It was a very easy way of disposing of the matter, so thoroughly scientific, and it did not involve the necessity of studying any new force or getting into trouble with any new laws of mental action; it was simply delightful, and the physiologists rubbed their hands gleefully over the apparent discomfiture of the shallow cranks who imagined they had discovered something new. There was only one troublesome circumstance about the whole affair. It was this: that cases were every now and then making their appearance which absolutely refused to be explained by the new theory of Dr. Carpenter, and the only way of disposing of these troublesome cases was to declare that the people who observed them did not know how to observe, and did not see what they thought they saw. This was the state of the question, and this the way in which it was generally regarded, when it was taken up for investigation by the Society for Psychical Research. Experiments on the subject of thought-transference fall naturally into four classes: (1) Those where some prearranged action is accomplished, personal contact being maintained between the operator and the sensitive. (2) Similar performances where there is no contact whatever. (3) Where a name, number, object, or card is guessed or perceived and expressed by speech or writing without any perceptible means of obtaining intelligence by the senses or through any of the ordinary channels of communication. (4) Where the same ideas have occurred or the same impressions have been conveyed at the same moment to the minds of two or more persons widely separated from each other. The first and second of these classes are simply examples of the "willing game" carried on under more strict conditions, but they are not counted as of special value on account of the possibility of information being conveyed when contact is permitted, and by means of slight signals, mere movements of the eye, finger, or lip, which might quickly be seized upon and interpreted by the sensitive, even when there was no actual contact. The third and fourth class, however, seem to exclude these and all other ordinary or recognizable means of communication. The following are examples of the third class, namely, where some object, number, name, or card has been guessed or perceived without the aid of the senses, and without any of the ordinary means of communication between the operator and the subject.