“While studying sensitivity of photographic plates to electron rays it suddenly was realized that polished metal surfaces might be able to pick up impressions of these beams, and when tests were made they showed that not only could such records be made on metals, but the amazing fact appeared that some metals are almost as sensitive as photographic film, and for very low velocity electrons much more sensitive.... “This young physicist one day was looking at the rough spots produced on the metal target of an x-ray tube by electron bombardment. Such spots are commonplace, familiar sights to laboratory workers. It occurred to Dr. Carr that perhaps long before the electrons produced the rough place they made an invisible impression, which might be ‘developed’ in the same manner that the still invisible image on a photo is brought out by putting it into a developing bath. Carr shot the electron rays at gold plates and developed them with mercury vapor, he shot them at silver and developed with iodine, he used hydrochloric acid to develop zinc plates and iodine to develop copper.” And now, if x-rays leave a permanent record on metal, why might not brain-rays, or thought-rays, leave a record upon a piece of paper? Why might not such energies be reflected back to another brain, as light is reflected by a mirror? Or perhaps the record might stay as some other form of energy, turned back into brain-rays or thought-rays by the percipient. We are familiar with this in the telephone, where sound vibrations are turned into electrical vibrations, and in this form transported across a continent and under an ocean, and then turned back into sound vibrations once again. That mental activities do leave some kind of record on matter seems certain; at any rate, it is the basic concept of the materialistic psychologist. For what is memory, to the materialist, but some kind of record upon brain cells? He compares these cells to photoelectric cells, and imagines a lot of stored up records which we can consult. If now it should be found that such memory records are impressed, not merely upon living brain cells, but upon the molecules or electrons which compose any form of matter, what would be so incredible about that? I have gone this far, in the effort to meet my materialist friends halfway. For my part, I have no metaphysics; I am content to say that I do not know what matter is, nor what mind is, nor how they interact. If you want to realize the inadequacies of the materialistic dogma, so far as concerns this special field, you may consult the work of Dr. Rudolph Tischner, a qualified scientist of Germany, whose book, _Telepathy and Clairvoyance_, is published in translation by Harcourt, Brace and Company. The last chapter, called “Theory,” deals with the suggested explanations in more detail than I have the space for here. _24_