may NIGHTMARE. 559 their object may be quite trivial, and in its attainment considerable risks be run. In these cases it seems as if the mind was absolutely wrapped up in one idea, and wholly unable to comprehend any thing else. If the eyes of the somnambulist are wide open, he sees nothing, and even though a bright light be presented before him, the iris will not contract, yet he moves about in a manner as if he were, in one respect, guided by understanding, the air of his movements being as if he knew what he was about, yet in another respect as though he was impelled by the most unaccountable folly, walking along the roof of the house, seating himself on the chimney, and finding his way in safety over precipitous places, past which it would be impossible he should go if awake, no matter how steady his head might be. Besides this complete condition of somnambulism there are intermediate forms, during which the various senses of seeing, hearing, etc., are in partial activity. There are also differences in the intensity or depth of the state, as is shown by the ease or difficulty with which the individual is aroused; sometimes to speak to him is enough, sometimes he must be violently shaken or otherwise roughly treated. It has been observed in some cases that where the patient spontaneously wakens under circumstances that affright him, he is at once broken of the habit. With dreams and somnambulism is also to be classed that sensation which often surprises and disturbs us when we are just passing Sensation into sleep, a sensation as though we were suddenly falling down of falling. stairs. This, with some persons, is of almost nightly occurrence. Its opposite, an inability to move, as though we were oppressed by some great weight, or spell-bound in some incomprehensible way, is nightmare. In this distressing affection there is a sense of oppression at Nightmare: the epigastrium, and a difficulty, or rather impossibility, of its causes. moving or speaking. A frightful dream, in which some alarming object is depicted with intolerable distinctness, accompanies these symptoms, the attack terminating by a struggle to shake off the object of dread, or to escape by flight, or to speak. On awaking, the sufferer finds himself trembling with terror, the respiration hurried, and the heart throbbing violently. The intellectual faculties are on different occasions in various states of activity, and sometimes the dream, and our actions consequent upon it, offer no violation of reason. Indeed, some individuals are affected by this trouble during the daytime, when they are wide awake and perfectly aware of what is going on; but, whether it occurs by night or by day, the sentiment with which it oppresses is that of unspeakable dread. Even at night we sometimes are conscious of its approach, when we are in the intermediate state between sleeping and waking. The cause of nightmare, in all its variety of forms, is disturbance of the respiratory function, which, by interfering with the arterialization of 560 sume. OF DEATH. the blood, affects the brain. This disturbance may be brought on in many ways, as by the pressure of the stomach after a hearty supper, or in diseased conditions, such as hydrothorax; but it is popularly supposed, where these morbid conditions are not obviously concerned, to be attributed to sleeping on the back. Though this is undoubtedly true in a great many instances, it is very far from being an essential condition, for nightmare may occur in any position that the sleeper may possibly asThe restraint upon the arterialization of the blood, which appears to be its essential condition, interferes with the circulation through the lungs on the principles that have been described in a preceding chapter, nor can the heart force a passage, however violently it may throb. The effect depends not so much upon the apparent rate and power with which the respiration is going on, for any embarrassment or difficulty in the introduction of air merely leads to snoring, which is in no manner connected with nightmare. The cause of this latter affection is to be sought for in the air-cells, which are unable to rid themselves, with their accustomed facility, of the carbonic acid and other effete products of respiration which they contain. Condition of 2D. OF DEATH. At all periods of life, the functional activity of the system occasions a waste of its tissues by the interstitial death of their parts, and healthy equi- therefore involves a necessity of repair. So long as the repalibrium. ration balances the waste, a healthy equilibrium is maintained; but when the nutritive powers decline, as old age approaches, a gradual deterioration of the system ensues. The period of greatest activity is also that of greatest waste, and of the most active and perfect repair, interstitial death and the removal of decayed material then occurring in the most rapid manner. The energy of life is thus dependent on the amount and completeness of death. At a later period, with advancing years, although the loss of substance through functional activity may be lessened, the renewal and restoration of the portions which are necessarily consumed are far more than correspondingly diminished. We thus become incapacitated corporeally and mentally, and, if no accident intervenes, we die through mere old age. On several occasions we have already noticed the analogy between the life of individuals and that of species. An analogy also may molecule, of an be traced in the circumstances and causes of their death, for Death of a ganism, of a species. individual or- the discoveries of geology abundantly show that thousands of species in the organic series have become extinct. The death of a constituent molecule in an animal body, the death of the individual animal itself, the death of the species to which it belongs, are all philosophical facts of the same kind, though presenting, perhaps, in their aspect a difference of interest and importance. The death of individuals, as has been said, may occur in two ways, by acci- Death from acdent or by old age. But death from old age is very unusual, cident and by old age. for even in the cases of those who are very far advanced in life, its close is ordinarily brought about by some lesion or derangement of the vital organs, thus, in reality, constituting accidental death. Most men desire that their final scene may be attended with as little derangement as possible of their ordinary mental powers, and Euthanasia. that it may be very brief. If this constitute the euthanasia, is or happy death, it certainly can not be thought that extreme old age desirable, constituting, as it does, a long-continued and dreary disease. The senses fail us in the same manner and in the same order that they do when we are falling asleep, their gradual deterioration bringing us back to the helplessness and imbecility of infancy. In the long interval during which this is going on, the aged man is not only a burden to himself, but a sad spectacle to every one around him; his perceptions are being gradually blunted; and though he is, as it were, by degrees passing into a final slumber, it is in that disturbed way which all have experienced when they fall asleep after severe fatigue. Gradual death. The different portions of the body die in succession: the system of animal life before that of organic, and of the former the sensory functions fail first, voluntary motion next, while the power of muscular contraction under external stimulus still feebly continues. The blood, in gradual death, first ceases to reach the extremities, its pulsations becoming less and less energetic, so that, failing to gain the periphery, it passes but a little way from the heart; the feet and hands become. cold as the circulating fluid leaves them, the decline of temperature gradually invading the interior. No one has ever yet offered a more accurate picture of the appearance of the dying than that presented by Hippocrates: "If the patient lies on his back, his arms stretched out, and his legs hanging down, it is a sign of great weakness; when he slides down in the bed it denotes death. If, in a burning fever, he is continually feeling about with his hands and fingers, and moves them up before his face and eyes as if he were going to take away something before them, or on his bed-covering as if he was picking or searching for little straws, or taking away some speck, or drawing out little flocks of wool, all this is a sign that he is delirious, and that he will die. When his lips hang relaxed and cold, when he can not bear the light, when he sheds tears involuntarily, when, dozing, some part of the white of the eye is seen, unless he usually sleeps in that manner, these signs prognosticate danger. When his eyes are sparkling, fierce, and fixed, he is delirious, The Hippoor soon will be so; when they are deadened, as it were, with cratic face. a mist spread over them, or their brightness lost, it presages death or N N great weakness. When the patient has his nose sharp, his eyes sunk, his temples hollow, his ears cold and contracted, the skin of his forehead tense and dry, and the color of his face tending to a pale green or leaden tint, one may give out for certain that death is very near, unless the strength of the patient has been exhausted all at once by long watchings, or by a looseness, or being a long time without eating." Post-mortem organic functions and passions. Even after death some of the organic functions continue for a time, more particularly secretion and the development of heat. In a former chapter, page 444, the capability of extraordinary muscular motions has been referred to. From other interesting observations on those who have been instantaneously decapitated by the guillotine, it has been asserted that the body can display what has been termed post-mortem passion and resentment. It may, however, be doubted whether this is really true. Perhaps these effects are only analogous to those convulsive manifestations which may be easily produced, in an intensely interesting way, by the application of voltaic batteries to those who have been dead for some time. agony. Physiologists often quote the sentiment of Montaigne, “With how little anxiety do we lose the consciousness of light and of Insensibility before the final ourselves." By this they would convey the idea that the act of dying is as painless as the act of falling asleep, and also as little perceived. They recall the fact which seems to support this view, that those who have been recovered after apparent death from drowning, and after sensation has been totally lost, report that they have experienced no pain; and, indeed, when we reflect that the sensory powers are the first to decline, the eye and the ear, at an early period in the article of death, failing to discharge their duty, and the general sense of touch becoming rapidly more and more obtuse, we can scarcely put any other interpretation upon the final struggles which constitute what is so significantly called the agony, than that they are purely automatic and therefore unfelt. Doubtless the mind, in this solemn moment, is sometimes occupied with an instantaneous review of impressions long before made upon the brain, and which offer themselves with clearness and energy now that present circumstances are failing to excite its attention, through loss of sensorial power of the peripheral organs, this state of things having also been testified to by those who have been recovered from drowning. Life closes at last in various ways. Some pass away as though they were really falling asleep; others with a deep sigh or groan; others with a gasp; and some with a convulsive struggle. ON THE INFLUENCE OF PHYSICAL AGENTS ON THE ASPECT AND FORM OF MAN AND ON HIS INTELLECTUAL QUALITIES. Differences in Form, Habits, and Color of Men.-Ideal Type of Man.-Its Ascent and Descent. Causes of these Variations. Doctrine of the Unity of the Human Race.-Doctrine of its Origin from many Centres. Variations in the Skeleton.-Four Modes of examining the Skull.-Connection of the Shape of The Intellectual Qualities of Nations.-Synthetical Mind of the Asiatic.-Analytical Mind of the European.-Their respective Contributions to Human Civilization.-Spread of Mohammedanism in Africa.-Spread of Christianity in America.-Manner of the Progress of all Nations in Civilization. Fig. 266. THERE are great differences in the aspect of men. The portrait of Newton is from the frontispiece of his immortal Principia. "Does he eat, Differences in and drink, and sleep, dispositions of form, color, and like other people?" ask- men. Sir Isaac Newton. Australian. ed the Marquis de l'Hôpital, himself a great contemporary French math |