The anatomy of humane bodies epitomized wherein all parts of man's body, with their actions and uses, are succinctly described, according to the newest doctrine of the most accurate and learned modern anatomists / by a Fellow of the College of Physicians, London.

CHAP. VII.

How Bloud is made of Chyle, of its Colour, and whether the Body be nourished by it.

ACcording to Dr. Harvey's observations there appears in an Embryo a punctum saliens, or red beating speck, which is Bloud, before any the least lineament of the Heart. So that what∣ever instrument of sanguification the Heart may appear to be afterwards, it contributes nothing to the elaborating of the first Bloud; but it seems rather to be made for the Bloud's sake to transmit it to all the parts of the Embryo or Foetus, than the Bloud to be made by it. But it must be confest that things proceed in the grown Foetus far otherwise than they do in the first formation. For the parts of an Embryo are nourished and encreased before it have a stomach to concoct any thing, and yet in a perfect Foetus none can deny that the Stomach does concoct and prepare nourishment for it: so it moves before the Brain is formed so perfectly

as to be able to elaborate Animal spirits; and yet after it is perfected, every one knows that the Brain does elaborate such spirits, as being sent into all the parts of the Body by the Nerves ena∣ble them to move. In like manner though there be Bloud in the Embryo before the Heart be for∣med, yet after it is perfected, nothing will hin∣der but it may at least contribute something to sanguification.

We will suppose then, that as all the other parts are formed by the Vis plastica or generative faculty of the (first) vegetative and (then) animal Soul, seated in the Ovum, but assoon as they are perfected and the Foetus excluded, are nourish∣ed by the Bloud; so the Bloud it self being at first made in like manner, assoon as the Veins, Heart and Arteries are compleated so as it can circulate by them, may, not improperly, be said to be nourished by the Chyle, the Heart assisting the assimilation of the one into the other. And this is done in this manner.* 1.1 The Chyle ascend∣ing by the Ductus thoracicus (as was described Book 1. Chap. 10.) and flowing into the Subcla∣vian vein, together with the returning venal Bloud is poured into the right ventricle of the Heart in its Diastole or Relaxation, then by its Systole or Contraction it is driven out from thence into the Lungs, from whence it ascends again in∣to the left ventricle of the Heart, out of which it is expelled through the Aorta, and passing along with the Bloud through the Arteries of the whole Body, returns again with it by the Veins to the Heart. For it undergoes many circulations before it can be assimilated to the Bloud. Which is evi∣dent, both because it is the Chyle (but little

alter'd) that is separated in the Placenta uteri for the nourishment of the Foetus, and in the Breasts for the Infant to suck, in the form of Milk; and also from hence, that if one be let bloud four or five hours (or later) after a full meal, there will a great quantity of the milky Chyle it self swim a top the coagulated Bloud. But every time the new infused Chyle passes through the Heart with the Bloud, the particles of the one are more intimately mixed with those of the other in its Ventricles, and the vital spirit and other active principles of the bloud work up∣on the Chyle; which being full of salt, sulphur and spirit, assoon as its Compages is loosened by its fermentation with the Bloud in the ventricles of the Heart (especially, but also in the Arteries) these principles having obtained the liberty of motion do readily associate themselves, and are assimilated with such parts of the Bloud as are of a like and suitable nature. Now whether this alteration that happens to the Chyle, especially in the Heart, should be said to be by fermentation, or accension, or by what other action, is a thing not yet (nor likely to be) agreed upon, it is so full of difficulty. But it seems to be by fermen∣tation, from the considerable heat observable in the Arterial bloud; and if there be any thing of accension, that seems to proceed, not from any part inherent either in the Bloud or Chyle, nor to be effected so much in the Heart and Arteries, as in the Lungs, whiles the Bloud passes through their Parenchyma out of the Vena arteriosa into the Arteria venosa, and is inspirited or impregnated with nitrous air drawn into them by inspiration. Which will be more evident by what follows.

Why the Bloud should be of a red colour rather than any other,* 1.2 no reason can be given but the will of the Creatour, though some attribute it to the Heart, others to the mixture of salt and sub∣acid juices with sulphureous; even as the Oyl of Vitriol being poured upon Conserve of Roses, or other thing that is of a palish red (if it contain any thing of sulphur) makes it of a most deep red. We will not spend time to shew in how many respects this similitude falls short of explain∣ing the reason of the Phaenomenon, but shall con∣tent our selves with inquiring from whence the difference of colour arises between the Venal and Arterial bloud. Every one knows that Bloud let out of a Vein into a Porringer, is indeed of a florid scarlet colour in its surface, but all that coagulates is of a dark red colour from the super∣ficies to the bottom, and of such a colour it ap∣pears as it streams out of the Orifice of the Vein. But if an Artery be cut, the stream then looks of a far brighter colour, like the superficies of the Venal bloud when it is congealed in a Por∣ringer. Now the Arterial bloud receives not this florid colour in the Heart but in the Lungs. For if it receiv'd it in the Heart, then might the right Ventricle be supposed to give it as well as the left: but that it does not do so, is clear by this experiment of Dr. Lower's. If you open the Vena arteriosa which receives the Bloud out of the right Ventricle, the Bloud differs nothing in co∣lour from the Venal, but its curdled part looks every whit as black. But if one open the Arteria venosa as it is entring into the left Ventricle, it has the perfect colour of Arterial bloud; which

shews, that as it ows not that colour to the left Ventricle any more than to the right, (being not yet arriv'd at it) so it must receive that alte∣ration of colour in the Lungs, in which the ni∣trous air being diffused through all the particles of the Bloud is intimately mixed with it, and (if you will) accends it. For if there be any such thing as a Flamma vitalis (properly so called) in Animals, though the Bloud be to it instead of the Oyl or other matter whereon it feeds, yet it oweth the continuance of its burning to the Air, without the continued inspiration of which the Animal cannot live, but instantly dies, even as a Candle is presently extinguished if you put it in a close place where the air cannot come to it, or by some Engine be suckt from it. But this by the bye. For I must confess that (notwithstan∣ding the plausibleness of the opinion) this alte∣ration of the colour of the Bloud by the Air in the Lungs, is no sufficient argument to prove any such vital flame, seeing the Arterial bloud being extravasated, retains its florid colour, when no doubt if there ever was any accension, the flame is extinguished. But this scarlet colour is meerly from the mixture of the particles of the Air with the Bloud, from which it transpires, in a great measure, through the pores of the Skin, while the Bloud circulates in the habit of the Body out of the Arteries into the Veins, whence the Venous bloud becomes so much darker in colour than the Arterial. And yet the Venous bloud it self when extravasated appears of a scarlet dye in its surface, which is meerly from its being expo∣sed to the Air; for if one turn the congealed Bloud in a Porringer upside down, the bottom which

at the turning is blackish, will in a little while turn red.

Though we have confessed that the Chyle does circulate through the Body several times before it be perfectly assimilated to the Bloud;* 1.3 yet we do not think that it passes into the nourishment of the parts in the form of Chyle. And therefore when speaking of the nutrition of the Foetus in the Womb (Book 1. Chap. 33.) we often mentioned a nutritious juice (which was Chyle a little al∣ter'd) we did not call it so with respect to the solid parts of the Foetus, but to the Bloud it self whose Pabulum or nourishment it is, assoon as the Umbilical vein is formed, as the Bloud is of the Body. For as to the increase of the first delinea∣ted parts of an imperfect Embryo, that is far dif∣ferent from ordinary nutrition.

The Bloud then consisting of particles of a dif∣ferent nature, each particle passes into the nou∣rishment of that part which is of the same nature. So the salt and sulphureous particles being equal∣ly mixt, are agglutinated and assimilated to the fleshy or musculous parts; the oily and sulphure∣ous to the Fat; the salt and tartareous to the Bones, &c. Now this is not done by any electi∣on or attraction of the parts, as if they pick'd and choos'd (with a kind of discretion) such particles of the Bloud as are suitable to their own nature: For the mass of Bloud is equally and in∣differently carried to all the parts: But there is that diversity of figure both in the several parti∣cles of the Bloud and in the pores of each part, that in the circulation through the habit of the Body some stick in these, and others in those,

where they are fasten'd aud united to the substance of the respective parts; and those which through their peculiar figure are unapt to adhere to one or other, return again to the Veins and so to the Heart, where they receive some new alteration. So that as the Life of the Flesh is in the Bloud (ac∣cording to Levit. 17. 11.) so has it its vital heat and nourishment from it also.

Notes

• * 1.1

  How chyle is turned into bloud.
• * 1.2

  The colour of the bloud.
• * 1.3

  Whether the body be nourish'd by bloud.