[Footnote 94: In many cases the post-hypnotic performance of an enjoined action, or the experience of a post-hypnotic hallucination, is associated with the partial recurrence of the hypnotic trance, or of some condition closely allied to it. Mr. Edmund Gurney has carefully investigated the question (_Proc. S.P.R._, iv. pp. 268-323. See also Delbœuf's article there quoted, "De la pretendue Veille Somnambulique," _Rev. Phil._, Feb. 1887), and has shown that, with some subjects, during the performance of the enjoined action a further command can be given, or a further hallucination imposed, and that the whole incident will have passed from memory a few seconds later. In the case of some persons hypnotised by Dr. Bramwell, and bidden to see after waking an imaginary scene in a crystal, I have myself observed that they retained no recollection a few minutes later of the scene which they had been describing; and in at least one case the subject at the time of the hallucination was apparently insensible to pain. On the other hand, as Mr. Gurney has pointed out (_loc. cit._, p. 270), "there are some cases in which no reason whatever appears for regarding the state in which the action is performed as other than normal," and the same remark apparently holds good of post-hypnotic hallucinations. And there are many persons who can see hallucinatory pictures in a crystal, a glass of water, etc., when in full health and in a perfectly normal condition. See Mr. Myers' article already referred to (_S.P.R._, vol. viii.).] [Footnote 95: _De la Suggestion_, p. 29.] [Footnote 96: _La Somnambulisme provoqué_, p. 233.] [Footnote 97: _Rev. de l'Hypnotisme_, November 1886, p. 148.] [Footnote 98: Professor Sully, to quote a recent instance, in his work on _Illusions_ in the International Scientific Series (ed. 1887), devotes less than a page and a half to the discussion of the sensory hallucinations of normal life, and sums up the subject by saying that "when not brought on by exhaustion or artificial means, the hallucinations of the sane have their origin in a preternatural power of imagination" (p. 117).]