which the parts are made is not blood but a certain liquid juice very like the White of an Egg. 60 13. Nevertheless blood may be the nourishment of such parts whose substance is mostly Sanguineous and what those are 61 14. The Manner how the Vital Heat is conserved and the vital spirits continually recruited ex Sanguine 62 15. The Reason of the Mication or panting Motion of the blood in the Arteries 64 Exercitation the Sixth Of the Motion of the Blood its Conditions and Causes Art 1. The Method of the whole Chapter 66 2. That the Motion of the Blood is Circular ibid. 3. From the vena Cava into the right ventricle of the Heart 67 4. From the right ventricle by the vena arteriosa into the Lungs ibid. 5. From the Lungs through the Arteria venosa into the Left ventricle ibid. 6. From the Left ventricle into the Great Artery and thence into the smaller arteries 68 7. From the smallest Arteries through the substance of the Flesh into the smallest veins ibid. 8. How the New-made blood is circulated with the old 69 9. That more blood passeth through the Heart in an hour than can be supplied from the Chyle in several dayes ibid. 10. The Necessity of this Circulation inferred from three Considerations viz. 70 11 The Quantity of blood contained in the Heart in its Diastole 71 12 The Quantity expelled out of it in its Systole ibid. 13 The Number of Pulses in an hour 72 11. That the Circulation is Universal in all the Arteries and veins of the body 73 12. But after a peculiar manner in an Infant unborn 75 13. That this Motion of the blood is Continual 76 14. Vehement 77 15. Swift ibid. 16. Of equal velocity in the Arteries and Veins 78 17. The blood not the Cause of its own Motion in respect of any Motive Faculty inhaerent in it 80 18. Nor in respect of its Ebullition ibid. 19. Nor of its Rarefaction 81 20. But of its Quantity distending the ventricles of the Heart 83 21. The blood not moved by Attraction 84 22. Nor by Vection ibid. 23. But by Impulsion of the Heart endowed with a Pulsifick Faculty if any such may be admitted ibid. 24. The Fabrique of the Heart a remote Cause of the Motion of the blood 87 25. The Motion of the Heart described as consisting of two contrary motions and a Respite betwixt them ibid. 26. And the Figure of it in each 88 Exercitation the Seventh Of the Depuration of the Blood Art 1. The Genealogy of the Excrements in the blood 91 2. Exemplified in the Destillation of Wine 93 3. The several sorts of those Excrements and their Definitions 94 4. The Reason why each particular Excrement is determinately imported into the part particularly comparated for its separation 97 5. Not that it is so directed by any Intelligence or Distinguishing Faculty 99 6. Nor that it is Attracted by the like Excrement contained in that part ibid. 7. But that there is a certain peculiar Conformity of the Magnitude and Figure betwixt the minute particles of this or that Excrement and the pores of this or that part peculiarly constituted for the reception of it 100 8. Which is also the Cause of the Separation of particular Excrements in particular parts 101 9. The Differences of Colatures used by Nature in the separation of Humors in the body 102 10. The Reason and Manner of the separation of the Serum from the blood in the Kidneys 104 11. Of the Phlegmatique Excrement in the stomach and Guts 105 12. Of the Bilious Excrement's accompanying the Phlegmatique so far 106 13. Why the blood is not carried immediately out of the trunk of the Vena portae into that of the Vena Cava but through the various meanders in the Liver 109 14. And why it is transmitted through the Parenchyma of the Liver ibid. 15. That the Parenchyma is the Principal part of the whole Liver 110 16. And a kind of Streyner 111. 17. Whose particles are contexed after a peculiar manner and pores of â—ivers sorts in respect whereof the Bile is therein separated from the blood Mechanically ibid. 18. The same inferred from Four Considerables viz. 112 The equal distribution of the capillary branches of all the vessels of the Liver ibid. The Pulsation of the vena portae within the Liver 113 The assistance of that pulsation by the Hepatique Nerve 114 The Resuscitation of vitality in the blood in the branches of the vena Portae within the Liver and a new Fermentation thereof previous to the separation of the Bile ibid. 19. The various Manner of the Excretion of Excrements after they are separated and collected 116 20. The particular Manner of the Excretion of the Bile and 117 21. The Cause thereof 118 22. Paradox that we have a certain Natural Feeling wholly distinct from the Animal and independent upon the Brain 119 Exercitation the Eighth Of Respiration Art 1. The Connexion of this discourse to the precedent 126 2. The Disparity betwixt Respirà tion and Pulsation both as to their Times or Periods and as to their Uses ibid. 3. Respiration described 130 4. The Efficient Cause of Inspiration is the Dilatation of the Breast impelling the ambient Aer into the Lungs ibid. 5. And the Cause of Exspiration is only the spontaneous Contraction of the breast 132 6. The Disatation of the Chest and Lungs not from any Motive Faculty congenial to the Lungs 133 7. Nor from the impulse of the blood out of the Heart into the Lungs 134 8. Nor from the motion of the Muscles of the Thorax 135 9. But from the Diaphragme moved by a congenite Faculty ibid. 10. Yet the Intercostal and Pectoral Muscles are allowed to conspire with the Diaphragme in respiration violent and arbitrary 137 11. The Final Cause of Respiration not the Refrigeration of the Heart or Vital Flame but the subtiliation of the blood which by the admistion of Aer is made the more convenient fewel of the vital Lamp and matter of the spirits 138 12. The same exemplified in the accension of flame in wood by Aer blown out of Bellows and 139 13. inferred from the structure of the Lungs 140 14. The Use of Expiration 141 15. A Problem of the respiration of the Foetus in the mother's womb 142 16. The motion of the Brain not dependent upon Respiration but upon the Pulsarion of the Arteries 145 17. The Secondary Uses of Respiration 147 Exercitation the Ninth Of the Lympheducts Art 1. The Lympheducts a new and excellent invention 149 2. To whom the honour of their discovery is to be ascribed ibid. 3. Their Description 150 4. Differences 151 5. Origination ibid. 6. Insertion ibid. 7. Situation and Progress 152 8. Liquor deduced partly from the Arteries and 153 9. paâ—tly fâ—â—m the Nerves 154 10. The Uses of that Liquor 155 Exercitation the Tenth Of the Distribution of the Nourishment through the Nerves Art 1. That the Nerves are vessells carrying the Nutritive juice
have undergone severall Circulations and as many fresh Accensions in the Heart For in every Circulation they grow more and more subtile and agile and so must at length be brought to the requisite height of volatility To which having once attained in the very next Circulation though they are restrained and kept in by the sides of the heart and coats of the arteries while they remain therein being diffused upon the outward parts of the body as they warm and vivify those parts so do they soon flye away and disperse themselves into air And while these thus flye away other Spirits lesse volatile are by the colder temperament of the parts by which they pass somewhat repressed so that the force of their expansive motion is much abated the Mication or panting of the bloud interrupted and the bloud wherein they are of Arterial or vital bloud is made venouse or Natural and such it continueth untill the next circulation bring it again to the heart there to be kindled afresh and exalted to the due heat of vitality Which once acquired it recovers its intermitted motion of Mication or rising and falling alternately and yeeldeth a fresh supply of spirits vital which being transmitted to the habit of the body are soon dispersed like the former And thus is the vital Flame kept alive at no lesse expence The Reason of the Mication or panting motion of the Blood in the arteries than a continual dissipation of the most votatile spirits of the blood For that vital Heat ariseth from within and the most subtile spirits are the first Movers to the excitement thereof the motion by which they do it being their indeavour to expand themselves and to dilate their bounds while the other grosser elements or ingredients of the bloud oppose them therein And this strife or Counter-activity of the spirits on one part and of the grosser ingredients of the blood on the other doth exhibite the general Essence of Heat To which may be added this short observation that in this Contention one while the spirits prevailing do lift up or swell the mass of bloud another while the grosser elements the contraction of the Heart and arteries assisting them prevailing countermand and interrupt that expansive motion and that by this alternate conquest of these Antagonists is made the Mication or Rising and Falling of the blood the one in the Dilatation the other in the Contraction of the Heart and arteries Forasmuch therefore as the vital Heat doth consist in the rarefactive motion of the spirits and the renitence of the grosser parts of the bloud and that the spirits for the most part at least alternately obtain the victory and dominion over their opponents it seems most consentaneous to truth that this vital Heat cannot be preserved without a perpetual expence of the most pure i.e. the most volatile spirits of the blood and consequently necessary that during life fresh spirits must be perpetually minted out of the blood to defray that vast and continual expence And this we conceive to be the true progress of Nature from the first reception of the spirits contained in the Aliment to their education into the Chyle their sublimation in the heart their gradual exaltation to the highest degree of volatility and lastly their dissipation through the skin into aer upon which depends the Conservation of the vital Heat and the continual Generation of the vital Spirits OF THE MOTION OF THE BLOOD ITS CONDITIONS AND CAVSES Exercitation the Sixth Of the Motion of the Blood its Conditions and Causes NAture which in all her works hath the End The Method of the Chapter and Means conducing to that End alwayes closely connected in one idea having ordained the perpetual generation of this vital Nectar the Blood in Animals for the Uses in the precedent Chapter recited that she might not be deficient in the means requisite to fulfill those Uses hath also ordained that the blood should be carried from the Fountain to all the parts in living streams by a certain admirable Motion necessary to its distribution through the whole body Now that we may fully understand the nature of this Motion we are to consider 1 the Manner 2 the Conditions 3 the Causes of it Concerning the FIRST we observe That the Motion of the blood is Circular that the blood is continually carried or rather driven from its fountain the Heart in the centre of the body by the Arteries to the circumference and back again from the circumference to the centre by the veins irrigating cherishing and vivifying all the parts as it passeth along and that therefore this Motion was by the glorious Inventer of it Dr. Harvey called the Circulation of the blood quòd Ejus enim semper redeat labor actus in orbem For in the first place From the Vena Cava into the right Ventricle of the heart the blood is effused out of the vena Cava into the right ventricle of the Heart as may be evidently seen in living Animals dissected especially in Coneys For if the trunck of the vena Cava be bound with a ligature both above and below the heart you may perceive all the blood contained in the space betwixt the ligatures to be speedily discharged into the right ventricle of the heart to which the vena Cava is conjoyned From the right ventricle of the heart it is the heart contracting it self expelled into the vena arteriosa From the right Ventricle by the Vena arteriosa into the Lungs and so into the Lungs but not through the septum transversum or middle partition of the heart as some have imagined conceiving the same to have some certain obscure passages from the right into the left ventricle only because they could without much violence thrust a style or probe through it when indeed those passages are not made by Nature but by the point of the probe the flesh of the heart being so tender as that it is easily penetrated by any hard and pointed instrument though but gently intruded Passing through the vena arteriosa into the very substance of the Lungs the bloud is immediately returned into the venosa arteria From the Lungs through the Arteria Venosa into the left Ventricle and through that into the Left ventricle of the Heart This is demonstrable thus Having made a ligature upon the great branch of the Arteria venosa neer the pericardium in the lungs of an Animal yet living you may observe that branch to be soon filled and much distended with bloud in that part which is toward the lungs and that emptied and flaccid that is next the heart and upon remove of the ligature the bloud will flow amain from the lungs to the left ventricle Now there being no other way by which this bloud can flow to the left ventricle but from the lungs it must of necessity descend thence by the Arteria venosa The left ventricle having thus taken in a quantity of bloud
sensum nobis ipsi adimamus neque dubitationis â—muli aut fatui aut aliud ejusmodi quidvis simus sed quod tum rectum est tum modestis Hominibus convenit quod quidâ—m evidens est promptè accipiamus quod autem dubium est per ocium quaeramus ¶ Errors of the Presse Correct thus PAge 1. line 20. read Plostique page 5. line 1 read Aristoteleans pagâ— 8. line 2 read Void and line 20. read 〈◊〉 〈◊〉 〈◊〉 〈◊〉 〈◊〉 page 10. line 7. read Homaeomerian p. 13. l. 10. read ructus acidus and l. 25 one and the same c. page 15. line 9. read difficultly page 17. line 13 read Pecquet page 26 line 29. read Pecquet page 31. line ult read other branches page 40. line 4 read it s own nature c. page 61. line 13. read apposition page 64. line 4. read Venous p. 72. l. 1. r. Slegelius and the same line 12. page 77. line penult read only thus much pag. 83. line 18. read draw themselves c. page 86. line 12. read Fracastorius page 89. line 29. read lax page 95. line 17. read voided page 114. line 7. read Capsula page 116. line 10. read Nerve page 157. line 19. read Nerve page 190. line 8. read veins page 192. line ult read covered page 193. line 17. read Taylors Mascle OF NVTRITION Exercitation the First Of Nutrition THe Platonist Article though He holds the Deity and the world to be coeternal Nutrition and Generation one and the same Act of the soul or Formative virtue doth yet allow the World to have been created by God and to solve the seeming contradiction saith that Priority was not 〈◊〉 〈◊〉 〈◊〉 〈◊〉 〈◊〉 in respect of time but 〈◊〉 〈◊〉 〈◊〉 〈◊〉 〈◊〉 in respect of Nature as the Sun and light are coaevous though the one be the Cause the other the Effect This certainly might be more justly said of the Generative Nutritive Faculties if at least they be not one and the same by one of which an Animal is produced and by the other conserved For though the Formative Virtue may seem to precede in its operation yet are the Stamina or rudiments of the Embryo scarce delineated or adumbrated when the Nutritive begins to augment and perfect them So as that it may rather be said to go hand in hand with the Plastick's faculty than to follow after it and what priority there seems to be in their operations is rather in respect of Nature than of time To forme and nourish are not only acts of one and the same soul but so alike that it is no easie matter to distinguish betwixt them For Generation and Accretion are not performed without Nutrition nor Nutrition or Augmentation without Generation To nourish is to substitute such and so much of matter as was decay'd in the parts namely flesh nerves veins arteries c. And what is that in reality but to generate flesh nerves veins arteries c In like manner Accretion is not effected without Generation for all natural bodies upon the accession of new parts are augmented and those nevv parts are such of which these bodies were first composed and this is done according to all the dimensions so that to speak properly the parts of an Animal are encreased distinguished and organized all at once Farther this is necessary both in respect of the Efficient cause and of the Matter The Former because idem esse principium efficiens As well in respect of the Matter as of the Efficient nutriens conservans in singulis animalibus necesse est nisi aliam formam in puero aliam in adolescente et in sene aliam constituamus The Latter because all Animals such as are produced per Epigenesin of which is our discourse not of such Insects as are produced per Metamorphosin are corporated of one part of the matter prepared by the Formative Spirit and nourished and augmented by the rest For Nature doth nourish and amplify all parts of an Animal with the same matter or humour not with a diverse out of which she constituted or framed them at the first Because whatsoever is superadded to the parts during their growth ought to be of the same substance with what was prae existent and so must consist ex congenere materiâ their Renovation as well as first Corporation being effected by Epigenesis Aggeneration or superstruction So that we may well conclude that Nutrition is nothing else but continual Generation and as necessary to the Conservation of every individual nature as Generation it self is to the conservation of the Universe To make this Necessity the more evident we are to consider The necessity of Nutrition two-fold viz. Augmentation Conservation 1 That forasmuch as an Animal cannot performe all the functions of which its nature is capable whilst it remains in the minute parts and rude beginnings in which it is first formed therefore there must succeed a Nutrition that may dilate and amplify those slender stamina by interweaving and assimilating so many other congenerous parts as serve to advance and augment the Animal to a convenient magnitude 2 That since the chief principle of life in every Animal is a certain indigenary Heat analogous to pure flame such as the most rectified Spirit of Wine yeelds upon accension which by continuall motion and activity agitating the minute and exsoluble particles of the body doth dissolve and consume or disperse them of necessity the whole Fabrick would soon be destroy'd unlesse there were a continuall renovation or reparation of those decayes by a substitution and assimilation of equivalent particles in the room of those dispersed and absumed So that we see the Necessity of Nutrition is Two-fold one in respect of Augmentation the other in respect of Conservation As to the continuall Decay or Depredation of the substance of our bodies wherein the latter necessity of Nutrition doth consist that we may the better understand the manner how it is effected we are to enquire into the Causes thereof viz. the Agent or Depredator and the Matter or substance depredated The Agent or Efficient Cause with all Philosophers The Efficient cause of the consumption of the parts is the Vital Flame we hold to be the Naturall Heat or Vital Flame at first kindled by the vegetative soul or Plastick spirit in the blood constantly burning in the Heart as in its fountain or primary Focus and thence by diffusion of it selfe through the arteries warming cherishing and enlivening all parts of the body This Lar familiaris is called 〈◊〉 〈◊〉 〈◊〉 〈◊〉 〈◊〉 ingenitus ignis by Hippocrates 〈◊〉 〈◊〉 〈◊〉 〈◊〉 〈◊〉 Accensio animae in corde the Kindling of the soul in the heart by Aristotle and generally known by the name of Calidum innatum the innate Heat The principle of life therefore being a certain Fire certain it is that the same cannot subsist or endure one moment of time unless it be perpetually maintained or fed with some
convenient 〈◊〉 〈◊〉 〈◊〉 〈◊〉 〈◊〉 succendiculum or Fewell which is thereby indesinently consumed for all Fire whatever that Elementary Fire which the Aristotelians conceive to be so pure as to need no pabulum or aliment being a meer Chimera doth conserve it selfe onely by the destruction of the matter in which it is generated So that indeed we have one and the same Cause both of our Life and of our Death or to speak more properly our Life is nothing but a continuall Death and we live because we dye For so long we live as this Vestall-Fire is kept glowing and shining in the sacrary of our heart and when the same is put out either by suffocation or want of sustenance life is instantly extinguished And perhaps it was to this Euripides alluded when he said Quis novit autem an vivere hoc sit emori An emori hoc sit quod vocamus â—ivere The Matter or substance consumed we conceive to be the Fluid parts of the body The Matter thereby consumed not the substance of the solid parts but the Fluid and cheifly the Blood and Spirits especially the Blood and spirits which having in them something of the nature of oyle or sulphur are the principal succendiculum or Fewell of the vital Flame and not the substance of the solid parts at least not in that large quantity vulgarly supposed For experience teacheth that sundry Animals as Bears Dormice Swallows c. do sleep all the winter long without receiving any supply of aliment and yet have all their solid parts of their bodies as large and firme when they awake again in the spring as when they first betook themselves to their dens or dormitories nay if we may credit Naturall Historians they grow fat in this time of their long abstinence Which doubtlesse is to be ascribed to this that the flame in their heart all that time being but gently moved and burning quietly doth consume very little of their spirits and blood In like manner we have examples of Leucophlegmatique virgins who upon a decay of Appetite have â—ndured long abstinence from all sorts of aliment and yet have not been emaciated in any proportion to their so diuturn fasting So that it is more than probable that there is not so rapid and profuse an exhaustion of the substance of the solid parts by the activity of the vital Heat as Physicians have vulgarly imagined In many diseases we confesse the habit of the body is much extenuated but that is only a subsidence or flacâ—idity of the Musculous flesh caused by the defect of spirits and blood by which the same was formerly distended and plumpt up not by any deperdition of the substance of the solid parts Lastly as for the Manner how the blood and spirits and The Manner how they are consumed is by continual Dispersion if you please to have it so also the less fixed and more easily exsoluble particles of the solid parts are absumed by the vital Heat it may be familiarly explicated by the example of the oyle consumed by the flame of a Lamp Flame as reason defineth it is a substance luminous and heating consisting in a perpetuall Fieri i. e an indesinent accension of the particles of its pabulum or combustible matter and perishing as fast as it is generated so that fire is made fire and again ceaseth to be fire in every the shortest moment of time and when there remain no more particles in the 〈◊〉 matter wherein iâ— mâ—y generate it seâ—fe anew it instantly perisheth Continuall Dispâ—rsion therefore being the proper effect of Fire the matter or sewell whereon it subsisteth cannot but be in perpetuall flux or decay In like manner that we may accommodate this to our present purpose the Lamp of life consisting in a continuall accension of vital spirits in the blood as that passeth through the heart those vital spirits transmitted by the arteries to the habit of the body no sooner arrive there but as they warme and vivifie the parts so do they immediatly fly away and are dispersed into the air carrying with them many aqueous parts and perhaps some sulphureous exhalations Moreover there being in all parts of the body certain sweet and balsamicall or conserving spirits as it were affixed unto and concorporated with them the vital spirits meeting with and acting upon them do by little and little render them volatile and at length wholly disperse them whereupon the minute particles in which they did reside become mortified as excrements of the body are ejected together with the exhalations of the blood And this is as we conceive the reason and manner of the depredation made upon the parts by the vital heat If your Curiosity extend yet further and you would enquire into the Quantity of Aliment daily devoured by this Biolychnium And in what Quality or Lamp of life the acute Sanctorius will tell you that according to his statique observations men commonly avoid as much by insensible perspiration in one day as by stool in fifteen But so great is the variety among men in respect of temperament diet age exercise the season of the year and other circumstances as that no definite compute can be made of this dispence And yet we may be certain that the proportion of blood and spirits daily exhausted by the flame burning within us is very great and that the most part of the matter of occult transpirations is the vital spirits which are continually generated and continually dispersed From the consideration of the Causes and Reason of the Deperdition of substance in Animals we may opportunely progresse to an enquiry into the Causes and Manner of the Renovation or Restauration of it by Nutrition The Efficient principle or 〈◊〉 〈◊〉 〈◊〉 〈◊〉 〈◊〉 as Aristotle calls it certainly The Efficient Principle of the Renovation of the parts what is the very same with the Generant or Formative because as we said afore Generation cannot be without Augmentation and Augmentation is Nutrition Not that we are of their judgment who hold that Life and Nutrition are different not in re but onely in ratione for the Embryo is nourished before the Empsychosts but that we conceive that Life doth consist in a continuall accension of vital spirits out of the blood which is the pabulum of the Lamp of life and that Nutrition doth consist in the restauration of what is consumed by an Apposition and Assimilation of consimilar or congenerous matter The Material or Constitutive principle we take to be a certain sweet And what the Material mild and balfamical Liquor analogous to the white of an egge out of which the chicken is formed For since all Animals are nourished with the same out of which they were at first fabricated according to that common Axiom iisdem nutrimur ex quibus constamus and that of Aristotle eadem materia est ex qua augetur animal ex qua constituitur primùm and since they have
Accessary Organical these observations being undeniable we may safely assert that the Vital Spirit in the Seminal matter being excited and assisted by the external heat of the Hen sitting upon the Egge and by degrees becoming active and infusing heat into the vital Liquor wherein it doth reside doth thereupon in processe of time induce the colour of bloud and that only by means of its vital Heat and Motion and that no other part is to be reputed for Principal Agent in the work of Sanguification Neverthelesse we do not hereby exclude Concurrent extrinsecal Agents or Causes but into that account readily admit the Hen whose warmth at first both excited and assisted the Vital Spirit in the work of Sanguification and the substance of the Heart it self which afterward conduceth in some sort to the same Nor do we repudiate Accessory Organical Causes as the Fabrick of the Heart the Arteries and Veins all which are inservient to the continual motion of the bloud Only we affirme that the Vital spirit by reason of its Heat and Motion hath a just right to the dignity of Principal Agent in making of Blood We say The Conversion of the Colliquamenâ—um into Bloud by the heat and motion of the Vitall Spirit illustrated by sundry analogous Experiments and Observations By reason of its Heat and motion For that Colours frequently are advanced from a white or pale to several kinds of Red meerly by Heat and Motion is demonstrable by sundry easie and familiar Experiments Our Confectioners well know that long boyling of Quinces and other Fruits doth give them a ruddy colour So likewise Fruits baked in an oven are more inclined to redness than while they were raw The same is true also even of Flesh and Bread which by baking or rosting acquire redness in their superficial parts and some Chymists affirme that a Tincture of Bread will assume a certain degree of redness after long digestion This is not we acknowledge common to all Liquors especially simple ones for simple waters and such as are destilled suffer little or no change of colour upon decoction though long But generally all Compound Liquors especially if they contain any Nutritive juice in competent quantity and have besides any touch of salt or Acid spirits in them are observed to acquire a sanguine tincture by decoction Upon which fertile hint as we conjecture that highly Learned Industrious in Apolog. pro circulatione sanguinis advers Parisan p. 119. and Acute Person Dr. ENT seems to have grounded that ingenious opinion of his that the Redness of the Blood ariseth ex Aciditate spiritus vitalis salinei from the Acidity of the vital spirits having their original from a certain seminal salt However we have good reason to perswade our selves that all vital Liquors i. e such wherein the vital spirits of Animals do reside are apt to acquire more or less of redness provided they obtain sufficient Heat and agitation or strife in their motions This is evident in all Sanguineous Animals in which the Chyle is first white and after changeth into bloud And as for Exsanguious Animals they also give some testimony of this truth as may be instanced in Oysters in which bloud is frequently found and yet without a prodigy in summâ—r time by reason their vital Heat seems then to be augmented and in winter when their Heat is again lessened below what is requisite to induce redness their vital juice is alwayes whitish To return to sanguineous Animals as they are generally hotter of constitution than Exsanguious so are their Sanguine parts alwayes hotter than their pale and white parts In like manner in cold diseases as the Green sickness Cachexy Dropsy and in all Phlegmatique constitutions the bloud is paler than in hot diseases and constitutions Again the venal blood as it loseth the heat which it had acquired in passing through the heart and arteries so doth it proportionately by little and little lose that florid and deep scarlet dye that it had in the heart and arteries For blood let forth of a vein appears blewish and comes short of that lively fresh scarlet that is observed in bloud effluxed from an Artery All which clearly shew by whose efficiency it is that the vital juice in Sanguineous Animals is excocted into Bloud and what conserves the same in its primitive purity and lustre viz. the vital spirit continually renewed in and enlivening the blood for that being once extinguished how soon doth the bloud degenerate into Cruor and lose its fresh scarlet tincture Having thus investigated what that is That the same Agent which maketh the first blood in an Embryo doth make it ever after in an Animal dâ—ring life which makes the First Bloud in an Embryo by converting the vital Liquor from a white into a purple Nectar we cannot be long in exploring what that is which in Animals maketh bloud all the life after by converting the Chyle likewise from a white into a red liquor It is an infallible rule you know that the identity of Effects dependeth upon the identity of Causes because an effect is not supposed to be untill it hath obtained existence from its proper causes and at the same time the causes give that existence they cannot but give also the identity belonging to it All which is imported in that common Axiome Idem quà idem semper facit idem For though Free and Arbitrary Causes may act at liberty and by varying the manner of their operating vary also their effects yet Natural ones are bound up to a determinate mode of energie and must as long as they continue the same act after one and the same way and so produce invariably the same effects Forasmuch therefore as the Efficient of the First Blood is an Agent Natural and not Arbitrary if it continue the same in an Animal while the Animal lives it must of necessity continue the same operation That it doth continue the very same during life is most certain because it is the Principle of life nor can life subsist for so much as one moment without it Nor doth this Efficient of Bloud only persist the same in the body that it was at the first conception but growes every day more vigorous potent and fit for the work untill the Animal hath attained to the flower of his age and to imagine that an Agent Natural such as the Vital Spirit should at any time become idle intermit its operation and not exercise all its forces is grossely absurd Conclude we therefore that the Vital Spirit as it is the Efficient Cause of Sanguification in the Embryo from the first Conception so is it constantly Author of the same work untill the Animal dieth OF THE VSES OF THE BLOOD Exercitation the Fifth IT followeth now Artâ—cle 1. that we enquire To what End Nature hath consigned so continuall a province That the Bloud is not the General Nourishment of the body Because as this of Sanguification to that
in a moment and the blood may be observed to flow in its course very swiftly so soon as the ligature is removed But how swiftly is not easily determined there being so great variety of Causes Natural Non-naturall and Preternatural that accelerate or retard the flux of the blood only thus may be inferred from the precedent compute of the number of Pulses and the quantity of blood expelled out of the left ventricle of the heart in every systole That the whole mass of blood doth pass through the heart once in an hour or two at most Yet is not the current of blood neer so swift in its channels while they are whole as when one of them vein or artery is cut because in that case the blood streams forth into the free and easily-yielding aer without any resistance but being confined in its vessels it is forced to distend them and drive-on the foregoing current 4 As swift in the Veines as in the Arteries For Of equall velocity in the Arteries and veins though the impulse be more vehement in the atteries as being continued to the heart than in the veins and therefore it might seem reasonable at first consideration that the motion should be proportionately more swift in the arteries yet considering that the Arteries are still smaller and smaller toward their extremities that the flux of the blood must needs be more and more retarded as it approacheth those extremities and on the contrary that the veins grow wider and wider from their extremities to the centre of the body and so the blood hath still larger and larger spaces to run through in its return to the heart we may safely conclude conjecturally that the velocity of the motion is as great in the veins as in the arteries This is also confirmed by sense for the Vena Cava in all that tract from the Liver to the subclavian division may be observed to beat as often as the Great Artery and so must import blood into the right Ventricle as fast as the Aorta doth export it from the left Which doubtless is the reason why the Vena Cava hath fleshy Fibres upon it when it approacheth the heart Nevertheless we conceive the motion to be swifter in the Arteries when the heart contracting it self doth impell the blood into and through them than when dilating it self again it doth intermit that its impulse Which is true likewise of the blood in the veins as may be sometimes observed in Phlebotomy when the ligature is not so streight as to cause much distension of the vein in which the incision is made for in that case the blood wil flow forth more swiftly every time the heart is contracted And these are the Conditions of this admirable motion of the blood Lastly concerning the CAUSE of this motion it is necessary that the blood be moved either by it self or by some other principle and if it be the Author of its own motion then that must be in respect of either an inherent motive-Faculty or of its Ebullition or of its Rarefaction or of its Quantity whereby the Ventricles of the heart are distended and so irritated as to discharge the same by contracting themselves If the motion be derived from an External principle then it must be referred either to Attraction or to Vection or to Pulsion Let us therefore see which of all these may be the most likely cause of the Motion of the blood First That the bloud is not the cause of its own Motion The blood not the cause of its owne motion in respect of any motive Faculty inherent in it ratione insitae sibi Facultatis by reason of any inherent Faculty may be inferred from hence that in bloud effused out of its vessels into the body or any other receiver no motion at all can be observed and it is hard to conceive that it should be so corrupted in a moment as wholly to lose a faculty essential to it Dr. Harvey we confess affirmeth that he observed a certain obscure motion of the blood in the right ear of the Heart where He supposeth the motion of the Heart first to begin and last to end after the Ear had ceased to move but we refer that to the Mication of the blood from the Vital Spirits not yet wholly extinguished Secondly That it is not the Author of its own motion Nor in respect of its Ebullition ratione Ebullitionis which Arist. calls 〈◊〉 〈◊〉 〈◊〉 〈◊〉 〈◊〉 is manifest from these subsequent reasons 1 No Ebullition can be constantly equall or of the same tenour but the Pulse of the heart and so the motion of the bloud is in temperate and healthy men for the most part equall 2 As the Ebullition is greater so would the pulse but in burning Fevers the Ebullition is extream great by reason of the great intension of the heat and yet the pulse is frequently small and weak as also in the beginning of putrid Fevers as Galen long since remarked 3 The blood suffers no ebullition as it passeth through the heart For if in the dissection of a living Animal you make an incision either into the left Ventricle of the heart or into the Great Artery neer it you shall perceive the blood flowing out at the hole to be pure and such as before it came into the heart not frothy boyling or rarefied and to continue such as at its first efflux yea more if you receive the blood issuing from an incision of the Vena Cava in one sawcer and that issuing from the left Ventricle in another you shall not be able to discern any difference betwixt the one and the other either soon or a good while after An invincible argument against the Ebullition of the blood first imagined by Aristotle and since defended by many great men his sectators 4 The plunging an arme or legg into cold water would suppress the Ebullition and consequently the motion of the blood For if you apply a close ligature to a mans arme and then immerge the same into cold water or Snow upon solution of the ligature he shall find the blood returning to his heart with so great a sense of cold as very much to offend him Which cold arising to the bloud from its being long detained in the extremities of the arme bound Dr. Harvey will have to be the cause of swooning immediately after blood-letting in many men the heart receiving injury from that acquired cold Thirdly Not ratione Rarefactionis because 1 in living dissections Nor of its Rarefaction where the heart yet continueth its motion no man ever hath or can observe any such thing as rarefied blood to flow from either the left ventricle or the Great Artery if cut but pure and such as is from the Ears let down into the ventrices 2 The Heart it self when cut in pieces or wounded may be observed to beat yet not from any rarefaction of the blood for then it hath no blood in
either of its Ventricles or Ears 3 It hath been observed in Doggs that after the point of the heart hath been cut off and the remainder turn'd upside down though the ventricles could not be halfe full the blood hath yet been squirted forth at the top even to the distance of three or four feet which were impossible in case the rarefaction of the blood were the cause of its motion 4 The musculous flesh of the heart is more firme and strong than to be subject to inflation and detumescence meerly from the rarefaction of the blood It must be a more forceible Agent that moves that great and weighty machine of the heart 5 If the blood were so much rarefied in the Ventricles then certainly ought the orifices of the Vena Arteriosa and Aorta to have been much larger because the blood would have required more room for its egress than for its ingress 6 The motion of the heart and of its valves would be confused for the Diastole of this and opening of them would happen at the same time and consequently the valves would become useless both which are repugnant to experience Besides the opening and shutting of the valves would be co-incident with the Systole of the Great Artery 7 That the blood should be rarefied in the heart and in a moment again refrigerated in the arteries is contrary both to sense and reason and if the rarefaction should so soon cease why is it at all It remains therefore that if the blood be the efficient of its own motion it must be so only ratione Quantitatis But of its Quantity distending the Ventricles of the heart by reason of its quantity filling and distending the Ventricles of the heart and irritating them to discharge it by contracting or shurting themselves For the heart being as it were burdened with the blood distending its cavities doth contract its Fibers and so its Ventricles to vindicate it self from that oppression no otherwise than the stomach guts bladder womb c. which being extended by meat chyle wind urine and the infant drive themselves together by the help of their Fibers and so exclude that was burdensome to them And thus is it probable that the Heart is continually moved by the blood like a Mill perpetually agitated by a stream of water which stream being cut off the motion instantly ceaseth This may be credited upon the force of this one experiment if the Vena Cava be intercepted by a ligature so soon as the heart hath disburdened it self of what blood it hath received from thence it instantly remitteth its motion and upon letting in the stream again by removing the ligature it as suddenly recovers it Than which there cannot be a more convincing argument that the quantity of the blood flowing into the ventricles is a cause of the motion of the heart and so of its own motion We say A Cause not the only cause for we shall soon find another efficient as necessary and immediate Thâ— blood not moved by Attraction to the motion as the blood in the respect mentioned That nothing doth Attract the blood either to or from the heart is evident from hence that in Nature there is no such thing as the motion of a body by attraction as hath been by solid and irrefutable arguments proved by that heroical wit Apolog pro circulat sang advers Parisan â—pag 27. ad 49. and most accomplish't Scholar Dr. Ent and also by our selves in the beginning of our discourse of Occult Qualities whither for expedition sake we referr the unsatisfied Nor is it moved per modum Vectionis by way of Carriage Nor by Vection For nothing can be imagined to carry along the blood in its course but the spirits and those would in respect of their Levity carry it only upward but we see that the blood is moved also downward and ad latera It remains therefore that the blood is moved in round But by Impulsion of the heart endowed with a Pulsifick Faculty per modum Pulsionis by impulsion or protrusion and the Impellent can be no other but the Heart contracting it self and so expelling the blood contained in its ventricles into the Great Artery from whence it is urged or pressed forwards into the smaller arteries by the succeeding current We conceive therefore that the Heart is endowed with a certain Motive-virtue inhaerent and essentiall called the Pulsifick Faculty which is conjoyned as a concomitant cause with the blood it self in giving it a due motion whether it be that this Faculty doth regulate the influx and efflux of the blood which would otherwise be irregular or that of it self it produceth the motion which cannot be afterward continued in case the flux of the blood be once interrupted That this Faculty is necessary may be inferred from these Reasons 1 As the Pulse so the influx of the bloud would be alwayes unequall unless it were regulated by a Faculty 2 When the bloud is moved vehemently in Fevers by the intense heat agitating and urging it and in men at the point of death propter extremos naturae conatus by reason of Natures agony and last efforts yet is the pulse more weak and low than at other times because the Pulsifick Faculty is either much opprest or much weakned On the other side though the Faculty continue strong yet is the influx of the bloud much diminished after large haemorrhages or upon great obstructions of the capillary arteries and veins in the habit of the body Which consideration seems to us sufficient to import the necessity of conjoyning a Pulsifick Faculty with the quantity of the blood distending and so molesting the Heart as a double proxime cause of the bloods motion 3 Though the heart be cut in pieces yet will each piece have a kind of weak pulsation as long as it continues warme which in all probability is to be ascribed to the Faculty implanted in all its Fibres and not yet utterly destroyed 4 It would be derogatory to the majesty of that Prince of all the parts the Heart to be moved by the violent impulse of an external principle and it self conduce nothing thereunto Notwithstanding these reasons alleaged we dare not set up our rest in this doctrine of the Ancients concerning a Pulsifick Faculty implanted in the heart only we have recited it as the most probable Conjecture of all others touching this abstruse Argument the proxime Cause of the Motion of the blood Nor shall we adhere to it longer than untill we shall be so happy as to meet with a more satisfactory solution of that admirable Phaenomenon In the mean time Modesty commands us to declare that we find this Knot to be too hard and intricate for the teeth of our weak understanding And well may we make this acknowledgment when the subtle Frucastorius after a long scrutiny into the same subject was at length forced to desist with Motum cordis soli Deo cognitum
esse opinor and that even Harvey himself professeth that He found it rem arduam difficultatibus plenam We remember the modest sayings of two great Men upon the like difficulties the one of Galen Quo pacto haec fiaut si scrutaberis lib. 15. de usu part cap. 1. exercit 307. num 29. convineeris te non intelligere neque tuam imbecissitatem neque Opificis tui potentiam the other of Scaliger Quandam humanae sapientiae partem esse quaedam aequo animo nescire velle veram sapientiam nolle nimiùm sapere And we think we need say no more in excuse of this our professed ignorance Besides this Two-fold Proxime Cause there is also another Remote one The Fabrique of the heart a remote cause of the motion of the blood viz. the Peculiar Conformation or Fabrique of the Heart and its vessells And among all the parts in this curiously framed Machine of the heart those which are most official or instrumental to the motion are the Fibers and fleshy columnes which serve not so much to the strength of the heart as to the motion of it For in the Systole all the Fibers both small and great as well those in the inside of the ventricles as those in the Septum or partition-wall betwixt them like an artificial network made in the forme of a purse being contracted or drawn together the blood contained in the ventricles must necessarily be expelled or pressed out of them The Motion of the heart which is called the Pulse The Motion of the Heart described as consisting of two◠contrary motions and a Respite betwixt them as being continual and made partly by the influx of the bloud partly by the Pulsifick Faculty residing in the heart it self doth consist of 3 things the Systole the Diastole and the Perisystole all which are to be explained by their proper Causes according as ocular Inspection and Reason doth dictate them to the understanding 1 The Systole being the proper and natural motion of the heart is the Contraction or drawing together of the heart to a narrower compass that so the blood contained in the right ventricle may be expelled through the vena arteriosa into the Lungs and that contained in the left may be expelled into the Great Artery and so into all parts of the body 2 The Diastole being a motion only Accidentary to the heart is a Dilatation or opening of the heart that the blood may flow into the right ventricle out of the vena Cava and into the left out of the Arteria Venosa 3 The Perisystole is a certain quiet or short respite betwixt the Contraction and Dilatation of the heart during the small time that the blood is entering into or issuing out of the ventricles In healthy men this pause is so short as not to be distinguished from either of the two contrary motions but sufficiently manifest in men at the point of death It is also double there being one respite betwixt the Systole and Diastole and another betwixt the Diastole and Systole And this is the natural state of the Heart As to the Figure or Forme of the heart in those contrary motions And the Figure of it in each from the dissection of Animals alive from the commodity of its motion and quiet and from the position of its Fibers and other parts we have learned it to be thus In the Systole it may be observed that 1 the point of the heart is drawn upward toward the Basis of it in order to the expulsion of the blood the length of it being diminished and bredth proportionately encreased because the basis is immoveable in respect of the cone which is fastned neither to nor by any vessells 2 The inner walls or sides toward the ribbs are brought neerer each to other because they are constringed and made narrower as may be perceived by putting a finger into either of the ventricles at the time of their contraction but the outward becoming tumid seem to be enlarged in latitude from the contraction of all parts inflated in the tension or stretching 3 The fore part of the heart is lifted up towards the sternum and chiefly neer the base for where the pulse is felt there doth the heart strike the breast with its base that part being lifted up and brought neer to the sternon and at the same time not in the Diastole is the heart vigorated and the arteries dilated and filled and the pulses are felt both in the breast and wrist the Diastole of the Arteries being coincident with the Systole of the heart But the Pulse is more plainly felt in the left side because there is the origine and orifice of the Aorta 4 The whole heart becomes tense and hard and contracted to a smaller bulk as is manifest both to the sight and to the touch 5 The heart appears white especially in imperfect Animals such as Serpents Frogs Eeles c. by reason of the expulsion of the blood in the Systole In the Perisystole when the heart is soft lux and in its proper state 1 the cone recedeth from the base and in some Animals the base also recedeth from the cone 2 The lateral parts both the interior and exterior are tended toward the ribbs 3 The anterior face of the heart sinks down and the posterior is depressed especially neer the orifice of the great Artery In the Diastole which beginns in the middle of the Dilatation and ends in the middle of the Contraction 1 the upper side is lifted up and distended by the blood falling into the ventricles out of the Vena cava and Arteria venosa the swelling sensibly beginning at the base and progressing to the cone But the base doth not them strike the breast because the Arteries at that instant are contracted and the heart ceaseth from expulsion of the blood 2 The heart is flaccid and soft because it is then only passive in receiving the blood 3 The sides become extense and the cavities enlarged and therefore if you put your finger into the heart during the Diastole you shall perceive no constriction as in the Systole 4 The heart appears red because of the tenuity of its walls and their repletion with blood 5 The Cone receding from the base makes the heart longer that it may be more capable of blood And thus doth the heart vary its Figure in each of these three positions OF THE DEPURATION OF THE BLOOD Exercitation the Seventh Of the Depuration of the BLOOD FRom the Circulation of the blood we as Nature advance to the DEPURATION or Defecation of it from its unprofitable or excrementitious parts And here we are to consider 1 the Generation 2 The severall sorts of Excrements generated in and to be separated from the blood 3 The parts in which and 4 The Manner how they are separated Concerning the FIRST we observe that the blood being a heterogeneous liquor The Genealogy of the Excrements consisting of
humors which passeth through the habit of the body but that it should be discharged in thick clouds of exhalations in every systole of the arteries this is plainly impossible because at that time the coats of the arteries are constringed and compressed and there might be an easier egress for them in the Diastoles when the cavities of the arteries are dilated So that among these many Arguments there is not one but doth clearly detect and throughly refute the Error of those Men who have confounded the Uses of the Arteries and Lungs of Pulsation and Respiration This capital Error eschewed we may the more safely progress to explicate the nature of Respiration as a thing in sundry particulars distinct from Pulsation though perchance instituted by Nature as in some sort subservient to the vital Faculty And that we may proceed methodically it is requisite we consider 1 the Manner of Respiration 2 the Efficient Cause and 3 the Final Cause or Use of it Concerning the First Respiration 〈◊〉 〈◊〉 〈◊〉 〈◊〉 〈◊〉 is an Action of the Breast and Lungs consisting of two contrary motions alternately successive or of two parts Respiration described viz. 1 Inspiration 〈◊〉 〈◊〉 〈◊〉 〈◊〉 〈◊〉 in which the ambient aer is impelled into the Lungs and chest at that time dilated 2 Exspiration 〈◊〉 〈◊〉 〈◊〉 〈◊〉 〈◊〉 wherein the same aer is again expelled out of the Lungs and Chest those parts spontaneously contracting or compressing themselves Concerning the Inspiration the grand Question is Whether the Breast and Lungs are dilated because they are filled and distended with the aer as a bladder is distended by aer blown into it or Whether they receive in the aer because they are dilated as a pair of Bellowes is filled with aer only because it is dilated or opened by external force To solve this difficulty in a word we say the Breast is first dilated The Efficient Cause of Inspiration is the Dilatation of the Breast impellinâ— the ambient 〈◊〉 into the Lungs before it can be filled with aer and that Dilatation or heaving up of the brest is the cause of the airs rushing in at the mouth and nostrills down the Aspera Arteria or wind-pipe into the Lungs For since there is no vacuity at least no Coacervate one in the world no body can be moved out of its place but the next body must give way and the next to that likewise give back till such a part of space as is adequate to the dimensions of the body first moved be made to receive it and the space which it abandoned be again fully possessed by another body succeeding into it we say since this is necessary it is manifest that the aer next incumbent on or contiguous unto the Breast and Abdomen being urged and impelled by the breast while that is dilated or expanded is forced to give back and press the aer next to it which likewise drives back the next aer untill at length the compressed aer wanting room to retreat into and endeavouring to avoid further compression its own Elater ingaging it thereto rusheth into the breast and there possesseth that room or part of space which was left by the breast when it began its motion So that so much aer is impelled into the breast as is driven out of its place by the superfice or outside of the breast during its expansion or dilatation As for the Attraction of Aer into the Lungs ad fugam vacui it is a meer dream as well because all motion is by Impulsion as because Nature doth not abhor vacuity primario or ex se In Physiolog-Epiarro-Gassendo-Charltoniae lâ—b 1. cap. 5 pag. 40. but only ex Accidente or in respect of the confluxibility of the insensible particles of Fluid bodyes as we have elsewhere amply demonstrated And if there were any Cause to be found that might blow the aer into the breast as it is blown into a bladder so as to distend it or at least if the aer could be conceived to enter into the breast spontaneously or of its own accord without impulsion so as to force or heave up the same then indeed would the Comparison betwixt the dilatation of the breast and that of a Bladder by wind blown violently into it hold good and we should not need to seek further But there being no such insufflating cause assignable and it being ridiculous to imagine the aer should spontaneously move it self so as to flow uncompelled into the cavity of the Chest as is manifest not only in dead men into whose breasts though their mouths and nostrils are wide open the aer doth not croud it self but also in living men when they at their pleasure keep their breasts compressed or hold their breath as the vulgar phrase is it seemes much more reasonable to explain the reason of Inspiration by that other similitude of the flux of aer into a pair of Bellows there being no other difference betwixt the repletion of the Chest and the repletion of a pair of Bellows with aer but only this that the Bellowes are opened by an externall force and the Chest is dilated by an internal And as for the Exspiration that is evidently from the compression of the breast and Lungs And the cause of Expiration is only the spontanâ—ous contraction of the Breast which is the naturall motion of Restitution For the Dilatation being an action whereby the parts of the Chest are distended into a position more large than is natural to them the Contraction seemes to be nothing else but a certain falling down or relaxation of the parts distended whereby they spontaneously return to their natural position and such as they hold in a dead body and this not onely in the Lungs but also in the Diaphragme which in dead bodyes is not extended downward to the stomach and guts as in inspiration but riseth upward toward the Lungs and Heart But if it be here demanded whether Inspiration or Exspiration be first we answer that it is necessary that the aer should be first inspired before it can be exspired and every ANIMAL dyes Exspirando in Exspiration Concerning the Second The Enquiry is By what cause the breast and Lungs are so dilated The Dilatation of the Breast and Lungs not from any Motive Faculty congeâ—iall to the Lungs as we have asserted And this indeed is a Difficulty not so soon resolved as proposed for besides the obscurity of the thing it self we find our selves benighted with the various opinions of Authors Some wil have that the Lungs are endowed with a certain Faculty of Dilâ—ting themselves and so elevating the whole breast as the Heart hath a pulsifick faculty by whose virtue the ventricles contract themselves in each Systole And hereupon was it that Aristotle the Author of this opinion doth compare the Lungs to a pair of Bellowes as if they did of themselves first attract the aer and then emit it again But though it be
caused only by the pressure of the thing sucked by the Aer impelled in round as we lately expressed in the cause of the influx of the aer into the Lungs in Inspiration certainly without the help of aer the Foetus cannot possibly suck in his nourishment To this Reason and we think it a weighty one may be added 1 the Authority of the Divine old Man lib de Natur. pueri who in most expresse termes saith 〈◊〉 〈◊〉 〈◊〉 〈◊〉 〈◊〉 viz. Foetibus 〈◊〉 〈◊〉 〈◊〉 〈◊〉 〈◊〉 Puer ab â—lto respirat ore naribus 2 that Chickens breathe in their shells through which the aer hath a more difficult passage than through the secundines and Fishes in the water And as the Chicken pipes within the shell not yet broken so hath it been observed and recorded by sundry learned and authentical Writers that Infants have been heard to cry in their Mothers wombs which were impossible unlesse they enjoyed the benefit of Respiration 3 The posture of the Child in the womb seems to assert the same For as there is an ample space betwixt the coats of the Secundines and the Child to the end that a sufficient magazine of milk for his sustenance might be stored up and conserved therein so is not that whole space filled up with that Liquor but in the upper part there remains so much space unpossessed by any thing but Aer as is sufficient for so gentle a Respiration as the Infant hath need of just as in the blunter end of an Egge we perceive a certain empty space after the Hen hath sate upon it And lest the Chorion should at any time be corrugated or shrieveled up together and so streighten or compresse either the Liquor or the Infant Nature hath affixed the same to the Placentae Uterina to the end that adhering to the bottome or upper part of the womb it might hang fast as an Apple hangs by its stem or as our Globes of Glass are hung up by strings to the Seeling of a room So that the Chorion thus adhaering to the Placenta Vterina which is fastned to the bottome of the womb and the Amnios in like manner adhering to the Châ—rion in the same upper part and the lower part of each membrane being depressed by the weight of the Infant and of the Humors contained in them it thence comes to pass that this Natural Machine both of the Child and Membranes though at first it were perfectly round as the yolk of an Egge is afterward made of an oval figure For though the Foetus sitting incurved or bowed forward as much as possible doth keep himself in a round figure because of taking up the lesse room for he sits with his leggs crossed his heels drawn up to his buttocks his elbowes resting on his knees one hand held up close to his ear the other to his cheek for the more firme and easie sustentation of his head yet in that situation he hath need of a Mansion of an Oval Figure that swimming in liquor he might keep his head above water and at his pleasure take in his nourishment by his mouth and also inspire the temperate aer surrounding his head in the void space of the Secundines according to the opinion of Hippocrates newly recited 4 Nor is the ingress of Aer into the womb impossible For albeit the mouth of the womb in pregnant women be shut up so as to exclude ones finger or as others will have it a small probe yet is it not so sealed or luted up as to exclude the Aer as may be inferred from hence that many Femals have superfoeâ—ations and more women especially in this our moist Iland are troubled with the Fluor albus all the time of their Gravidation neither of which could be unless the Cervix Uteri were pervious For if there may be an ingress for the seed of the male after a former Conception and as free an egress for the matter of the Fluor albus all the time of the gestation of the Foetus then doubtless Hâc etiam penetret per cuncta meabilis Aer These Reasons duely perpended though it seems a Paradox yet is it no light and vain Conjecture that the Foetus doth respire in the womb at least gently and placidly and in proportion to the pulsation of his heart which being calmly and softly moved as are the hearts of Dormice and other Animals that sleep all the winter hath but a small necessity of Aer However reflecting upon the singular fabrique of the vessels in the heart of an Infant unborn which all Anatomists conceive made by the providence of Nature only in defect of Respiration as we proposed it a Problem so we leave it to the consideration of wiser heads Here also we may opportunely touch upon the Motion of the Brain The Motion of the Brain dependent not upon Respiration but upon the Pulsation of the Artsries which consisting as that of the Lungs of a Diastole and Systole many have referred to the Inspiration and Exspiration of Aer as if the Brain were dilated for the admission of Aer and contracted again for the exclusion of it Whereas indeed this Motion doth not belong 1 to the substance of the Brain for that being very soft tender and delicate seems uncapable of any such dilatation and compression Nor 2 to the Membranes investing the braine because as Riolan observed in the head of a Sheep the diastole and systole of the brain hath been continued long after part of the skull and Membrans also were cut off But only to the Arteries 1 because the Motion of the brain is exactly coincident and concordant with that of the Arteries as may be discerned by the touch in the heads of Infants new born and in large wounds of the skull 2 Because the chief Pulsation is in the upper part of the Dura Mater which is conspersed with store of Arteries ascending from the Plexus Arteriosus Mirabilis and disseminating themselves upon it 3 Because Waleus observed that in some persons who fell into extrem agonies and swooning fits upon great fractures of the skull the motion of the brain ceased and was begun again as their Pulses recovered 4 Of what Use should the inspired Aer be to the Brain For Refrigeration It cannot be the temper of the brain being such as seems to require rather Caâ—efaction And as for the Generation of Animal spirits Dr. Harvey hath upon good reasons made it doubtfull whether there be any such or not and if there be certainly they consist only of the purest and most subtile parts of the blood and not of Aer by the admistion of which they must needs become more crass and unfit for those noble uses Encheirid Anatom lib. 4. c. 2. to which they are consigned And therefore Riolan said well Nec spiritibus permiscetur Aer in Cerebro quia debent esse subtilissimâ— alioquin permixtione aeris crâ—ssiores evaderent nec tam celeriter in
and transportation of it to the principle of its Dispensation For it seems the Nutritive juice is first imbibed by the small branches of the Nerves of the sixth Conjugation and those though very many being yet too few for the transportation of so large a quantity of that rich Nectar as is required to the nourishment of the whole body Nature hath conjoyned with them a vast number of other Nerves as Auxiliaries in that great work So that it is not dissentaneous to reason to conceive that by these Nerves and their Coadjutors the Succus Nutritius is carried to the brain and Spinal Marrow thence to be afterward derived to all parts for their sustenance Concerning the Fourth What is the Motion of the same in the Nervs viz. not continual nor vehement but by intervalls and slow and gentle to the brain in sleep and from it to the members after sleep viz. the Motion of the Succus Nutritius in the Nerves though it be a problem of great obscurity yet doth the light let in at the postern gate of Conjecture discover thus much that it is not continual as that of the blood in the Arteries and veins but by intervals nor violent but slow and gentle as the defect of any swelling on either side of a Nerve bound about in a living creature doth sufficiently manifest Nor is it unreasonable to conceive that in a short time after each meal immediately upon the distribution of the Chyle through the Venae Lacteae the Succus Nutritius is imbibed by the Nerves of the sixth Conjugation and by them carried to the brain and Spinal Marrow Which perhaps is the reason why alwayes within an hour or two after meat we perceive a certain dulness in our heads together with an indisposition to motion and a propensity to sleep according to that proverb When the belly is full the bones would be at rest and soon after all those vanish again and we perceive our selves more light strong and active than before our refection because then the nourishment begins to be diffused from the principle of Dispensation of outwards into the limbs and other parts of the body And with this opinion agrees that observation of Bartholinus that the Lympheducts are more plainly discernable about five or six hours after meat than at other times as being at that time more filled with the superfluities of the Succus Nutritius Nor is it improbable that the Brain and Spinal Marrow are chiefly nourished in sleep and that then the Nutritive Liquor is usually carried to them relaxing them with its sweet and mild vapours and so both inducing and prolonging sleep From whence perhaps it comes that after long sleeps we perceive our brains to be oppressed and beclouded with vapours our senses dull and the motive-faculty enervated Besides in sleep all motions of humors flowing to the patts by the Nerves seem to be suspended and yet the Circulation of the blood is certainly at that time more free and quick than while we wake So that It cannot be thought the cause of that cessation but the Nerves onely which intermit their office of distributing the Succus Nutritius during sleep And all this will appear more reasonable if we reflect upon the flux of humors in the Nerves immediately after sleep For then the Brain and Spinal Marrow re-contract themselves and become more tense so that the Nutritive liquor is from thence transmitted partly to the members to be nourished and partly to the Glandules as well such as serve for the excretion of its absolute Excrement as those that serve for the reduction of its relative viz. it s acrimonious parts that are returned into the blood for the reason formerly mentioned And concerning the Last And what the Causes of that Motion viz. the motions of the Diaphragme of the Brain and of the Nerves themselves viz. the Causes of this Motion of the Succus Nutritius we may be allowed to conceive at least untill Time shall have dispelled that Obscurity which yet surrounds this abstruse Theoreme and the industry of some more dextrous Anatomist pierced deeper into the mystery of the Nerves a subject not much lesse inscrutable than the Nature of the Soul it self which useth them as her principal instruments we hope we may have the liberty to conceive that the Succus Nutritius is not imported to the brain and Spinal Marrow nor exported from thence to the members by any Attraction similary or Elective against which we have formerly alleadged convincing arguments unnecessary to be here repeated but as the blood and indeed all other humors of the body are moved by meer Impulsion or Protrusion the immediate Cause of all motions in Nature And the Agents in this case impelling we conceive to be the motions of the Diaphragme of the Brain and of the Nerves themselves For since the Depression of the Diaphragme is generally admitted to conduce to the distribution of the Chyle out of the stomach guts Venae Lacteae common Receptacle and Ductus Chyliferi successively into the subclavian Vein by alternately compressing all those parts and so compelling the Liquor contained in them to flow upward and indeed to all other Natural motions why may not the same be thought sufficient also to the Expulsion of the Nutritive juice both out of the Praeparing Glandules into the Nerves of the Sixth conjugation and their Auxiliaries and out of them into the brain and Spinal Marrow their position being such as renders them no lesse subject to compression by the descending Diaphragme than the Venae Lacteae common Receptacle and other Chyliferous parts are If this seem difficult we may have recourse to the reason of the ascention of a liquor from the bottome through all parts of a sponge cloath or other filamentous substance as is experimented in the percolation of Aqua Calcis made by a long piece of woollen cloath whose one end is dipt in the water and the other hung over the brim of the vessel containing it which we have professedly explained in the 356 page of our Physiology and seems to be the same with the reason of the ascention of the nutritive juice of all plants from the roots to the top of the branches And as for the Motion of the Brain though it may seem to be no other but what is impressed upon the brain by the Pulsation of the Arteries ascending from the Plexus Arteriosus mirabilis chiefly to the Dura Mater and copiously disseminating themselves upon it yet since it is credible that the Pulsation of the arteries doth promote the flux of the liquor in the Nerves in other parts especially such where Nerves are either contiguous or neer enough to Arteries to participate of their impulse why may not the motion of the Brain also to which the Nerves are continued serve to ex-press the liquor out of them toward the parts wherein they are terminated Besides it is most certain that immediately after sleep the whole Brain together with the
Galen also doth not obscurely intimate in 1. de mot Musculor cap. 8. where he saith Aequipollens musculorum motus fit quando neuter tonum Animalem habet auxiliarm non aequipollens verò cum alter solus dominatur quare necessum est ut vincat contractio istius musculi qui ab Animali Facultare adjuvatur For what can be understood by this Tonus Animalis or Facultas Animalis unless it be the distention of the conquering muscle by Animal spirits sent from the brain at the pleasure of the Soul 4 What 's the reason the swelling of each Muscle when it moveth that a muscle is never moved but it becomes more hard and swelling in the middle than before as is most evident in both the Masseter and Temporal Muscles when we chew our meat unless because it is then filled and distended with a greater gale of spirits issued out of the store-house of the Brain For it seems more reasonable that this swelling in the body of the Muscle is the Cause of its Contraction than on the contrary that the Contraction should be the cause of the Swelling as those contend who would have the motion to be performed without the afflux of spirits 5 If a Nerve be cut asunder the Muscle into which it was inserted the privation of motion in a Muscle whose Nerve is cut off doth for ever become uncapable of motion and this certainly for no other reason but because the intercourse of the spirits betwixt the brain and that particular Muscle is wholly destroyed So that we may well conclude that the Soul cannot cause voluntary motion but by the distribution of Animal spirits through the Nervs into the Muscles The necessity of Animal spirits as the Immediate Instrument of the soul thus appearing we are next to speculate the Conditions requisite in the Immediate Instrument of the Motion it self that so we may come to a clear understanding both of the structure and diversity of the Muscles and at length of the reason of their moving the members the thing at which our Scrutiny is chiefly levelled As for the requisite Conditions therefore of this last Instrument we observe 1 That in an organ of voluntary Motion is required such a Constitution vvhy a Muscle is composed for the most part of Flesh. as may render it fit to receive the Animal spirits at the pleasure and command of the soul. Which makes it manifest that a hard inflexible and bony substance is most incompetent to an instrument of motion for which reason perhaps Galen adventured to affirme that any part made hard and stiffe by a thick Cicatrice becomes unfit for motion and that it must be such a part as being soft rare spongy and flexible and distinguished with multitudes of Fibers may most easily and readily admit the Gale of spirits flowing into its substance and be by them filled or distended Which is the reason why the substance of the Muscles is for the most part Fleshy than which no part is more soft rare flexible and distendible as Galen hath observed in 1. de usu part cap. 13. 2 Lest the spirits might flow into this flesh of a Nerve indeterminately or at randome and scatteringly there ought to be such peculiar vessells or Conduits which being continued from the brain or spinal marrow quite home to the Flesh into which they are inserted may both carry the spirits thither and preserve them from straying or dispersing by the way and by which the Soul or Regulating Faculty principally residing in the brain the original of the Nervs may rule the members as a Coachman rules his horses by the rains of his bridles that we may use the same comparison with Galen 1. de mot musculor cap. 1. Now the Nervs being the only parts of the whole body thus qualified Nature most wisely inserted one or more of them into each Muscle So that from this constitution of the Nervs it appears that they make the second Essential part of a Muscle Nay according to strict truth we may adventure to say that the Flesh and Nerve are the principal ingredients required to compleat the essence of a Muscle because there are some Muscles viz. those of the Temples of the Forehead of the Eyes of the Bladder of the Fundament c. in whose bodies are neither Tendons nor Ligaments to be found but only Nervs and Flesh distinguished with various Fibres 3 Because in some Members Of a Ligament by reason of their Gravity there is a greater resistence to motion than the Musculous Flesh in respect of its softness and tenderness is able to overcome therefore ought there to be an addition of some stronger and tougher substance which being connected or united to the Flesh of the Muscle may both corroborate the same and firmly conjoyn it to the bones so as to enable it to move the ponderous member to whose bones it is fastned Now this Nature foresaw when she furnished some Muscles with Ligaments especially such as were ordained to bear great stress in moving the greater and more weighty members Which Galen most elegantly expresseth thus Ut enim ossa quae dearticulantur exactè simul ligarentur ac continerentur ne facilè in motibus vehementioribus à sese abrumperentur Ligamentum quoad maximè potuit durum atque ab injuriis remotissimum efficere oportuit ut autem ossibus à Musculis tractis promptè obsequeretur molle rursus esse oportuit atque ob id ipsum imbecillum Atqui forte quidem imbecillo ac durum molli est contrarium Quaenam igitur fuerit in his Naturae solertia quae corpus invenit quod commoditatem utramque haberet idemque ab injuriis tutum esset ex ipsad Anatome discas licet c. 12. de usu part cap. 2. 4 Besides the connexion of the Musculous Flesh to the bone Of a Tendon by the mediation of a Ligament there must be also something to render it prompt easy and agile in its motion so as to answer the celerity of the influx of the Spirits and to fulfill the command of the Soul as it were in an instant Which Nature reflecting upon superadded also a Tendon or Chord which in respect both of its subtility and of its tough and strong Contexture or substance and also of its connexion to the joynt doth make the motion more facile and quick than otherwise it could possibly be as appears in the Muscles of the Hands and Feet c. 5 That these parts named viz. the Flesh of a Membrane investing it Nerve Ligament and Tendon might no be endangered by lying uncovered or confused therefore hath Nature cloathed the whole Muscle with a proper Membrane or Coat which hath these two further Uses that it causeth the Muscles that are contiguous to slip up and down easily and without enterfearing each other and preserves the spirits immitted into the body of the muscle moved from passing quite through or dispersing themselves