406. Equally remarkable are the hypnopompic pictures, as I have termed them; those, namely, which accompany the departure of sleep. For it often happens (as in the cases cited by Gurney in Phantasms of the Living) that a figure which has formed part of a dream continues to be seen as a hallucination for some moments after waking; - a strong testimony to the vividness of dream-visualisation. The generation of a hallucinatory figure (however useless an achievement) marks probably the highest point which man's visualising faculty ever reaches; and it is noteworthy that with most persons this point should be attained in dream alone. Sometimes, it may be, this prolongation of hallucination may best be described as an after-image, sometimes as the result of a "suggestion" inspired by the dream. In these hypnopompic cases the vivid visualisation seems to originate in sleep; while in illusions hypnagogiques the vividness belongs to an intermediate phase.

407. The degree of acuteness of all the senses in dream is a subject for direct observation, and even - for persons who can at all control their dreams - for direct experiment. I have elsewhere described' some efforts of my own to test my own power of visualisation in dream; with the result, as I must confess, that I have not found it superior to my very low waking capacity. Some correspondents, however, report a considerable apparent accession of sensory power in dream. An impressive dream, dreamt by Mrs. A. W. Verrall, of Cambridge, and at once carefully recorded, had for its theme an intensification of each sense in turn. Mrs. Verrall has poor musical perceptions, and when told in her dream that the sense of sound was next to be exalted, she anticipated little pleasure. The sensation came, however, as something entirely new, - as " very harmony, which I had only heard till then in echoes, - in the rhythm of verse, or in the sighing of the wind among the pine-trees. My hearing was purified, not by the fulfilment of desire, but by the creation of desire, which in its very birth attained fruition." (See Dr. Hodgson's experience in 407 A.) Others speak of the increased vividness of dramatic conception, or of what has been called in a hypnotic subject " objectivation of types." "In each of these dreams," writes one lady, "I was a man; - in one of them a low brute, in the other a dipsomaniac.

I never had the slightest conception of how such persons felt or thought until these experiences." Another correspondent speaks of dreaming two disconnected dreams, one emotional and one geometrical, - simultaneously, and of consequent sense of confusion and fatigue.

1 S.P.R. Proceedings, vol. iv. p. 241.

408. The "Chapter on Dreams," in R. L. Stevenson's volume, Across the Plains (already referred to in Section 314), contains a description of the most successful dream-experiments thus far recorded. By self-suggestion before sleep Stevenson could secure a visual and dramatic intensity of dream-representation which furnished him with the motives for some of his most striking romances. His account, written with admirable psychological insight, is indispensable to students of this subject. I am mentioning these well-known phenomena, as the reader will understand, with a somewhat novel purpose - to show, namely, that the internal sensory perceptions or imaginative faculty of sleep may exceed that of vigilance in something the same way as the recuperative agency of sleep surpasses the vis medicatrix of waking hours.

409. I pass on to a less frequent phenomenon, which shows us at once intense imagination during sleep, and a lasting imprint left by these imaginations upon the waking organism; - an unintended self-suggestion which we may compare with Stevenson's voluntary self-suggestion mentioned just above.

The permanent result of a dream, I say, is sometimes such as to show that the dream has not been a mere superficial confusion of past waking experiences, but has had an unexplained potency of its own, - drawn, like the potency of hypnotic suggestion, from some depth in our being which the waking self cannot reach. Two main classes of this kind are conspicuous enough to be easily recognised - those, namely, where the dream has led to a "conversion" or marked religious change, and those where it has been the starting-point of an "insistent idea" or of a fit of actual insanity.1 The dreams which convert, reform, change character and creed, have of course a primâ facie claim to be considered as something other than ordinary dreams; and their discussion may be deferred till a later stage of our inquiry. Those, on the other hand, which suddenly generate an insistent idea of an irrational type are closely and obviously analogous to post-hypnotic self-suggestions, which the self that inspired them cannot be induced to countermand. Such is the dream related by M. Taine,2 where a gendarme, impressed by an execution at which he has assisted, dreams that he himself is to be guillotined, and is afterwards so influenced by the dream that he attempts suicide.

Several cases of this kind have been collected by Dr. Faure;8 and Dr. Tissié, in his interesting little work, Les Rêves, has added some striking instances from his own observation. I quote, in 409 A, one of M. Faure's cases as a sample, showing that in an apparently healthy subject an apparently causeless dream may leave traces quite as persistent as any hypnotic suggestion could implant from without. The dream is in fact a self-suggestion of the most potent kind. The case of Dr. Holbrook (409 B) seems to belong to the same category.