The various kinds of disturbed sleep taken notice of in this little work, are all so many modifications of Night-Mare, and may be all remedied by observing the rules here laid down, as they will be found to originate from one or other of the causes here specified. The regimen and treatment I have recommended are directed to the root of the disease, that is, to the hypochondriac or hysteric temperament; for Night-Mare, disturbed sleep, terrific dreams, &c. may be considered only as symptoms of great nervous derangement, or hypochondriasis, and are a sure sign that this disease exists to a great extent. Thus, while the patient is seeking, by the means recommended, to get rid of his Night-Mare, he will find his general health improving, and the digestive organs recovering their proper tone. THE INCUBUS, &c. This disease, vulgarly called Night-Mare, was observed and described by physicians and other writers at a very early period. It was called by the Greeks, εφιαλτης, and by the Romans, _Incubus_, both of which names are expressive of the sensation of weight and oppression felt by the persons labouring under it, and which conveys to them the idea of some living _being_ having taken its position on the breast, inspiring terror, and impeding respiration and all voluntary motion. It is not very surprising that persons labouring under this extraordinary affection, should ascribe it to the agency of some dæmon, or evil spirit; and we accordingly find that this idea of its immediate cause has generally prevailed in all ages and countries. Its real nature has never been satisfactorily explained, nor has it by any means met with that attention from modern physicians which it merits: indeed it scarcely seems to be considered by them as a disease, or to deserve at all the attention of a physician. Those, however, who labour under this affection to any great degree, can bear testimony to the distress and alarm which it occasions; in many cases rendering the approach of night a cause of terror, and life itself miserable, from the dread of untimely suffocation. The little attention paid to this disease by medical men, has left the subjects of it without a remedy, and almost without hope. Its nature and its cause have been altogether misunderstood by those who have lately given any opinion upon it. It appears a general opinion that it only happens to persons lying upon the back, and who have eaten large suppers; the causes of it have consequently been traced to mechanical pressure upon the lungs, arising from a full stomach; and a change of position, together with the avoiding eating any supper, has been thought all that was necessary to prevent its attack. To those, however, who are unfortunately afflicted with it to any degree, it is well known by experience, that no change of position, or abstinence, will secure them from the attacks of this formidable disturber of the night. As I have so long been an unfortunate victim to this enemy