The Philosophy of Mystery · 17 of 35

Nature of Sleep

“——Sleep, gentle sleep!

Nature’s soft nurse.”

Henry IV. Part ii.

Ida. I begin to perceive the importance of this digression on the nature of mind. You wish us to believe, there is a temporary desertion of the spirit from the body, and therefore the body sleeps?

Ev. Not absolute desertion, but a limit to its influence. Many have thought in conformity to your question; and indeed, Ida, it is a belief so holy, that I may feel it to be almost an impiety to differ.

From the time of Aristotle to Haller, the term “Sleep” expresses that condition which is marked by a cessation of certain mental manifestations, coincident with the degree of oppression; for it is an error to say that the body sleeps,—it is the brain only, perhaps I may say, the cerebrum, or the fore lobes; for I believe the lower part of it (that which imparts an energy to the process of breathing and of blood circulation) is never in a complete sleep, but merely in a state of languor, or rather of repose, sufficient for its restoration,—if it were to sleep, death would be the result.

This repose is in contrast with a state of waking, that activity of mind in which ideas are constantly chasing each other like the waves of ocean; the mode of displacing one idea being by the excitement of another in its place.

In that state of sound sleep which overcomes children, whose tender brains are soon tired, or old persons whose brains are worn, and in persons of little reflection,—the mind is perfectly passive, and its manifestations cease.

So writes Professor Stewart,—that there was a total suspension of volition during sleep, as regards its influence over mental or corporeal faculties; and I may even adduce a scrap from Burton, although I am an admirer of the quaint old compiler for little else than his measureless industry:—

“Sleep is a rest or binding of the outward senses, and of the common sense, for the preservation of body and soul. Illigation of senses proceeds from an inhibition of spirits, the way being stopped by which they should come; this stopping is caused by vapours arising out of the stomach, filling the nerves by which the spirits should be conveyed. When these vapours are spent, the passage is open, and the spirits perform their accustomed duties: so that waking is the action and motion of the senses, which the spirits, dispersed over all parts, cause.”

Astr. But is volition always suspended even in sound sleep? Was it not the opinion of Berkley, that the mind even then was percipient? How else can we account for the waking exactly at one predetermined hour? If we retire to sleep at the latest hour, or oppressed with fatigue, so strong an impression is produced in our mind, that the breaking of our sleep is almost at the given moment.

Ev. I will answer you at present, Astrophel, only by analysis; it is not yet time to explain.

I may grant that there is some latent effect,— passive memory, if you will,—for we do not count the hours in sleep, and calculate our time by the clock; but we wake, and soon the bell strikes.

We have on record some very curious instances of the periodical recurrence of ideas in a waking state, the measurement of time being referrible to mental impression, mechanically established by constant habit.

There was an idiot once, who was in the habit of amusing himself constantly by counting the hours as they were struck on the clock. It chanced, after some time, that the works of the clock were injured, so that the striking for a time had ceased. The idiot, notwithstanding, continued to measure the day with perfect correctness, by counting and beating the hour. This is a story of Dr. Plott’s, in his History of Staffordshire.

There is one of more modern date, somewhat analogous to this.

I may quote Holy Writ in support of this passive condition of true sleep; nay, even its similitude to death. How often do we find allusions to sleep and death as synonymous! Sir Thomas Brown was impressed so deeply with this likeness, that he “did not dare to trust it without his prayers.” And the Macedonian, who wished for more worlds to conquer, confessed his sleep proved to him his mortality. I may quote ancient poetry also in my support. Homer and Virgil describe sleep as the “Brother of Death;” and, among the profane poets of later times, the same sublime association is traced of this

“Mortis imago—et simulacrum.”

Among the ancient allegories, sleep is portrayed as a female, with black unfolded wings,—in her left hand, a white child, the image of Sleep; in her right, a black child, the image of Death.

On the tomb of Cypselus, according to Pausanias, night is thus personified.

Cast. How true, then, was the thought of the first deep sleeper, on the sensation of slumber: —

“——There gentle sleep

First found me, and with soft oppression seiz’d

My drownéd sense, untroubled; tho’ I thought

I then was passing to my former state,

Insensible, and forthwith to dissolve.”

But how fearful is this resemblance which changes “tir’d nature’s sweet restorer” into a type of death! Pr’ythee, Evelyn, do not affright me thus, by clothing sleep with terror, as if it were disease and danger.

Ev. Why tremble for the mortal sleep of the just and good, who will feel, with William Hunter, on their death-bed, “how pleasant and easy it is to die;” and with another moralist, —

“Oh what a wonder seems the fear of death,

Seeing how gladly we all sink to sleep;

Night following night!”

Fear not, Castaly; I do not term slumber and gentle sleep disease, but signs of health. Not so, however, many a profound sleep, and its advances towards coma; those results of exhaustion from excess, or from intense and direct narcotics, as opium sleep, and the paralyzing senselessness from extreme cold, as in the story of Sir Joseph Banks and Dr. Solander in the antarctic regions.

You are aware that many remedies in medicine may be so intense as to cause fatality: inflammation, too, is the restorative process of wounds, but if in excess it is fatal. Appetite also, to a certain degree, is healthy; but craving and thirst, its extremes, are proved, by suffering, to be morbid.

If the mind is composed to perfect rest, it is lulled to senselessness; then metaphysically we are said to sleep: the mind is not excited by thought, and, in consequence, its supply of arterial blood is less, the more rapid flow of which would be the cause of waking.

Within certain limits sleep is a remedy; but it becomes perilous when intense, or too much indulged. One eccentric physician, as we read in the learned Boërhave, even fancied sleep the natural condition of man, and was wont to yield to its influence during eighteen of the twenty-four hours; but apoplexy soon finished his experiment.

This negative quiescence (for sleep is not a positive state) allows the restoration of energy, and then we wake. Even the senses accumulate their power in sleep; the eye is dazzled by the light when we wake, from the sensitiveness imparted by this accumulation.

The conceits regarding the cause of sleep are so various, that if I were to discuss their merits I should only weary your patience, as I perceive I have already done.

Some have thought that sleep arose from certain conditions of the blood in the vessels and nerves of the brain; its congestion in the sinuses; or a reflux of a great portion of it towards the heart: the result of depressed nervous energy—exhaustion, fatigue, cold, and the influence of powerful narcotics, or the combustion of charcoal. Others, that sleep arises from the deposition of fresh matter on the brain, and its sudden pressure. Then we have the cerebral collapse of Cullen, and of Richerand; the deficiency of animal spirits of Haller; the diminished afflux of blood to the brain of Blumenbach; and the exhausted irritability of the Brunonian theory adopted by Darwin.

Where the truth lies I presume not to decide, but it is clear there is a necessity for the occasional repose of the mental organ:

“Non semper arcum

Tendit Apollo.”

Watchfulness invariably reduces, even in the brute: the wild elephant is tamed by the perseverance of the hunter in keeping it constantly awake.

The mind, then, as it is manifested to us (for deeply important is it that we confound not the perfect and pure, because unembodied essence of the soul, with its combined existence in the brain—that union from which a thought is born ), the mind cannot exert itself beyond a certain period without a sensation of fatigue in the brain, as palpable as the exhaustion from excessive muscular exertion. And this depends on a natural law, that organs after acting a certain given period, flag and lose their energy. Thus the first harbinger of sleep is the closing of the lids from languor, and relaxation of the muscles. Muscular fibre will, however, regain its expenditure by simple rest, requiring a certain period for this re-accumulation, like the charging of an electrical jar. Sleep, however, is not always a sequence of exhausted irritability of muscle; we may be too tired to sleep; and thought and memory also will keep the mind awake, and prevent nervous energy from renewing corporeal vigour.

The excitement of thought beyond certain limits is both painful and destructive, evincing its effects by various grades of mental disorder, from simple headache to confirmed mania. Our first ray of hope, in fever, is often the coming on of a quiet sleep, and in the sad cases of delirium tremens we must either sleep or die; the effort of philosophical determination to overcome the depression only adding to its intensity, as in the case of a person worn out by labour, in attempting to labour on. This conflict cannot be more pertinently exemplified than by some passages in the life of Collins, by one who knew him well:—

“He languished some years under that depression of mind which unchains the faculties without destroying them, and leaves reason the knowledge of right without the power of pursuing it. These clouds which he perceived gathering on his intellects, he endeavoured to disperse by travel, and passed into France; but found himself constrained to yield to his malady, and returned. His disorder was no alienation of mind, but general laxity and feebleness, a deficiency rather of his vital than intellectual powers. What he spoke wanted neither judgment nor spirit, but a few minutes exhausted him, so that he was forced to rest upon the couch, till a short cessation restored his powers, and he was again able to talk with his former vigour.”

I believe that sensibility and fatigue of mind, by inducing sleeplessness, may often be the source even of mania.

The sleep of animals is usually light, especially that of birds, and they are easily startled when at roost. The cackling of the geese on their awaking, you know, saved the Roman capitol. Yet sleep is altogether very nearly balanced with waking. Some animals sleep often, like the cats, but they are long awake, and prowling in the night. The python and the boa are also long awake, and then sleep for many days during the process of digestion. Indeed, all the feræ fall into sound sleep after feeding; while the ruminants scarcely sleep at all; nor do they crouch like the feræ, with the head between the legs: but then their whole life is one scene of quiet; rumination is a mindless reverie. The West Indian slaves and the Hottentots, or woolly bipeds, resemble the brute animal in this, that they fall asleep as soon as their labour is concluded.

That activity of mind in excess may induce even mania, I may offer two impressive, although negative, proofs, from the records of Dr. Rush.—“In despotic countries, and where the public passions are torpid, and where life and property are secured only by the extinction of domestic affections, madness is a rare disease. Dr. Scott informed me that he heard of but one single instance of madness in China.”

“After much inquiry, I have not been able to find a single instance of fatuity among the Indians, and but few instances of melancholy and madness.”

I may add, that Baron Humboldt assures us of this immunity among the wild Indians of South America.

Ida. And may not this melancholy effect be averted by caution and rule? We have a saying in Herefordshire, that “Six hours are enough for a man, seven for a woman, and eight for a fool.”

Ev. There cannot be a fixed rule on that point, except the prevailing law of nature,—the feeling of necessity; but this may often lead astray.

It is calculated that one half of a child’s life is passed in sleep, and one quarter to one sixth of the adult existence; but for old age there is no essential period or limit. Old Parr slept almost constantly about the close of his life; while Dr. Gooch records the case of one whose period of sleep was only one quarter of an hour in the twenty-four. It is well to inure an infant to a gradual diminution of its time of sleep, so that at ten years old its period should be about eight hours.

The strength or energy of brain will, when aided by custom, modify the faculty of controlling the disposition to slumber. Frederick the Great, and our own Hunter, slept only five hours in the twenty-four; while Napoleon seemed to exert a despotic power over sleep and waking, even amid the roaring of artillery. Sir J. Sinclair slept eight hours, and Jeremy Taylor three. As a general precept, however, for the regulation of sleep in energetic constitutions, I might propose the wise distribution which Alfred made of his own time into three equal periods,—one being passed in sleep, diet, and exercise, one in despatch of business, and one in study and devotion. Careful habit will often produce sleep at regular and stated periods, as it will render the sleeper insensible or undisturbed by loud noises; the gunner will fall asleep on the carriage amid the incessant discharge of the cannon; and, if I remember right, the slumbers of the bell-ringer of Notre Dame were not broken by the striking of the quarters and the hour close to his ear.

Ida. And at what seasons should we wake and sleep? It seems to me, that the Creator himself has written his precepts in the diurnal changes of this world, that are still so healthfully observed by the peasant, but so strangely perverted by the capricious laws of fashion, and even by the romantic

“sons of night,

And maids that love the moon;”

always excepting Astrophel and Castaly. It moves my wonder that they who have looked upon the beauty of a sunrise from the mountain, or the main, can be caught sleeping, when such a flood of glory, beyond all the glare of peace-rejoicings and birth-lights, bursts upon the world.

Ev. The wisest have thought with you, Ida, although there was one idle poet, even Thomson, who confessed he had “noe motive for rising early.” It was the custom of Jewel and Burnet to rise at four; and Buffon, we are told, rewarded his valet with a crown, if he succeeded in getting him up before six.

It is to slight the creation, not to enjoy the beauties of daylight; and it is the natural time for sleep, when the dews of night are on the earth. The proof of this:—There were two French colonels who were marching their troops, one by day, the other by night; and the loss in men and horses was very far greater among the night marchers.

Cast. I believe it was Panza, who “never desired a second sleep, because the first lasted from night till morning,”—that immortal Sancho Panza, whose quaint rhapsody we must all echo so gratefully,—“Blessed is he that first invented sleep.” The eulogies of this blissful state, and the wailings of a sleepless spirit, have ever been a favourite theme of the poet, and our own ancient dramatists,—as Beaumont and Fletcher, in the play of “Valentinian,” and Shakspere, from the lips of Henry IV. in his beautiful invocation, and Young, and many others.

Ev. Sleeplessness is one of the severest penalties of our nature. In the darkness and silence of night the wakeful mind preys on itself; the pulse is rapid, it is a throb of anguish,—to the wearied thought there is no conclusion, and the parched tongue prays in vain for the morning light. In the curse of Kehama, I think the sleepless lid is one of the most cruel inflictions; and in the severe disorder which we term hemicrania, this curse is to a degree realized.

The sleeplessness of Caligula is related by Suetonius. In Bartholinus, we read of one who slept not for three months, and he became a melancholy hypochondriac. And Boërhave, from intense study, was constantly awake during six weeks.

Ida. We are happy in our quiet minds, are we not, dear Castaly? Yet, if we are ever summoned to the couch of one wearied by night watching, Evelyn will tell us how we may soothe the pillow of a sleepless mind, to which the secret of inducing slumber would be a priceless treasure.

Ev. Study the causes of insomnia, or sleeplessness, Ida; as those which excite nervous irritability,—coffee, green tea, small doses of opium, the protracted use of antimony, &c.; and believe not in the virtues of vulgar remedies, often as dangerous as they are ridiculous. There is a batch of these which Burton has gleaned from various authors; as a sample,—nutmegs, mandrakes, wormwood; and from Cardan and Miraldus,—the anointing the soles of the feet with the fat of a dormouse, and the teeth with the ear-wax of a dog, swine’s galls, hares’ ears, &c.

I might offer to you many plain precepts for the alleviation of the light causes of sleeplessness; and while I dole them out to you in very dullness, you will fancy my gold-headed cane to my chin, and other essential symbols of an Esculapius of the olden time. Adopt, then, a free ventilation in summer, and airing in winter, of the chamber. This should never be a mere closet, always above the ground floor, neither very light nor dark, the window not being close to the bed, and, above all, not in the vicinity of stoves, ovens, and large kitchen fires. Do not allow the windows to be open throughout the night, to admit the cold dew or air; and, in winter, the basket-fire should be placed there for an hour before you enter your chamber. A slight acceleration of the circulation may be produced by gentle exercise before rest; and two or three wafer biscuits or spring water, to prevent the wakeful effects of both chilliness and hunger. A light woollen sock may be worn, which is unconsciously displaced when sleep comes on, and the night-cap should be little more than a net, except during the very cold months. The position of the body should be that which is the easiest, except the supine, which induces congestion and often “night mare;” and if there be much sensitiveness of the surface, the hydrostatic bed should be employed, but that not too long, as it will become heated by protracted pressure. Children should not be enveloped in clothes, nor crowded in bed; nor should infants be shaken, or tossed, or patted, as foolish nurses too often do.

There are many simple modes of inducing slumber: I allude not to poppy and henbane, nor to the pillow of hops, which, in the case of the third George, was the charm that sealed up the lids of the king; but to other modes, such as a tedious recital, (something like my own dull prosing,) the gentle motion of a swing, a cot or cradle, the ripple of a stream, and the dashing of a waterfall, the waving of a fan, the caw of rooks, the hum of bees, the murmur of an Æolian harp —

Cast. So gracefully wound up in that quaint morceau, the “Fairy Queen,” when Archimago sends the spirit to fetch a dream from Morpheus —

“Cynthia still doth steepe

In silver dew his ever-drooping head,

Whiles sad night over him her mantle black doth spred.

And more to lull him in his slumber soft,

A trickling stream, from high rocke tumbling downe,

And ever dringling rain upon the loft,

Mix’d with a murmuring winde, much like the soune

Of swarming bees, did cast him in a swoune.”