DR. BINNS'S ANATOMY OF SLEEP.

PzawArs few things better indicate the difficulty of physiological or physical knowledge, than the fact that the professors are not able to tell what sleep is. Once in twenty-four hours the most industrious physiologist sleeps : if the subject occupies his wakin thoughts, it is most probable that he experiences every mode at that peculiar form of existence, from dozing and dreams to the sound slumber when mind and body are alike exhausted. But what sleep is he cannot satisfactorily define; and though the cri- ticism of Dr. BINNS may prove that other definitions are wrong, we fear that his own attempt has not succeeded in reaching the right. But the Doctor's Anatomy of Sleep has a more practical object than mere description ; he would produce what others cannot define. Nay, not only produce it, but produce it "at will," and "sound and refreshing." The end and aim of his volume seems to be to lead the reader through every variety of sleep, or rather through every variety of existence which is not waking, in order to establish his recipe on a legitimate deduction ; but, it strikes us, without success. The rule which he gives may produce sleep at will, but as a logical corollary it is quite irrespective of all that has gone before : nor do we perceive that the charm is altogether con- nected with "nzonotordsm," or the monotonous dwelling upon one idea; because we can conceive many other states of monotomsm than fixing the attention upon the breathing. Still, if the "hurt mind" can procure its "balm" by the following method, let it care. not for logical or metaphysical objections, but continue the idea of Sancho Panza and breathe a "blessing on the man who first in- vented sleep" — " at will," whether he be Dr. Bums or MT. GARDN ER—for to this last Dr. BINNS ascribes the honour of the discovery.

BOW TO PROCURE SLEEP.

Let him turn on his right side; place his head comfortably on the pillow, so that it exactly occupies the angle a line drawn from the head to the shoulder would form ; and then, slightly closing his lips, take rather a full inspiration, breathing as much as he possibly can through the nostrils. This, however, is not absolutely necessary, as some persons breathe always through their mouths during sleep, and rest as sound as those who do not. Raving taken a full in- spiration, the lungs are then to be left to their own action ; that is, the respira- tion is neither to be accelerated nor retarded. The attention must now be fixed upon the action in which the patient is engaged. He must depict to himself that he sees the breath passing from his nostrils in a continuous stream : and the very instant that Ile brings his mind to conceive this apart from all other ideas, consciousness and memory depart ; imagination slumbers ; fancy becomes dormant, thought subdued; the sentient faculties lose their susceptibility ; the vital or ganglionic system assumes the sovereignty ; and, as we before remarked, he no longer wakes, but sleeps.

This train of phienomena is but the effort of a moment. The instant the mind is brought to the contemplation of a single sensation, that instant the sensorium abdicates the throne, and the hypnotic faculty steeps it in oblivion.

And is this all ?" the reader may ask. It is all the matter-of- fact but sleepless wight will learn, that can be of use to him in procuring " sound and refreshing slumber." But there are a variety of other things relating to sleep in the volume, many curious and most of them readable. Dr. BINNS gives a general view of the physiology of life, tracing its progress from plants to man ; he enters into an elaborate description of the brain ; he treats of sleep in all its various phases, including somnambulism, trances, mesmeric slumber, and its other phmnomena, as well as ecatacy, catalepsy, and the very equivocal condition of Lord SHREWSBURY'S Catholic saints, which Dr. SINNS was first inclined to consider the effects of some anomalous disease, but which the Peer, in personal con- ference, has convinced him is a miracle. In discussing these various subjects, the author sometimes adduces a theory of his own, or somebody else's ; but generally speaking, he confines himself to cases or facts, of which he has collected a vast num- ber; some curious, striking, and pretty well authenticated, others only " curious if true"; the Doctor being a believer in phreno- logy and a disciple of mesmerism, as well as having faith in modern miracles.

It may readily be conjectured from this account, that The Ana- tomy of Sleep has little value as a sound exposition or a scientific conjecture. Dr. Birms is a pleasant collector and retailer of facts, but a somewhat credulous and undiscriminating metaphysician and physiologist. Whenever he meets with any thing that strikes him, he prints it, without regard to its age, authenticity, or probable truth. What scientific or medical proof, for instance, could there be of a case occurring in the time of HENRY the Sixth ? Some of his stories appear to us to be derived from the same veracious chronicles that recorded fights of dmmons and showers of blood, and some seem pure inventions. Had such anecdotes been stated as what they were, the only objection would have been one of pro- priety; but Dr. Mass does not always draw a proper distinction between facts, recorded by a man like ABERCROMBIE, and the stuffings of some fable-monger; nor does be always furnish the reader with his authorities, and consequently with the means of judging for himself As an example of the pleasant closeness of parts of the book, we take a few examples ; but as Dr. Bungs professes to have derived much from other writers, we do not know how much of the merit is to be ascribed to himself.

SLEEP OF ANIMALS AND MAN.

MOJA animals sleep more than man ; some indeed for months—as the hiber- nating tribes of bats, dormice, marmots, and bears. Cats and dogs would seem to have the faculty at will, as have some idiots and persons of a low order of intellect. The ideas, or impressions upon their minds, are so feeble, or so few, or are made at such long intervals, that succession is lost for want of conti- nuity: hence the organ retains imperfectly, and but for an instant, the image which the external senses have presented to it ; weariness supervenes; uncon- sciousness follows; and lastly, sleep, as a necessary consequence of inanition, is Induced.

It is observed, however' that monkies do not sleep so much as other animals. Whence is this apparent deviation from the ordinary law of nature affecting animals? Is a monkey a reasoning animal ? Observe a dog chained : he twists his chain, shortens it, and cuts himself off from his platter. Does he seek to untwist it—to restore the links to their wonted extension ? No; he continues tugging and bowling, till some friendly hand frees him from his toils, and restores him to his former range. But how is it with the monkey under similar difficulties ? Why, be deliberately untwists the chain which he cannot sunder, and hence evinces something like reason.

Is the sleeplessness of monkies, then, a proof of reason ? We think so. But infants, they are frequently sleepless ? Yes; but never in a state of health. Restlessness in them is always an indication of hunger or a symptom of disease.

The absence of sleep cannot be long sustained. Damiens slept on the rack ; Luke in his iron crown ; and a battalion of infantry have been known to slumber during a march ! Muleteers frequently sleep on their mules, post-boys on their horses, and seamen "on the high and giddy mast." " Massa call you, ' said a Negro to his comrade who had fallen asleep near him : "Sleep has no massa," replied the wearied boy ; and he was right. We may bear the priva- tion of fire, food, and even drink, longer than we can the want of sleep.

So that SRAKSPERR was physiologically correct in his trait, " Chief nourisher in life's feast.'

APPROACH OF SLEEP.

The phienomena of natural sleep may be thus described. Its approaches are marked by a sense of muscular fatigue; the legs become weary, the arms in- dolent in their movements, and the hand unsteady in its object. Yawning, Without our having the power to prevent it, follows or precedes this state ; the attention languishes; the most interesting narrative fails to awaken it ; we become captious, and even fretful. In the meanwhile, external impressions begin to fade. If we attempt to read, the lines run into each other; and if we look from the candle to the page, the letters will appear of a greenish or bluish cast. The memory becomes confused; the eyes grow dim and lose their Mil- liancy, while the upper lids fall, in spite of our efforts to uphold them; next, the muscles of the back and neck relax their tension, and the head falls un- willingly forward. But the sense of hearing remains still unimpaired; and w hear and understand the conversation of those around us, when we can no longer distinguish their persons or perceive their gestures. Anon, a SOCCeSSIMI of pleasing reveries approach and depart in calm succession. The brain ap. pears to float in a dreamy sea of peaceful enjoyment; a pleasing delirium su- pervenes, and we no longer wake—we sleep. The organs of tI.. se./lea, laid asleep in succession, awake in the same order. Sounds and light produce im- pressions, confused at first, on the eyes and earl: in a little while, these sen- sations grow distinct ; we smell, we taste, we judge of bodies by the touch. Thus it Is, then, we return to the state of wakefulness, to a sense of the condi- tion of our being.

DURATION OF SLEEP.

Of the duration of sleep the period varies in various men. John Hunter. Frederic of Prussia, Napoleon, and other great men, slept but little. The Duke of Wellington is also a little sleeper. Boerbaave says, that on one occasion, his mind being much engaged, he could not sleep for six weeks. He probably meant to write not "soundly." He adds the case of a student, who adopted the strange theory, that the natural condition of man was sleep ; and to test the truth of the doctrine, slept eighteen hours of the twenty-four; and, as might have been expected, died of apoplexy. The elder Deserozilles seems to have slept but two hours in the twenty-tour.—Annales de Chimie. However, the number of hours passed in sleep vanes from six to twelve. The indolent, and those whose avocations or fortunes doom them to inert life, sleep many more hours than are necessary ; but eight or nine hours would seem to be about the intellects which every man ought to take who values his health, or expects his to be in a fit state to enjoy life.

Habit, climate, constitution, calling, age, modify, however, the duration. Infancy requires much sleep; youth more than is generally allotted to it in England; and manhood is the medium between the wants of youth and the necessities of age. Some old people, as we have previously remarked, Bleep much. Parr slumbered away the greater part of his time; and De Biome, when eighty-three years of age, slept twenty hours of the four-and-twenty. But these are exceptions to this law of nature; and Rickerand affirms that old men have short sleep, light, and broken ; as if, says Grimaud, according to Stahl's notions, children foresaw that, in the long career before them there was time enough for performing at leisure all the acts of life ; while old men near to their end, feel the necessity of hurrying the enjoyment of good already about to escape. Dr. Ellietson writes—" Old people sleep lightly and fre- quently; and altogether but little, unless lethargic diseases come upon them, which is very common. I heard Baxter the coachmaker declare he never took more than three hours sleep during the most active period of his life. The celebrated General Elliot never slept more than four hours out of the four-and- twenty; and his food consisted wholly of bread, water, and vegetables."