The most remarkable features of the experiences I am about to record are the methodical consecutiveness of their sequences, and the intelligent purpose disclosed alike in the events witnessed and in the words heard or read. . . . I know of no parallel to this phenomenon, unless in the pages of Bulwer Lytton's romance entitled The Pilgrims of the Rhine, in which is related the story of a German student endowed with so marvellous a faculty of dreaming, that for him the normal conditions of sleeping and waking became reversed; his true life was that which he lived in his slumbers, and his hours of wakefulness appeared to him as so many uneventful and inactive intervals of arrest, occurring in an existence of intense and vivid interest which was wholly passed in the hypnotic state. . . . During the whole period covered by these dreams I have been busily and almost continuously engrossed with scientific and literary pursuits, demanding accurate judgment and complete self-possession and rectitude of mind. At the time when many of the most vivid and remarkable visions occurred I was following my course as a student at the Paris Faculty of Medicine, preparing for examinations, daily visiting hospital wards as dresser, and attending lectures. Later, when I had taken my degree, I was engaged in the duties of my profession and in writing for the Press on scientific subjects. Neither had I ever taken opium, haschish, or other dream-producing agent. A cup of tea or coffee represents the extent of my indulgences in this direction. I mention these details in order to guard against inferences which might otherwise be drawn as to the genesis of my faculty. It may, perhaps, be worthy of notice that by far the larger number of the dreams set down in this volume occurred towards dawn; sometimes even, after sunrise, during a 'second sleep.' A condition of fasting, united possibly with some subtle magnetic or other atmospheric state, seems, therefore, to be that most open to impressions of the kind.