In this way we could understand motor phenomena. Raps are less easily explained, unless we consider them as facts analogous to electrical discharges. The rap would then be equivalent to the noise of a spark; it would be invisible, though in some cases it might be perceived.
Lights and forms raise problems much more difficult of solution. They may be susceptible of the following explanation: we will suppose that particles of a very attenuated substance, e.g. the ether or any other kind of rarefied matter, existed capable of being acted upon by nerve force; they would become charged, and dispersed, according to the lines of force, and these lines would be determined by the action of nerve centres, and would take form corresponding to those particular centres. They would have a certain plasticity, if I may thus express myself, and this plasticity would be in connection with those centres, possessing preponderating physiological activity.
If this connection existed with the superior ideative centres, we would have intelligible, definite forms, such as faces of human beings, heads of animals, and objects; should connection with the inferior centres be established, undefined forms only would be obtained.
Their luminosity would depend upon the state of condensation of this rarefied matter of which they are constituted. Those subject to lesser condensation would be the most luminous; and it might happen, that a form of greater density would be surrounded by a luminous atmosphere of lesser density.
One could, in this way, explain the relative independence of the forms, and phosphorescent nature of the pictures.
These are the hypotheses which might be made. I indicate them with much reserve, simply to show the theoretical route towards which my experience tends to direct me. I set them forth summarily, without discussing them in detail. I do not conceal from myself the fact that my ideas are far from being definite, and that the hypotheses I timidly express would fare badly under rigorous analysis. I have found no better, and I have the impression that they ought to contain a particle of truth.
I beg to be excused for having again infringed upon the rule I imposed on myself, for having presented purely theoretical considerations, which I am the first to acknowledge as premature. I have not seen the curious facts I relate without trying to penetrate into their cause, nor have I been able to resist the desire to make known, not what is a definite opinion, but what is for me a hypothesis worth examining.
Besides the phenomena described in this and preceding chapters, I have observed others which might be compared with them, for they seem to me to have a certain connection with them. I refer to tactile sensations such as touch, contact, and stamped impressions, etc. I will briefly describe them.
I. It is only with Eusapia Paladino, that I have felt tactile sensations in a positive manner. With this medium certain sitters, and especially those seated next to her, have the feeling of being touched on the back, on the arms, and hands, on the head and body. The phenomenon is usually produced under the following conditions. Eusapia’s hands being or appearing to be held by her neighbours, the latter see the curtains come near them, and then feel themselves touched. The touch is sometimes given without any movement of the curtains. The sensation of the touch varies: it is now that of a finger which is thrust into the thigh, now of a large hand resting on the back, now fingers pinching you, or seizing you on the head, the neck, chin, etc. Numerous examples of these contacts will be found in the report of the l’Agnélas experiments (Annales des Sciences Psychiques, 1896).
In our seances at Choisy 1896, the same phenomenon was often reproduced. In that series we were careful to have as much light as possible; we arranged a system of different coloured lights. One of the lights which gave us the best results was that of a lantern, the glass sides of which were replaced by parchment. It gave a softened yellowish light. From the private account of these seances I take the following extracts. Seance of the 8th October:—