Page:Mind (Old Series) Volume 9.djvu/425

 VISUAL HALLUCINATIONS IN HYPNOTISM. 413 and which a man however wise and well informed could not possibly foresee, I have nothing to say, but I have found that the more carefully I inquired, whether it was into the facts of hereditary similarities of conduct, into the life-histories of very like or of very unlike twins, or now introspectively into the pro- cesses of what I should have called my own Free-will, the smaller seems the room left for the possible residuum. VISUAL HALLUCINATIONS IX HYPNOTISM. By ALFRED BINET. I offer the following summary of experiments made upon five hysterical girls at the Hospice de la Salpetriere in Paris ; having treated the subject at greater length in the Revue Philosophique of last May. Visual hallucinations verbally suggested in the somnambulist stage of hypnotism fall under the following rule : The imaginary object is perceived under the same conditions as a real one (Ch. Fere). (1) The hallucination is suppressed by a screen, like the ex- ternal view of a real object. Some patients, however, continue to experience the hallucination in spite of the screen placed before their eyes ; but we may be sure that in these the view of real objects is subject to the same conditions, and also continues in spite of the screen. Further, attentive observation shows that in this case it is upon the screen that the subject projects the hallucinatory image. (2) The hallucination naturally takes the bilateral form, like external vision. In the absence of special suggestion the subjects perceive the imaginary object with each of the two eyes as if it were a real object. If the patient has one eye colour-blind, this eye, which cannot see real colours, is equally incapable of seeing imaginary colours ; coloured hallucinations cannot be suggested to this eye. It was the same in a case of spontaneous hallucination ob- served in an hysterical mad woman. She always saw at her left side a man dressed in scarlet ; when this patient's right eye was closed, and her left eye, which was colour-blind, alone remained open, the man in question appeared to her grey and enveloped in clouds. This rule is, however, by no means absolute. There are hyp- notics to whom coloured hallucinations can be suggested through their defective eye. The loss of the sense of colours results from a paralysis of cortical origin, and we can see that the verbal sug- gestion may overcome this paralysis in certain patients and fail in others.