Изображения страниц


I. SLEEP in man is the periodical rest of the brain, with suspension of volitional muscular activity. The system of relation, by means of which man comes to know and is linked with the outside world and his fellow beings, is in abeyance for the sake of repose and repair. In perfect sleep there is a stoppage of senseimpressions, a locking up or deadening of consciousness. The system of maintenance of the individual, as digestion, respiration, secretion, is alone doing work, and that probably slowed to half or three-quarters speed. The only parts, then, of the nervous system inevitably active are those essential to the persistence of life-functions simply automatic and called orderlyreflex, which are as unperceived as if the fore-brain were wanting -a condition shown experimentally in animals after decapitation, or when the connection between the brain and spinal cord has been interrupted. Beheaded frogs will whisk off a drop of acid from their skin, make purpose-like defensive movements when pinched by a forceps, pushing their feet against the instrument; croak when the back is stroked, and take a sitting posture: all like will-acts with a whole brain, and yet they are necessarily only inconscient reflex instincts of the lower nervous centers. Dacoits, a band of thieves in India, steal a mattress from under a sleeper without waking him, first deepening sleep by fanning the victim, then tickling the part of the body next the operator, when the sleeper automatically edges away a little. The fanning and tickling are repeated till the man sidles quite off his bed.

A notion of the distinction between conscious volitional activity and that which is only automatic is essential to the right understanding of the phenomena of sleep. In the wak ing state, when a sensation comes to the gray cells of the forebrain, there is always a perception, which may or may not give

rise to a will-act, while the reception of a stimulus by a lower center gets only an automatic answer. Sleep is not a single state, but a series of states. This may be made plain by an analysis of an after dinner snooze, when "cibum sequitur somnus;" or of a catch-nap at church or in a carriage. For a while it is the "mystic middle state" 'twixt sleep and wake. When the exposition of sleep gains upon us, the eyelids grow heavy and droop, consciousness gets confused, we have a hazy notion of what is going on about us, and fancy often makes some play at the outposts of dreamland; there is gradual loosening of the muscular system, the eyelids close, the head bobs and then falls on the chest; and, as we steal away from our own company, the muscular sense that by which we feel the possibilities of our muscles, and which gives us the notion of the presence of our bodies-is deadened and soon lost, as well as the intuition of time and space; and then we are "off." Lucretius's description is perfect:

"Debile fit corpus, languescunt omnia membra;

Brachia, palpebræque cadunt, poplitesque cubanti
Sæpe tama submittuntur, viresque resolvunt.”

are, to some extent, en rapport still with our surroundings; consciousness is "scotched, not killed," dim impressions loiter, and a slight noise, a spoken word, even in a low tone, the stopping of the carriage or of the drowsing preacher, recall consciousness, for the moment a little dazed. If the doze has not been vexed, the awakening is by steps, and if we heed, we shall find that the muscular sense first goes on duty, and the certainty of the lower limbs is the earliest dawn of personality. In customary sleep, externality and the measure of the body are first lost, the mental images fading away last in clouding thoughts and flittering fancies.

The hypothesis that the mind apparatus is a complex of the rind cells of the fore-brain, made up of many organs, each having its fitting office, is built on the broad basis of observation and experiment. Gall's theory of multiple sites for the several mind faculties, though true in principle, was chained to a fictive skullchart, which put it out of court. The plotting of the brain rind by later neurologists, known as "localization," is the outcome of

tried and satisfying experiment and observation, and is, within limits, demonstrable. Its possibilities of development are large, if not spoiled in its cradle by over-forcing, and if, from time to time, it is put in the fining pot and assayed by what Goethe called active and self-conquering skepticism (thätige u. selbstüberwindende Skepsis).


Much of the brain is a dark continent, and mind is still the most obscure chapter of anthroposophy. The philosopher bows before its mystery, which passeth understanding, and owns that it can be studied only in its manifestations-states of consciousThe tie between mind and matter is near, sure, and lasts while life lasts; but its nature is unknown, and modern science allows that it fails to find out the catena of causality that shall link them in a single line. They will never be reduced to a common term. Nevertheless there is a true blend, and we cannot consider the data of mind apart from the data of matter.

No brain no mind, no mind without a working brain. There is a necessitated correlation between the zoɛiv and the ovoia -the facts of phenomena and the facts of substance. Goethe said, No spirit without matter, no matter without spirit. The newest branch of psychology, psycho-physics, is doing much to give a closer touch to the understanding of many of the vexed problems of mind, and, not to overstate its strength, to free them from the conceits of metaphysic-the crackling of thorns under a pot-and the gyves of theology.

The study of mind on these lines is not a surrender to materialism, in the vague and unreasoned sense of the Philistine when he plants his scarecrow, and casts soil at Science in her loving and earnest striving after truth. Such twinship of mind and matter is thinkable, and in full agreement with the quests of modern science. "Truth," said Sir J. Herschel, "never can be opposed to truth."

From present proved data we have, then, full warranty to credit the hypothesis that the cell clusters of the rind are the material organs of mind by which its objective tokens are made known; that they are autonomous yet heteronomous, independent yet interlocked with a central power, and subject to its controlling and combining force, like our States and general gov

ernment. In sleep these groups may be variously conditioned. Some may be resting or getting food, while others are wide awake, full fed, and kinetic.

Burton calls sleep "a binding of the outward senses, and of the common sense, for the preservation of body and soul;" and Lucretius says, "jacet sine sensu corpus onustum." This notion of the shutting up of the five watchful senses-the closing of the sensory thoroughfares in sleep-is constantly repeated by poets, and even physiologists. It is, however, not a fact. In deep sleeps-somnia vera-common-value sensations are, probably, not perceived. But the absence or lessening of consciousness in sleep is not due to disability of the sense end-organs; they are in good form and fit for service, though, perhaps, a trifle dull. They are alive to the impact of the irritant, answer the call, and send off the message; but it fails to get heed at the central station, and does not, therefore, become a concept. There is either no subjective conversion of the objective impression at all, or it is imperfect. The shortcoming is not, then, in the end-organ, which does its work, but in the receiving one, which is not in good gear, or quite out, as sleep is deep or not. It fails to register, or registers faintly or amiss, as between sleeping and waking. It is a case of non capiendo recipit; what is offered is not laid hold on. It may be said that such is not the case with the organ of sight, for it is curtained by the lids and does not receive the stimulus. This objection is overruled by the facts of dreams and of somnambulism.

Psycho-physic methods have taught us how to ascertain the liminal intensity of the sleep-value, and the amount of intensive irritation needed at different stages to cause awakening. Kohlschütter ascertained, by direct measurement, that the intensity of sleep increases, at first quickly, then more slowly, until the end of the first hour (Möningshoff and Priesbergen say one and threequarters), after which time it diminishes, at first quickly, then very slowly, reaching its terminal value at waking time. Often, without apparent cause, though always on account of an excitation, there is a sudden lowering of intensity, attended by an inconscient movement of the limbs, sometimes by a partial turning over of the trunk, and even an utterance of words, generally incoherent; this is followed by an immediate deepening.

Many interesting cases of "most fast sleep," sleep "in spite of thunder," are of trustworthy record. At the attack on Rangoon, the captain of one of the steam frigates actively engaged slept for two hours near one of the working guns. At the battle of the Nile boys fell asleep on the decks from sheer fatigue. During long marches cavalrymen sleep soundly. Napoleon, it is said, could sleep in the midst of battle. The sudden cessation of an accustomed noise will wake the sleeper, as well as calling his name. Dr. Carpenter says that Sir Edward Coddington told him that, as a youth, serving as signal lieutenant, he often remained on the lookout fifteen to twenty hours, and when relieved and he went below, his sleep was so sound that no noise could wake him, though trial was often made; but when the word "signal" was whispered in his ear he would rouse at once. The tired doctor is quick to hear the first tinkle of his night-bell, the tick of the instrument wakes the drowsy telegraph operator, and the weary mother starts up from sleep at a moan or rustle of her babe. Habit and periodicity are immanent in the nervous system. We awake at the accustomed time, as well as at an unusual hour fore-set on going to bed. Here an impression has been registered in the waking state, and is liberated at a given moment with the exactness of an alarmwatch.

A much-debated question is, whether there is ever total suppression of ideation in sleep; whether the circuit of thought is open, closed, or works fitfully. The pure metaphysicians and the psycho-physicists are not at one on this point:

"Mulciber in Trojam, pro Troja stabat Apollo.”

Outside of dreaming there is good right to hold that latent mental energy—unconscious cerebration-goes on, adjusted to the sleep-value. Many a plaguing problem and intellectual act have been carried out during sleep. Charlotte Brontë, when stalled in a tale, would think the matter over before falling asleep, and the next morning all would be clear.

The physical mechanism of sleep is obscure. All the theories are unsatisfying, from the "labefaction of the animus" of Lucretius to the modern hypotheses of a "lessened blood-supply" of

« ПредыдущаяПродолжить »