Some years ago a gentleman of my acquaintance started out with the intention of constructing a telephone by means of which it would be possible to speak directly to the spirit world! He had in mind great delicacy of apparatus, a system of "relays," by means of which it would be possible to augment an initial stimulus, however slight, a magnifying apparatus which would greatly increase the volume of sound, on the lines of the ampliphone and the microphone, etc. I do not believe that very definite results were ever achieved, and he is still at work upon the problem. Needless to say, this idea of his was ridiculed in all quarters; but I myself do not see any valid reason why some such device should not succeed--provided, of course, that a spiritual world exists at all. If such a world exists, if the intelligences which reside therein can at times produce physical phenomena, then it is certainly conceivable that some energy may be set into operation which may produce the desired results--some energy which we, too, can utilize and which the spiritual entity can also manipulate; in other words, _an energy common to the two worlds_. Were such a common medium or mediator found, communication would certainly be established, and it only remains for us to discover the common energy. Personally, I believe that this intermediary is most probably _vitality_--the life-force, without the presence of which such manifestations would be impossible. A living, human being is necessary, upon whose presence these phenomena depend, and without whom they could not occur. It is thus obvious that there is a definite connection between these phenomena and _life_, which can hardly be due to chance; it must stand in some intimate and causal relation.[9] 14. Many students of psychical phenomena believe that, in the case of Eusapia Palladino, e.g., this connection is clearly discernible, and that it is upon the externalization of her vital force that many of these phenomena depend. Even the materializations are thought to be due to this same cause--due to the moulding, in space, of this plastic intermediary projected beyond the limits of her bodily organism. Certain it is that such a projection does at times take place, and it seems rational to suppose that "raps" may be due to the explosive expulsion of this neural energy after it has reached a certain "tension." One quite striking incident which has been narrated to me by a physician of my acquaintance tends rather to confirm this view. It is that, when he was trying on various occasions to move a table, _a la_ Palladino, he failed to do so, but whenever he lifted his hands away from the table, "sparkling" took place between his hands and the table-top, closely resembling the electric spark which jumps from point to point when the tension has reached a certain limit.