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so through the delusive hope that you have a real chance, which you must not mar, of presently going to sleep. Of course, if you are very anxious to go to sleep, this very anxiety is quite sufficient to prevent you doing so. I know persons who can never count on more than two hours' sleep at a time, and the amount of time is absolutely astounding during which people are absolutely sleepless in cases of mania or fever. Nature, however, is very wonderful in her compensations, and adapts herself most curiously to all changes in the constitution. As a rule, too, opiates can insure sleep when absolutely necessary. opiates have their limits, which are speedily reached. Sir William Hamilton would take five hundred drops of laudanum without being able to detect hardly the slightest effect I remember also rather a distinguished literary man on whom anodynes were as powerless as water. Most wearisome of all weariful feelings is that of counting the hours of the clock during the sleepless hours in which existence is a mere burden and drug.
It is said, with every appearance of truth, though the proof is not conclusive, that sleep is due to a diminished supply of arterial blood in the head. The brain matter becomes unable to undergo the changes through which the mind makes its manifestations. Physiologists are agreed that towards evening, or after a certain number of hours of work, the involuntary
organs, the heart and lungs, lose their wonted activity and suffer a periodical diminution of action. Blumenbach describes the case of a patient trepanned in whom the brain was observed to sink during sleep and enlarge on waking, obviously arising from the circulation being diminished in the former state and increased in the latter. 'Arterial blood alone can cause the waste of the brain, for venous blood has already parted with its oxygen to the materials met with in its course. Matter in a state of inertia cannot manifest the existence of a power. Motion alone shows that some power is in operation. If the portion of matter used as the organ of manifestation be placed in such a condition as to render that manifestation impossible there is no evidence to the world that power was exerted.' It was an old error among physiologists that there was more blood, or at least as much, during sleep as in wakefulness; but this was disproved by Blumenbach, and still more convincingly by a philosopher who made one of the cruel, though striking, experiments with which medical science abounds, and which finds its horrid culmination in vivisection. He cut away part of the skull of an animal, and cemented in its place a piece of glass, through which he could observe the brain in its different states. This experiment has been repeated in Germany, in England, and in America with like. results. In the waking state the brain is larger than
it is during sleep; while in the latter condition it becomes pale and bloodless. If the animal be disturbed by dreams, a blush suffuses parts of the brain. The eye, which may be looked upon as an exposed part of the brain, acts in a similar way; for it has been shown that the optic disc is whiter, the arteries smaller, and the veins larger in sleep than in a waking state.
The two great objects of sleep are, first, the restoration of wasted organs; and, secondly, the storing up of force. It is evident that any material disturbance or defeat of these two great objects is ruinous, and within a very short distance of a certain line becomes fatal. It is wonderful, however, in how many instances at what a remote point Nature begins to draw this line of destiny. During sleep, force is stored up in the body in a remarkable manner, as has been shown by a series of interesting experiments. The King of Bavaria erected a chamber, supplied with every appliance for measuring the air which enters it and for ascertaining the composition of the air that passes from it. This chamber is sufficiently large to enable persons to live comfortably in it during the time that they are made the subjects of experiments. Among other remarkable results which have flowed from the enlightened liberality of the Bavarian king, we have a series of experiments made on various individuals during their waking and sleeping state,
from which many interesting results have been derived, set forth by scientific journals, and by a serial unsurpassed in its scientific and intellectual character, the North British Review.
I cannot, however, agree with the reviewer in his minatory and disrespectful language towards that large, most respectable, and most solvent section of the British public that habitually indulges in an afterdinner nap. 'The post-prandial sleeper draws his chair to the fire, in order that his nap may be undisturbed. There are two physiological reasons for this act. Less oxygen is entering his body to burn the food, and he feels cold; but this cold would excite the respiratory organs to increased activity and disturb his contemplated enjoyment. An after-dinner sleeper temporarily resembles the permanent condition of a pig fattened for the butcher. In its case fat accumulated round the viscera pushes up the diaphragm against the lungs, and compels them to play in a contracted space. When the animal further distends its stomach with food it gives a few grunts as an ineffectual attempt at a more active respiration, and is in a deep sleep in a few minutes. Obese men, from a similar cause, are also prone to sleep.' I call this an unkind and even an unfeeling remark. Would it not also be simpler and more correct to say, that the blood is driven from the surface to the centre to aid digestion? Neither shall I be deterred by the
great authority of the reviewer from counselling people to enjoy their customary siesta. If Nature makes a man sleepy, I think that she designs that a man should go to sleep. She is quite as philosophical as any of the philosophers. There is a bastard sort of sleep, a condition of coma, consequent on repletion, which ought to be avoided; and moderation, not an immoderate moderation, in diet should be preserved. After dinner, also, some employment of the gentlest kind may be wisely taken in hand-a glance at a newspaper or magazine, the writing of some trifling notes, a stroll in the garden, and a slight dessert, where dessert is always best taken, off the fruit trees. Then take a nap, after thus idly dallying with the charms of leisure. I believe that a brief nap of this sort is invariably attended with salutary effect. It has always been noted that to close the eyes even for a few minutes in sleep is a wonderful relief to the brain. Some men have fallen asleep on horseback, and others can even sleep while walking, besides the unfortunate somnambulists. I know two men who were walking along a country road on a dark night. A clutched B's arm tightly and deliberately walked with closed eyes. Some time afterwards B said: 'I hope, A, you are walking very carefully, for I have kept my eyes closed for the last half hour.' Fortunately the two Gothamites had contrived to keep clear of the ditches.