NOTES. 155

caprice of his own mind, suggests, is a not uncommon and a very interesting phenomenon. It was observed, for instance, by Elliotson, who pointed out a good many hypnotic peculiarities which his successors are now gradually rediscovering. It is a hypnotic exaggeration of a familiar phenomenon, namely, of the large infusion of erroneous inference which we most of us import into the account which we render to ourselves of our ordinary sensations. A particularly curious case is briefly described in the Journal of the Society for Psychical Research, June, 1884. A man was brought to us who, when hypnotised, could often name cards held in front of him, although his eyes had been plastered up and bandaged in a most elaborate way. The man's friends took this for clairvoyance, and the man assented, being sure that he could not see the cards in the usual way. They ' flashed upon him,' as he said. Now after a good deal of puzzling over the case, Mr. R. Hodgson found that he also could sometimes manage to see over similar bandages, through small chinks between the skin and the paper gummed over the eyes. *" But he, too, found that he saw fitfully, the power of vision seeming to come and go, and he actually could not tell with which eye he was seeing, except by covering each eye in turn with his hand. The distorted position of the eyeball, and the minute and oddly-placed channels of vision, produced so much confusion that there seemed no reason to suppose that the hypnotised subject's belief that he was seeing 'clairvoyantly' was other than genuine. The case of M. Bergson's boy seems to have been a similar one. And his idea that he was reading from the book seems to have been a sort of com- promise between the feeling that he was reading somewhere and the hypno- tiser's suggestion that the words were being transferred supernormally from mind to mind. Thus far, then, M. Bergson's narration and explanation seem credible enough, and his argument as against thought-transference in this boy's case seems well made out. But he proceeded to further experiments which, as recounted, seem incredible, and which may lead some readers to distrust the accuracy of the whole series. To explain the difficulty, I must first point out that the word hyperses- thesia is loosely used for three different classes of phenomena. It is used (1) for an exaggeration of the familiar action of specialised organs, as when the eye is sensible to very small amounts of light. It is used (2) for alleged perceptions, which would imply a specialisation of what I may term our undifferentiated fund of nervous sensibility in novel directions. Sensibility to the action of magnets, of metals in contact, of medicaments at a distance, may or may not exist, but should scarcely be called by the same name as (say) the eye's extra sensitiveness to light. And again, the word is used (3) for cases where our non-specialised organs are credited with performing functions which, so far as we can see, demand a definite sense-specialisation, or our specialised organs are credited with functions which, on measurable anatomical grounds, appear to overpass the limits of their specialisation. This last class of cases must be received with extreme caution. Well, M. Bergson says that he showed the boy a microscopic photograph of twelve men, its longest diameter 2 mm., and that the boy saw and imi- tated the attitude of each man. Also that he showed the boy a microscopic preparation, involving cells not greater than '06 mm. in diameter, and that the boy saw and drew these cells. Now I might, in the first place, object that thought-transference was not formally excluded, since M. Bergson himself knew the photograph and the look of the cells. I do not press this, for the other experiments seem to me to negative thought-transference in this case ; I merely point out that