lights and lights of other colours should be tried, to see whether they affect the phenomena in any manner. These are but a few of the many tests and experiments that might be made, and which would doubtless suggest themselves to the mind of the investigator as soon as the legitimacy of the subject were once granted. Again, in the case of telepathy. Once the facts were proved, the fascinating study of the laws and causes would begin. Under what mental, physical, and, possibly, spiritual conditions does telepathy operate? What is the best mental condition of the agent? of the percipient? What would be the effect of hypnotic trance? What of dreams? (These are not original ideas, but they have never been followed out as they should be, and might be, if the subject were pursued scientifically as other questions in science are.) Again, might not telepathy be facilitated if we chose individuals of the same general temperament? If we chose two individuals to whom the same chord on the piano appealed (say the common chord of G minor or C sharp), and this chord were struck repeatedly, might not telepathic transmission be facilitated under such conditions? If both subjects were hypnotized, and the agent were told to "will" certain figures, etc., might not the percipient receive them more easily? If both agent and percipient were placed in a strong magnetic or high-tension electric field, might not this in some way influence communication? Again, these are but a very few of the experiments which might be tried, once telepathy became an accepted fact. In the case of clairvoyance the field is even greater, but here more original work has been done, owing largely to the fact that many of the experiments have been conducted upon subjects in the hypnotic trance, and hence more fully resembled "laboratory experiments." Still, much remains to be done, particularly in the realm of the _explanation_ of clairvoyance, and in the investigation of the neural and general physiological concomitants of the condition. In the field of "thought-" and "spirit-photography," the possibilities of research and experimentation are obvious and almost unlimited. The recent researches of Dr. Ochorowicz in "radiographs," and of Commandant Darget in thought-photography and the so-called V-rays, are of extreme importance, if true. Here is a field which any one may invade; and, with the aid of a camera and specially sensitive plates, might accomplish really valuable and striking results. Very rarely have attempts been made to photograph apparitions (probably because they were too fleeting and unexpected), and the forms at seances have been photographed on only a few occasions. The human "aura"--granting it exists--should certainly be capable of being photographed, under certain conditions, as well as the radiation said to issue from magnets, crystals, etc., as explained by Reichenbach.