Dr. Willis's practice of physick being the whole works of that renowned and famous physician wherein most of the diseases belonging to the body of man are treated of, with excellent methods and receipts for the cure of the same : fitted to the meanest capacity by an index for the explaining of all the hard and unusual words and terms of art derived from the Greek, Latine, or other languages for the benefit of the English reader : with forty copper plates.

CHAP. I. The Anatomy of the Blood; and its Resolution into five Principles: A comparing it with Wine and Milk.

THE Doctrine of Fermentation being explicated, it remains that we handle the chief Instance or Example of it, to wit, Feavers. For it seems that a Feaver is only a Fermentation, or immoderate Heat, brought into the Blood and Humors. Its Name is derived from Februo (or Pur∣gament, which also is derived from Ferveo, to be Hot) which Word indeed is commodiously put to every Feaver; for that the Blood in this Disease grows hot; and besides, by its fervor, as working must, it is purged from its filthinesses. But that this Fermentation or feaverish Effervency may be rightly explicated, these three things are to be con∣sidered. First, What the fermenting Liquor is; whether only Blood, or any humors besides. Secondly, In what Principles in the mixture, and in what proportion of them this Liquor consists. Thirdly, and lastly, By what motion and turgescency of those Parts or Particles, of which the Blood is made, the Feaverish Effervescency is stirred up. These be∣ing thus premised, the Doctrine of Feavers shall be delivered, not from the Opinions of others, but according to the comparisons of Reasons, picked (though from ours, yet) from diligent and frequent Observation, and confirmed by certain Experiments; all which however, I willing∣ly submit to the Judgment of the more skilful.

It plainly appears, even to the Sense, that the Blood doth hugely boil up, and rage in a Fea∣ver; for every one (though rude and unskilful) being in a Feaver, complains of the Blood be∣ing distempered, and of the same growing hot in the Vessels, and as it were, put into a fury. Al∣so, besides the Blood raging in the Veins and Arteries, it may be lawfully suspected, that that Juice with which the Brain and Nervous Parts are watered, is wont oftentimes to be in fault; for when this Liquor is seen to be carried back from the Blood, into the nervous stock by a con∣stant motion, and certain Circulation, and from thence through the Lymphatick Vessels, into the bosom of the Blood, it is probable, if by reason of a Taint contracted from the Blood, that humor be depraved in its disposition, or is perverted from its equal motion, that from thence the Rigour, and Pain, Convulsion, Delirium, Phrensie, and many more Symptoms of the Nervous kind, usual in Feavers do arise.

After the Blood and Nervous Liquor, two other Humors, for that being apt to grow hot, fall into our consideration, viz. The Chyme or nourishing Juice, continually coming to the Mass of Blood, and the serous Latex, perpetually departing from the same, which, though they be the first and last Liquors separated from the Blood, and distinct from it, yet being con∣fused with it, they ought to be esteemed as its associate parts or complements; for the nourish∣able Juice being fresh brought, is accounted the crude part of the Bloud, and to be assimilated; and the Serum, it's stale part, and to be carried away. And after this manner, so long as either are circulated with the Bloud it self, in the Vessels they participate of the heats of the first begot∣ten Bloud, and oftentimes occasionally begin them, or increase them being begun; but by what means these things come to be be done, is declared hereafter in their proper places. As to the rest of Humors, which are only the Recrements of the nutricious Juice, or the bloud, when they are included, either in their proper Receptacles, or constrained in the narrow spaces in the Viscera, neither wash the several parts of the Body with a continual lustration, as the Bloud or Nervous Liquor, or the other Humors but now recited, are to be exempted from this Rank; sometimes perhaps they may be the occasional Cause that the Bloud doth conceive an undue Effervency, or that it persists in it longer; but it is only the Bloud, (with the the Nervous Liquor, the alible Juice, and Serum Associates)

which boiling up above measure, with its heat, and stirred up with a rage through the Vessels, diffuses the preternatural heat, and induces the formal reason of the Feaver: but how this comes to be done, is not to be known plainly, but by a more near beholding the Nature of Blood, and as it were an Anatomy made of its Liquor.

There are in the Blood, (as in all Fermentative Liquors) Heterogeneous Particles, which as they are of a diverse Figure and Energy, remain a long while in the mixture, by their mutual opposing one another and subaction, the motion of Fermentation is continually conserved; as is perceived in Wine, Beer, and other Liquors: then, if the mixtion of the Liquor be some∣what unlocked by the adding of Ferments, the Native Particles being •…•…reed from their bonds, do yet more swell up, and induce Fermentation, with a more rapid motion and heat: which is seen in a familiar Experiment of the Chymists, viz. when fluid Salts are mixed with saline Liquors of another kind; from thence a great heat and ebullition are stirred up. Wherefore we ought to inquire concerning the Blood, of what Particles it consists, that it should be fit to Ferment, (as Wine, Beer, and other Liquors) of its own Nature: then by the help of what kind of Ferments, both its Natural and Feaverish heats are performed, with warmth, and a more quick motion.

The Mass of the Blood, by the Opinion of the Antients, was thought to consist of four Hu∣mors; to wit, Blood, Phlegm, Choler, and Melancholy: and it was affirmed, that according to the eminency of this, or that Humor, diverse temperaments are formed; and that by reason of their fervors or exorbitances, almost all Diseases do arise. This Opinion, tho' it flourished from the time of Galen, in the Schools of Physicians, yet in our Age, in which the Circular motion of the Blood, and other affections of it were made known, before not understood, it began to be a little suspected; nor to be so generally made use of, for the solving the Phaenomena's of Diseases: because these sort of humors do not constitute the Blood, but what are so called (except the Blood) are only the recrements of the Blood, which ought continually to be separated from it: For in truth the Blood is an only humor; not one thing about the Viscera, and another in the habit of the Body; nor is it moved at one time by Phlegm, and another time with Choler, or Melancholy, (as is commonly asserted) but the Liquor growing hot in the Vessels, is only Blood, and wheresoever it is carried through all the parts of the Body, it is still the same, and like it self. But because by reason of the abundance of the implanted heat in some, and because of the smalness of it in others, the Coction of the Aliment is now quicker, now slower per∣formed in the Bowels, and in the Vessels; therefore the temper of the Blood (tho'but one, and always the same Liquor) becomes diverse: and according to the various disposition of this, it may be said that men are Choleric, Melancholic, or of another temperament. Besides, because whilst the Blood is made in its Circulation in the Vessels, some parts continually grow old, and others are supplied anew, hence from Crudity, or too much Coction, there is a necessity that what is excrementitious should be heaped together: which notwithstanding by its effervescency, (as by the working or depuration of Wines it comes to pass) it is separated from its Mass, viz. the watry humor, fixed in the Bowels, or solid parts, is it which is called Phlegm: some Reliques of adust Salt and Sulphur, being separated in the Liver, and received by the Choleduct Vessels are called Choler; the Earthy feculences being laid up in the Spleen, are termed Melancholy. In the mean time, the Blood if rightly purified ought to want Choler, Phlegm and Melancholy: even as when some Wines, or Beer are purified, the more light Particles are carried upwards, which constitute its Flowers or Head; and the dregs are prest down to the bottom, which grow toge∣ther into Feces or Tartar: yet none can truly say it, Wine or Beer is composed of Froth, Tar∣tar, and a Vinous Liquor. But as these humors, commonly so called, are made out of the other Principles, viz. Choler out of Salt and Sulphur, with an admixtion of Spirit and Water; and Melancholy, out of the same, with an addition of Earth; and as the Blood is immediately forged out of these kind of Principles, and is wont to be resolved sensibly into the same, I thought best, the common acception of humors being laid aside, to bring into use these celebrated Principles of the Chymists, for the unfolding the Nature of the Blood and its affections. There are there∣fore in the Blood, as in all Liquors apt to be Fermented, very much Water and Spirit, a mean of Salt and Sulphur, and a little of Earth. The Blood being loosned by putrefaction, exhibits the same separated and distinct. Also in the Blood contained in the Vessels, or being fresh let out from them, we may discover their energies and effects: besides, when in the Food, whereby we are fed, by the Juice of which the Liquor of the Blood is made, these same are implanted, no man will go about to deny that the Blood also is made from them: wherefore I will briefly run through these, and endeavour to shew by what means the Consistency, the Properties, and the Affections of the Blood are made by them.

1. Spirits (which readily obtain the chief place) are a subtil, and greatly volatile por∣tion of the Blood. Their Particles, always expansed, and endeavouring to fly away do move about the more thick little Bodies of the rest, wherewith they are involved, and conti∣nually detain them in the motion of Fermentation. The Liquor of the Blood continually boils up with their effervescency or growing hot, and equal expansion in the Vessels, and the rest of

the Principles are contained in an orderly motion, and within the bond of the exact mixture; if any Heterogeneous thing, or unagreeable to the mixture, be poured into the bloody Mass, pre∣sently the Spirits being disturbed in their motion, rage, shake the blood, and force it to grow hugely hot, until what is extraneous, and not missible, is either subdued, and reduced, or cast out of dores. By the irradiation, or rather the irrigation or watering of these, the Bodies of the Nerves are inflated, the Functions of the Viscera, and also the Offices of motion, and sensation are performed: from the want of Spirits, also from their motion being depraved or hindred, arise great vices of the Natural oeconomy or Government. The more quick motion and effer∣vescency of these in the blood, (above what is in Wine) chiefly depends upon the Ferment of the Heart; because, whilst the blood passes through the Bosom of the Heart, its mixture is very much loosned, so that the Spirits, together with the sulphureous Particles, being somewhat loosned, and as it were inkindled into a flame, leap forth, and are much expanded, and from thence they impart by their deflagration, a heat to the whole. By reason of this kind of expan∣sion, and suffusion of heat, there is made a continual expence of Spirits, which being rarified, as it were inkindled, continually fly away, and are evaporated forth adoors: and as long as we live there is made a continual reparation of these by aliments, chiefly the most delicate; which contain in themselves very much of Spirit and swelling matter: from which juice being drawn by digestion, and collated to the blood, is assimilated to it and fills up its defects. When the Blood of Animals is distilled, the Spirits (like Aqua Vitae) ascend of a limpid co∣lour, they are made very sharp and pricking, by the adhesion of the Salt; yet they are not so easily drawn off, as the Spirits of Wine, but that there is need of a more intense fire to force them, because they are hardly driven from the fellowship of the thicker parts, with which they are involved.

2. That there is plenty of Sulphur in the Blood, it is plainly seen, because we are chiefly fed with fat and sulphureous Aliments, also the Nutriment from the blood, carried to the solid parts, goes into Sulphur and Fatness. It is most likely, from the dissolution of this, that the red Tin∣cture of the Blood doth arise: for sulphureous Bodies, before any others, impart to the solvent Menstruum, a colour highly full of redness; and when by reason of too great Crudity, the Sulphur is less dissolved, the blood becomes watery and pale, that it will scarce dye a Linnen Ragg red. The Mass of blood being impregnated with Sulphur, and together with Spirits, it becomes very Fermentable: which however, whilst it enters the Ventricles of the Heart, there suffers a greater effervescency, or rather accension; and on the Particles chiefly sulphureous, being inflamed, and thence diffused through the whole, the lively and vital heat in us depends. When the sulphureous part is carried forth, and doth too much luxuriate in the blood, it perverts its disposition from its due state, that therefore the blood being either depraved, or made more bilous or Cholerick, doth not rightly Cook the nourishing Juice; or being inkindled throughout, it conceives heats and ardours, such as arise in a continual Feaver. For the Sulphur being too much exalted; and swelling more than it ought, stirs up great heats in the blood: and they whose blood is more plentifully impregnated with Sulphur, are most obnoxious to Feavers. By reason of the Par∣ticles of this being incocted with the Nutritious Juice, and from thence carried to the solid parts, fatness, softness and tenderness, come to our Body. From the Flesh or Blood putrefying, by rea∣•…•…on of the abundance of evaporated Sulphur, a most evil stink breaths forth: In the distillation of Blood, Sulphur ascends under the form of a blackish Oyl, which also by reason of the Empyreuma, stinks most wickedly.

3. That Salt is in the Blood, is evinced by the Salt; which, tho' fixed, is drawn forth, by being eaten, from Vegetables, and from other eatable things, at first less volatile, afterwards by the most excellent digestion of Nature, and Circulation, is highly volatilised; that it passes through, not only without a remaining Caput Mortuum, all the members and parts of our Body, but also the blood being exposed to distillation, ascends the Alembic, and leaves the dead Head as insipid earth: If at any time the saline Particles are not rightly exalted in the Blood, by rea∣son of ill digestion, but remain crude, and for the most part fixed, from thence the blood be∣comes thick and unfit for Circulation, so that Obstructions are begot in the Bowels and solid parts, and serous Crudities are every where heaped together: But if the Salt be too much carried forth, and suffers a Flux, the Spirit being depressed, or deficient, a sour and bitter disposition is given to the blood, such as is observed in Scorbutical People, and those sick of a Quartan Feaver. Also from the Salt, for this reason being variously coagulated, the Stone, Kings-Evil, Gout, Le∣prosie, and very many other Chronical Diseases arise. But when Coction being rightly per∣formed in the Bowels and Vessels, the Salt is duly exalted, and being associated with the Spirit, is volatilised, then by reason of its mixture, the Liquor of the Blood more equally ferments; also is defended from Putrefaction, Stagnation, and Coagulation: Also the saline Particles, bridle the fiercenesses of the Spirits, and especially of Sulphur; wherefore, those who have their blood well filled with a Volatile Salt, are less obnoxious to Feavers: also hence those who ofte•…•… are let blood, are more apt to Feavers.

4. Besides, There are in the Blood, (as it is a thick Humour, and hath a gross consistence) many Earthy Particles: from hence also, its too great Volatilisation is as it were supported, and its too hasty accension hindered: even as Charcoal-dust, is added oftentimes to Gun-Powder in a greater proportion, that all its parts may not take fire at once, and too soon: Further, from the Terrestrial Particles of the Blood, and Nutritious Juice, the bulk and increase of the Body proceeds. Lastly, from the distillation of the Blood, a light and friable Caput Mortuum, is left in great plenty.

5. Upon the watery part of the Blood depends its fluidness; for from hence its stagna∣tion is hindered, and the Blood is circulated in the Vessels, without growing thick or stiff: also its too great conflagration, and adustion is restrained, and its heat attempered. When Blood is distilled a clear and insipid Water is drawn off, at least in a double proportion to the rest; for from hence the matter of Urin, Sweat, and every humid Excrement, for the most part proceeds.

What things were but now asserted, concerning the Principles of the Blood, and the affe∣ctions to be deduced thence, will better appear, if we consider a little the Blood, according to its sensible parts, and shall compare it with other Liquors which are in daily use amongst us. Those sort of Liquors, which have a very great Analogy with the Blood, are, viz. Rich Wine and Milk. As to the Reasons of Fermentation and growing Hot, it is most fitly compared to Wine; as to its consistency, coagulation, and departure of the parts one from another, it is likened to Milk.

In the first place therefore, it is observed of Wine, that so long as it is shut up in the Vessel or Pipe, its subtil and spirituous Particles, do perpetually agitate, or very much shake others more thick, break them, and render them fit for an exact mixtion; what is heterogeneous, and and unfit for subaction or mingling, is separated by its growing hot: In the mean time the puri∣fied Liquor greatly fermenting, is in perpetual motion, whereby all the parts (as Atoms, va∣riously moved up and down, in a beam or streak of light) do stretch themselves forth on every side, and contend with a constant rowling about, from top to bottom, and from thence to the top again. By the attrition and refraction of the Particles, very many Effluvia of Atoms, go away from the Liquor, which if the Vessel being closely shut, they are kept within; the Liquor grows too exces∣sively hot, and oftentimes causes the containing Vessel to burst in pieces. Blood, much after the same manner being shut up within the Veins and the Arteries, is urged with a constant Circu∣lation: The Vital Spirit makes subtil, breaks, and exactly molds the more thick Particles; what is heterogeneous, and not mixable, it expels forth of dores; in the mean time by the refraction and kneading of the parts, Effluvia of heat do constantly stream forth, and evaporate through the pores; which being shut in, if transpiration be hindred, presently by reason of the too great boiling of the Blood a Feaver is inkindled.

Secondly, We will observe concerning Wines, that they grow turgid, or swell up, if any ex∣traneous thing, and of a Fermentative Nature, be poured to them; yea sometimes, that they are moved more than ordinary of their own accord. For, when by a long digestion, the sulphureous part of the Wine is too much exalted, it conceives a greater heat than it ought, and (unless pre∣sently appeased) perverts the disposition of the whole Liquor, with its swelling up. It seems to be for the very like reason, that the Feaverish heat which is wont to be introduced by reason of the same Causes, is stirred up in the Blood, as shall be shown in the next Chapter, where we treat of the Motion and Heat of the Blood.

The third Observation, or comparing of the Blood with Wine, shall be of this sort: Wines (as a•…•…so many other Liquors, as for example, Beer, or Sider) have their times of crudity, maturation, and defection. For when they are first made, the spirituous parts are so obvolved by the others more thick, that they shew themselves but little, and put forth almost nothing of strength or ver∣tue: and as the other Particles, are not yet subtilised, nor truly concocted, the whole Liquor re∣mains crude, and of an ungrateful taste; and if put to distillation, not any Spirit ascends. From this state it comes by degrees to perfection, and when the Spirits being extricated from their intangle∣ments, obtain their own right, and have subtilized and exalted the more thick Particles of the rest, the whole mass of the Liquor becomes Clear, Spirituous, Sweet, and Balsamick. Lastly, When by a long Fermentation, the Spirits are consumed, and begin at length to fail, the state of defection is induced, whereby Wines, and other Liquors, either pass into a tastlesness, or at last the Salt and the Sulphur being too much exalted, are made sowr or unsavory. In like manner the Blood also, while it is Circulated in the Vessels, may be considered according to this kind of threefold disposition: First, in the making or crudity, which has relation to the Chyme new made in the Viscera, and freshly poured to the Blood; the Particles of which, like to unripe Fruit, are crude and undigested. Secondly, In the perfect state or maturation, which belongs to the Blood being snfficiently wrought, and made Volatile, according to all its Particles after it is infpired by Ferments, and its inkindling in the heart exalted. Thirdly, In its defe∣ction, which respects the Blood; after it hath burned forth, and its spirituous parts are very much flown away, and the rest growing old and poor, have need to be removed; and so they are

either the Reliques of Salt, which are with the Serum strained forth continually by the Urine; or they are Particles of Salt and Sulphur, boiled and baked together, which are strained forth by the virtue of the Liver into the choleduct Vessels: or lastly, they are dregs and earthly re∣crements of the Blood it self, which are carried into the Spleen, and there (as it were a Caput Mortuum, exalted by a new digestion) go into a Ferment, at length to be transmitted to the Blood. Whilst after this manner, the generation of the Bloud, and its due maturation are truly dispatched, it is pleasingly circulated within the Vessels, neither wanting in motion or heat, nor inordinately troubled with them. But if either the supplement of the nourishing Juice, be not made agreeable with the rest of the Bloud, nor assimilated with it, but that either by reason of the defect of Concoction, it is washed into a very crude humour, or because of its excess, it is rosted into a burnt matter; or if the Bloud growing old, does not lay aside what it casts off, and give way to a new nutritious Humor; I say, by reason of these kind of Vices, concerning Sanguification, or the making of Bloud, the Bloud is variously perverted srom its due temper and equal motion, and now becomes watery and cold; now sharp or salt; now acid, austere, or by some other way degenerate; and sometimes obnoxious to stagnations, and sometimes to immoderate heats.

We may observe these kind of degrees of Crudity, Coction, and Defection in the Bloud, both of the sound and of the sick; in healthful persons after a more plentiful Repast, Surfeit, or hard Drinking, when too much of Serum or of Juice, is poured to the Blood, its whole Mass being too much diluted with a crude humor, becomes more watery, and less spirituous; wherefore men are rendred sluggish, and unfit for motion or exercise. In sick persons the Phlegmatic Constitution of the Body, induces such a crudity of the bloody mass, as is discern∣ed in the white Dropsie, the Dropsie, Pica, or longing Disease, and the Chlorosis, or Green Sickness. Also the state of this kind of crudity, comes in an intermitting Feaver, and in truth is the cause of the Feaverish accession, viz. by reason of the dyscrasie of the Bloud; the nourish∣ing Juice being heaped up, is not assimilated to it, but for the most part goes into a crude, or otherwise degenerate matter; with which, when the Mass of Bloud is filled to a plenitude, swelling up, it brings on the Fit.

The state of Maturation, concoction being finished, happens in healthful persons, some hours after Eating, especially in the morning, to wit, when the supplement of the Chyme is spiritua∣lized, and as it were enkindled in the whole, by reiterated Circulations; for then men are made more nimble and lively, and more ready for studies, or any business.

The state of Defection is in the blood of sound men after fasting long, hard labour, and want of Food; for then the Vital Spirit being very much evaporated, the mass of the Blood be∣gins to become as it were lifeless, wherefore they presently languish, and are made weak. More∣over, the blood by a too long coction is burned, and grows bilous, from whence those accustom∣ed to want Food, or fasting, for the most part become sad and melancholic. Some Diseases habitually induce such a disposition of the blood; such are the Scurvy, the yellow Jaundies, the Cachexia (or evil state of the body when the nourishing Juice turns to ill humors) long Fea∣vers, and most Chronical Diseases, in which, the whole mass of blood passes from a spirituous, into either a sowr, sharp, or austere Nature.

So much for the comparing of bloud with rich Wine; what follows, being a similitude of it with Milk, consists in the diversity of the parts, and their setling apart, which is chiefly seen in its being let forth from the Veins, and grown cold in the Dish. For when the heat and vital Spi∣rit, which conserve all things in the mixture, are flown away, the remaining parts depart from one another of themselves, and a separation of the thin from the thick, and of the Serum from the fibrous bloud is made. This sort of separation of the parts, succeeds almost after the same manner, as in the coagulation of Milk. There are in Milk, Buttery, Cheesie parts, and Whey. The like is in blood, so long as it doth not much recede from its natural temper: for it is good, when being let forth of the Veins, it grows cold in the Porringer, its parts do settle after the same manner; to wit, the more pure portion, and sulphureous (like Cream) comes together on the Superficies, which in healthful people, looks brightly red, and this answers to the flower∣ing or head of the Milk: under this lies a purple thick substance, which consists of little Threds and Fibres joyned together, and as it were concreted into a clotty substance or parenchyma, such as the Liver: For the heat being consumed, and the bond of the mixture loosned, the Fi∣brous parts lay holdon one another, and by their weight, settle into a more thick Coagulum, which answers to the Cheesie part of the Milk: In the mean time, the Serous or Wheyey parts, be∣ing thrust forth from the rest, get their own Nature, and constitute a clear Liquor, like water; which as it is thinner, ascends to the top, and swims upon the rest. Further, as the Whey of Milk is wont to be further coagulated, and doth yet contain in it self some parts both Buttery and Cheesie; so this Liquor swimming on the Blood, if it be exposed either to the fire, grows thick, like the White of an Egg a little rosted, or if an acid Liquor be powred to it, it will be precipitated into a white Coagulum. This being seen, some have thought this watery Latex, to be the nourishing Juyce, which imparts nourishment to the whole Body, from the mass of

the blood, in the time of its Circulation, an d that the rest of the blood is only the Vehicle of Heat and Spirits, and serves for no other use. But to me it seems more likely, that in this watery Liquor is contained the nourishing Juyce, which is employed on the Nerves, and the commonly termed Spermatic parts, for nourishment is supplied to the Musculous stock, from the fibrous blood of the Parenchyma, or the Liver, Lights and Milt. After this manner, blood being not much vitiated, goes into parts like Milk; but if it be exceedingly depraved, when it settles, it shews a far different disposition, and as to its single Contents, is allotted into various appearances; for the Cream growing together on the top, is seen to be sometimes white, sometimes green, now yellow, or of livid or Lead colour; also it becomes not tender, but ve∣ry viscous or clammy, that like a Membrane, it can scarce be pulled in pieces. When the blood long growing hot with a Feaverish Distemper, is let forth from the cut Vein, in its Superfi∣cies, instead of a Scarlet Cream, there grows together often a white Skin, or of some other colour; the reason of which is, because the blood is throughly rosted, by two great Ebullition, and its more pure portion, as it were by a certain elixation, is boiled forth from a red and tender substance, to a white and tough; but if in the mean time the bloody mass be not suffi∣ciently purged from the adust recrements of Salt and Sulphur, the colour of this little Skin becomes yellow or livid, and therefore the Water swimming over it, is often tinged by the same means. Further, the Purple Crassament or thick substance is also various, viz. sometimes it is of a blackish colour, when the blood is scorched too much, by a long effervescency. When the Fibres are vitiated, as in the Liver, they grow not together, but the Liquor like Beasting Milk, remains somewhat thick, and yet fluid; which indeed argues a great corruption of the blood; as uses to happen in a putrid Feaver, a very great Cachexy, sometimes the watery Latex is wanting, as in Hectical people, and in too great a Diaphoresis. Sometimes it superabounds, as in Dropical people, neither will the whole go into a white Coagulum, by heat: In some Ca∣chectical people, the blood being made more watery, appears like watered flesh. I knew one endued with a vicious habit of Body, that was wont to have blood of a whitish colour, and like to Milk when it was let forth, and afterwards, when he grew better by Chalybeat Mede∣cines, his blood was moderately red; but concerning the setling of the blood, and its appear∣ances, there is enough. But as blood being emited from the Vessels by its coagulation and de∣parture of the parts one from another, imitates the various substances of congealed Milk, so sometimes being shut within the Veins and Arteries, like some fused by a Coagulum, enters all together into the like mutation from Morbific Causes; by reason of which change, being hin∣dred in its Circulation, or somewhere congealed and fixed according to its portions, it produces many Distempers: for it seems, that from hence the Pleurisie, the Squinancy, the Inflammation of the Lungs, the Dysentery, take their Original, and to this Cause the Pestilent Diseases ow c•…•…iefly their deadliness, as shall be said hereafter in its place.

It is sufficient that we have hitherto drawn a parallel of the blood, from which comparison with Wine and Milk, may be gathered what sort of Particles and Substances it comprehends in it self, viz. Spirituous, and very agil or nimble (such as generous or rich Wine has) for the heat and motion; and besides soft and tender (such as are in Milk) for the nourishment of the Body. Yea also, this Analogy of it with Wine and Milk, is yet further confirmed by the use of them in our Diet, out of which the blood is generated; forasmuch as Milk is the best and most simple Aliment, and with it Infants, and Children, who have need of a plentiful provision of blood, are nourished chiefly: But Wine copiously begets Vital Spirits before all other things, and being weak and fallen, excellently restores them; wherefore it is wont to be esteemed in∣stead of Nectar for old men, or those of ripe years.

The Nature and Analysis of the blood flowing within the Vessels, being opened after this manner, the nutricious Juice deserves yet our consideration, being supplied from the blood, and separated out of the mass of blood, for the nourishment of the solid parts, and cleaving to them (whereby it may be the better assimilated) like Dew. For the Nerves, tendons and the rest of the solid parts of the whole Body, are washed with a certain alible Juice. The Vital Spirits, having obtained the Nervous Bodies for a Vehicle of this, blow them forth at length, and expeditiously execute the actions of Sense: also that Humor coming upon the solid parts, and assimilated with them, enlarges their Bulk and Growth. This is not a place to enquire after the Origin, Birth, and manner of the Dispensation of this: It shall suffice only that we have noted, that it is supplied from the mass of blood, and (as it is rendred highly probable by the most Learned Dr. Glisson, and Dr. Wharton) after it hath past through the Nervous part by a certain Circulation, what remains, being now made as it were poor and lifeless, is sent back by the Lymphatic Vessels, to the blood. Whilst this Juice, being little cocted, or purged from dregs, is sent from the depraved blood, to the Nervous parts, 'tis wont variously to irritate them into Cramps and Convulsive Motions; also, no few Symptoms in Feavers, arise by reason of the depravation, and irregular Motion of this Juice, as shall be more largely laid open in an∣other place.