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. V. How the Body of Man is nourished and encreased.

I. What Nou∣rishment and En∣crease is. FOrasmuch as those parts that are so turned into our Substances, as to preserve our Body in the ••ame state and condition only, are said to nourish us; and that those parts, which being transmuted into our Bodies, do make it greater in Bulk than it was before, are said to encrease it, and make it grow, we may easily apprehend what Nourishment and Growth is.

II. The Pro∣gress of our Food from our Mouth to the Sto∣mach, Guts, &c. The manner how both these are performed will more plainly appear, by taking an exact view of the changes of those Aliments, whence the Princi∣ples of our Blood are derived. First, It is evident that, besides the Culinary Preparation of the Ali∣ment, it is chewed by the Teeth, and being ming∣led with the Spittle is sent down into the Stomach. 2ly. That in the Stomach it undergoes a special Fermentation, whereby it is yet further dissolved. 3ly. That from this dissolved and digested Mass, by another peculiar effervescence or working in the Guts, are separated the more useful and pure parts of the Chyle, from those that are more thick and gross, which are yet farther dissolved and atte∣nuated in the Lacteal Veins, and the Kernels of the Mesentery, as also by the Commixture of the Lymphatick Juice; and at last being mingled with the Blood in the Veins, are carried to the Heart; where having past another effervescence, they be∣come united with the rest of the Blood, there being now no more any difference between them.

III. How the Chyle is driven out of the Sto∣mach into the Guts. When, I say, that the Chyle is driven out of the Stomach into the Guts, I do not thereby own any Expelling Faculty residing in the Stomach, as the Antients did suppose, this being done by the Ani∣mal Spirits flowing through the Nerves into the Membrans of the Stomach, and drawing them together. And forasmuch as these Membrans of the Stomach do immediately infold and embrace the Chyle, in a healthful state of the Body, the said Liquor must of necessity be expelled through the Lower Orifice of the Stomach, into the Guts, as is manifest from a Bladder filled with water, the neck of it being left open; for as soon as you press this Bladder with your Hands, the water gusheth out immediately at the Neck. Moreover, the pressure of the neighbouring parts, as of the Liver, Spleen, Guts, Midriff, the Pancreas, or Sweet-bread, and especially of the three last, con∣tribute much to this Expulsion: for the Midriff is driven downwards by constant Inspiration, and pusheth upon the Stomach that lies under it, as may be seen in the cutting up of Living Beasts.

IV. The nou∣rishing of the Body is performed by the help of the Blood And forasmuch as it is observed that a Body can∣not be nourished, as long as the Blood continually flows from it, but that on the contrary it wastes and consumes; we may well conclude, that Blood concurs to the Nourishment of the Body, and that it is a substance, which acquires another nature, so as to supply those parts that are dissipated, and turn to Excrement.

V. The opinion of the An∣tiens con∣cerning Nu∣trition and Crowth. Which Change the Antient Physicians explain∣ed, by saying, that when the Blood was come to the utmost parts of the Branches of the Capillary Veins, it sweat through them in the form of a Dew, which afterwards turned into substance not unlike to Glew, of a mean consistence; which Glewy substance was then attracted by the several parts of the Body, according to their several needs. So as that the Flesh attracted those particles that were most proper to be changed into Flesh; the Bones, the most fit to be turned to Bones; and that the same Attraction and Assimilation was performed by the help of 2 Faculties, the one whereof they called the Attractive, and the other the Assimila∣tive Faculty.

VI. This opini∣on rejected. But forasmuch as there is no such Attraction in our Bodies, and that our parts are not endued with any knowledge whereby they might be able to di∣stinguish such particles of the Blood as are like and fit for them, from those that are otherwise; this opinion seems to be very contrary to Reason. Neither do they make out, how the Venal and Arterial Blood comes to be changed into Dew, and thence into a Glew; neither can they demon∣strate what those wonder-working Attractive and Assimilative Faculties are, they do so much talk of.

VII. How Nutri∣tion and Growth are performed. We say therefore, that the Nutrition of Mans Body is thus performed. The Blood being come forth from the Heart, wherein it hath received its utmost perfection, is driven towards the ends of the Arteries. For as soon as the Arteries become di∣lated, and as it were blown up, the small particles of the Blood they contain, run against the roots of some Filaments, which proceeding from the Ex∣tremities of the Branches of the Arteries, do con∣stitute the Bones, Flesh, Skins, Nerves, Brain and the other solid Members, according as they are in themselves of a several Juncture or Texture, and thus have the force to drive them a little forwards, and to take up their places. And then as soon as the said Arteries fall again, they leave the parti∣cles of Blood in the several places wherein they are, which abiding there, are by this means united to the part they touch. Now supposing this to be the Body of an Infant or a Youth, the matter whereof is very soft, and its Pores readily dilata∣ble, if the particles of Blood, which are pusht out of the Arteries for the restoring of the solid Parts, be somewhat greater than those, into whose room they come, or if it happen that 2 or 3 par∣ticles crowd into one place, the Body by this means must needs grow and encrease.

VIII. How the Parts of the Aliment become changed into Parts of our Body. But this apposition of Parts chiefly proceeds from the diversity of Figures, that is, as well in the several Particles of Blood, as in the Pores of the parts of the Body: for by this means it is, that when the Blood is driven into the Parts, some of the said particles are more fit to stop in these Pores, and others again in others; where being variously complicated and figured, they become im∣mediately united with the substance of the Parts, and wholly changed into their nature: whereas those particles, which because of their peculiar con∣figuration, are not sit to adhere or cleave to these or the other Pores, are driven further to others; till at last the residue of the Blood, whose particles were not adapted to enter any of the Pores, are remanded through the Veins to the Heart; there to be further digested, and to acquire a new Apti∣tude for their union with the several parts of the Body.

IX. Blood, as Blood, doth not nourish. Yet we must not imagine that Blood, as it is Blood, doth nourish; for the red particles of Blood do not nourish our Body, but only the Chylous parts that are in it: for if the Blood, as such, did nou∣rish our Bodies, then it must certainly perform this function to the Heart it self, and the Lungs which are so near to it; for the Coronary Artery of the Heart, as soon as it is got out from it, doth pre∣sently, by a retrograde motion, return to it again. Thus also in the Lungs, the Blood takes but a very short course. So that it cannot be otherwise, but that these 2 parts, must have the Blood dashing against them with more force, than it doth against any of the other parts of the Body: If therefore in any part nutrition were performed by the Blood

dropping out of the Vessels, the same must surely happen here, seeing that the Blood hath more force to enter upon them, by opening the small Orifices of the Vessels. But we do not see it does so in ei∣ther of these parts; for we find the substance of the Heart and Lungs in a natural and sound state, not moistned with extravasated Blood, but with a certain clear moisture.

Nay what is more, it is evident that the Blood never comes out of its Vessels, without causing some Disease or other; for if this happens in the Lungs, it causeth the spitting of Blood, and if in other parts, Swellings and other Diseases.

X. The Chyle passeth through the Lacteal Veins, to the Snb∣clavial. The Physicians of old were of opinion that the Chyle, being by the Branches of the Vena Porta suckt out of the Stomach and Guts, were by them carried to the Liver. But our Modern Anatomists demonstrate that the Chyle is driven through the Lacteal Veins only to the Subclavial, and more particularly GASPER ASELLIUS, in the disse∣ction he made of a Dog, whom before he had or∣dered to be well fed, in the year 1622. which discovery hath been further improved by others, who have found that the Lacteal Veins, filled with a Milky Juice, are Vessels different from the Mesaraick Veins: forasmuch as in Living Ani∣mals they appear distinct from the Mesaraicks which are Red, if the dissection be administred 4 hours after the Animal hath been fed, that is, at the time when the distribution of the Chyle is made; for after that time they disappear again. But how∣ever tho' these be empty, they always appear like so many Strings or Fibres, and are never found fill'd with Blood.

XI. The smal∣ness of the Lacteal Veins, con∣duceth much to the form∣ing of the Blood. Neither doth the smallness of the Lacteal Veins in the least embarras this opinion, for this was de∣signed so on purpose by the Provident Care of Nature, to prevent the more gross and earthly parts of the Chyle from entring into them, as also that the Chyle through them might be, by degrees and leisurely distributed according to the necessity or requirings of the Body, and the more easily changed into Blood in the Heart, by that new disposition of parts it acquires by passing through it, and the Effervescence it undergoes there. For as the whiteness of Snow, and the colours of other Bodies, proceed only from the contexture and Po∣sition of the Parts: So the Blood derives its Red∣ness only from that position of parts, which it obtains by its frequent passing through the Heart.

XII. Why the Lacteal Veins are supposed to be of use for the Nourishing of the Body. The Reasons that induce us to admit the use of the Lacteal Veins are; First, Because the Chyle, which is of a White Colour, cannot by the Mesa∣raical Veins be conveighed to the common Ocean, because they are manifestly filled with the Blood; whereas the Lacteal Veins are white, that is, of the colour of the Chyle that passes through them. 2ly. The Lacteal Veins do never appear till after the Body hath been fed, and only about the time when the food begins to be distributed; which is a strong argument to perswade us, that the Chyle passeth through them. 3ly. The quantity of the milky liquor that is in these Veins, may be en∣creased, by pressing the Guts, whilst they are as yet full of Chyle.

XIII. The pas∣sage of the Chyle from the Guts. The Chyle therefore being duly prepared, pas∣seth through the Guts, where the Alimentary Parts are separated from the unprofitable and excremen∣tal, and thence run into the Lacteal or Milky Veins, which carry the said Liquor into the Com∣mon Receptacle: From whence 2 other Vessels con∣vey it through the Thorax or Chest, near the Back∣bone, up to the Subclavial branches of the Vena Cava, and there empty themselves.

XIV. The Birth is not wholly nou∣rished in the Womb by the Mouth. Another Point to be examin'd is, how the Birth is nourished in the Mothers Womb; since it cannot take in its Food wholly by the Mouth, but at first rather by Apposition, and afterwards by the Navel. For the situation and disposition of its Parts will not admit of this, seeing that the whole Body lies crouded together, and hath its Mouth shut up be∣tween its Knees. And tho' as soon as it is born, it reacheth to the Mothers or Nurses Breast; yet is this only the effect of Natures Providence, which as it teacheth the Birth to fetch its breath; so likewise she directs it, where to meet with Food.

XV. But by the Umbilical Vessels. But that the Birth receives its Nourishment by the Navel, may be proved from the Courses of Women, which generally cease in those that are with Child, because the Blood is then defrauded of the Chyle and its Nutricious Juice, which at that time is kept in the Womb for the Nourishment of the Birth. And for the same Reason, as soon as the Birth is born, the Breasts are fill'd with Milk; because the Juice which before was employed to feed the Birth, mounts up to the Breasts, where it is changed into a white Liquor. And this is fur∣ther confirmed by those Women who do not Suckle their Children, for these perceive the Milk to return from the Breast to their Womb, where it is eva∣cuated. To which may be added, that if the Birth in the Womb were nourished by the Mouth, it seems that it should also breath; which it is impossible it should do, as long as it is in the Womb. Yea further, should the Infant open his Mouth in the Womb, it would be in danger of being choaked with the Liquor wherein it swims. So that it is very probable, that the Birth, when it is perfected, is only, at least chiefly nourished by the Umbilical Vessels.

XVI. Flesh is not the Natural Food of Man. Now forasmuch as Man feeds on Flesh, Fish, Herbs and Fruits, it may be enquir'd which of these is his most Natural Food. Indeed if we examine the matter strictly, the feeding on Flesh doth not seem Natural to him; yea, if we consider the Instruments he makes use of in Eating, we shall find it contrary to the intent of Nature. For we find that those Animals that feed upon Flesh, as Wolves, Lions, and the like, have their Fore-Teeth long, sharp, and at some distance from each other; because Flesh cannot well be prepared for the digestion in the Stomach, without such In∣struments as may pierce deep into the Substance of it, and pluck it to pieces. Whereas those Ani∣mals that feed upon Herbs, as Sheep, Oxen, Horses, &c. have short Teeth, which are ranged close together; whence it may be easily guess'd, that Man who is furnish'd with such like Teeth, was designed to feed chiefly on Herbs and Fruits.

XVII. Children love Fruits more than Flesh. This is further confirmed by the Example of Children, who following the Instinct of Nature, do prefer Fruits before Flesh: For Nature not being as yet debauch'd in them, they manifest by their Choice, what Food she design'd for them. So that it is not to be question'd, but that if Chil∣dren,

as soon as they are weaned, should be kept from the eating of Flesh, they would the more strongly desire Fruits, and choose them before all other Food whatsoever.

XVIII. The Eating of Flesh was un∣known to the first Men. This Intent of Nature may further be illustrated from the Custom of the first Men that lived in the World, who fed only upon Fruits. And ac∣cordingly the Holy Scriptures assure us, that the eating of Flesh was not permitted till after the Flood. If it be Objected, that some men have been found in the World, that have fed upon flesh, as the Savages of Brasile, &c. it may be easily answer'd, that these did not follow the guidance of Nature, but their own depraved Lusts and Affections, which prompted them not only to the eating of Flesh, but even to the devouring of Mans Flesh.

XIX. Nature de∣monstrates the same, by denying us Instru∣ments ne∣cessary for the Eating of Flesh. Moreover, had Nature intended Flesh to be our nourishment, she would without doubt have fur∣nish'd us with Instruments fit for that purpose, nor have put us to the shift of making use of Knives, which other Carnivorous Animals do not stand in need of. Besides, why have we such an aversion to Raw flesh, and cannot endure to taste of it till it be prepared by Fire; but only to shew, that Flesh is not our Natural food, being only introduc'd by Lust, which hath quite changed our Nature from its Primigenial Inclination and Temper.

XX. Man would be every whit as strong, if he liv'd only on Herbs and Fruits. Neither let any Man object here, That Man would be much weaker, if he should confine him∣self to feed on Herbs and Fruits only; for we see that Horses and Bulls are very strong and hardy Animals, which yet feed upon nothing but Herbs, and Corn or Pulse. How swift is a Stag, how lively vigorous and long Liv'd; and this only by feeding on the Grass of the Field? So that I should be easily induc'd to believe, that in case a Man were brought up like a Beast in the Fields, he would not be inferiour to Stags in running, nor to Apes in climbing of Trees; which his delicate and tender Education do now make him unfit for.