What becomes of this enormous quantity of energy which must be liberated during the process if the dissociation theory of the phenomena is correct? Why is its liberation not apparent, and painfully apparent, to the experimenters? How is it prevented from being dissipated and how is it collected again and recondensed into matter? This point seems to me to be insuperable. If the object within the box is dissociated, then energy must inevitably be liberated. If energy is liberated, then it cannot conceivably escape detection in such quantities. I hope I have made my point clear. I am quite sure that any scientist accustomed to think in terms of energy will at once see the difficulty to which I allude. I can see only one way out and that is to suppose that in some mysterious manner the liberated energy is stored in a "reservoir," so to speak, _which is not situated in our space at all_, and this at once lets us in for the original idea of a fourth dimension and higher space and all the rest of it. Hence I maintain, and I think I have reason to maintain, that if these phenomena do actually occur at all, then we are compelled to admit that four-dimensional space does actually exist; and this no matter whether we accept as the proximate cause of the phenomena a simple four-dimensional movement or the far more elaborate and less satisfactory notion of dissociation and re-integration. The reader will now understand why it is that I attach such great importance to these phenomena of apport and of the "apparent penetration of matter by matter." If one of these phenomena could be established by absolutely incontrovertible experimental evidence, with the same degree of certainty, for instance, as the phenomenon of levitation without contact has been established by the recent researches of Crawford, I should regard the four-dimensional hypothesis as virtually proven. I should be much interested to hear whether any interested reader can get out of the difficulty, assuming the authenticity of the phenomenon for the sake of argument, but I do not think that it will prove possible. * * * * * I will now pass to the consideration of the nature of the evidence that exists for the actual occurrence of this sort of phenomenon. I will preface my remarks by two quotations from writers who appear to hold somewhat different views on the subject. In "The Physical Phenomena of Spiritualism" Mr. Hereward Carrington says: