He started off that day, and returned in exactly a week, having, as he said, slept eight hours every night during his absence. All his disagreeable symptoms had disappeared, and he was enabled to resume his business with his mental faculties in their full vigor. * * * * * 2d. _Those positions of the body which tend to impede the flow of blood from the brain, and at the same time do not obstruct its passage through the arteries, while causing hyperæmia, also produce insomnia._ Several cases have come under my observation in which the influence of position as affecting the disposition to sleep was well marked. It is very evident that the recumbent posture is more favorable to a state of congestion of the brain than the erect, or semi-erect. Individuals who, by excessive mental exertion, have lessened the contractility of the cerebral vessels, almost always experience great difficulty in getting to sleep after lying down, even though previous to so doing they may have been very drowsy. A gentleman, who was a patient of mine a few weeks since, informed me that several years ago he had an attack of wakefulness, which lasted for three or four months, and which was particularly characterized by inability to sleep while lying in bed. While sitting in his office he would often fall asleep in his chair, and previous to going to bed he would be overcome by drowsiness. The moment, however, that he lay down, his mind was aroused into activity, and all sleepiness disappeared. He left off work, traveled, and in a short time recovered perfectly. It will be recollected that in the other cases I have cited in this memoir, the phenomena were always more strongly marked after the persons affected lay down; and I have always insisted upon the avoidance of the recumbent posture as one of the most important means to be employed in the cure of insomnia. The following is one of the cases referred to above.