The Curiosities of Sleep
By Dr. Woods Hutchinson in the American.
THE first and chiefest curiosity of sleep is sleep itself. All theories and explanations of it, however carefully worded, have proved inadequate. We do 걏not even know what We once thought We did about it.
Take for instance the long and widely accepted view which even to-day stands highest in the estimation of physiologists, as most nearly approaching an explanation of the phenomenon, that sleep is due to cerebral anemia, or a lowered supply of blood to the brain. That the amount of blood in the brain is distinctly diminished during sleep is abundantly proved both by observations upon the brains of animals through trephine openings made for the purpose and upon human brains exposed by fractures of the skull or openings made for the purpose of removing tumors. A less gruesome illustration is afforded by the slight sinking in of the fontanel, or “soft spot,” on the top of a baby’s head during sleep. Drowsiness and loss of consciousness may also be produced by pressure upon the carotid arteries supplying the brain; Further, anything that draws the blood from the brain—to the skin, for instance, by a hot bath, or to the stomach by a cup of hot milk or beef tea, or to the feet by warming them—helps to induce sleep.
We also know that part of the blood withdrawn from the brain goes to the skin, causing the characteristic rosy flush, and part to the muscles, causing slight but appreciable enlargement of the arms, limbs, hands and feet. This is why our shoes and gloves sometimes feel too tight for^ us when dressing in the morning. This rush of blood to the skin accounts for that most annoying aggravation of itching or painful sensations in diseases of the skin which so often occurs at bedtime. As one of our leading dermatologists whimsically puts it: “The skin wakes
up as the brain goes to sleep.” But this so
fact is far from forming an explanation, since it simply raises the questions :
What is the cause of the anemia?
How is it brought about before falling asleep, and how overcome before waking?
Moreover, it is an open question whether this anemia is not simply a sign of lessened activity on the part of the brain, an effect, instead of a cause, of sleep.
The most modern and up-to-date theory of sleep is the neuron one of Duval and Cajal. This is based upon the interesting fact which Cajal was largely instrumental in demonstrating, that the nervous system, instead of being one continuous tissue, is made up of a series of distinct and separate cells, whose only means of communication is by “touching, fingers” with the tips of their delicate, twig-like processes (arborizations, dendrites), and that these “fingers” have the power of movement, can retract and thus break the connection or circuit. When the cells of the brain become fatigued, they are supposed to draw in these processes. This shuts off messages from the sense organs, and unconsciousness, or sleep, results. When rested, they yawn and stretch out their arms, so to speak, communication is again restored, and we wake up.
Unfortunately, the numerous* attempts to demonstrate this retraction of the dendrites by examination of the brains of animals killed instantaneously during sleep have not carried conviction to the majority^ of observers, though a similar process is generally regarded as proved to take place in the deep sleep induced by chloroform and other narcotics. And of course, even granting this mechanism of sleep, it advances our knowledge but little to prove that the brain cells curl up and go to sleep, in place of the identical procedure on the part of the whole
body, which can be demonstrated in any kitten.
Then, there is Pfluger’s attractive theory, that the brain cells during the day use up oxygen more rapidly than it can be supplied to them from the lungs, via the blood; and when this oxygen-starvation reaches a certain degree, the cells sink below the level of activity necessary to consciousness. During sleep, expenditure falls below the intake, and thus the balance necessary to consciousness is restored. This, like the cerebral-anemia theory, has a solid basis in fact, viz. : that of the total intake and outgo of oxygen during the twenty-four hours, only about forty per cent, is taken in during the twelve hours of daylight, while sixty per cent, is given off in the form of carbon dioxide; and, on the contrary, during the twelve hours of the night nearly sixty per cent, of the total oxygen is taken in, and only about forty per cent, of the C02 given off. In other words, the body during the day spends or gives off from twenty to forty per cent, more oxygen than it takes in, during the night takes in twenty to forty per cent, more than it gives off. Thus balmy sleep is literally “tired nature’s sweet restorer” of the oxygen balance. Good poetry is often very close to good science. In support of this view may be cited the well-known drowsiness, deepening into unconsciousness, which comes on inatmospheres overcharged with carbon dioxide, ranging all the way from that of a stuffy room to the “choke damp” of the coal mines or the “foul air” at the bottom of a well. But it can equally be seen that these states are not true sleep, but slow poisonings, narcoses, tending not to refreshment and awakening, but to increasing sluggishness, and finally death.
This fact brings us to the crux of the entire problem, the one great positive fact which emerges from the negatives of all these theories, and to develop which alone was the purpose of their discussion here : that sleep is not a negative process, but a positive one; not a mere cessation of^ activity, but a substitution of constructive bodily activity for destructive. The “anabolic,” or upbuilding processes are in excess of the “katabolic,”
or downbreaking, processes during sleep. During the waking hours the balance is reversed. It is not sleep that leads to death, but waking. Men have been known to sleep for weeks and even months at a stretch, with but little injury. Persistent wakefulness kills in from five to ten days. It is credibly reported that, with Oriental refinement of cruelty, death by sleeplessness is one of the methods of execution for certain higher-class criminals in China. The wretched victim is forcibly prevented from going to sleep until death from exhaustion closes the scene, which is said to be seldom later than the fifth or sixth day.
It should of course be explained that absolute sleeplessness is a very different thing from the insomnia of our nervous patients who “don’t sleep a wink all night”—which latter means that they were awake from three to five times during the hours of darkness.
Another of the curiosities of sleep is the singular difference of its quality in different individuals. Some fortunate men are able to get as much rest out of four or six hours’ sleep as the average man does out of eight or nine; just as some men will get enormously fat on a slender diet, while others with a huge appetite and intake are walking skeltons. This fortunate power of rapid recuperation may almost be said to be one of the characteristics of greatness. At all events it has occurred with sufficient frequency in great and successful men to have done great harm among average individuals. By a ludicrously infantile process of human logic many of our self-constituted guides to success have assured the young idea that this great man became great simply because of his determination to work eighteen or twenty hours out of the twenty-four, therefore : “Go thou and do likewise, and like success shall be thine.” The hugeness of the non sequitur is obvious, but this is far from being the only instance. Men of huge muscles, who happen to be born “brothers to the ox,” write books and publish journals telling the average youth how to get strong by imitating their little peculiarities and bad habits. Doddering old centenarians, who happened to be born with the smoldering vitality (and often the
brilliant intellect) of the mud-turtle, prate fatuously of the onions and sour milk and frugal diet which they allege have brought them to this enviable degree of profitless persistence upon the planet. As well might the elephant endeavor to explain the secret of how to weigh three tons, or the boa constrictor write a pamphlet on how to grow forty feet long.
Of course the majority of great men require as much sleep as the average individual, and many of them more. Some of the greatest, so far from taking three or four hours’ sleep a day, have been able to work only two or three hours out of the twenty-four. Two successive hours of work was a day’s work for Darwin, four for Spencer, and three hours a week for the philosopher, Descartes, who spent from eleven to thirteen hours a day in bed. But enough of them had this singular quality of getting as much rest in four or five hours as other men do in eight to enable the proverb-maker to find texts for his sermons.
Another curiosity of sleep is the many misleading analogies which have been drawn between it and other states. First among them is the beautiful poetic comparison which has almost become an ari tide of faith, embodied in the phrase,
“Death and his brother Sleep”; and, “We are such stuff As dreams are made on; and our little life
Is rounded with a sleep.”
From a physiological point of view, sleep and death are as far apart as the poles. The only similarity between them is that they are both accompanied by unconsciousness. The one is a positive, reconstructive, intensely vital process, selflimited and tending inevitably to an awakening. The other is negative, destructive, utterly lifeless, tending to dissolution and decay, with no possibility of any physical awakening.
Nor is there any similarity between true sleep and the drowsy, sleepy comatose conditions of fevers and fatal illnesses. They are narcoses or poisonings of the brain by poisonous materials, toxins either of germ origin or manufactured by the abnormal processes of the body
tissues themselves. They are not selflimited, but end only when the tissues of the body have succeeded in producing a sufficient amount of antitoxin to neutralize the poisons which cause them. If the body fails to do this, they deepen to coma and, finally, death.
This opposition between death and sleep does not, however, destroy one consoling analogy which has been drawn between them, and that is that they are both painless, and cause neither fear nor anxiety by their approach. It is one of the most merciful things in nature that the overwhelming majority of the poisons which destroy life, whether they be those of infectious diseases or those which are elaborated from the body’s own waste products, act as narcotics and abolish consciousness long before the end comes. While death is not in any sense analogous to sleep, it resembles it to the extent that it is in the vast majority of instances not only not painful, but welcome. Painracked and fever-scorched patients long for death as the wearied toiler longs for sleep. The fear of death which has been so enormously exploited in dramatic literature, sacred and otherwise, is almost without existence in sickness. Most of our patients have lost it completely by the time they become seriously ill.
“While many of the processes which lead to death are painful, death itself is painless, natural, like the fading of a flower or the falling of a leaf. Our dear ones drift out on the ebbing tide of life without fear, without pain, without regret, save for those they leave behind. When Death comes close enough so that we can see the eyes behind the mask, his face becomes as welcome as that of his ‘twin brother,’ Sleep.”
Nor is there a much better basis for the generally accepted analogy between true sleep and that curious “winter sleep” known as hibernation. The subject of hibernation is such an enormous one, and there is such a lack of definite information—and consequent difference of opinion—as to its true character, that only the merest outline of the drift of scientific opinion in regard to it can be given here. To put it very crudely, it appears to be a dropping from the animal almost to the vegetable stage of vitality. Every vi|fl
process is reduced to the lowest ebb consistent with its continuance. All voluntary muscular movements, of course, cease absolutely, the eyes are closed, the animal, which has usually retired to some sheltered and protected spot, becomes unconscious, the respirations become so shallow that the closest observation fails to detect them. The temperature of warm-blooded hibernators falls toward the cold-blooded level. The heart is slowed down to the lowest possible rate and vigor consistent with life. Even the muscles of the alimentary canal cease to contract rhythmically, its glands cease to secrete, and its terminal opening becomes closed with a plug of dried mucus. Later observations seem to indicate that by cutting off the intake of oxygen, carbon dioxide accumulates in the blood and tissues until it produces a light permanent narcosis or anesthesia, and this condition continues for periods varying from weeks to months, until either change of temperature or the exhaustion of fat or other food material stored up in the body beforehand causes the animal to waken and come forth in search of food. In the majority of cases, the animal goes into this state just at the close of the season of plenty, with his tissues well loaded with fat, and emerges in the spring thin and gaunt, having presumably supported such low grade of life as existed by consumption of the energy stored up in his fat. It must, however, be admitted that there are a number of exceptions to this rule, at both ends, so to speak, some animals going into their winter sleep in moderate flesh or even thin and emerging apparently little changed in the spring; others going to sleep plump and fat, and awakening in apparently the same condition. So that the fat-burning hypothesis, plausible as it sounds, cannot be accepted without reservation.
On the other hand, it is only fair +o say that in the last-mentioned instance, animals emerging within a few pounds of the same weight which they went to sleep at lose flesh with great rapidity after resuming their activities, and are ravenously hungry, thus raising the suspicion that the maintenance of weight has been due to an accumulation of water in the
tissues in place of the fat which has been burnt up and utilized.
Another interesting fact about this process is that it is not caused by cold, as was at one time universally supposed. This was first brought to our attention by the fact that fishes, amphibia, reptiles and some of the mammals living in hot climates go into this trance-like condition during the season of heat and drought. In fact, a new word has had to be coined covering this form of the habit, estivate (literally “summerate”), contrasting with hibernate, Secondlv, it was found that only a small percentage of animals ever hibernate at all, and they of the class whose food supply is absolutely cut off in the winter, such as squirrels, mice, rats, bears, marmots, etc. These animals, if kept in captivity and supplied with plenty of food, will after a time lose the hibernating habit altogether. So that it appears to be literally an economy on the part of nature, a going down to avoid punishment in the form of starvation, whenever an adequate supply of energy through food Is cut off. The change is exceedingly widespread through the animal kingdom, being habitual in nearly all terrestrial invertebrates, and in most of the coldblooded animals, especially fishes, amphibia, reptiles, and occurring in a number of mammals, but in no birds—the latter for the reason that they can solve the food problem in another way, by migration either north or south, as the season demands. In fact, it may almost be said that most land invertebrates, amphibia, reptiles and fishes possess the power of going into this curious carbondioxide narcosis at will, if one can imagine these creatures having a will at all. So lethargic are they then, and so completely indifferent to their surroundings, that they may be exposed to extraordinary extremes of heat and cold without apparent injury. They may be dried almost to mummification, frozen or submerged in water for long periods, without apparent injury. Even warm-blooded animals like dormice and woodchucks, when asleep for the winter, may be put under water for hours at a stretch without apparent injury, so completely is respiration suspended.
Fascinating and mysterious as is the subject of hibernation, enough of it is known to make it perfectly clear that it has nothing in connection with true sleep. Instead of the oxygen intake being increased, it is diminished to the lowest possible level; instead of the animal waking refreshed and invigorated, he is weak and emaciated. Instead of being a recuperative process, it is a trial of endurance on the part of the tissues—how long they can possibly last without further supply of energy. Although so widely spread among his ancestry, there is no adequate proof of its occurrence in man. It is one of the “Lost Arts.” What a blessing we would find it in this nerveracked age, if we had onD retained it!
Some of the trance-like conditions into which individuals fall and lie for days or weeks may possibly involve some trace of the survival of this ancient habit. But the vast majority of these conditions occur in semi-civilized, excitable men or hysterical women, so that there is always a possible question of simulation; and the majority of cases which have been carefully studied by competent observers have been found to be frauds, being surreptitiously supplied with food and drink by their attendants or family. The same is true of the alleged power possessed by Hindu fakirs and ascetics of all ages^of going into states of trance in which they allow themselves to be buried alive and dug up again and revived after several months have elasped. In one instance on record an individual of this class allowed himself to be buried alive and his grave watched by a guard of English soldiers, and was dug up at the end of the time, exceedingly dead. In another the English officer in charge became alarmed on the third day and had the fakir “resurrected,” when he was found still alive. A reed or bamboo at one corner of the grave to supply air would explain all these cases. The whole subject is involved in such an atmosphere of mystery and “fakery” (a word most appropriately derived from the title of its devotees themselves) that it is impossible to attach serious weight to the claims made.
Most of the claims, both Occidental and Oriental, to the power of existing
for indefinite periods in this trance-like sleep seem to rest simply upon the wellknown power possessed bv many weakminded individuals, of throwing themselves by auto-suggestion into a hypnotic sleep. In this condition, or awake, life can of course be easily supported for many days, or even weeks, without food, as has been often illustrated by the feats of professional fasters who easily reach forty or even sixty days. It is, however, a significant fact that none of these “sleeps” can be carried on in a hospital where the patient is under the observation of competent and unsympathetic nurses. For, although food can be done without, water cannot, and these sleepers will invariably be found resorting to the water bottle and responding to the calls of nature within twenty-four hours. In their own homes, where they can help themselves surreptitiously to the water on the washstand, they may keep up the farce for weeks without detection. All “sleepers” investigated by physicians are found to take water regularly, and often food, and are usually cases of hysteria or mild insanity.
It might be incidentals mentioned, for the relief of anxious souls, that the risk of any individual passing into a trance and remaining in it long enough to be buried alive is exceedingly slight. There is no authentic instance of this having ever occurred. I took occasion to investigate this question some years ago, and communicated with a number of leading undertakers, and they all unanimously denounced it as one of the myths of the nineteenth century. One of them, at the time president of the National Funeral Directors’ Association, informed me that he had carefully investigated every instance of “burial alive” reported in the newspapers for fifteen years past and found every one of them to be, in his own language, “a pure fake.” However, I cannot fight that battle to a finish here, tempting as the field is.
The last remaining counterfeit of sleep, the hypnotic trance, is so obviously different in character that its discrepancies hardly need to be mentioned. Every one who has seen it will be struck with the difference. It has no relation to fatigue, but may be induced at any time and at
any stage of vigor, though most commonly and easily in individuals, whose mental processes are at such a low ebb that there really is not much difference between their sleeping and waking stages as far as any practical results are concerned. It is not recuperative, but rather depressing, and the patient feels, as he says, queer and dizzy when he wakes up. Instead of the brain being anemic, it is congested, the skin is pale instead of flushed, and there is no increase in the relative oxygen intake. In fact, the condition is an auto-narcosis, or perversion of consciousness, and does nothing but harm, instead of good. It may, of course, be used in expert hands as a method of treatment, but its field of usefulness in this regard is becoming more and more limited every year, and the tremendous claims made for it by Bernheimand the Nancy School have dwindled already to a surprising extent.
The chief question which has always confronted us in our efforts to utilize it, “How can a weak mind be made stronger by becoming absolutely dependent upon another?” still faces us unanswered.
Nor are the sleeps produced by hypnotics much more nearly akin to true sleep in either nature or effect. The more powerful of these, like opium and its derivatives (morphine, codeline and heroin), chloroform and ether, are so obviously pure narcotic poisons that they are seldom resorted to for this purpose excepting in “Baby’s Friends” and “Soothing Syrups.” The apparent slumber produced by these is a toxic narcosis like that due to the toxins of fever already discussed. They have of course a certain field of usefulness in expert hands in a limited class of conditions, such as after severe and painful accidents or surgical operations, where the tissues are ready and anxious for normal sleep but are prevented from getting it by acute pain. In these conditions, a sufficient dose of opiate administered by a competent physician may relieve this intense pain and allow the patient to sleep naturally and with refreshing results. It is of course obvious thev should not be used to make sleep possible in this way in chronic painful diseases, or where the
pain is likely to recur, on account of the danger of forming a habit.
There is a group, however, of weaker drugs, such as chloral, sulphonal, trional, veronal, etc., which, being much less poisonous and producing few or none of the unpleasant after effects and discomforts of the stronger drugs, are extensively used by both the profession and the laity for this purpose. They nearly all belong, however, to the methane group of which chloroform and ether are the leading members, and are narcotic in their action, benumbing the brain tissues in order to produce sleep, and are poisonous if taken in considerable amounts. Just as we find out the dangers of one of them a new one is brought in by the pharmacists with a great flourish of trumpets, and announced as equally effective in producing sleep, and absolutely non-poisonous or harmless to the most delicate constitution; and it is eagerfy pounced upon by the sleepless among the public and profession and sells extensively for several months. Then reports of death from its use begin to come in, and its users and prescribers take fright, and it drops back with the others.
The man who works all day in an illventilated room and takes little or no exercise, or the woman who slaves over her housework or her silly fancy work and almost forgets that there is such a thing as open air, the business man who is driving himself too hard and keeps up on stimulants, the individual who is in an early stage of pulmonary consumption or Bright’s disease, when they find that they cannot sleep, instead of regarding it as nature’s danger signal, demanding investigation and change of habits, swallow some sleeping draught and persist in their suicidal course until a breakdown results that they can no longer shut their eyes to. There is no such thing as uncaused sleeplessness any more than there is uncaused loss of appetite, or strength, or weight. All of them are signals of trouble, and should be regarded and promptly investigated as such. Hypnotics have their place in medicine like other poisonous drugs, but that place is becoming steadily smaller as cases are more painstakingly and intelligently studied.