Gall relates the case of a miller, who every night got up and worked in his mill, _asleep_; and Martinet, of a saddler, who also worked nightly in his sleep; and Dr. Pritchard, of one who had been subject to epileptic fits, thus: “They ceased entirely until the nineteenth year of his age, when he became a somnambulist, working during the night at his trade as a saddler, getting out on the roof of the house, going out to walk, and occupying himself in a thousand various ways. Soon after this the fits of epilepsy reappeared, occurring every five or six days, increasing in duration, and commencing from that time only with a sensation of heat, which from the _epigastrium_ rapidly extended to the head, and produced complete insensibility. He was, at various times, relieved by bleeding; and, in the twenty-fourth year of his age, being then a soldier, he escaped three months without a return of his epilepsy. In the following year, he was astonished to find himself one night on the roof of the house, wet with rain; the impression which he thence conceived, produced, some time afterwards, an attack of epilepsy, followed by contraction of his fingers and toes.” In many cases, however, there is some predeterminate motive for the walk, which excites the memory in the sleep. The somnambulist has been _thinking deeply, ere he retires to rest_, and the walk occurs early in the night; so that we might believe a mood of musing had really _prevented sleep_, and itself been the cause of the phenomena. Thus may be explained the miracle recorded by Fulgosius. Marcus, the freedman of Pliny, dreamed that a barber, sitting on his bed, had shaved him, and awoke well trimmed;—Marcus had _unconsciously shaved himself_. And also other cases related by Dr. Pritchard, of which I will offer you a fragment. “——He is just recovering from a singular state of reverie, in which he has passed twenty-four hours. It began in the evening, with a _rigor_, which continued more or less the whole night. From that time he remained constantly in motion, walking up and down the room or about the house. He kept his eyes open, but was unconscious of external impressions; sometimes he muttered to himself, and by his gestures and the motions of his hands it appeared that he fancied himself to be working in his usual occupation. In this state he remained all the ensuing night and a part of the following day. During that time, he never ate or drank any thing in a natural manner; he sometimes caught hold of a piece of bread, and, having bitten it hastily, threw it down, and drank in the same way, immediately continuing his work. If he was spoken to, he was some time without taking any notice, and then would reply hastily, as a person does who is disturbed by a question when in a reverie.” Our study of these curiosities of mind teaches us how intimately combined in their essence are all the species of illusion.