An entire body of philosophy according to the principles of the famous Renate Des Cartes in three books, (I) the institution ... (II) the history of nature ... (III) a dissertation of the want of sense and knowledge in brute animals ... / written originally in Latin by the learned Anthony Le Grand ; now carefully translated from the last corrections, alterations, and large additions of the author, never yet published ... by Richard Blome.

CHAP. IX. Of Sleep and Waking.

I. Why In∣fants are most chiefly addicted to sleep. INfants and Children soon fall asleep, and be∣ing in a sound Nap, sleep long and are not easily wakened.

Children are very much abounding with moi∣sture, with the thickness whereof the Pores of the Choroidal Contexture, and the Arteries called Ca∣rotides are somewhat streightly closed and shut, and consequently afford not a very free passage to the Animal Spirits. For as we see sometimes the Sails of Ships slack and lank, when there blows but a gentle gale of Wind, not strong enough to stretch and expand them; so when there is not so great a plenty of Animal Spirits proceeding from the Heart as to fill the Marrow of the Brain, and to keep all its passages open, Sleep must needs arise. Since then in Children and Infants, Hu∣mours very much abound, the Motion of the Animal Spirits is by the resort of them to the Brain, much diminish'd, and the Pores of the Brain apt to be obstructed.

II. Who they are that soonest fall asleep. Hence it comes to pass, that they who have a more than ordinary Cold and Moist Brain, as per∣sons of a decrepit Age generally have, soon fall a sleep. On the contrary, those that are of a more dry and hot temperament, pass many times whole Nights without sleep, and being vigorous and in the prime of their Age, are satisfied with a smaller portion of sleep than Children or old People.

III. Why we fall sooner asleep sit∣ting by a Fire, than in another place. We Sleep sooner lying down than in any other posture, and sooner by a Fire than elsewhere.

That we sooner sleep lying than otherwise, is because our Heart is then parallel with the Hori∣zon; whence it comes to pass, that the Blood pro∣ceeding from the sinister Ventricle of the Heart, passes to and fro with an equal force, which, when we stand or sit, it cannot do, for then the more subtile part of the Blood only ascends; so that in regard the grosser part is conveyed to the Head through the two Carotides, and the two Vertebral Arteries, consequently the fewer Spirits are from thence generated; the want whereof causes an inclination to Sleep. But that we sooner than ordinary sleep by the Fire, is because the Pores of our Body are much enlarged by the fiery particles, so that our Body becomes like a course Sieve or Cullender, by reason whereof the Ani∣mal Spirits take their flight the faster; thus the Body tired and debilitated, drops at last into a sweet sleep.

IV. How Tobac∣co taking, both pro∣cures and drives a∣way sleep. It is vulgarly affirmed that the smoaking of To∣bacco both induces sleep and drives it away; and that it both excites and expels Hunger and Thirst.

The Reason is, because the Animal Spirits be∣ing stroak'd, and as it were led into a Dance by this sort of Fume, grow absolutely deaf to all troublesom accidents; nay, whatsoever of difficul∣ty lies upon them to be done or suffered by them,

they go through with ease and undisturbed: Wherefore to Soldiers and Mariners the use of To∣bacco is a thing not only of advantage, but almost of necessity, forasmuch as it renders them undaunt∣ed and fearless, and ready to undergo all dangers, patient of Hunger, Cold and Labour; as gently raising and exalting, and as it were tickling the Animal Spirits to quick and expansive motions, and is a recreation to them, no less than the carou∣sing of full Glasses of Wine to others.

V. Poppy, Saf∣fron, &c. cause sleep. Poppy, Saffron, Mandrakes, and the like stu∣pefie, benumb and lay asleep those that take them.

The Reason seems to be, because Plants of this Nature are full of a very Uliginous or Clammy sort of Juice, with which the Pores of the Cho∣roidal Contexture, being stopped, are disabled from conveying to the Brain the Spirits proceed∣ing from the Heart. For as some Plants are ob∣structive to the Spleen, others to the Liver, and hinder them from performing their usual office; so the Poppy, Mandrake, Saffron, &c. have a sen∣sible power of obstructing the said Contexture, and causing fewer Spirits to be transmitted from the Heart to the Brain. For all Somniferous or sleep∣ing things, whether outwardly applied, or taken inwardly, infuse a certain moistning all over the Bo∣dy, and so induce a Refrigeration or Cooling, by which the abundance of Spirits is diminish'd, or their motion retarded. By the like Reason, those who are troubled with a Catarrh or Rheum, are apt to fall asleep, and to be opprest with a kind of stupidity or heaviness, by reason of the abun∣dance of Humour which lies about the Fountains of the Nerves and stops their passages.

VI. Why Baths excite to sleep. Balneo's generally cause sleep in those that use them.

This they do, not so much from the immedi∣ate virtue of Bathing, but so far as they commu∣nicate to the Humours circulating through the Pores certain sweet particles proceeding from those emollient Herbs infused in the Bath, whereby it comes to pass, that the Blood is somewhat restrain∣ed, and disturbed in its over-violent Career, so as that it drives not into the Brain with so much vehemence as before, nor is there so great a quan∣tity of Spirits to be discerned, from the want whereof sleep arises.

VII. How the L••••hargy induces sleep. Certain Diseases, as the Lithargy and others, create in the Patient an excessive drousiness, and at length plunge him into a deep sleep.

And this by reason that the proximate cause of this affection is the obstruction of the Pores of the Brain, proceeding from a gross Humour, and the want of Animal Spirits immerst in the overflow∣ing stagnation of Humour, by which means those affected with this Distemper, must needs be apt to fall asleep. And such a sleep it is, that it may be accounted not only the Chain and Fetter of all the exteriour Senses, but also the Oblivion of all things. Wherefore those that have taken in the Infection of the Plague, if they are of a sleepy Constituti∣on, and give themselves up to repose, become the more deeply infected, and Nature is the less able to resist the Contagion. Moreover, those that have drunk Poisoned Potions, if upon the drink∣ing of them they are overtaken with sleep, they suffer in a higher degree, and the Poison the sooner reaches their Vitals. Because too much evaporation oppresses the Natural Faculties and renders them dull, heavy and uncapable of over∣coming the Evil.

VIII. Why the Cock wakes at Mid∣night. The wakeful Cock certainly shakes off Sleep about Midnight; Whence MANTUAN,

The Bird that's sacred to the Sun's bright Ray, Bids Night adieu, salutes th' approaching day.

Cicero in his 2d Book of Divination judges DE∣MOCRITUS to have most excellently ex∣plain'd the reason why Cocks Crow before Day, as follows, The Meat being gone off from the Sto∣mach, and dispers'd into the whole Body, the Cock, saith he, in the silence of the Night, having digested his Meat, and being satisfied with rest, to express his content, lifts up his Crowing Voice, and displays his Gay Wings. But with this opini∣on of Democritus I am no way satisfied. Because if the Cock rowses from sleep, and Crows after Midnight, by reason of the digestion of his Meat, it should follow from thence, that afterwards he would no more indulge to rest; but this Experi∣ence contradicts. Besides, he Crows as well at Noon, being full, as also after treading of the Hen; so that this Reason might better be given, namely, that the Sun having past the Nights Me∣ridian, and now steering towards the Morning, agitates and drives before him a cold Nocturnal Gale, by the shuddering approach whereof the Cock being roused out of his sleep, flutters with his Wings and sets a Crowing.

Or why may we not affirm, that certain times are allotted to all Creatures for sleep, and this par∣ticularly to the Cock, at which by an innate mo∣tion it wakes, and having its Spirits in agitation, sets a Crowing, and by his Crowing testifies his wakefulness? For why may not the Spirits of the Cock, as well as of a Goose, or any other Bird of that Nature, inclosed in the Brain, excited either by its own abundance, or by some external mur∣muring noise, so open those passages in which the said Spirits use to have their course from the Brain to the proper Organs of the Senses, as from the Center to the Circumference, as by a concourse made to move the Nerves attendant to the foresaid motions?

IX. Why we are most apt to be sleepy after Meals. Soon after Dinner or Supper we are more apt to fall asleep than at other times. Whence many have taken up a custom of setting themselves to sleep after Meat, to which Custom Nature seems to invite, and few can put it off without much re∣luctance.

The Reason is to be derived from the very concoction of the Meats; for when at that time a cruder Chyle from the Stomach and the Intestines is mingled with the Blood, and hinders the rare∣faction thereof, it must needs follow that the Brain, by the loss of Spirits, is refrigerated at that time, and so contracts a certain sleepy dispo∣sition, so that the Spirits which remain are scarce sufficient to keep the passages of the Nerves open and tite: Hence we find by experience, that the external parts of the Body are after Meat refrige∣rated, so that the Head hangs down, and the Eye∣brows fall, if we do not rouze and set upon some serious affair, and find work for the Ani∣mal Spirits.

X. How it comes that we are more apt to wake out of our Sleep by Night than by day. Sleep is not so easily broke off by Day as by Night, as we find by experience in the Spring and Summer, in which, by reason of the Suns light coming in at the Chamber Window, we are more difficultly rous'd from Sleep than in the Winter when the Sun is at a distance, and we are surround∣ed with Mist and Darkness.

This proceeds not from Light, as from the effi∣ent Cause; as if Light were indued with a faculty of procuring Sleep; but only by accident, foras∣much as our Eyes, being weak, and smitten with sudden cold, are apt to wink, and at last to close and be quite shut: For when we open our Eyes, the Light comes upon them, and smites them, and they not knowing how to send back the Rays, are offended and disturbed to be so smitten by them, shut down the Eye-lids again, and betake them∣selves immediately to a renovation of Sleep and Re∣pose. Hence it comes to pass that waking at broad day, and opening our Eyes, we feel a kind of force and pain in so doing; in regard the Light smites not the Retine Tunicle by degrees, but all on a suddain.

XI. Why the extream parts of our Body are apter to be cold in sleep than when we are awake. When we are asleep, we are more apt than at other times to be cold in the extreme parts of our Body, but hot within.

This most probably proceeds from hence, name∣ly, for that the Blood not being at that time agita∣ted by any passion, or any violent exercise, flows so quietly that it hath not force enough to convey any heat to the extremities of the Body, whence they be∣come cold, at least in those persons whose Lungs are in a good temper: But for those that are troubled with bad humours, or are Asthmatick, they cannot indure to lie covered, by reason that the heat which they bring upon themselves by being covered, very much augments their inward heat.

XII. Why those that lie ••ll at ease, are easily wakened. Those that lie not at ease, by reason of the Sheets not lying smooth under them, or the hardness of the Bed, or a necessity of making Water; are very often interrupted in their Sleep, and forc'd to lie awake a long time.

The Reason is, because the Animal Spirits which are bred during Sleep, and continually re∣pair'd by the motion of the Blood through the Heart, can have such a plentiful confluence, as that having thereby the power of opening the Ori∣fices of the Nerves, they fill them in such a man∣ner as is necessary to extricate their Filaments, and give occasion to the Soul to perceive those Objects: For whatsoever gives disturbance to any sense, and interrupts the usual rate of motion, is an absolute Enemy to all Repose.

XIII. Why at∣tentive reading af∣ter Meals, induces sleep. We find by experience, that when we are very attentive in Reading or Studying presently after Dinner or Supper, we are apt to fall asleep, but not in the least when we are present at the acting of a Comedy, or the sight of any thing that moves to Laughter.

The Reason is, because any studious attention, or serious exercise of Mind, draws the Blood more copiously toward the Head, and gathers it together from all parts of the Body towards the very midst of the Brain. By which means it comes to pass, that upon the Blood penetrating the Brain there follows a great recourse of Nervous Juice that way, by which the Spirits are presently obstructed, and their intermediate places taken; but it falls out otherwise, when after Dinner we repair to a Comedie, because then the Animal Spirits being diffused with pleasure, distend and enlarge the Brain; so as that the passages being streightned by that inflation, stop the course of the Sopori••e∣rous Humour, and hinders it from forcing into the Brain.

XIV. How Coffee happens to drive away sleep. Coffee is said very much to keep away sleep, and procures an extraordinary disposition to wake∣fulness, and an unwearied exercise of the Ani∣mal Faculty; forasmuch as upon the drinking of this Liquor any one may sit late at night for the carrying on of any Studious Contemplative or Wakeful business.

This effect in my Judgment may very well be imputed to those adust particles of the Coffee, which mingling first with the Blood, then with the Nervous Juice, keep by their agility and restlesness the pores of the Brain open, and the Spirits having now shaken off all Curb or Bridle, are prick'd as it were with Goads and Stimulations to the longer and more continued performance of their Offices. In like manner the Cause of a very wakeful temper may be imputed to a torrid and Melancholick Blood which supplies the exteriour Brain with such a sort of Nervous Juice as is parch'd and fill'd with adust particles, and is neither fit to remain longer within the pores of the Brain, nor kindly to receive and contain the Animal Spirits.

XV. In what the excess of Coffee is hurtful. This kind of Drink, tho' of very common use, and in some cases very wholesom and medicinable, yet at other times, and in other cases it may be hurtful and unwholesom; and this not only Rea∣son, but also common Observation tells us; foras∣much as excessive drinkers of Coffee are very often Lean and Paralytick, and many times unapt for Generation: In regard, since the Blood, by the frequent and excessive use thereof, becomes in a great measure acid and adust, it is consequently the less apt and capable to nourish.

XVI. How it is that Chil∣dren are rock'd a∣sleep by the motion of Libration. In Children Sleep is procur'd by the motion of Libration, so called, or rocking in a Cradle.

The Reason is, because this rocking to and again stirs the Humours of the Brain; by the access of which Humours to the Brain and Origin of the Nerves, Obstructions are created: As when any sort of Liquor is injected with a force upon what∣soever Object is capable to receive it, it sinks in the deeper, especially if the Body into which it en∣ters be tender and soft, as the Brain of Children most certainly is.

XVII. How some duly come to wake at set hours. Some wake constantly at set hours.

This comes to pass, partly by reason of daily custom, and partly because at certain set hours those men have sufficient plenty of Animal Spi∣rits to puff up the Tubes of the Nerves, and also the Muscles; as appears in those that are more hungry at some times than others: Of which there can be no other reason given, than because by that set time the Blood has made several circulati∣ons through the Heart, and by that means hath obtained such a due degree of acidity, as is requi∣site for the exciting of Hunger in the Stomach.

XVIII. How many hours are to be allot∣ted for sleep. As for the time allotted for Sleep. That which the Schola Salernitana hath decreed in this point, is most generally received.

Seven hours in Sleep the Eyes to hold, Is long enough for Young and Old.

But in this matter a certain set time cannot be ap∣pointed to all alike, but rather the different tempe∣rament of this or that person is to be consulted. For to those whose Blood is more thin and subtile, as the Spaniards, Italians and French, a shorter time of Sleep is sufficient; for example, the space of five hours or thereabout, which would be too short for those that have their Blood more gross and viscous, for such Blood should be allowed time to pass often through the Heart before it can be made thin enough to afford matter for the gene∣rating of Spirits.