1919] PRESIDENTIAL ADDRESS 651 press or on the careless gossip of ill-informed acquaintances. Many of our members are quite as much alive to a priori difficulties as any outsider can be. Of late years the published work of the Society has dealt rather with questions of another sort, involving telepathy, whether from living or other intelligences, and some of the most experienced and cautious investigators are of opinion that a case has been made out. Certainly some of the cross-correspondences established are very remarkable. Their evaluation, however, requires close attention and sometimes a background of information, classical and other, not at the disposal of all of us. In this department I often find my estimate of probabilities differing from that of my friends. I have more difficulty than they feel over telepathy between the living, but if I had 110 doubts there I should feel less difficulty than many do in going further. I think emphasis should be laid upon the fact that the majority of scientific men do not believe in telepathy, or even that it is possible. We are very largely the creatures of our sense-organs. Only those physicists and physiologists who have studied the subject realize what wonderful instruments these are. The eye, the ear, and the nose—even the human nose—are hard to beat, and within their proper range are more sensitive than anything we can make in the laboratory. It is true that with long exposures we can photograph objects in the heavens that the eye cannot detect; but the fairer comparison is between what we can see and what can be photographed in say T\5-th second—all that the eye requires. These sense-organs, shared with the higher animals, must have taken a long time to build up, and one would suppose that much development in other directions must have been sacrificed or postponed in that interest. Why was not telepathy developed until there could be no question about it ? Think of an antelope in danger from a lion about to spring upon him, and gloating over the anticipation of his dinner. The antelope is largely protected by the acuteness of his senses and his high speed when alarmed. But would it not have been simpler if he could know something telepathically of the lion's intention, even if it were no more than vague apprehension warning him to be on the move ? By telepathy is to be understood something more than is implied in the derivation of the word, the conveying of feeling or information otherwise than by use of the senses, or at any rate the known senses. Distance comes into the question mainly because it may exclude their ordinary operation. Some appear to think that all difficulty is obviated by the supposition of an unknown physical agency capable of propagating effects from one brain to another, acting like the transmitter and receiver in wireless telegraphy or telephony, On a physical theory of this kind one must expect a rapid attenuation with distance, not suggested by the records. If distance is an important consideration, one might expect husbands and wives with their heads within two or three feet of one another to share their dreams habitually. But there +-5, where /u, is the cosine of the angle between the secondary (or scattered) ray and the backward direction of the incident ray. W. F. S.]spheres are easily demonstrated.