Much may be done also by suitable mental training. The reading of exciting fictions, and the witnessing of sensational theatrical exhibitions, are always prejudicial to persons subject to attacks of somnambulism.
CHAPTER VIII.
THE PATHOLOGY OF WAKEFULNESS.
As nations advance in civilization and refinement, affections of the nervous system become more frequent, because progress in these directions is necessarily accompanied by an increase in the wear and tear of those organs through which perceptions are received and emotions excited; and, in addition, the mode of life, as regards food, clothing, occupation, and habits, is being constantly removed farther from that standard which a regard for hygienic considerations would establish as most advantageous. If, as we have every reason to believe, each thought involves the destruction of a certain amount of nervous tissue, we can very well understand why, as we go forward in enlightenment and in all the elements of material and intellectual progress, we are at the same time, unless we also advance in the knowledge of the laws of our being, hurrying ourselves with rapid strides to a state of existence in which there is neither waste nor repair.
I am far, however, from desiring to be understood as intimating that a high state of civilization is antagonistic to long life or health. What is lost in these directions as regards the nervous system is more than made up by the increased provision afforded for comfort in other ways. But while we have improved the hygienic condition of our cities and dwellings; while we as a rule clothe our bodies according to the principles of sanitary science and common sense; and while cleanliness of person has become the rule, and filthiness the exception, we have made little or no progress in the hygienic management of those organs which place us in relation with the world, and a healthy condition of which is so essential to our happiness.
Among the many derangements in the normal operation of the nervous system, induced by irregular or excessive cerebral action, those which relate to the function of sleep are certainly not the least in importance, whether regard be had to the actual comfort of the individual or to the serious consequences to which they may give rise. To the consideration of some of these morbid conditions I propose to devote the remainder of the present volume, and first to inquire into the most important of them, wakefulness or insomnia.
As a symptom of various diseases which affect the human organism, wakefulness is sufficiently well recognized by systematic writers on the practice of medicine, though, even here, it is very certain that its pathology has seldom been clearly made out. As a functional disorder of the brain, arising from inordinate mental activity, it has received scarcely any notice. This neglect has, doubtless, been in a great measure due to the fact that it is only within late years that the condition in question has become so common as to attract much attention. At present there are, probably, but few physicians engaged in extensive practice in any of our large cities who do not in the course of the year meet with several cases of obstinate wakefulness, unaccompanied, in the early stages at least, by any other prominent disorder of the system.
In my opinion, no one cause is so productive of cerebral affections as persistent wakefulness, for not only is the brain prevented from obtaining rest, but it is kept in a state of erethism, which, if not relieved, must sooner or later end in organic disease. Southey laid the seeds of that disorder which terminated in the loss of his intellect, by watching at the bedside of his sick wife during the night, after the excessive literary labors of the day.[121] Newton’s mind also suffered in the later years of his life through deprivation of sleep;[122] and Dr. Forbes Winslow, in remarking on Southey’s case, says: “No brain can remain in permanent health that has been overtasked by nightly vigils still more than by daily labor.”[123]