity of the raps did not seem to me to be proportional to the muscular movement made. 3. The intensity of the raps did not seem to me to vary in proportion to their distance from the medium. The following are the facts upon which my conclusions rest: I frequently observed that when we had raps that were feeble and occurred only at intervals, an excellent means of producing them was to form the chain upon the table, the hands resting upon it, and the observers putting their fingers in light contact. One of them, without breaking the chain (a feat he accomplished by holding in the same hand the right hand of his neighbor on the left and the left hand of his neighbor on the right) moved his released hand in circular sweeps or passes over the table, at the level of the circle formed by the opened hands of the observers. After having made this movement four or five times, always in the same direction,--that is to say, after having thus traced four or five circles over the table, the experimenter brought his hand over toward the centre at a variable height and moved it down towards the table. Then he abruptly arrested this movement at a distance of seven or eight inches from the top. The abrupt stoppage of his hand was tallied by a rap in the wood. It is an exceptional case when this process does not yield taps,--that is to say, when there is a medium in the circle capable, even feebly, of producing them. The same experiment can be made without touching the table, but forming around it a kind of closed chain. One of the operators then acts as in the preceding case. I have no need to recall to the minds of my readers that with certain mediums, raps are produced without any movement being made. Almost all mediums can obtain them in this way by keeping perfectly quiet and having patience. But one would say that the execution of the movement acts as a determining cause. It seems as if the accumulated energy received a kind of stimulus.