When, by confinement and this process, the air is deprived of its appropriate supply of oxygen, the purification of the blood is interrupted, and it passes, without being properly prepared, into the brain, producing languor, restlessness, and inability to exercise the intellect and feelings. Whenever, therefore, persons sleep in a close apartment, or remain for a length of time in a crowded or ill-ventilated room, a most pernicious influence is exerted on the brain, and, through this, on the mind. A person who is often exposed to such influences can never enjoy that elasticity and vigor of mind which is one of the chief indications of its health. This is the reason why all rooms for religious meetings, and all school-rooms and sleeping apartments, should be so contrived as to secure a constant supply of fresh air from without. The minister who preaches in a crowded and ill-ventilated apartment loses much of his power to feel and to speak, while the audience are equally reduced in their capability of attending. The teacher who confines children in a close apartment diminishes their ability to study, or to attend to instructions. And the person who habitually sleeps in a close room impairs mental energy in a similar degree. It is not unfrequently the case that depression of spirits and stupor of intellect are occasioned solely by inattention to this subject.
Another cause of mental disease is the excessive exercise of the intellect or feelings. If the eye is taxed beyond its strength by protracted use, its blood-vessels become gorged, and the bloodshot appearance warns of the excess and the need of rest. The brain is affected in a similar manner by excessive use, though the suffering and inflamed organ can not make its appeal to the eye. But there are some indications which ought never to be misunderstood or disregarded. In cases of pupils at school or at college, a diseased state, from overaction, is often manifested by increased clearness of mind, and temporary ease and vigor of mental action. In one instance, known to the writer, a most exemplary and industrious pupil, anxious to improve every hour, and ignorant or unmindful of the laws of health, first manifested the diseased state of her brain and mind by demands for more studies, and a sudden and earnest activity in planning modes of improvement for herself and others. When warned of her danger, she protested that she never was better in her life; that she took regular exercise in the open air, went to bed in season, slept soundly, and felt perfectly well; that her mind was never before so bright and clear, and study never so easy and delightful. And at this time she was on the verge of derangement, from which she was saved only by an entire cessation of all intellectual efforts.
A similar case occurred, under the eye of the writer, from overexcited feelings. It was during a time of unusual religious interest in the community, and the mental disease was first manifested by the pupil bringing her hymn-book or Bible to the class-room, and making it her constant resort in every interval of school duty. It finally became impossible to convince her that it was her duty to attend to any thing else; her conscience became morbidly sensitive, her perceptions indistinct, her deductions unreasonable; and nothing but entire change of scene and exercise, and occupation of her mind by amusement, saved her. When the health of the brain was restored, she found that she could attend to the “one thing needful,” not only without interruption of duty or injury to health, but rather so as to promote both. Clergymen and teachers need most carefully to notice and guard against the dangers here alluded to.
Any such attention to religion as prevents the performance of daily duties and needful relaxation is dangerous, and tends to produce such a state of the brain as makes it impossible to feel or judge correctly. And when any morbid and unreasonable pertinacity appears, much exercise and engagement in other interesting pursuits should be urged, as the only mode of securing the religious benefits aimed at. And whenever any mind is oppressed with care, anxiety, or sorrow, the amount of active exercise in the fresh air should be greatly increased, that the action of the muscles may withdraw the blood which, in such seasons, is constantly tending too much to the brain. At the same time, innocent and healthful amusement should be urged as a duty.
There has been a most appalling amount of suffering, derangement, disease, and death, occasioned by a want of attention to this subject, in teachers and parents. Uncommon precocity in children is usually the result of an unhealthy state of the brain; and in such cases medical men would now direct that the wonderful child should be deprived of all books and study, and turned to play out in the fresh air. Instead of this, parents frequently add fuel to the fever of the brain, by supplying constant mental stimulus, until the victim finds refuge in idiocy or an early grave. Where such fatal results do not occur, the brain in many cases is so weakened that the prodigy of infancy sinks below the medium of intellectual powers in after-life.
In our colleges, too, many of the most promising minds sink to an early grave, or drag out a miserable existence, from this same cause. And it is an evil as yet little alleviated by the increase of physiological knowledge. Every college and professional school, and every seminary for young ladies, needs a medical man or woman, not only to lecture on physiology and the laws of health, but empowered by official capacity to investigate the case of every pupil, and, by authority, to enforce such a course of study, exercise, and repose as the physical system requires. The writer has found by experience that in a large institution there is one class of pupils who need to be restrained by penalties from late hours and excessive study, as much as another class need stimulus to industry.
Under the head of excessive mental action must be placed the indulgence of the imagination in novel-reading and “castle-building.” This kind of stimulus, unless counter-balanced by physical exercise, not only wastes time and energies, but undermines the vigor of the nervous system. The imagination was designed by our wise Creator as a charm and stimulus to animate to benevolent activity, and its perverted exercise seldom fails to bring a penalty.
Another cause of mental disease is the want of the appropriate exercise of the various faculties of the mind. On this point Dr. Combe remarks: “We have seen that, by disuse, muscles become emaciated, bone softens, blood-vessels are obliterated, and nerves lose their characteristic structure. The brain is no exception to this general rule. The tone of it is also impaired by permanent inactivity, and it becomes less fit to manifest the mental powers with readiness and energy.” It is “the withdrawal of the stimulus necessary for its healthy exercise which renders solitary confinement so severe a punishment, even to the most daring minds. It is a lower degree of the same cause which renders continuous seclusion from society so injurious to both mental and bodily health.”
“Inactivity of intellect and of feeling is a very frequent predisposing cause of every form of nervous disease. For demonstrative evidence of this position, we have only to look at the numerous victims to be found among persons who have no call to exertion in gaining the means of subsistence, and no objects of interest on which to exercise their mental faculties, and who consequently sink into a state of mental sloth and nervous weakness.” “If we look abroad upon society, we shall find innumerable examples of mental and nervous debility from this cause. When a person of some mental capacity is confined for a long time to an unvarying round of employment which affords neither scope nor stimulus for one half of the faculties, and, from want of education or society, has no external resources; the mental powers, for want of exercise, become blunted, and the perceptions slow and dull.” “The intellect and feelings, not being provided with interests external to themselves, must either become inactive and weak, or work upon themselves and become diseased.”
“The most frequent victims of this kind of predisposition are females of the middle and higher ranks, especially those of a nervous constitution and good natural abilities; but who, from an ill-directed education, possess nothing more solid than mere accomplishments, and have no materials for thought,” and no “occupation to excite interest or demand attention.” “The liability of such persons to melancholy, hysteria, hypochondriasis, and other varieties of mental distress, really depends on a state of irritability of the brain, induced by its imperfect exercise.”