The first Medical and Physical DISCOURSE. Of the growing hot or inkindling of the Blood.

IT is long since I designed to print my Meditations concerning the remaining Pathology of the Brain and Nervous stock: But when many Diseases of that kind affect the animal Spirits, and not rarely the whole Hypostasis of the corporeal Soul more immediately than the Humors or solid Parts; I there∣fore thought it necessary first to publish the Disquisitions of the nature of this Soul, and its manner of subsisting, and also of its Parts and Powers, that from these things rightly known, its preternatural Passions may at length be the better disco∣vered. But concerning these very hard matters, and difficult to be unfolded, when I had begun to frame (as I think) probable and rational Arguments, I saw well that they would be looked upon and laughed at by some as unusual things and Paradoxes; which indeed it becomes me not to take ill, but to let every one freely to enjoy his own sense, and to use in all things his own opinion and judgment. Among the many things conjecturally proposed by me, (which I could not avoid) two chief Arguments are opposed, to wit, that I had affirmed, that the blood for the con∣tinuing of life was inkindled, and that the animal Spirits, for the motive act, were exploded: which terms, though perhaps they may sound rough and strange to be applied to the animal oeconomy; yet if any one shall weigh the Reasons and Ar∣guments which do perswade to the truth of either opinion, I doubt not, but that there will be none who will not give their assent, or easily pardon me for mine. In the first place therefore, because there are so many opinions concerning the growing hot of the Blood, for that some attribute it to an innate heat, others to a flame in the Heart, some also to a fermentation of the bloody mass, and others to its inkind∣ling; therefore I shall endeavour more narrowly to introspect the matter, and as much as I am able, to build upon a more certain Ratiocination, its genuine Cause, though very abstruse.

We have formerly discoursed concerning that Soul, which is common to the more perfect Beasts, with that subordinate or more inferiour of Man, and have shewed it to be indeed Corporeal, and to consist of two parts; the one of these root∣ed in the blood we called a Flame, and the other dwelling in the Brain and nervous stock, Light. As we shall here only treat of the former, I think it will be no difficult matter to make use of the same Reasons and Instances, which truly conclude, or at least very like truth, that in the first place the blood is animate or hath life: second∣ly, Page  25 that this Animation is in its accension or inkindling, or consists in an affection most analogical to this.

1. Not only the opinions of Philosophers, but the undoubted testimony of the Sacred Scripture plainly asserts the animation of the blood: to wit, the use of blood was forbidden in the Mosaical Law, for this reason, because the Blood is the Life or Soul; which is also apparent by the observation of the most famous Harvey, for that its motion is to be observed by the eye, shews that it first lives and last dyes. For the greater proof of this, it is commonly known that Animals only live so long as the blood remains in its due plenty and motion; and that they presently dye, if ei∣ther too great a quantity of this be taken away, or its motion suppressed.

But as to the second Proposition, to wit, that the life or soul of the fervent blood depends upon its inkindling; this will appear probable, if I shall shew: First, that the liquor of the blood ought to be very hot in the more perfect living Creatures. Secondly, that this growing hot can be produced or conserved in the blood by no other means besides accension or inkindling. Thirdly, that some chief affections, as it were proper passions of fire and flame, are agreeable to the life only of the blood growing hot. Fourthly and lastly, these being clearly shewn, some other less signal accidents and properties, in which common flame and life agree, are added, and also we will unfold how and in what respect they differ among themselves.

As to the first we affirm, that the blood is perpetually moved in all living Crea∣tures; besides in the more perfect it doth estuate or grow hot in act. Indeed its un∣discontinued motion is required, both for the conservation of the disposition of the blood it self, whose liquor would otherwise be subject to stagnation and putrefaction, as also that being carried about in the whole body, it might be able to give a due tribute to all parts. For that the offices of the blood, at least in the more perfect living Creatures, are divers and manifold, viz. to instil matter in the Brain and nervous stock for the animal Spirits to dispense the nutritious Juyce into all the solid parts, to suggest to the motive parts an elastic Copula, and besides to separate all recrements and worn out Particles, and to put them aside into convenient Emun∣ctories.

But although the mere motion of the Blood in less perfect Animals, or at least its moderate swelling up, such as may be perceived in Wine and other Liquors agitated into Fermentation, is able to sustain and perform the oeconomy of Nature; to wit, for as much as both a crude nutriment is every where received from the river of the blood, though cool, continually flowing into all parts of the whole Body, and that fewer spirits and more thick, as it were separated by percolation or straining, enter the Brain and nervous stock with that plenty, that may suffice for local motion, and the Organs of the few senses to be rudely actuated: yet the blood watering the bo∣dies of more perfect Animals, require offices of a far more excellent kind; for it ought not only to be carried about with a continual and more rapid motion, but very much to swell up, yea actually to grow hot or effervent: to wit, for that end, that its frame or substance being very much loosned, it may more copiously send forth the respective Particles of various kinds, every where falling off from it, and may dispose them here and there for the use and wants of Nature.

But first, for that the animal Spirits are continually to be supplied in great plenty from the mass of blood, and that there is need for the elastic Particles requisite for the locomotive function, to be thence perpetually poured into all the Muscles, it seems very necessary that the liquor from whence these generous and manifold sup∣plements are drawn should be actually hot, or rather should burn forth; to wit, that the aforesaid Particles, not sufficiently to be unlocked but by heat or burning, should freely run out from the substance or frame of the liquor: which truly is ma∣nifest, because from Wine, and also from the same bloody Liquor, and all other spirituous things, a subtil and spirituous humour is copiously drawn, but not to be performed by distillation without heat or fire. Yea the sulphureous Particles, al∣though they are less apt to be exhaled from any Liquor, yet they most readily fly out by inkindling the subject. By these there is an apparent necessity of the blood's growing hot for the perfection of the animal as well as vital function; but that it may appear by what means this is done, to wit, whether by Accension, or by Fermenta∣tion, or by any other way, we shall first in general inquire, by what means, and for what causes any liquid things are wont to grow hot; then we shall consider, to which of these the growing hot of the blood ought to be attributed.

Page  26Concerning these we say, that there are only three ways, or so many kinds of causes, by which Liquors conceive a heat, viz. first, by fire or heat being put to them, as when water is made to seeth or boil over the fire, or that it grows hot by the heat of the Sun, a Bath, or Stove, or by the dissolution of quick Lime; instances of all which are commonly known. For the same reason Bath-waters seem to boil. For, that we may instance in our own Baths, to wit, they are impregnated neither with Sulphur nor fixed Salt, as I have plainly experimented, by distilling and evapora∣ting them, and by pouring into them precipitating Liquors; yea by dissolving them with Sulphur, and many other ways. They most resemble Lime-water, and they, as we believe, grow hot from a like cause, to wit, by imbibing the fiery little bodies somewhere hid within the Earth. Of these, unless it had been superfluous, we had here given a fuller description, which may perhaps be done at some other time. Secondly, when saline Corrosives, which are of a diverse kind, being mingled with themselves, or with sulphureous things, work mutually one on another with a great strife and agitation of Particles, and oftentimes excite heat, yea sometimes fume and flame; as when the Spirit and Butter of Antimony are poured to, or mix∣ed with stygian Water, wherein lixivial Salts are melted, or with Oyl of Turpen∣tine, or other distilled things; besides when corrosive Liquors eat metallick Bodies, they often grow hot. Thirdly, and the only way besides (as I suppose) whereby a liquid thing is made hot, is when any humour, being very much imbued with Sul∣phur or Spirit, conceives a burning by putting a flame to it, and so grows hot by burning forth. This is ordinarily seen in oily or very spirituous Liquors, being in∣kindled and inflamed.

There remain indeed some other ways of Calefaction, to wit, Fermentation, Pu∣trefaction, and Attrition, whereby more thick Bodies, or Solids, often conceive a fervour, but they produce not such an effect in Liquids: whilst the mealy Mass or Dough is fermented, the active Particles being stirred up into motion, unfold them∣selves on every side, and lift up the bulk or substance of the subject; in the mean time, for as much as the sulphureous Particles being agitated with them, take hold one of another, and begin to be combined, a certain heat, though more remiss, is excited; in like manner from Putrefaction, Dung or wet Hay get an heat, to wit, for as much as the sulphureous Particles, within included, are very thickly heaped up together, then being combined together, they break out in troops: yet no Li∣quors, either thin or thick, whether they ferment or putrifie, do for that reason at any time grow hot: For Wines, whilst in fermenting they break in pieces the sides of the Tun, or overflow the top of the Vessel with a great noise and ebullition, do not actually grow hot, yea not so much as grow warm. The blood being let out of the Body, and placed in convenient Glasses, either to ferment or putrifie, doth not get any actual heat: yet in truth we grant the Blood in living Creatures to be fermented, and by fermenting to be putrified, yea and some other offices of the ani∣mal oeconomy to perform the same: moreover, we have formerly shewed from its Fermentation being hindred, or too much increased, or otherwise depra•ed, divers kinds of diseases to be produced: yet we deny the heat of the blood to be excited by Fermentation. Because neither the blood of more frigid Animals, nor Wines, nor any other Liquors, though agitated with the highest Fermentation, are for that reason actually hot. And indeed the reason seems evident enough, to wit, because the sulphureous Particles being raised up in the more thick subjects, though they lay hold on one another mutually, and being more thickly heaped together, raise up heat: yet in Liquids, the same kind of Particles, however stirred up or agitated, are imme∣diately disjoyned by the watry coming between, and are hindred from their mutual embrace and combination; so that they cannot of themselves produce an actual heat: For the same reason, hard Bodies being rubbed one against another, or violently knocked or bruised, do not only produce heat, but oftentimes fire; whenas yet Liquids, however shaken and agitated, do not grow warm. Therefore as there are only three ways, whereby actual heat may be begotten in all Liquors, we shall in∣quire to which of these the heat of the Blood may be ascribed.

First, Some say it is the first way, from the opinion both of the Ancients, and of some of the Moderns: the Blood is said to grow hot, by reason of some hot thing put to it, to wit, whilst those affirm an innate heat, and these a little flame to be pla∣ced in the Heart, and to heat the blood passing through it; but either of these opi∣nions easily fails, from which it is clear, that the Heart is a mere Muscle, her doth Page  27 contain in it self any tinder or matter for a flame or heat (I know not how) implant∣ed, fit for their continuance. For though it be confessed, that on the continual motion of this Bowel, (which is only animal) the Circulation of the Blood doth de∣pend, yet the Heart borrows heat altogether from the blood, and not the blood from the Heart.

Secondly, As to what respects the second way of making hot a liquid thing, to wit, whereby a great heat is excited by the mixing of saline Corrosives together, or also oily, or by corroding a metallick Body, I think there is none that will se∣riously assert, that the blood grows hot from such a cause; for that its liquor, in its natural state, is always homogene, and although it be stuffed with plenty of Salt, it is however with that which is volatile gentle, and benign only: But there is not to be found, either in the Heart, or in any other place a saline or any otherwise heterogene Mine, whereby the bloody liquor, by working or corroding, may get or conceive an heat: to wit, it behoves either such a Mine or the Body to be corroded, to be perpetually renewed, because the ebullition and heat raised up by the strife of Salts, ceases as soon as the Salts are combined, or the Body corroded. If at any time the saline Particles of the humours in our Body depart from their right temper, and become enormous and unbridled, for that reason the blood, as to heat and motion, enters into some irregularities; yet it seems impossible, that it should originally and perpetually become hot by the congression, and strife, or corrosion of the Salts.

Thirdly, As to the third way, whereby Liquids are made hot, though it may seem an uncouth saying, That the blood is so inkindled, yet since we cannot attri∣bute it to any other way besides, what should hinder from attributing its heat to this Cause? And the rather, for that the proper passions of Fire and Flame are agree∣able to the life of the Blood alone.

For indeed these three things are chiefly and principally Essentials, requisite for the perpetuating flame. First, that there be granted to it, assoon as it is inkindled, a free and continued accession of the Air. Secondly, that it may enjoy a constant sulphureous food. Thirdly, that its recrements both sooty, as also the more thick, be always sent away. So then if I shall shew these things to agree after the same manner with life, as flame, and to those only, without doubt, I think that life it self may be esteemed a certain kind of Flame.

In the first place therefore, that a flame may be inkindled, and remain inkindled, there is need of a free and undiscontinued access of Air, and that not only, that the va∣porous Effluvia's, threatning the suffocation of the flame, may be carried away, and always depart, but much rather, that the nitrous food necessarily requisite for the burning of any thing, may be supplied by the Air. For indeed every sublunary fire, and especially flame, is compounded or made up altogether of sulphureous Particles, breaking out in heaps from a combustible Body, and of nitrous Bodies, which every where flow in the Air, meeting with them: when Particles of Sulphur, breaking out slowly or interruptedly, get to themselves a few nitrous, only planted near them, a fire is usually produced, such as is seen in a burning Coal: But when the former going away more impetuously, either of their own accord, or forced by blowing, presently lay hold on very many nitrous Particles flowing round about in the whole circuit, a flame arises. In truth the whole region of the Air is abundantly stuffed with nitrous little bodies, which are every where ready for the constituting of fire and flame, and they being any where inkindled, meet them after the manner of a stood, although not always after the like manner or measure, because it is observed at some times, especially in the Winter-cold, when the Air abounds more in Nitre, that fire or flame doth more ar∣dently burn, and diffuse farther its heat: on the contrary, in rainy weather, as also when the beams of the Sun shine upon the fire, and so dissipate the Nitre of the neigh∣bouring Air, the fire is so dull'd, as is commonly said, that it is extinguished by the Sun. If at any time the nitrous Particles of the Air are excluded from the sulphureous of any subject breaking out in the inkindling or burning, the fire and flame quickly perish; which appears, because this or that being put into a Glass, after the Air is sucked out or excluded, they presently expire. Further, in the open Air, although a naked fire propagates a fire in a fireable matter by mere contact, yet a flame is hard∣ly inkindled without a flame be put to it, or a very strong fire: because, for the stirring up of a flame very many nitrous Particles of the Air, implanted round about, ought to be inkindled at once; as if Nitre and common Sulphur being pound∣ed Page  28 together, be commixed (because both incentives agree) even the least spark falling into such a mixture begets an highly impetuous flame, which desiring no far∣ther a nitrous food, is inkindled or burns under water, in a place void of air, or in any place as freely as in the open air. In like manner the least sulphureous things, as a bit of ponderous wood, being cast into a red-hot Crucible, in which Nitre is fused, the same at first touch presently conceive a flame, and continue till it be wholly consumed: But that fire and flame being included in a place empty of air, expire by reason of the food of Nitre being drawn away, rather than choaked by their own proper smoke,* the Illustrious Mr. Robert Boyle hath most clearly de∣monstrated by very many Experiments. For a Candle being lighted, and put into a capacious globe of Glass, and the Vessel stopped up: assoon as the air was sucked out by a wind-instrument, the flame did expire. Moreover he observed, what con∣cludes for our Hypothesis,* that the flame contracted it self according to all its dimen∣sions, assoon as ever the Engine began to suck, then after the second or third draught of the drawn forth air, the flame about the utmost extremities appeared very blue, and to go back more and more from the Tallow, till at length getting to the top of the snuff it expired: the same Candle being again lighted, and shut up in the reci∣pient, this worthy Gentleman tryed how long it was able to sustain its light, when the air was not exhausted, and he found it to endure much longer lighted than before. From these it clearly appears, that the flame shut up, expires not so much because it is suffocated by its own proper smoke, as because it is destitute of the nitrous food of the Air. For in the former Experiment the air being exhausted, there was more space for the smoke and fume, that the flame might not be stifled, and yet this dyed sooner, the Recipient being empty, than the same being full of air; besides, the flame dying became bluish, for as much as it participated of more Sulphur than Nitre; and it left the Tallow, and expired at the top of the snuff, for that it followed its most necessary food as far as it was able,* to wit, the nitrous Particles of Air. The same Experiment succeeded alike in live Coals, viz. the naked fire, after the food of Nitre was drawn away, suddenly dyed. Here also it doth what the flame of a Candle doth in Mines or Caves under ground, where the nitrous air is wanting or dispelled, at first it be∣comes more contracted and blue, and then a little after expires.

I have been more large in this Argument, because there is for both the like necessi∣ty of drawing in of the air, after the same manner, for the sustaining the life of the Blood, and for the continuing of flame. For the more hot Animals, if they are hin∣dred from respiration dye quickly, wherefore the same means of killing is most ready and common to shut up the breath, which being wholly obstructed, life perishes as a flame. If it should be objected, that those choaked do dye, because the foot or smoke being retained, blow up and intumifie the bloody mass, which for that reason, the bulk or substance being increased, and made almost immoveable, fills the bosom of the Heart, and hinders its motion: I say, that this is improbable, because if the Arteries, every where in the Limbs and about the Neck, be strained hard together with Ligatures, that the blood being straitned as to the compass of its circuit, be very much stopped about the Praecordia, (more certainly than can happen from the mere retained smoke) yet for that cause death neither presently follows, nor any deadly Symptoms. That this happens in those that are hindred from respiration, be∣cause the vital flame of the blood is wanting of the nitrous food of the Air, rather than overthrown by its proper soot or smoke being detained,* the most Famous Boyl also by his Experiments hath put it out of doubt; for he hath observed, that hot living Creatures being put within a glassy Globe, and shut up, did far sooner expire, the air being drawn away from them, than the same being left within it, though in the former case, there was more space left for the receiving the smoke, left the re∣taining of it might constipate the blood: yet however, if the heat of the blood should arise from Fermentation, or the congression of dissimilar Particles, or from an ebulli∣tion, by reason of admitted heat, or from any other cause besides accension, it is so far that that effect could be inhibited or suppressed by reason of the air being excluded, that on the contrary it would rather for that cause become more strong or intense. For it appears, by a common observation, that Liquors chiefly fermentable, the more strictly they are kept in the Vessel, the more they grow hot, and the air being admitted through some vent-hole, they presently cease from their fury. Moreover, Mr. Boyl's Experiments clearly shew, that the effervescencies or growing servent, stirred up by the ebullition of unlike Particles, or by corrosion, also the boiling up of Page  29 hot water in a glassie Sphere, are above measure increased after the air is sucked out, Experiment. Physicom. 41, 42, 43. That most ingenious Tract of the aforesaid Author supplies us with many Experiments, whereby it is abundantly manifest, that the intestine motions of those Particles, and almost of every thing, besides fire and life, are very much heightned or made strong in the space emptied of air; but their act, presently after the air is withdrawn, is extinguished: hence we may conclude, the life of a living Creature to be either fire, or something analogical to it. The like to these is yet more clearly observed by the diggers of Minerals, who ordinarily experiment in subterranean Caves, where either the Nitre is wanting, or is driven away by some strange damp or vapour, so that they are in danger of being stifled or smothered, at the same time the flame of the Candle is diminished, becomes blue, and at length expires.

The second thing requisite to sustain a flame, is a constant supply of sulphureous food, whereby it may continually be fed, which being substracted, or by reason of some incongruous mixture depraved, the flame is extinguished; as is perceived in a Lamp, which for want of oyl, or water poured in its place, expires: further, as this sulphureous food is more or less suggested, sometimes more plentifully, some∣times more sparingly, the flame being more or less intense, is sometimes produced clear, sometimes smoaky; in the mean time, the food being constantly consumed by burning, goes away partly into vaporous Effluvia's, and partly into ashes, which are made up of some Particles of Earth, Salt, and Sulphur: But it is much otherwise in Liquors exposed to Fermentation, to which if new Particles be continually admi∣nistred, and the old ones depart, the Fermentation is hindred or disturbed.

In like manner, as in Flame, the Blood of the hotter Animals (and this only in all natural things, besides fire) requires a constant and copious sulphureous food; and that being quickly worn, is for the most part consumed in vaporous Effluvia's, a Caput mortuum being left of Earth, Salt, and stinking Sulphur: In the mean time from its food consumed by burning, it disposes other Particles for other uses. That the life or flame of the blood doth continually want aliment, there is none but daily finds it in himself: For if that be for some time denied, the vigor of the blood is diminish∣ed, yea and consuming the solid parts, it snatches into its bosom their remnants, and other humours of the Body whereby it may be fed. If the nutriment daily sug∣gested from things taken, be too thin and watry, the fervour of the blood, like flame without food, uses to be remitted; but if the food be very sulphureous and swelling with a vinous Spirit, and plentifully taken in, the blood is presently infla∣med, and often breaks out into a Feaver, as it were an open burning. In the interim out of that food of the blood exhausted or consumed, as it seems by accension, hot Effluvia's full of soot and vapour go away, which according to a just account, far ex∣ceed all the other excrements of the Body; and that their nature is plainly fiery, the frequent burning of the mouth and tongue, and infecting them with blackness like the soot or smoke of a Chimney, witnesses; besides, from the inflamed blood adust Feces, like a Caput mortuum, are sent into the Bladder of the Gall, Spleen, and per∣haps into other Emunctories.

Thirdly, That inkindled Flame may for some time continue, there is need of continual ventilation, to wit, that its sooty Effluvia's may still fly away, which else being detained and heaped together thereabouts, will suffocate the fire, because by obstructing the Pores of the inflamed Body, they hinder the eruption of the sulphu∣reous matter to be inflamed. Although this condition doth often interfere with the other more potent, viz. the necessity of nitrous food to be so drawn in from the air, that it can scarce be distinguished from it; yet we may plainly perceive, from the de∣tained soot gathered together about the snuff, the light to be put out: for which cause a Lamp, whose wick is made of plumous Alum or other incombustible matter, will not (as it promises) endure any long time, because the soot sticking to the wick, hinders the access of the oyl to the flame; for this reason blasts of wind from the Air wiping away the sootiness, doth not only render the flame more clear, that is free from fume and thick vapour; but food being sufficiently given to it, it be∣comes more durable.

Even as Flame, the life of the Blood requires also continual ventilation; to which end, besides the greater breathing places of the Breast, innumerable lesser, viz. the Pores of the skin gaping every where through the whole Body, do send forth Efflu∣via's departing plentifully from the boiling blood; which if it happens to be hindred, Page  30 or too closely shut up, the blood will grow excessively hot, being as it were beset with fume and vapour: besides, there is need to shorten its circuit, that passing through the Lungs with a more frequent turn, it might there, as much as it can, dispel all its soot or smoak. When the Heavens are heated, the Air seems as it were immoveable and to stagnate, we are wont very much to estuate or grow hot about the Praecordia; for that the blood being fed with a more sparing nitrous food, doth not burn so clearly, but glows with a more suffocating and intrinsick burning: fur∣ther, for that the Particles of the Air being less nimble, when they are inspired and expired or breathed forth, do not so readily convey away the vaporous Effluvia's of the blood; hence it is, that we fan the Air, that it may be made more moveable, and carry away more quickly and plentifully the soot or smoke from our Praecordia.

There yet remain some other smaller Considerations of Fire and Flame, respecting indeed not so much the Essence, as the production and extinction of either, which, whether and how far they may agree with the life of the Blood, we shall briefly in∣quire into.

Fire or Flame is produced two ways, viz. either it is kindled from another fire or flame, or begot by an intestine motion of sulphureous Particles. We have largely shewed the Species of either, and the manner of their being made, in our Tract of Fermentation (only we omitted there, that the accession of nitrous food was necessary for the sustaining it) even as flame, the life also of the hot or warm Blood, we have observed to be produced by a twofold way, to wit, it is either inkindled from ano∣ther life or soul, as in Creatures that bring forth alive; or intrinsical Particles pre∣disposed to animation, are at length raised up to life with the blood by a long cherish∣ing of external heat, as in oviparous or egg-laying Creatures.

If it be further demanded, when and how the vital Flame is kindled first in the Blood? I say, some small beginnings of it are laid up from the conception it self in the Genital humour, to wit, when the rudiment of the bodily Soul culled out from the Souls of the Parents, as a little spark stricken from those flames, is hid in a convenient matter; which being from thence raised up by the Mothers heat, begins a little to glow and shine, and afterwards being daily dilated with the blood brought forth, and leisurely increased, is equally extended with the Body, which it actuates and animates. But yet as long as the young one is included in the Egg or Womb, the vital fire, getting very little or scarce any aery food, doth not yet break out into open flame, but like a Brands end covered over with ashes, burns only slowly and very little, and spreads abroad scarce any heat; wherefore both the formation and increase of the Embryo depends very much on the Mothers heat, or the cherishment of some other analogical thing, whereof being destitute it perishes: but as soon as the young one is born in due time, and begins to breathe, the vital fire presently receiving the nitrous food, largely unfolds it self, and an heat or effervescency being raised up through the whole bloody mass, it inkindles a certain flame; and because the blood then first rushing into the Lungs, having there gotten an accession of Air, begins to burn, the flesh of that Bowel, at first reddish, is shortly changed into a whi∣tish colour, like burnt ashes, and the blood it self undergoes a notable alteration; for what did flow of a dark Purple colour into the Pneumonick Vessels from the right side of the Heart, returning from thence presently out of the Lungs, becomes Crimson, and as it were of a flame-colour, and so shining, passes through the left Ven∣tricle of the Heart and the appending Arteries.

Indeed that in Creatures new-born, the colour of the Lungs is so suddenly chan∣ged, I think it ought to be attributed to the blood, there at first more openly in∣kindled, and their flesh as it were somewhat roasted; although the mere inflation of the Lungs in a dead Embryo produces the like effect, because the Membranes of the Lungs and the Parenchyma being distended and increased into a greater capacity, shake off the stagnating blood, and so draw it away into little and scarce to be discer∣ned rivulets.

As to the Colour of the Blood, so variously changed into circulating from a dark purple to a crimson, and from this to that, I say, that the immediate cause of this is, the admixtion of the nitrous Air with the Blood; which certainly appears, be∣cause the change into a crimson, begins in that place where the blood chiefly gets the access of the Air, viz. whilst it is transferred out of the Arteries into the Pneu∣monick Veins; for in those it appears of a dark Purple, in these every where florid, as the most Learned Doctor Lower hath observed. Further, it yet farther appears, Page  31 that this alteration of the colour proceeds from the admixture of the Air, because that crimson colour follows in the superficies of all blood, let out of the Vessels by reason of its meeting or mingling with air; and if the flowering or top be taken away, another presently arises. Besides, the blood being let out of a Vein, and very much struck with a switch or rod, it becomes crimson through all: and in like manner the blood of living Creatures shines at first within the Pneumonick Veins, to wit, presently after the influx of the air by the Wind-pipe; and from thence, by reason of the same Particles of inkindled air being yet retained, it passes through all the Arteries still florid; in the mean time, from the Nitre of the Air mingled with the sulphureous Particles, and burning with them, the blood being greatly rarified, and in truth expanded into flame, impetuously swells up within all the passages of the Pneumonick Vein and the great Artery, sending from it self copious breaths and hot Effluvia's; but being dilated towards the ends of the Arteries, and returning towards the Heart, that it may enter more closely into the little mouths of the Veins, it lays aside its turgid and burning aery Particles, and being presently made more quiet and half extinct, and so both its vigour and also its colour being changed, it returns through the passages of the Veins, that at length running into the Lungs, it might renew its burning. After this manner, that the inkindled blood might flame through the whole Body with a perpetual and equal flame, and successively renew its burning in all its Particles, it ought to be carried about by a perpetual course from the nest of its accension into all parts, and from these to that. For this end the Machine or Engine of the Heart was needful, as a Pin or Cock, which being made with a double bosom, might receive in it self from the whole Lungs the blood fresh inkindled, that it might presently drive forward, whilst burning, into every part of the whole Body, and might then receive the burnt and half extinguished blood returning from the whole Body; which being imbued with new inflammable juyce, it might deliver to the Lungs to be re-inkindled.

In performing this task, although the Heart be a mere Muscle, and exercised only with an animal motion, seems to serve alone for the Circulation of the Blood; yet in the mean time, it so much helps to moderate the accension of the blood and its burning, according to the rage of the passions, and to direct other works and uses of the animated Body, that we have thought the vital or flamy part of the Soul to have its chief, and as it were Imperial seat in the Heart and Lungs, in every distem∣per or affection, as of Grief, Joy, Fear, and the like; also in the fits of Diseases, the Heart is disposed after a various manner, and hence it comes to pass, that the blood flowing in fluctuates, and is inkindled with a diverse rage; of which there will be a more opportune place of discoursing, when we shall treat of the Passions.

Whilst we consider that the burning of the Blood, and for that reason the vital or flamy part of the Corporeal Soul doth not appear lively or vigorous in all, nor ever after the same manner or measure; yet it exists according to the various consti∣tutions of the blood, to wit, as it is more or less sulphureous, spirituous, saltish, or watry, yea and according to the divers constitutions and conformations both of the food, with which this flame is nourished, as also of the little spiracles or breathing holes, by which it is eventilated; and further, of the Heart it self, whereby it is agitated and driven about here and there; the accension of blood varies also in every one, by means of several other accidents, to wit, as its flame is sometimes great, clear, and expanded, sometimes small, contracted, or cloudy, sometimes equal and in order, sometimes unequal and often interrupted, yea and it becomes subject to many other mutations; also because the Soul it self having gotten a various nature or disposition, it conceives divers affections and manners, whereof we shall speak here∣after; for as much as it is not a little thing, that the disposition of the whole Soul depends upon the temperament of the bloody mass, and the degree and manner of its accension or inkindling.

It clearly appears, from what hath been said, that Fire and Life do dye or are ex∣tinguished alike many ways, to wit, there is an end of either, if the access of nitrous food, or the departure of Effluvia's be hindred, or if the oily or sulphureous aliment, requisite to either, be consumed, too much withdrawn, or perverted from its in∣flammable disposition; of each whereof it is so clearly apparent, that there needs no farther explication.

Thus far we have shewn, that the Life of the Blood, or that part of the Soul grow∣ing therein, is a certain kind of Flame; let us now see by what means it is disposed Page  32 to burning, and how near it comes to the similitude of a burning Candle or Lamp.

A common Lamp, whether designed to give heat or light, for the most part is wont to be made after this manner; to wit, the Oyl flowing perpetually to the wick, gives continual food to the flame; wherefore as there is but one fire-place or hearth only of light and heat, the action of either is limited only to one place, and so as often as there is need of more places at once, or divers parts of the same space or body to be illuminated or made warm, we place here and there divers lighted Candles or Lamps. But if an Instrument made with great artifice (such as is truly an animated Body) with one liquor only contained in it, should be made hot throughout the whole, and to be kept always warm, it ought not only to be lightly inkindled in the wick, but in the whole superficies, and derived by fit Tubes or Pipes to all the parts of the Machine, then the burning liquor ought to enjoy, proportio∣nably to all its parts, an access of nitrous Air, and to lay aside Effluvia's and other re∣crements, and ought also to have a supply of that constant expence: these kind of offices are not to be performed any where up and down, but only in some set places; therefore the burning liquor ought to be carried about through the whole with a perpetual turn, that all its portions might enjoy successively all those priviledges, and at once heat the whole capacity of the containing Machine, to wit, both the in∣ward and outward recesses. Indeed such a Bannian or Bathing Engine, artificially made, might aptly represent the real Divine handy-work of the Circulation of Blood, and what burns in it, the Life-lamp.

But it may be objected, that the Blood seems not to be inflammable of its own na∣ture; further, since there is no flame of this heat or effervency to be beheld with the eyes, it may well be doubted, whether there be such a thing or no. I say first, That the Chymical Analysis of the blood shews very many particles of Sulphur and of Spirit, yea a plentiful stock of inflammable Oyl, which are however mixed with other more thick Elements, in a just proportion, to bridle their too great inkindling; to wit, that this liquor might flame out by little and little, and only through fewer parts, for the constituting of a benign and gentle Lamp of life: wherefore the blood being let out of a Vein upon a burning fire, doth in some measure burn, though it is not like the Spirits of Wine, or Oyl of Turpentine turning all into a flame; besides, the whole mass of blood, as the Oyl of a Lamp, ought not to be fired; yea its bur∣ning is instituted for that end, that whilst all the Particles of the Mixture being freed, some sulphureous and spirituous are consumed by burning, others more sub∣til being sent in Troops, might serve for the necessary uses of the animal Regiment; and also others more thick or crass and nourishing, as it were boiled or roasted, might be dispensed for the cherishing all parts; besides, that all the dead, or worn out, and excrementitious may be sent away by fit or convenient sinks, and others constantly substituted in their places by nourishment.

But in the interim, that the vital Flame, which destinated to so many offices, we suppose to be inkindled in the Blood, (otherwise than the common flame, which is plainly conspicuous) appears not at all, a probable reason thereof may be given; as it is most thin, and burns in the Heart, and its depending Vessels as it were shut up in Receptacles, it doth not clearly flame out, but perhaps remains in the form of smoke, or a vapour, or breath; yea, although the blood should openly flame out, yet it might be so done, that its shining being most thin, may not be perceived by our sight, as in the clear light of the day we cannot behold a glowing red hot Iron, nor shining sparks, nor false fires, nor rotten wood, nor many other things shining by night; why then may not the vital fire, even thinner than they, quite escape our sight? Although sometimes hot living Creatures use to send forth a certain fire or flame only conspicuous by night: For we have known in some endued with a hot and vaporous blood, when they have put off their inner garments at night going to bed near a fire or Candle, a very thin and shining flame to have shewn it self, which hath possessed the whole inferiour region of the Body. The reason of which affection seems wholly the same, as when the evaporating fume of a Torch just put out is again inflamed by a light inkindling, and manifestly argues that another flame, the root of this extrinsick one, lyes hid within the Body. For this very cause it is, that from the Mains of Horses, and the Skins of Cats, or other hot Animals being shaken, little sparks as it were of fire leap out, and often flames, only conspicuous in the dark, arise. Besides, we here take notice in a burning Feaver, caused by immoderate drinking of Wine or strong Waters, that the blood, as the flame of it is very much Page  33 increased, doth grow excessively hot, and such are wont to emit dry breaths, and sharp Effluvia's of heat, not like those that proceed from fermenting or boiling Li∣quor, but only inflamed. That which some in Feavers have imagined to have seen or observed even burning fires and flame in the eyes, argues indeed that the flame of the blood is very strong, and also that it penetrates the inclosure of the Brain. I knew a certain ingenious Man of a very hot brain, who affirmed, that after a very plentiful drinking of Wine, he was able in the darkest night to read clearly; from hence also may be collected, how the accension of the blood, like that of burning Li∣quors, is to be increased or made stronger, viz. by an agitation of the parts, and a more plentiful affusion of sulphureous food.

But that in the hot blood of living Creatures, the Properties, Affections, and many other accidents of Fire or Flame are found without the manifest form or species of it; what if we should say the cause to be, for that the vital flame of the blood is subjugated, or made subordinate to another form, viz. to the corporeal Soul? Wherefore, although it retains the chief qualities and affections of common flame, yet it loses the species of flame or fire; for in every natural mixture, the superiour form exercises a Right and Dominion over all included Particles whatsoever, how∣ever fierce and untameable they may be in themselves, and stripping them of their species, ordains and disposes them to peculiar actions in that proper Concrete: when the form of fire excels, that bright burning, that it might propagate large∣ly its ends, destroys and consumes all inflammable objects. But if the form of the corporeal Soul be induced upon the fire, kindled within the blood, it burns forth without fulgor or shining, or destruction of the subject, and is invisible, and as it were subjugated flame, is ordained for the sustaining of life and its offices: but truly the Divine Providence, from the very Creation of the World, hath seemed to have predestinated Forms to natural Bodies, to wit, that they might remain as so many Figures or Types, according to which every portion of matter framing the Con∣crete, whether animate or inanimate, might be modificated; so that the Mass, ac∣cording to the virtues of the hidden Seeds, being disposed after this or that manner, happens to have the form of a Stone, a Plant, or Brute, or of any other kind; then the acts and affections, appropriate to such a Species, follow the form it self. When therefore Life or Soul is destinated to these kind of Functions of the more perfect Animals, for the performing of which, the blood, after the manner of burning Li∣quors, ought to be perpetually hot, and as it were inkindled; what should hinder, but that the act of Life, or of that corporeal Soul (consisting in the motion and ag∣glomeration or heaping together of most subtil and agil Particles) may be called a certain Burning or perpetual Fire of the bloody Mass? Wherein although the ac∣cidents and chief qualities of common fire are implanted, yet the form of fire is ob∣scured, as being subjugated to a more noble form, viz. of the corporeal Soul: not much unlike water, which being congealed into Ice or Snow, lays aside the species of water for a time, and may be applied to other uses far distant from fluidity.

But truly, though we affirm, that the corporeal Soul doth stick in the Blood, yet we do not, that it is adequated or limited to it: because whilst the more thick portion of it, as the Roots of some Tree, fixed in the Earth, are sowed in the bloody Mass, the more noble part of the same Soul, as the higher branches, are expanded in the Brain and nervous System; or as we before hinted, when the vital or flamy part of the Soul is contained in the blood, the animal or lucid portion of it is contained in the Head and its Appendix; by which just limit the Sphere of either may be de∣fined, neither may the vital flame impetuously break through the animal Region, the substance of the Brain being more cold, and also shining or bright, is opposed to it, as it were an icy or glassie Bar, whose interiour frame or substance, the small and slender as it were rivers of the blood, for the sake of cherishing heat, can enter: but truly spirituous Particles plentifully flow from its juyce or liquor, every where heaped up near the confines of the Brain, and there disposed as it were to be stilled forth, which being immersed in the Brain, and more exalted, affords matter, out of which the animal Spirits are procreated, to be derived through the Nerves into the various Regions of the Body.