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anon difficulty in getting his mental powers into their continued very long. By lying flat upon a millstone usual state of activity.
while performing its evolutions, sleep is soon produced, A heated church and a dull scrmon are alınost sure and death, without pain, would be the result, if the exto provoke sleep. There are few men whose powers periment were greatly protracted. Apoplexy, which are equal to the task of opposing the joint operation of consists of a turgid state of the cerebral vessels, protwo such potent intluences. They act on the spirit duces perhaps the most complete sleep that is known, like narcotics, and the person seems as if involved in a in so far that, while it continues it is utterly impossicloud of anconite or belladonna. The heat of the church ble to waken the individual: no stimulus, however might be resisted, but the sermon is irresistable. Its powerful, has any influence in arousing his dormant satuonotony falls in leaden accents upon the ear, and soon culties. When the circulating mass in the brain is subdues the most powerful attention. Variety, whether diminished beyond a certain extent, it has the same of sight or sound, prevents sleep, while monotony of effect on the opposite state; whence excessive loss of all kinds is apt to induce it. The murmuring of a blood excites sleep. river, the sound of a Eolian harp, the echo of a distant Opium, hyoscyamus, aconite, belladonna, and the cascade, the ticking of a cluck, the hum of becs under whole tribe of narcotics, induce sleep, partly by a spea burning sun, and the pealing of a remote hell, all ex cific power which they exert on the nerves of the ercise the same influence. So conscious was Boer- stomach, and partly by inducing an apoplectic state of haave of the power of monotony, that in order to pro- the brain. The former effect is occasioned by a modecure sleep for a patient, he directed water to be placed rate—the latter by an over dose. in such a situation as to drop continually on a brass A heavy meal, especially if the stomach is at the pan. When there is no excitement, sleep is sure to same time weak, is apt to induce sleep. In ordinary follow. We are all kept awake by some mental or circumstances, the nervous energy or sensorial power of bodily stimulus, and when that is removed our wake this viscus is sufficient to carry on its functions; but fulness is at an end. Want of stimulus, especially in when an excess of food is thrown upon it, it is then a heated atmosphere, produces powerful effects; but unable to furnish, from its own resources, the powers where sufficient stimulus exists, we overcome the ef- requisite for digestion. In such a case it draws upon sects of the heat, and keep awake in spite of it. Thus, the whole body-upon the chest, the limbs, &c., from in a crowded church, where a dull, inanimate preacher whence it is supplied with the sensorial power of would throw the congregation into a deep slumber, which it is deficient; and is thus enabled to perform such a man as Massilon, or Chalmers, would keep them that which by its own unassisted means it never could in a state of keen excitement. He would arrest their have accomplished. But mark the consequences of allention, and counteract whatever tendency to sleep such accommodation! Those parts, by communicawould otherwise have existed. In like manner, a ting vigor to the stomach, become themselves debiliprosing, monotonous, long-winded acquaintance is apt tated in a corresponding ratio, and get into a stato io make us doze, while another of a lively, cnergetic analogous to that from which they had extricated this conversation keeps us brisk and awake. It will gene
The extremities become cold, the respiration rally be found that the reasoning faculties are those heavy and stertorous, and the brain torpid. In consewhich are soonest prostratod by slumber, and the ima
quence of the torpor of the brain, sleep ensues. It ginative the least so. A person would more readily had parted with that portion of sensorial energy which fall asleep ıf listening to a profound piece of argumenta-kept it awake, and by supplying another organ is itself tion, than to a humorous or fanciful story; and proba thrown into the state of sleep. It is a curious fact, bly more have slumbered over the pages of Bacon and that the feeling of sleep is most strong while the food Locke, than over those of Shakspeare and Milton. remains on the stomach, shortly after the accession of Cold produces sleep as well as heat, but to do so
the digestive process, and before that operation which a very low temperature is necessary, particularly with converts the nourishment into chyle has taken place. regard to the human race; for, when cold is not exces When, therefore, the sensorial power is sufficiently sire, it prevents, instead of occasioning slumber: in exhausted, we naturally fall asleep. As this exhausillustration of which, I may mention the case of sere tion, however, is a gradual process, so is that of slumral unfortunate women, who lived thirty-four days in a
ber. Previous to its accession, a feeling of universal small room overwhelmed with the snow, and who lassitude prevails, and exhibits itself in yawning, * scarcely slept during the whole of that period. In very peevishness, heaviness, and weakness of the eyes; innorthem and southern latitudes, persɔns often lose their difference to surrounding objects, and all the characterlives by lying down in a state of drowsiness, occasioned istics of fatigue. If the person be seated, his head nods by intense cold. The win:er sleep, or hybernation of and droops; the muscles become relaxed ; and, when animals, arises from cold: but as this species of slum circumstances admit of it, the limbs are thrown into ber is of a very peculiar description; I have discussed the recumbent position, or that most favorable for comit separately in another part of the work.
plete inaction. The senses then become unconscious The finished gratification of all ardent desires has the of impressions, and, one after the other, part with seneffect of inducing sluniber : hence, after any keen ex sation; the sight first, then taste, smell, hearing, and citement, the mind becoines exhausted, and speedily touch, all in regular order. The brain does not all at relapses into this state. Attention to a single sensa
once glide into repose : its different organs being suction has the same effect. This has been exemplified cessively thrown into this state; one dropping asleep, in the case of all kinds of monotony, where there is a | then another, then a third, till the whole are locked up want of variety to stimulate the ideas, and keep them in the fetters of slumber. This gradnal process of inon the alert. If the mind,' says Cullen, “is attached tellectual obliteration is a sort of confused dream-a to a single sensation, it is brought very nearly to the mild delirium which always precedes sleep. The state of the total absence of impression ;' or, in other ideas have no resting-place, but float about in the conwords, to the state most closely bordering upon sleep.
* We yawn before falling asleep and when we wake; yawn Remove those stimuli which keep it employed, and ing, therefore, precedes and follows sloep. It seems an effort of sleep ensues at any time.
nature to restore the just equilibrium between the flexor and ex. Any thing which mechanically determines the blood tensor muscles. The former have a natural predominancy in the to the brain, acts in a similar manner, such as whirling system; and on their being fatigued, wc, by an effort of the will, round for a great length of time, ascending a lofty purpose of redressing the balance, and poising the respective mountain, or swinging to and fro. The first and last muscular powers. We do the same thing on awaking, or even of these actions give rise to much giddiness, followed
on getting up from a recumbent posture--the flexors in such cir
cumstances having prevailed over the extensors, which were in by intense slumber, and at last by death, if they be
a great measure inert.
fused tabernacle of the mind, giving rise to images of hence diarrhea, menorrhagia, &c., are checked during the most perplexing description. In this state they the intervals of slumber. continue for some time, until, as sleep becomes more From the diminished vascular action going on upon profound, the brain is left to thorough repose, and the surface, we would be apt to expect a decrease of they disappear altogether.
perspiration, but the reverse is the case. Sleep relance Sleep produces other important changes in the sys the cutaneous vessels, and they secrete more copi
The rapidity of the circulation is diminished, ously than in the waking state According to Sancioand, as a natural consequence, that of respiration : the rius, a person sleeping some hours undisturbed, will force of neither function, however, is impaired; but, perspire insensibly twice as much ax one awake. This on the contrary, rather increased. Vascular action is tendency of sleep to produce perspiration is strikingly diminished in the brain and organs of volition, while exhibited in discases of debility ; whence the noctoral digestion and absorption shall proceed with increased sweats so prevailing and so destructive in all cachectic energy. The truth of most of these propositions it is affections. Sanctorius farther states, that the insensilot difficult to establish.
ble perspiration is not only more abundant, but less The diminished quickness of the circulation is shown acrimonious during sleep than in the waking state; in the pulse, which is slower and fuller than in the that, if diminished during the day, the succeeding sleep waking state ; that of respiration in the more de is disturbed and broken, and that the diminution in liberate breathing which accompanies sleep. Dimi- consequence of too short a sleep, disposes to fever, unnished action of the brain is evident from the aboli- less the equilibrium is established, on the following day, tion of its functions, as well as direct evidence. A by a more copious perspiration. case is related by Blumenbach, of a person who had Sleep produces peculiar effects upon the organs of been trepanned, and whose brain was observed to sink
vision. A priori, we might expect that, during this when he was asleep, and swell out when he was awake. state, the pupil would be largely dılated in consequence As for the lessened vascular action in the voluntary of the light being shut out. On opening the cyclids powers, this is rendered obvious by the lower tempera- cautionsly it is seen to be contracted; it then quivers ture on the surface which takes place during the slum with an irregular molion, as if disposed to dilate, but at bering state. Moreover, in low typhus, cynanche ma length ceases to move, and remains in a contracted ligna, and other affections attended with a putrid dia state till the person awakes. This fact I have onen thesis, the petechiæ usually appear during sleep when
verified by inspecting the eyes of children. Sleep also the general circulation is least vigorous, while the pa communicates to these organs a great accession of senroxysms of reaction or delirium take place, for the sibility, so much so, that they are extremely dazzled by most part, in the morning when it is in greater strength a clear light. This, it is true, happens on coming out and activity:
of a dark into a light room, or opening our eyes upon In some individuals the stronger and more laborious the sunshine even when we are awake, but the effect respiration of sleep is made manifest by that stertorous is much stronger when we have previously been in sound commonly denominated snoring. Stout apoplec- deep slumber. tic people—those who snuff much or sleep with their mouths open, are most given to this habit. It seems to
Sleep may be natural or diseased the foriner arising arise principally from the force with which the air is
from such causes as exhaust the sensorial power, such drawn into the lungs in sleep. The respiratory muscles
as fatigue, pain, or protracted anxiety of mind; the lat
ter from cerebral congestion, such as apoplexy or plethbeing less easily excited during this state do not act so readily, and the air is conscquently admitted into the
The great distinction between these varieties is, chest with some degree of effort. This, combined with
that the one can be broken by moderate stimuli, while the relaxed state of the fauces, gives rise to the sterto
the other requires either excessive stimuli, or the forous noise. Snuffing, by obstructing the nasal pas
moval of the particular cause which gave rise lo il sages and thus rendering breathing more difficult, has
During complete sleep no sensation whatever is er. the same effect; consequently snuflers are very often perienced by the individual : he neither feels pain, hun. great snorers. The less rapidly the blood is propelled ger, thirst, nor the ordinary desires of nature. He may through the lungs, the slower is the respiration, and the
be awakened to a sense of such feelings, but during perlouder the stertor becomes. Apoplexy, by impairing existence if they can indeed be said to exist where
fect repose he has no consciousness whatever of their the sensibility of the respiratory organs, and thus reducing the frequency of breathing, produces snoring to
they are not felt. For the same reason, we may touch a great extent; and all cerebral congestions have, to a
hiin without his feeling it; neither is he sensible to greater or less degree, the same effect.
sounds, to light, or to odours. When, however, the That sleep increases absorption is shown in the dis
slumber is not very profound, he may bear music or appearance or diminution of inany swellings, especially conversation, and have a sense of pain, hunger, and ædema of the extremities, which often disappears in the
thirst; and, although not awakened by such circum. night and recurs in the daytiine, even when the patient stances, may recollect them afterwards. These imkceps his bed, a proof that its disappearance does not pressions, caught by the senses, often give rise to the not always depend on the position of the body : that it
most extraordinary mental combinations, and forin the increases digestion, and, as a natural consequence, nu
groundwork of the most elaborate dreams. trition, is rendered probable by many circumstances :
I am of opinion that we rarely pass the whole of hence it is the period in which the regeneration of the any one night in a state of perfect slumber. My body chiefly takes place. Were there even no aug reason for this supposition is, that we very seldom te mentation given to the assimilative function, as is main
main during the whole of that period in the position in tained by Broussais and some other physiologists, it is which we fall asleep. This change of posture must clear that the body would be more thoroughly nourished have been occasioned by some emotion, however obthan when awake, for all those actions which exhaust it scure, affecting the mind, and through it the organs of in the latter condition are quiescent, and it remains in a
volition, whereas in complete sleep wo experience no state of rest, silently accumulating power, without ex
emotion whatever. pending any.
The position usually assumed in sleep has been Sleep lessens all the secretions, with one exception- mentioned ; but sleep may
ensue in any posture of the that of the skin. The urinary, salivary, and bronchial body; persons fall asleep on horseback, and continue discharges, the secretions from the nose, eyes, and ears, riding in this state for a long ume without been are all formed less copiously than in the waking state. awakened. Horses sometimes sleep for hours in the The same rule holds with regard to other secretions, standing posture ; and the circumstance of somnamba
lism shows that the same thing may occur in the hu tain hour, the anxiety of mind thus produced not only
prevents the sleep from being very profound, but reSome animals, such as the hare, sleep with their tards its accession; and even after it does take place, eyes open; and I have known similar instances in the we very seldom oversleep ourselves, and are almost human subject. But the organ is dead to the ordinary sure to be awake at, or before, the stipulated time. stimulus of light, and sees no more than if completely Shortly after falling asleep, we often awake with a shut.
sudden start, having the mind filled with painsul imAnimals which prey by night, such as the cat, hyem, pressions ; although we often find it impossible to say &c., pass the greater part of their time in sleep; while to what subject they refer. Some persons do this rethose that do not, continue longer awake than asleep.gularly every night, and there can be no doubt that it The latter slumber part of the night and continue proceeds from the mind being tortured by some disawake so long as the sun continues above the horizontressing vision ; which, however, has faded away withThe propensity of the former to sleep in the day time out leaving behind it any feeling, save one of undefinaseems to proceed from the structure of their eyes ; as ble melancholy. There are some persons who are sure they see much better in darkness than in light, and con to be aroused in this startling and painful manner if sequently pass in slumber that period in which their they happen to fall asleep in the position in which they vision is of least avail to them. It is a very curious at first lay down, who nevertheless escape if they turn fact, however, that these animals, when kept in capli themselves once or twice before falling into repose. vity, reverse the order of their nature, and remain This fact we must take as we find it: any explanation awake by day while they sleep by night. This fact as to its proximate cause scems quite impracticable. has been ascertained in the menagerie at Paris. In Disease exercises a powerful intluence upon sleep. such cases I apprebend that soine corresponding change | All affections attended with acute pain prevent it, in must take place in the structure of the eyes, assimila- | consequence of the undue accumulation which they ting them to those animals which naturally sleep by occasion of sensorial power. This is especially the night.
case where there is much active determination of blood M. Castel observes, that the greater part of animals to the head, as in phrenetic affections, and fevers in sleep longer in winter than in summer. It is precisely general. on account of perspiration that in the first of these Sleep is always much disturbed in hydrothorax; and seasons sleep is more necessary than in the second almost every disease affects it, more or less ; some preIn winter, the want of perspiration during the day is fur- venting it altogether, some limiting the natural propornished in sleep; in summer, the diurnal sweat supplies tion, some inducing fearful dreams, and all acting with that of the night, and renders much sleep less neces a power proportioned to the direct or indirect influence sary. In other words, during summer the perspiration which they exercise upon the sensorium. is so much excited by atmospheric temperature, that a From the increased irratibility of the frame and reshorter time is sufficient to give issue to the fluids | laxed state of the cutaneous vessels during sleep, the which have to be expelled by this means. For the system at that time is peculiarly apt to be acted upon same reason, the inhabitants of very cold climates by all impressions, especially of cold ; and those who sleep more than those who live in the warmer latitudes. fall asleep exposed to a current of air are far more apt
The profoundness of sleep differs greatly in different to feel the consequences thereof than if they were broad individuals. The repose of some is extremely deep ; awake. By a law of nature the sensibility of the systhat of others quite the reverse. One will scarcely tem is increased by any suspension of the mental or obey the roar of cannon ; another will start at the voluntary powers, for the same reason that it is diminchirping of a cricket or the faintest dazzling of the ished, while these powers resume their action. In moonbeans, Heavy-minded, phlegmatic people gene drunkenness, for instance, where the mind is vehementrally belong to the former class; the irritable, the ner- ly excited, we are far less susceptible of cold than in a vous, and the hypochondriac to the latter, although we state of sobriety. shall at times find the cases reversed with regard to Sleep is much modified by habit. Thus, an old artilthe nature of sleep enjoyed by these different tempera-lery-man often enjoys tranquil repose, while the cannon
Man is almost the only animal in whom much are thundering around him ; an engineer has been known variety is to be found in this respect. The lower to fall asleep within a boiler, while his fellows were grades are distinguished by a certain character, so far beating it on the outside with their ponderous hamas their slumber is concerned, and this character runs mers; and the repose of a miller is nowise incommoded through the whole race ; thus, all hares, cats, &c., are by the noise of his mill. Sound ceases to be a stimulight sleepers ; all bears, turtles, badgers, &c., are the lus to such men, and what would have proved an inex
In man, the varieties are infinite. Much of pressible annoyance to others, is by them altogether this depends upon the age and temperament of the in-unheeded. It is cominon for carriers to sleep on horsedividual, and much upon custom.
back, and coachman on their coaches. During the batThe profoundness of sleep differs also during the le of the Nile, some boys were so exhausted, that they same night. For the first four or five hours, the slum- fell asleep on the deck amid the deafening thunder of ber is much heavier than towards morning. The cause that dreadful engagement. Nay, silence itself may beof such difference is obvious; for we go to bed ex coine a stimulus, while sound ceases to be so. Thus, hausted by previous fatigue, and consequently enjoy a niiller being very ill, his mill was stopped that he sound repose, but, in the course of a few hours, the might not be disturbed by its noise ; but this so far from Decessity for this grudually abates, and the slumber na-inducing sleep, prevented it altogether ; and it did not turally becomes lighter.
take place till the mill was set a-going again. For the That sleep from whicl. we are casily roused is the same reason, the manager of some vast iron-work who, healthicst: very profound slumber partakes of the na slept close to them amid the incessant din of hammers ture of apoplexy.
forges, and blast furnaces, would awake if there was On being suddenly awakened from a profound sleep any cessation of the noise during the night. To carry our ideas are exceedingly confused ; and it is some the illustration still farther, it has been noticed, that a time before we can be made to comprehend what is person who falls asleep near a church, the bell of which said to us. For some moments, we neither see, nor is ringing, may hear the sound during the whole of his hear, nor think without our usual distinctness, and are, slumber, and be nevertheless aroused by its sudden in fact, in a state of temporary reverie.
cessation. Here the sleep must have been imperfect, When ibere is a necessity for our getting up at a cer otherwise he would have been insensible to the sound : * 'Jurnal Compleucntaire.'
the noise of the bell was no stimulus ; it was its ces
sation which, by, breaking the mopotony, became so, life ; but very young children always sleep away the and caused the sleeper to awake.
most of their time. At this carly period, the nerves The effects of habit may be illustrated in various being extremely sensitive and unaccustomed to impresways. 'If a person, for instance, is accustomed to go sions, become easily fatigued. As the children get to rest exactly at nine o'clock in the evening, and to older, the brain besides becoming habituated to impresrise again at six in the morning, though the time of go- sions, acquires an accession of sensorial power, which ing to sleep be occasionally protracted till twelve, he tends to keep it longer awake. For the first two or will yet awake at his usual hour of six ; or, if his sleep three years, children sleep more than once in the twenbe continued by darkness, quietude or other causes, till ty-four hours. The state of the fætus has been dena the day be farther advanced, the desire for sleep will re minated, by some writers, a continuer sleep, but the turn in the evening at nine.'
propriety of this definition may be doubted; for the Persons who are much in the habit of having their mind having never yet manifested itself, and the volunrepose broken, seldom sleep either long or profoundly, tary organs never having been exercised, can hardly be however much they may be left undisturbed. This is said to exist in slumber, a condition which supposes a shown in the cases of soldiers and seamen, nurses, moth- previous waking state of the functions. Middle-aged ers, and keepers.
persons who lead an active life, seldom sleep above Seamen and soldiers on duty can, from habit, sleep eight or nine hours in the twenty-four, however mach when they will, and wake when they will. The Em- longer they may lie in bed; while a rich, lazy, and peror Napoleon was a striking instance of this fact. gormandizing citizen will sleep twelve or thirteen hours Captain Barclay, when performing his extraordinary at a time. feat in walking a mile an hour for a thousand succes Sleep is greatly modified in old people. They usualsive hours, obtained at last such a mastery over him- ly slumber little, and not at all profoundly. Sometimes, self, that he fell asleep the instant he lay down. however, when they get into a state of dotage, in conSome persons cannot sleep from home, or on a different sequence of extreme old age, the phenomena of childbed from their usual one : some cannot sleep on a hard, hood once more appear, and they pass the greater part others on a soft bed. A low pillow prevents sleep in of their time in sleep. The repose of the aged is most some, a high one in others. The faculty of remaining apt to take place immediately after taking food, while asleep for a great length of time, is possessed by some they often solicit it in vain at that period at which, durindividuals. Such was the case with Quin, the cele- ing the former years of their lives, they had been accusbrated player, who could slumber for twenty-four hours tomed to enjoy it. The celebrated 'de Moivre slept successively—with Elizabeth Orvin, who spent three-| twenty hours out of the twenty-four, and Thomas Pant fourths of her life in sleep—with Elizabeth Perkins, latterly slept away by far the greater part of his exislwho slept for a week or a fortnight at a time—with Mary Lyall, who did the same for six successive weeks— Those who eat heartily, and have strong digestive and with many others, more or less remarkable. In powers, usually sleep much. The great portion of Bowyer's life of Beattie, a curious anecdote is related sleep required by infants is owing, in part, io the pro of Dr Reid, viz., that he could take as much food and digious activity of their digestive powers. The majority immediately afterwards as much sleep as were sufficient of animals sleep after eating, and man has a strong tenfor two days.
dency to do the same thing, especially when oppressed A phenomenon of an opposite character is also some with heat. In the summer season, a strong inclinatim times observed, for there are individuals who can sub
is often felt, to sleep after dinner, when the weather is sist upon a surprisingly small portion of sleep. The
very warm. celebrated General Elliot was an instance of this kind : Á heavy meal, which produces no uneasy feeling he never slept more than four hours out of the twenty- while the person, will often do so if he fall asleep. AC four. In all other respects he was strikingly abstinent; cording to Dr. Darwin, this proceeds from the sensorial his food consisting wholly of bread, water, and vegetables. actions being increased, when the volition is suspended. In a letter communicated to Sir Jolin Sinclair, by John The digestion from this circumstance goes on with inGordon, Esq. of Swiney, Caithness, mention is made
creased rapidity. Heat is produced in the system fastof a person named James Mackay, of Skerray, who died
er than it is expended ; and, operating on the sensitive in Strathnaver in the year 1797, aged ninety-one : he actions, carries them beyond the limitations of pleasure, only slept, on an average, four hours in the twenty-four, producing, as is common in such cases, increased fre and was a remarkably robust and healthy man. Fred
quency of pulse.' In this case, incomplete sleep is erick the Great, of Prussia, and the illustrious surgeon, supposed, for, when the slumber is perfect, no sensaJohn Hunter, only slept five hours in the same period; tion whatever, either painful or the reverse, can be erand the sleep of the active-minded is always much less
perienced than that of the listless and indolent. The celebrated
In recovering from long protracted illness, accomapsFrench General Pichcgru, informed Sir Gilbert Blane, nied with great want of rest, we generally sleep much that, during a whole year's campaigns, he had not above
far more, indeed, than during the most perfect health. one hour's sleep in the twenty-four. I know a lady This seems to be a provision of nature for restortng the who never sleeps above half an hour at a time, and vigour which had been lost during disease, and bring the whole period of whose sleep does not exceed three ing back the body to its former state. So completely or four hours in the twenty-four ; and yet she is in the does this appear to be the case, that as soon as a tha enjoyment of excellent health. Gooch gives an in rough restoration to health takes place, the portion of stance of a man who slept only for fifteen minutes out sleep diminishes till it is brought to the standard at of the twenty-four hours, and even this was only a kind which it originally stood before the accession of illness. of dozing, and not a perfect sleep: notwithstanding
After continuing a certain time aslecp, we awake, which, he enjoyed good health, and reached his seven
stretch ourselves, open our cyes, rub them, and yawn ty-third
several times. At the moment of awaking, there is mistake in this case, for it is not conceivable that hu
some confusion of ideas, but this immediately wears man nature could subsist upon such a limited portion away. The mental faculties from being in utter corpor, of repose. Instances have been related of persons who begin to act one after the other;* the senses do the never slept ; but these must be regarded as purely fabulous.
* In the gradual progress from intense sleep, when there
can be no dream, to the moment of porfai vigilance, se what The period of life modifies sleep materially. When occurs. The first cerebral organ that awakes enters into the a man is about his grand climateric, or a few years be
train of thinking connected with ice faculty : some kind of dream yond it, he slumbers less than at any former period of more vivid ; ' and as the number of activa organa increases,
is the result ; as organ alter otgan awakes, the dream becom
At last, the mind, the senses, and the locomo
CHAPTER III. tion being completely restored, what are our sensations?
Instead of the listlessness, lassitude, and general fatigue = experienced on lying down, we feel vigorous and refreshed. The body is stronger, the thoughts clearer
In perfect sleep, as we have elsewhere stated, there and more composed; we think coolly, clearly, ration is a quiescence of all the organs which compose the ally, and can often comprehend with ease what baffled brain ; but when, in consequence of some inward erus on the previous night.
citement, one organ or more continues awake, while One or two other points remain to be noticed. On the remainder are in repose, a state of incomplete awaking, the eyes are painfully affected by the light, sleep is the result, and we have the phenonmena of but this shortly wears away, and we then feel them dreaming. If, for instance, any irritation, such as pain,
stronger than when we went to bed. The muscular fever, drunkenness, or a heavy meal, should throw the E power, also, for a few seconds, is affected. We totter perceptive organs into a state of action while the re
when we get up; and if we lay hold of any thing, the flecting ones continue asleep, we have a consciousness band lacks its wonted strength. This, however, as the
of objects, colors, or sounds being presented to us, just current of nervous energy is restored throughout the
as if the former organs were actually stimulated by havmuscles, immediately disappears ; and we straightway ing such impressions communicated to them by the expossess redoubled vigour. On examining the urine, we
ternal senses ;* while in consequence of the repose of find that it is higher in its colour than when we lay the reflecting organs, we are unable to rectify the illudown. The saliva is more viscid, the phlegm hardersions, and conceive that the scenes passing before us, and tougher , the eyes glutinous, and the nostrils dry. This want of mutual co-operation between the differ
or the sounds that we hear, have a real existence. If we belake ourselves to the scale, we find that our weight has diminished in consequence of the nocturnal
ent organs of the brain accounts for the disjointed perspirations ; while, by subjecting our stature to mea
nature, the absurdities, and incoherencies of dreams. suremeut, we shall see that we are taller by nearly an
Many other doctrines have been started by philosoinch than on the preceding night. This fact was cor
phers, but I am not aware of any which can lay claim rectly ascertained in a great variety of instances, by and so totally unsupported by evidence, that it is ditfi
even to plausibility ; some, indeed, are so chimerical, Mr. Wasse, Rector of Aynho in Northumberland ; and is sufficiently accounted for by the intervertebral car
cult to conceive how they ever entered into the imagitilages recovering their elasticity, in consequence of the
nations of their founders. Baxter, for instance, in his bodily weight being taken off them during the recum
Treatise on the Immortality of the Soul,' endeavours bent posture of sleep.
to show that dreams are produced by the agency of Such are the leading phenomena of sleep. With re
some spiritual beings, who either amuse, or employ gard to the purposes which it serves in the economy,
themselves seriously, in engaging mankind in all those these are too obvious to require much detail. Its main imaginary transaction with which they are employed in object is to restore the strength expended during wake- dreaming. The theory of Democritus and Lucretius is fulness; to recruit the body by promoting nutrition equally whimsical. They accounted for dreams by and giving rest to the muscles"; and to renovate the supposing that spectres, and simulacra of corporeal mind by the repose which it affords the brain. Action things constantly emitted from them, and floating up is necessarily followed by exhaustion ; sleep by check
and down in the air, come and assault the soul in sleep. ing the one restrains the other, and keeps the animal The most prevailing doctrine is that of the Cartesians, machine in due vigour. Mr Carmichael supposes sleep who supposed that the mind was continually active in to be the period when assimilation goes on in the brain. sleep; in other words, that during this state we were In this respect, I believe that the brain is not differently
always dreaming Hazlitt, in his · Round Table,' has situated from the rest of the body. There, as else
taken the same view of the subject, and alleges, that if where, the assimilative process proceeds both in the he has been dreaming about,
he will at once be recall
a person is awakened at any given time and asked what slumbering and in the waking state; but that it is only ed to a train of associations with which his mind has at work in the brain during sleep analogy forbids us to admit So long as circulation continues, a deposition of
beer, busied previously. Unfortunately for this theory Matter is going on ; and circulation, we all know, is at
it is not sustained by facts ; experiments made on purwork in the brain as in other organs, whether we be the individual had such a consciousness of dreaming as
having shown that, though in some few instances, ssicep or awake. According to Richerand, one of the is described, yet in the great majority he had no congreat purposes, served by sleep, is to diminish the acti- sciousness of any thing of the kind. The doctrine, vity of the circulation, which a state of wakefulness has therefore, so far as direct evidence is concerned must the invariable effect of increasing. The exciting causes' de observes, “to which
fall to the ground ; and yet, unsupported as it is either
organs are subject during the day, tend progressively to increase their ac
by proof or analogy, this is the fashionable hypothesis zion. The throbbings of the heart, for instance, are
of the schools, and the one most in vogue among our more frequent at night than in the morning ; and this
best metaphysical writers. action, gradually, accelerated, would soon be carried to
There is a strong analogy between dreaming and insuch a degree of activity as to be inconsistent with life, sanity., Dr. Abercrombie defines the difference beif its relocity were not moderated at intervals by the re
tween the two states to be, that in the latter the errocurrence of sleep.'
neous impressiou, being permanent, affects the conduct;
whereas in dreaming, no influence on the conduct is To detail the beneficent purposes served by sleep in produced, because the vision is dissipated on awaking the cure of diseases, as well as in health, would be a work of supererogation. They are felt and recognised in somnambulism and sleep-talking, the conduct is in
This definition is nearly, but not wholly correct; for by mankınd as so indispensable to strength, to happi- fluenced by the prevailing dream. Dr. Rush has, with Dess, and to life itself
, that he who dispenses with great shrewdness, remarked, that a dream may be conchat portion of repose required by the wants of nature, is in reality curtailing the duration of its own ex
sidered as a transient paroxysm of delirium, and deliistence.
rium as a permanent dream.
Man is not the only animal subject to dreaming. We does the complication of dreams; and if all the internal organs
have every reason to believe that many of the lower are aware, bo man is still asleer lor!!! nwakening senses * This internal stimulation of particular organs without the idiog Mian Ino direct comment
concurrence of outward impressions by the senece, is more fully Carmicko
heim, p. 92. stated under the head of Spectral Ilusions.