Conditions of the Production and Action of the Force.—I have said that the conditions for the production of the force are little known. In the absence of precise laws, I shall present what has been verified in a greater or less degree in the case of the three following points:
a. Conditions of action relative to the operators.
b. Conditions relative to the objects to be moved.
c. Conditions relative to the mode of action of the operators upon the objects to be moved.
The Will. The first and the most indispensable condition, according to M. Gasparin, is the will of the operator. "Without the will," he says, "we obtain nothing; we might sit there in chain twenty-four hours in succession without getting the slightest movement." Farther on, the author speaks, it is true, of unexpected movements different from those which the will prescribes; but it is evident that he is referring to a necessary combination of prescribed movements and external resistances, the effective movements being the resultant of those that have been willed and of forces of resistance developed in external objects. In short, the will is always the prime mover and originator.
Nothing, it is true, in the experiments at Valleyres gave any authority for believing that it could be otherwise than this. But it is also certain that this purely negative result, or provisional generalization, deduced from a limited number of experiments,—cannot invalidate the results of experiments inconsistent with those, in case such should exist. In other words, the will may ordinarily be necessary, without always being so. Similarly, contact is ordinarily necessary, and always has been so with a large number of operators, without, however, giving them the right to conclude that contact is the indispensable condition of the phenomenon, and that the different results obtained at Valleyres were only illusions or error.
Since we are dealing here with a point of capital importance, I shall take the liberty of stating with some detail circumstances which seem opposed to the thesis maintained by M. Gasparin. These facts, or data, have as guarantee the testimony of a man whom I should like to be able to name, because his scientific culture and his character are known of all men. It was in his house and under his eyes that the events took place which I am going to relate.
At the time when everyone was amusing himself with making tables turn and speak, or in directing the motions of lead-pencils, fixed in movable sockets, over sheets of paper, the children of the house amused themselves several times with this sport. At first, the responses obtained were such that you could see in them a reflex of the unconscious thought of the operators, a "dream of waking performers." Soon, however, the character of the replies seemed to change. It seemed as if what they revealed could hardly have emanated from the mind of the young interrogators. Finally, there was such an opposition to the commands given that M. N., uncertain as to the true nature of these manifestations in which a will different from the human will seemed to appear, forbade their being called forth again. From that time forth, sockets and table rested undisturbed.
A week had scarcely rolled by, after the events just narrated, when a child of the family, he who had formerly succeeded best in the table experiments, became the actor, or the instrument, in strange phenomena. The boy was receiving a piano-lesson, when a low noise sounded in the instrument, and it was shaken and displaced in such a way that pupil and teacher closed it in haste and left the room. On the next day, M. N., who had been informed of what had happened, was present at the lesson, given at the same time,—namely, when the dusk was coming on. At the end of five or ten minutes he heard a noise in the piano difficult to define, but which was certainly the kind of sound one would expect a musical instrument to produce. There was something about it musical and metallic. Soon after, the two front legs of the piano (which weighed over six hundred and sixty pounds) were lifted up a little from the floor. M. N. went to one end of the instrument and tried to lift it. At one time it had its ordinary weight, which was more than the strength of M. N. could manage; at another, it seemed as if it had no longer any weight at all, and opposed not the least resistance to his efforts. Since the interior noises were becoming more and more violent, the lesson was brought to a close, for fear the instrument might suffer some damage. The lesson was changed to the morning and given in another room situated on the ground floor. The same phenomena took place, and the piano, which was lighter than the one up-stairs, was lifted up much more; that is to say, to a height of several inches. M. N. and a young man nineteen years old tried leaning with all their might on the corners of the piano which were rising. Then one of two things happened: either their resistance was in vain, and the piano continued to rise, or else the music-stool on which the child sat moved rapidly back as if pushed or jerked.
If occurrences like that had only taken place once we might think that the child or the persons present were laboring under some illusion. But they were repeated a great number of times, for a fortnight, in the presence of different witnesses. Then, one day, a violent manifestation took place, and thenceforth no unusual event occurred in the house. At first, it was in the morning and in the evening that these perturbations manifested themselves; then, invariably at any and all hours, they occurred every time the child took his seat at the piano, after five or ten minutes of playing. The phenomena happened only with this boy, although there were others present (musicians); and it made no difference which of the pianos in the house he used.