| Angle: | 1° | 30' | 15' | 9' | 7' | 6' | 5' | 3' | 2' |
| Distance between the centres of two neighboring papers: | 131 | 65 | 33 | 20 | 15 | 13 | 11 | 6½ | 4mm. |
| Percentage of correct inferences: | 80 | 79 | 78 | 81 | 84 | 80 | 77 | 68 | 68% |
Beginning with an angle of 1' (distance between the centers of two neighboring papers = 2 mm.), the subject was unable to focus, with sufficient steadiness of vision, upon one paper alone, and the movements, for that reason, ceased to manifest themselves. Comparing the results obtained in the case of this subject with those obtained from two others, whose reactions had remained normal, B. and Miss St., we find that with them there were only 53% correct inferences in both cases (based each upon 200 tests), when the angle was 5'. In my errors, too, I often shot wider of the mark. In another series of 200 tests, in which Miss St. "merely thought of the places", I had a percentage of 56% correct inferences, and my errors did not become any coarser. Miss St. believed this a case of true telepathy, but I had been guided in my judgments entirely by her unwittingly made movements—or rather the direction—of her eyes. The magnitude of these movements bore a constant relationship to the distance between papers as it was conceived by the subject.
Reviewing the experiments discussed in this chapter, we find that the same kind of movements and postures, which had been noted in persons experimenting with the horse, tended to recur in the laboratory, in so far as the mental attitude of the subjects, given in their introspective accounts, corresponded with that of the questioners of the horse.
FOOTNOTES:
[N] It was Charles Darwin[7] who first pointed out that the expressive movements (of the coarser sort) to be noted in nearly every race and people show a great, though by no means complete, similarity. The similarity is most pronounced in the shaking of the head to signify negation and nodding to denote affirmation. It will be noted that the former is essentially of the nature of a turning toward, and the latter a turning away.[8] These same movements have been reported in the case of the blind and deaf Laura Bridgman,[9] and we have been explicitly assured that they were a spontaneous development, and not acquired by imitation. For it is by imitation and never before the completion of the first year, that our children acquire these movements. On account of his unreliability, we can put but little stock in the statement of Garner,[10] a writer on the speech of monkeys, that these same gestures have been observed in the case of those animals. My experiments show that the same movements, greatly diminished in scope, as a rule accompany the mere thought of "yes," "no," etc. I cannot, however, regard the assertion as an established fact that every thought process whatsoever is connected with some form of muscular movement, as has been generalized by the French physiologist Féré,[11] and the American psychologist Wm. James.[12]
[O] The productions of mind-readers, so-called, also, are based upon the perception of involuntary movements, insofar as they are not based upon pre-arranged schemes and trickery. But there we have to do principally with tactual perception, since the reader touches the hand of the subject and is guided by its tremor. Some of the expert mind-readers, however, conduct tests without touching the subject. They depend chiefly upon auditory impressions: the sound of footsteps,[13] involuntary whisperings[14] and the changes in the subject's respiration[15] and the murmuring of the spectators. To a less degree visual signs also are involved: posture and facial expression of the subject, and movements of eyes and lips.[16] Even the heat radiating from the person's body is supposed to have some influence.[17] And my own experience has taught me that surprising results may be obtained by the utilization of the movements described in the preceding chapter.
It may be that these truly microscopic movements also play some part in bringing about the success of some of the experiments in telepathy, so-called, (transference of thought from one person to another, ostensibly without any mediation of the senses known to us.) In spite of the huge mass of "experimental evidence" which has been collected, chiefly in England and in America, it appears to me that telepathy is nothing but an unproven hypothesis based upon experimental errors.
[P] For registering the curves a Hering kymograph was used, with a loop 2½ metres long. The kymograph rested on felt. With the aid of the Marey model a pneumographic record was taken now of the thoracic, now of the abdominal, breathing, never both simultaneously, since this was extrinsic to my purpose, and it would have made the whole experiment too complex. The time was recorded by means of the Jacquet chronograph. For purposes of making more exact measurements the acoustic current interrupter of Bernstein was used, attuned to 100 vibrations per second. But this necessitated such rapid revolution of the drum of the kymograph that the curves were not compact enough for purposes of demonstration. The levers were all fitted with micrometer adjustments. They wrote tangentially and, except the one registering the breathing curve, all points lay in one vertical line. The error of deflection and that due to the rondure of the writing-surface were both very slight on account of the comparative length of the levers and the small extent of the excursions, and for that reason synchronous points lie practically in one perpendicular. Only the breathing curve has been moved somewhat to the left, 7.5 millimeters in figures [6] and [7], 2 millimeters in [figure 8], 4.5 millimeters in [figure 9]. (When the breathing was very profound, as occasionally happened, the error of deflection would, of course, have to be taken into account.) The curves here used as illustrations have been reproduced in the exact size of the originals by the zinco-graphic method, though somewhat compressed vertically in order to economize space.
[Q] My own expressive movements, on the other hand, are as pronounced as ever. I still find the attempt to suppress them as difficult now as when I was working with the horse ([page 57]). I could not, of course, procure a curve of these movements of my own.
[R] Slight head movements accompanying the pulse-beat were until recently regarded as the symptom of certain diseases of the vascular system (the so-called symptom of Nusset), but H. Frenkel has now shown them to exist also in normal individuals.[19] I myself discovered such movements (lateral as well as sagittal) more or less pronounced in all the curves obtained from my subjects. The most striking case was that of a young physician whose circulatory system was perfectly healthy. In most instances I was able to note these oscillatory movements directly and to count them without much difficulty. For purposes of control the radial pulse was always determined at the same time. The observation of the phenomenon appears to be especially easy in the case of somewhat full-blooded individuals.