his own speculations he would hardly be able clearly to solve any one of the Phaenomena of this or that particular Passion for instance whence it is that Blushing is the proper sign of Shame Paleness the Character of suddain Fear Sadness the inseparable concomitant of Hate sic de caeteris In a word he would as soon be at a loss in tracing the intricate Labyrinth of Human Affections as a blind man that should undertake to give the Chorography of a whole Countrey meerly from a relation of some memorable action done in some part of it Nor should I believe such a man half so likely to temper and compose the tumults of his inordinate Passions as a skilful Anatomist who understands by what impressions they are occasion'd upon what parts of the brain those impressions are made what sympathy and confederation Nature has instituted between those parts and the Cardiac nerves how those nerves divided into innumerable fibres contract the ventricles of the heart and how that Contraction according to the various degrees of its force and velocity necessarily impells the blood more or less copiously and violently through the arteries into the parts most concern'd in the Passion at that time most urgent For certainly he that hath the advantage to understand all these things is better instructed to appease the impetuous Commotions at any time rais'd within his breast by reducing the rebellious appetites of his inferior Faculties to obedience to the contremands of his Superior or Reason in which one thing the summ of all Moral Philosophy consists and which advanced into a Habit becomes Virtue it self So that take the Counsel given by Apollo in which of the two senses ye like best viz. either as directing to learn the admirable frame of the Body or as intimating that wisdom consists chiefly in the regulation of the Affections still the study of Anatomy will be requisit to acquiring the Knowledge of Ones-self 2. Requisite it is also to conduct even a Naturalist to the Knowledge of GOD. I mean the knowledge of not only the Existence of a Supreme Being in the World but also of his Eternity omnipotent Power infinite Wisdom and inexhaustible Goodness for as to the Divine nature it self that we must all with holy astonishment confess to be to Human Understanding incomprehensible for how can a finite have an adaequate notion of an Infinite Most true it is indeed that there are in every part of the Universe certain marks or impresses of a Divine hand and the smallest Insect that creeps upon the earth the very grass whereon we tread yea even things Inanimate proclaim the Glory of their Maker inciting us to venerate praise and adore Him so that St. Paul preach'd true Natural Theologie to Infidels when he taught that the invisible things of God are known by the visible things of his Creation and Heraclitus gave a memorable hint of his piety toward the Summum Numen when inviting into his poor smoaky cottage some proud strangers that disdain'd to put their heads under so vile a roof Enter said he nam etiam hîc Dii sunt here also are Gods And in truth every page in the great Volume of Nature is full of real Hieroglyphicks where by an inverted way of Expression things stand for words and their Qualities for Letters Whence perhaps Plato in Timaeo took a hint of that sublime thought of his that the World is Gods Epistle written to mankind But if we survey the Epitome of the World the Temple of Mans Body in which as in a Model or Exemplar all parts of the Greater World are represented in little we shall there find something more august more Majestical Who can observe that so magnificent a pile is rais'd only è luto out of a little slime that from a few drops of the Colliquamentum or Genital humor of a substance Homogeneous or simple are formed more than two hundred bones more Cartilages very many ligaments membranes almost innumerable myriads of arteries and veins of nerves more than thirty pair with all their slender branches and continued fibres near upon four hundred muscles a multitude of glandules and many other parts all divers each from other in substance consistence colour texture fabric c. Who can I say observe this without being forced to acknowledg the infinite Power of the Divine Architect who makes the very Materials of his building Who can look into the Sanctum Sanctorum of this Temple the Brain and therein contemplate the pillars that support it the arch'd roof that covers and defends it the fret-work of the Ceiling the double membrane that invests it the resplendent partition that divides it the four vaulted cells that drain away impurities the intricate labyrinths of arteries that bring in from the heart rivulets of vital blood to heat and invigorate it the Meanders of veins to export the same blood the Aqueducts that preserve it from inundation the infinite multitude of slender and scarce perceptible filaments that compose it the delicate nerves or chords spun from those threds the original of that silver chord as Ecclesiastes calls it or Spinal marrow upon which the strength of back and limbs chiefly depends and many other parts of the wonderful Engine and not discern an infinite Wisdom in the design and construction of them And as for the infinite Goodness of God that is no less conspicuous in the connexion of so many and various instruments into one complex Automaton by which they are so admirably combin'd that every one works for it self and for the public at once that every one performs its peculiar office apart yet all co-operate to one and the same common end the subsistence safety and welfare of the whole and that if any one happen to be put out of order or tune all the rest sympathize with it and the whole Harmony of Functions is discompos'd Add to this stupendous Machine an internal Principle to give it life sense voluntary motion and understanding and then ye may say with Cicero Jam verò animum ipsum mentémque hominis rationem consilium prudentiam qui non Divinâ curâ perfecta esse perspicit is his ipsis rebus nobis videtur carere If then the admirable fabric of our Body demonstrates the Power Wisdom and Goodness of the Maker whom the Scripture most emphatically calls Yotzêr Hakkôl the Former of all things Jer. 10. 16. and if it be by the help of Anatomy alone that we come to contemplate and understand the excellency of that fabric we may safely conclude that to study Anatomy diligently and reverently is to learn to know God and consequently to venerate Him Deum enim colit qui novit After this what others out of ignorance may think or speak to the prejudice of this so useful Art of Dissection I am neither concern'd nor solicitous to know but this I openly declare that if I knew an Atheist if there can be such a Beast in the world I would
delivers the first into a free injoyment of her essential immortality but dissolves the latter into the Elements or matter of which it was composed is an opinion very antient highly consentaneous to reason and defended not only by many eminent Philosophers as well antique as modern but even by some Divines of great learning Piety and Fame among whom I need name only Gassendus of the Roman and Dr. Hammond of our Church The former of which hath professedly asserted it in Physiologia Epituri cap. de Animae sede the other in Notes on the 23. Verse of the 5 Chap. of St. Pauls first Epist. ad Thess. Where interpreting these Words of the divinely inspir'd Author 〈◊〉 〈◊〉 〈◊〉 〈◊〉 〈◊〉 integer vester spiritus anima corpus he conceived that the Apostle divides the whole Man into his three constituent parts viz. the Body which comprehends the Flesh and Members the Sensitive or Vital Soul which is common also to Brutes and the Spirit by which is denoted the reasonable Soul originally created by God infused into the Body and from thence after death to return to God and this his exposition he confirms by agreeing Testimonies of many Ethnic Philosophers and some antient Fathers Much more I should here have said in defence of this opinion had I not thought it less labour to direct the unsatisfied to a little Treatise intitled a Natural History of the Passions publish'd about three Years past where the Author professedly handles it Now if either of these two recited opinions be granted to be true and 't is no easy task to refute either of them then both my positions that occasioned my recital of them may be also true and so the supposed inconsistency of them solved Presuming then that what I have said concerning the First Act of the Blood or the Generation of Original Life in the Blood and the manner how it is performed is probable and sufficient to explicate the Theorem I here conclude my discourse of it ¶ The SECOND Act of the Blood in the race of Life is the Excitation of the Motion or Pulsation of the Heart and Arteries which seems to be done in this manner The Blood descended partly out of the Trunc of the Vena Cava partly from the Arteria Venosa into the Ears or Portals of the Heart and there beginning its expansive motion fills them even to distention and by that distention irritates or incites their Fibres which are numerose and strong to contract themselves by the motion of Restitution By this constriction of the Fibres on all sides the cavities of the Ears of the Heart are necessarily closed or streightned and by consequence the Blood newly admitted into them is sequeez'd out into the two Ventricles of the Heart forcing the Valves called Tricuspides or Trisulcae which are seated at the Gates or Mouths of the Ventricles and open from without inward to open themselves and give way The Blood thus propuls'd into the Ventricles of the Heart and somewhat increasing or intending its expansive Motion fills them even to distention and to the shutting of the Valves which it so lately open'd so that at that time no more Blood can be admitted nor what is admitted recoyl or return by the Wicket through which it enter'd The Ventricles of the Heart being thus filled and distended and by virtue of their Fibres spontaneously contracting themselves into a much narrower compass strongly compress the Blood contained in them and force it to thrust back three other Valves call'd Sigmoides which open outwards and to rush forth partly into the Venae Arteriosa leading it into the Lungs from the right Ventricle partly into the Aorta or great artery from the left By this constriction of the two Ventricles of the Heart which is their proper and natural Motion the Circulation as they call it of the Blood is chiefly effected that Blood which is out of the right Ventricle express't through the Vena Arteriosa into the Lungs being impell'd forward till it arrive in the Arteria Venosa that brings it into the left Ventricle and that which is expell'd from the left Ventricle into the great Artery being by the Branches thereof distributed into all the parts of the Body The Blood being in this manner squirted out and the irritation ceasing the Ventricles instantly restore themselves to their middle position and make way for the reception of more Blood from the Ears of the Heart as before and then being by the Influx and expansive Motion thereof again distended and irritated repeat their Constriction and thereby eject it and this reciprocation or alternate dilatation and constriction or Diastole and Systole of the two Ventricles of the Heart together with the Arteries continued to them is what we call their Pulsation and the grand cause of the perpetual Circuition of the Blood as the alternate expansion and repression of the Spirits during that pulsation is that motion which Dr. Glisson first named the Mication of the Blood comprehending the double motion in that single appellation The Blood then it is that alone excites the Pulsation of the Heart and Arteries by distending them not by reason of any actual Ebullition or any considerable Rarifaction it undergoes in either of the Ventricles or in their avenues but as I humbly conceive merely by its quantity rushing in Not by Ebullition or Effervescence as Aristotle who gave it the Name of 〈◊〉 〈◊〉 〈◊〉 〈◊〉 〈◊〉 believ'd 1 Because no ebullition of any Liquor whatsoever proceeding either from external Heat or from intestine Fermentation is constantly equal or uniform whereas the Pulse of the Heart and Arteries and consequently the motion of the Blood that causeth it is in Men healthy temperate and undisturbed by Passion constantly equal or of the same tenor and rhythm 2 Because the greater the Ebullition of the Blood the greater would be the pulsation of the Heart but in burning Fevers though there be a very great effervescence of the Blood arising from an extraordinary effort of the vital Spirits contending against oppression by the putrefactive or febrile Ferment yet the Pulse most frequently is low and weak as Galen himself observed 3 Because in living dissections if either of the Ventricles of the Heart or the great Artery be pierced with a lancet pure and florid Blood indeed will spring from the Wound in every Systole but not frothy not boyling nor meteorized nay not to be by any sign of difference distinguished from Blood at the same time emitted from the Vena Cava of the same Animal An Argument certainly of itself sufficient to subvert the Ebullition of the Blood in the Ventricles of the Heart excogitated by Aristotle at least if he were Author of the Book de Respiratione vulgarly ascribed to him to solve the Phaenomenon of the Pulse and to this day obstinately defended by many learned men seduced by the Authority of his great name 4 If the Blood suffer'd any such Ebullition an immersion or
plunging of the Body into cold Water would depress and calm it and consequently repress the motion of the Heart but the experience of divers attesteth the contrary For these reasons therefore among many others here for brevities sake omitted I reject the supposed Ebullition of the Blood passing through the Ventricles of the Heart I reject also the suddain and impetuose Rarifaction attributed to it by the greatest of Aristotle's Rivals Monsieure des Cartes and strenuously propugned by Regius and others his Disciples For 1 If you open the Thorax of any more perfect Animal alive and while the Heart yet continues to beat strongly thrust an incision Knife into either of the Ventricles or into the great Artery the Blood thence issuing will not appear spumose or rarified at all but indistinguishable from Blood taken out of the Vena Cava just at its entrance into the right Ear of the Heart 2 If you cut out the Heart itself and squeez out all the Blood conteined in it you shall observe it to vibrate itself a little and to continue the rhythm of its Pulses till it be grown cold and this not from Blood rarified for now there remains none within its Ventricles but most probably from the reliques of the vital Spirits which yet inhering in the Fibres and little Pullies of the Heart are the cause that they alternately contract and relax themselves 3 The musculose Flesh of the Heart is of a contexture too firm and solid to be inflated by a little Froth and a greater force is requir'd so nimbly to agitate so massive and ponderose a Machine 4 If the Blood were so impensly rarified in both the Ventricles of the Heart doubtless the Orifices both of the Vena Arteriosa and of the Aorta ought to be much larger because the rarified Blood would require more of space to its egress than to its ingress 5 There would arise a confusion of the motion of the Heart and its Valves for the diastole of these would be coincident with the diastole of that which would annihilate the use of the Valves both which are repugnant to experience and to the institute of Nature 6 No reason why the Blood should be pufft up by great rarifaction in the Heart only that it may sink and be condensed again so soon as it is thence emitted into the Arteries for what use can there be of the supposed rarifaction which the very next moment ceaseth These then are the reasons that hinder me from believing that a drop or two of Blood can be by the heat of the Heart so extremely rarified as to replenish and distend the Ventricles thereof when the Cavity of the least of the Ventricles in a Man of middle Age and Stature will easily contein according to Harvey's accompt two Ounces much more according to Lower's lib. de corde cap. 3. and when I am fully convinced that in the State of Health and Quiet the whole mass of Blood is transmitted through the Heart at least thirteen times in the space of an Hour supposing no more than 2000 Pulses in that time which would be impossible if only a few Drops were received into each Ventricle in every Diastole and expel'd again by the following Systole For evident it is even to Sense that in the Diastole both Ventricles of the Heart are filled with Blood even to distention so that if you feel them at that time with your Hand they will be found tense and hard and that by the Systole all the Blood receiv'd is express'd the Sides being then strongly drawn together and the Cone pull'd up toward the Basis so that little or no room can be left within to contein Blood If you open an Eel or Viper alive you may observe the Heart to become white in the Systole because all the Blood conteined in it is then squeez'd out and red again in the Diastole from new Blood admitted and filling it Nor are we to doubt but the same happens in the Hearts of greater Animals also though the Parenchyma or muscular Flesh of the Heart be in them so thick as to hinder the Eye from discerning the like alternate change of Colours in their constriction and dilatation Taking then the total Repletion of the ventricles in every Diastole and the total Exinanition of them by every Systole for granted and Supposing that in a Man of a middle size each of the Ventricles of the Heart conteins about two ounces of Blood when it is fill'd and that the Pulses of the Heart made in the space of an Hour exceed not the number of 2000 which yet is the lowest computation I have hitherto met with among Anatomists it will necessarily follow that no less than 4000 Ounces of Blood are transmitted through the Heart in the space of an Hour which amount to 332 Pints at 12 Ounces to the Pint whereas the quantity of Blood contein'd in the Body of a Man of a Sanguine complexion tall Stature and plentiful Diet is not allowed by accurate Anatomists to exceed 25 Pints at most Let us therefore grant our Man to have that proportion of 25 Pints to be transmitted through his Heart by 2 Ounces at every pulsation and the consequence will be that the whole Mass of his Blood must pass and repass through his Heart thirteen times in the space of an Hour or else the pulsation of his Heart and his Life too must cease for want of Blood to continue the Motion But since few Men have either so much Blood or in the state of Health so few Pulses as we have now supposed 't is highly consentaneous that in most Men all their Blood runs through the Heart oftner than thirteen times in every Hour Now to come to the scope or use of this Computation if only a few drops of Blood rarified be transmitted through the Heart of a Man at every Pulse 2000 pulses could not transmit so much as a fourth part of 25 Pints in an Hour and in the mean time all the rest of it must stagnate and grow cold and then what would become of his Life which depends upon the actual Heat and perpetual Circuition of the Blood This argument certainly is if not apodictical yet morally convincing that Monsieur des Cartes his opinion of the impense Rarifaction of the Blood in the Ventricles of the Heart is manifestly erroneous There remain's then nothing to which the Diastole of the Ventricles of the Heart can be reasonably attributed but the Quantity of Blood flowing into and distending them For the substance of the Heart being as well without as within Musculose Robust Thick and intertext with Fibres of all orders or positions and furnish't also with fleshy Columnes which being commodiously placed in the Ventricles help much to the constriction of them so soon as the Blood flowing in hath distended them they being thereby irritated instantly begin to contract themselves by that contraction girding in the Ventricles and squeezing out the Blood After the same
manner that the Stomach Gutts Bladder Womb c. membranose and fibrose Cavities of the Body when they are above measure fill'd and distended do by spontaneously constringing themselves forcibly expell whatever irritates them And that in every Diastole of the Heart Blood rushes into the Ventricles in a quantity sufficient to distend them seems inferrible even from this that it is abundantly brought in both by the Vena Cava and by the Arteria Venosa and that it is continually driven on thitherward partly from the habit of the Body by the tonic motion of the parts partly from the Lungs by help of their motion according to the fundamental Laws of its Circuition But why do I insist upon Reasons when an easie Experiment offers itself to determine the Question In a Dog opened alive if the two Vessels that bring Blood into the Heart namely the Vena Cava and Arteria Venosa be girt with Ligatures so that the course of the Blood be there intercepted the Ventricles by three or four Systoles emptying themselves their orderly pulsation will cease only a little undulating Motion and irregular vibration will thereupon immediately succeed and upon solution of the Ligatures and influx of Blood the Heart will instantly repete its pulsation I conclude therefore that the Blood causeth the Dilatation of the Heart not by its Ebullition nor by its Rarifaction but only by its replenishing and distending the Ventricles thereof and that the Heart by its spontaneous constriction expresses the Blood into the Lungs and great Artery and so the motion of both is perpetuated I admit nevertheless a certain gentle and pacate expansive Motion of the Blood to be excited in the Ears and Ventricles of the Heart as necessary to the generation of Original Life though not of force sufficient to move the whole Machine of the Heart For the vital Spirits in the Blood though brisk and vigorose in their endevor to expansion chiefly when they are agitated by the motion of the Heart are notwithstanding somewhat checkt and repulsed by the reluctancy of the grosser Particles of the Blood and therefore it cannot be imagined they should suffice to dilate the Heart also I admit also a constant invigoration of the Fibres and fleshy Columns or Pullies of the Heart by a continual Influx from the Brain that they may the more expeditely and strongly and without lassitude perpetuate the Systole of the Heart For that such an Influx is necessary every Moment to recruit their Vigor and conserve the due firmness of their tone is evident from this singular Experiment If the Nerves of the eight pare be constringed closely by ligatures in the neck of a Dog ye will admire what a suddain and strange mutation will thereupon ensue The Heart which before performed its motions moderately and regularly will instantly begin to tremble and palpitate and the poor Animal will labour of anxiety and extreme difficulty of breathing while the ligatures continue on the Nerves above but upon removing them all those dismal Accidents which are perhaps to be ascribed to the surcharge of the Heart and Lungs by Blood not so fast discharged as it is imported and that by reason the Systoles are rendred weak and languid the influx from the Brain that should invigorate the contracting Fibres and Pullies being intercepted all the Accidents I say will foon cease and the Heart renew its pulsation as before To this Anatomic Experiment I might have added Arguments of the same importance drawn from the Palsie and Convulsions to which the Heart itself is liable had not the industrious Dr. Lower Author of the alleged experiment prevented me lib. de motu cordis cap. 2. and were I not conscious that I have staid too long upon the cause and manner of the Excitation of the Pulsation of the Heart and Arteries or second Act of the Blood in the race of Life ¶ Proceed we therefore to the THIRD viz. the Distribution of the Blood into all parts of the Body which is an act wholly Mechanic and to be attributed to the Systole of the Heart and Arteries thereto continued To the Constriction of the Heart because the Blood contained in the right Ventricle is thereby of necessity express'd into the Vena Arteriosa and so into the Lungs and that in the left is thence expell'd into the great Arterie and driven on through the Branches thereof into all the parts of the Body Nor can it seem strange that this Constriction of the Heart should be effected with force sufficient to impell the Blood in a continued stream through the Pipes of the Arteries till it arrive at the extremities of them yea till it enter into the very substance of the parts in which they are terminated For if we attently consider 1 the structure of the heart that it is a Muscle of a substance Solid thick and firmly compacted every where intertext with various Fibres and corroborated within with fleshy Columns and fibrose Pullies and of a Figure fit to perform vigorose Motions 2 that if you put your Hand upon the Heart of any large Animal open'd alive you shall find it hard and tense not easily yielding to the Gripe and if you thrust a Finger into either of the Ventricles you shall feel it to be with great violence girt and pincht by the Systole thereof 3 that if you pierce the great Arterie neer the Original of it with a Lancet the Blood will be in every contraction squirted thence with incredible impetuosity and to great distance 4 that in some Men the Heart invaded by Convulsions hath vibrated itself with such stupendous Force that the very Ribbs have been thereby broken as the observations recorded by Fernelius Hollerius Forestus and Carolus Piso attest 5 that in Horses and Doggs after they have run the beating of their Hearts may be plainly and distinctly heard to a considerable distance If I say we consider these things we shall soon be induced to believe that the Systole of the Heart is more than sufficient to impell the Blood to the extreme arteries And as for the spontaneous Constriction of the Arteries that also must needs contribute somewhat to the Pulsion of the Blood by less'ning the Pipes through which it flows Remarkable it is that the Contraction of the Arteries is not Synchronical or coincident with the contraction of the Heart For the Systole of the Heart is perform'd in the time of its contractive Motion and the Diastole in the time of the remission thereof but on the contrary the Diastole of the Arteries is perform'd when they endevor to contract themselves and their Systole when they remit that endevor The reason is because the exclusion of a sufficient quantity of Blood out of the Ventricles of the Heart being perform'd the first cause that impugned the contraction of the Arteries viz. their distention by that Blood rushing into them instantly ceases and the three Semilunar Valves are shut to prevent the regress of it and at
the same time the rest of the Blood in the Arteries remits its expansive Motion which was the other cause that hinder'd the Arteries from contracting themselves and those two impediments removed for that time the Fibres of the Arteries now prevail and by contracting themselves return to their middle posture of quiet by that contraction pressing the Blood forward on its Journey till it be impell'd into the substance of the Parts From whence after it hath done its Office it is soon forced to return toward the Heart through the Veins partly by more Blood flowing after and pressing it behind partly by the renitency and tonic Motion of the parts partly by the tension of the Muscles in the habit of the Body and in fine by the Pulsation of the Vena Cava which though but light is yet perceptible at its approach to the Heart where to that end it is furnisht with fleshy Fibres so that from thence Walaeus in Epist. de motu Sanguinis concluded that the circular Motion of the Blood beginn's from that part of the Vena Cava If I do not here particularly explain the reason and manner how each of these various Causes conduceth to the effect ascribed to their Syndrome or concurse it is because I presume that the whole History of the Circuition of the Blood with all its helps and circumstances is well known to the greatest part of my Auditors and because I hast to the FOURTH Act in the race of Life which beginns where the distribution of the Blood through the Arteries end 's and is the Communication of Life from the Blood distributed to all parts of the Body For these receiving the Blood impregnate with Original Life are thereby in a moment heated anew invigorated incited to expand themselves and made participant of Life Influent i. e. they are stirred up to the actual exercise of Augmentation or nutrition and of all other their Faculties And this Participation of Life is that vital Influx with so great Encomiums celebrated by Anatomists and the Heat of the Body both actual and vital and the general cause at least Sine qua non of all the noble Actions of the whole Body I say the General Cause because it is this influent Vital Heat that revives and stirrs them up to activity when without it all parts would be dull flaggy and torpid and yet notwithstanding it is not sufficiently able of itself to produce those Effects unless so farr forth as it is at the same time contemperated and determinated to this or that particular effect by that which some call the peculiar temperament and others the Spiritus insitus of that Member or Part whose proper Office it is to cause that effect For this vital Heat or general enlivening and invigorating influence operates one thing in the Liver another in the Spleen another in the Stomach and Gutts another in the Kidneys Sic de caeteris assisting and promoting the faculties of all parts so that no one can execute its proper function without it as the irradiation of the Sun is requisite to make the Ground fruitful and to excite the Seeds of all Vegetables lying in it and indeed this vital Heat is to Animals the Sun within them their Vesta perpetual Fire familiar Lar Calidum innatum Platonic Spark pepetually glowing not that like our common Fire it shines burns and destroys but that by a circular and incessant Motion from an internal Principle it conserves nourishes and augments first itself and then the whole Body Undè Entius noster in Antidiatribae pag. 6. in hunc finem extructum est cor quod calentis sanguinis rivulis totum corpus perpetim circumluit Cumque Plantae omnes à Solis benigna irradiatione vigorem vitamque adeo suam praecipùe mutuentur animalibus caeteris cordis calor innascitur unde tanquam à Microcosmi sole partes omnes jugiter refocillantur Ac propterea minùs placet quòd plantarum germen Corculi nomine indigitaveris Good reason then had our most Sagacious Harvey to sing so many Hymns as it were to this Sol Microcosmi that continually warms comforts and revives us Discoursing of the Primogeniture of the Blood in an Embryon Lib. de Generat Animal exercit 50. he falls into this elegant encomium of it Ex observatis constat Sanguinem esse partem genitalem fontem vita primùm vivens ultimò moriens sedemque animae primariam in quo tanquam in fonte calor primò praecipùe abundaet vigetque à quo reliquâ—â— omnes totius corporis partes calore influente foventur vitam obtinent Quippe calor Sanguinem comitatus totum corpus irrigat fovet conservat Ideoque concentrato fixoque leviter sanguine Hippocrates 〈◊〉 〈◊〉 〈◊〉 〈◊〉 〈◊〉 nominavit veluti in lipothymia timore frigore externo febrium insultu contingit videas illicò totum corpus frigescere torpere pallore livoreque perfusum languescere evocato autem rursum sanguine hui quam subitò omnia calent denùo florent vigent splendentque Nec jecur munus suum publicum exsequitur sine influentia sanguinis caloris per arteriam Caeliacam Imò vero Cor ipsum per Arterias Coronarias influentem unà cum sanguine caliditatem vitamque accipit Quippe nullibi est caloris affluentia citra sanguinis influxum per arterias Sanguis denique totum corpus adeo circumflùit penetrat omnibusque ejus partibus calorem vitam jugiter impertit ut Anima primò principaliter in ipso residens illiûs gratiâ tota in toto tota in qualibet parte ut vulgò dicitur inesse meritò censeatur In another place Exercit. 51. vindicating the Supremacy of it over all parts of the Body he breaks forth into this memorable expostulation Si Neoterici quidam verè dicant animalium semen coitu emissum esse animatum quidni pari ratione affirmemus animam esse in sanguine cùmque hic primò generetur nutriatur moveatur ex eodem quoque animam primùm excitari ignescere Certè sanguis est in quo vegetativae sensitivae operationes primò elucent cui calor primarium immediatum animae instrumentum innascitur qui corporis animaeque commune vinculum est quo vehiculo animae omnibus totius corporis partibus influit In a third place Exercit. 70. where he with cogent reasons refutes the vulgar error de calido innato he puts an end to all false notions and all disputes concerning that Subject and then concludes in these words Solus sanguis est calidum innatum seu primò natus calor animalis Habet profectò in se animam primò ac principaliter non vegetativam modò sed sensitivam etiam motivam permeat quoquoversum ubique praesens est eodemque ablato anima quoque ipsa statim tollitur adeo ut sanguis ab anima nihil discrepare videatur vel saltem substantiae cujus actus sit anima
aestimari debeat These remarkable texts I have recited not to prolong my discourse but to confirm whatsoever I have said of the generation of Life original in the Blood and of the communication of influent Life from the same Blood to all parts of the Body that so I might with more assurance leave this fourth Act of the Blood fully explain'd and pass to the ¶ FIFTH and last Which consisteth in the dffusion of the exhalations of the Blood raised by the expansive Motion or actual Heat of it and which reduceth it from the State of Arteriose Blood to that of Venose For the Blood newly impregnate with Life and kept a while in restraint by the thick Walls of the Heart and firm Coats of the Arteries no sooner arrives at the habit of the parts but instantly it begins to disperse its more volatile Particles in Steams or Exhalations and those being diffused it becomes calm and sedate and is in that composed condition transferred into the capilray Veins to be at length brought again to the Heart Of these Exhalations the more subtil and fugitive part exspires into the Aire by insensible transpiration the rest striking against membranose and impervious Parts or perhaps against the very Parenchyma of them is stopped and repercuss'd and condensed into a Dew Which after it hath moistned the parts is by their tonic motion squeez'd into the Lympheducts and by them carried off toward the Centre of the Body In the mean time the Blood after this manner calmed and recomposed returns quietly and slowly toward the Heart therein to be quickned heated and impregnated anew by the expansive Motion of its Spirits being driven on all the way by more Blood continually following and pressing it and by other concurrent Causes by me a little before particularly mentioned And this I believe to be the manner and reason of the perpetual Circuition of the Blood during Life Now reflecting upon the five Acts of the Blood described in the circular Race of Life the Sum of all my perplex and tedious disquisition concerning it amounts to no more but this That the Mication of the Blood proceeds originally from the expansive motion of the Spirits of it somewhat restrain'd and repulsed by the gross and less active parts and incited by that opposition that from this Mication Life Original is as it were kindled in the Blood passing through the Heart that Life influent is communicated to all parts of the Body from the Blood transmitted to them through the Arteries and from the union of the vital Spirits contain'd in the Blood so brought into them with the Spiritus insitus of every part that receives it that to that noble end Nature hath ordained that the Blood should be speedily distributed to all parts through the Arteries by the Heart spontaneously contracting itself and so soon as it hath done that its grand Office of reviving them and diffused its exhalations be brought back again to the Heart therein to conceive vital Heat anew and in fine that the Life of all Animals depends immediately or primarily upon the regular Mication and next upon this perpetual Flux and reflux of the Blood by the glorious Inventor of it Dr. Harvey rightly called not the Circulation but CIRCUITION of the Blood Quòd ejus semper redeat labor actus in orbem How probable these things are Ye who are Philosophers and Anatomists have indeed a right to Judge but ye must pardon me if I adventure to say that ye have no right to Judge whether they be true or not For what Seneca Natural Quaest. lib. 7. cap. 29 with great Wisdom and Modesty spake of his own reasonings about the nature and causes of Comets may be with equal reason applied also to mine concerning Life which in more then one thing resembles a Comet viz. Quae an vera sint Dii sciunt quibus est scientia veri Nobis rimari illa conjecturâ ire in occulta tantum licet nec cum fiducia inveniendi nec sine spe Huc item referri potest quod Atheniensis hospes respondebat Clinio apud Platonem 〈◊〉 〈◊〉 〈◊〉 〈◊〉 〈◊〉 Vera haec esse approbare cùm multi de iis ambigant solius Dei est If you grant them to be consentaneous to right reason and observations Anatomic I may then not impertinently conclude this Disquisition with the same Sentence with which my Master Gassendus is said to have concluded his Life Quantula res est vita hominis ¶ EPILOGUE AUGUSTUS ye know notwithstanding he had long enjoyed whatever the greatest part of mankind calls Happiness could not yet when dying afford to call Human Life by any better Name than that of a Comedy or Farce asking his Friends that stood by him Ecquid iis videretur mimum vitae commodè transegisse And that this Farce consisteth of five natural Acts too I have endevored in my precedent Discourse to evince Why then may not ye expect that I should in keeping of Decorum so far persue this double Analogie as to my short History of Life to subjoyn an Epilogue Supposing therefore that ye do I hold myself obliged to add one such as seems to me to be neither indecent nor impertinent It shall be a short History or Tale call it whether ye please Written by Philostratus in lib. 4. cap. 16. de vita Apollonii Tyanei Which I through hast forgot to touch upon in its due place and in which there occurrs more than one thing worthy to be remarked Be pleased then to hear first the Story itself in the Authors own Words and then my brief reflections upon the things therein chieflly considerable The Story is this The things I thence collect are these 1. That the Maid was not really Dead but only seemed to be so and consequently that the raising of her by Apollonius was no Miracle For the Author himself though in the first Line so bold as to call it 〈◊〉 〈◊〉 〈◊〉 〈◊〉 〈◊〉 a Miracle is yet so modest in the second as to render it doubtful by these Words 〈◊〉 〈◊〉 〈◊〉 〈◊〉 〈◊〉 Virgo mori visa est the Maid seemed to be Dead i. e. She was not really Dead and after in his Philosophical descant upon the act of her resuscitation in these Utrum verò scintillam animae in ipsa Apollonius invenerit quae ministros medicosque latuerat an decidens forte pulvia dispersam penè jam extinctam animam calefaciens in unum congregaverit difficile conjectatu est Which is a plain confession that probably she was only in a Swoun because the Rain that fell upon her Face might raise her 2. That 't is probable the Maid lay intranced from a violent fit of the Mother For this terrible Accident invaded her 〈◊〉 〈◊〉 〈◊〉 〈◊〉 〈◊〉 in the very Hour of her Marriage a time when Virgins commonly are most prone to have their Blood and other Humours violently agitated by various Passions which many times cause great commotions
with requisite Vigor endevor to expand themselves and then the Fever first invades as shall be more fully explicated when we come to examine the process of Fermentation in the Paroxysm of an intermittent Fever In the mean time it follows to be inquired wherein this Aptitude of the Fermentum Febrile to fix the Spirits of the Blood doth chiefly consist I conceive with Dr. Glisson that it is radicated in a certain Lentor or clamminess of the Crudities mixt with the Blood analogous perhaps to that viscidity observed in Wine and Beer not perfectly fermented which are therefore call'd Pendula or Ropy nor can they be ever corrected unless by a new Fermentation which exciting the oppressed and sluggish Spirits contained in the Liquor and dissolving the clammyness of the grosser Parts quickly clarifies it For what can be imagined more apt to Clog oppress and fix the Spirits of the Blood so as to hinder their expansive Motion than such a pendulous clamminess of Crude Humors diffused through the whole Mass of it I believe therefore that the formal reason of every febrile Ferment in putrid Fevers doth consist in such a Lentor of the Blood As for that kind of it that arises from defect of Concoction in the Stomach and that may therefore rightly enough be distinguished by the Name of Crude Chyle it seems not at first to be affected with the pendulous Clamminess here described but only with a certain disposition or tendency toward it by reason the Spirits of the Chyle have not been sufficiently excited and exalted from the State of Fixation to that of moderate fluxility as they ought to have been and yet this tendency may be sufficient by degrees to induce a clamminess upon the whole Mass of Blood when crudities are daily increased and accumulated as commonly they are before a Putrid Fever is generated Other kinds of it are almost all derived either from transpiration intercepted or from extravasation of Humors as in internal Apostems and in the Dropsy or from inflammations and tumors where the course of the Blood is stopt For part of the Blood so arrested and for want of due Motion corrupted being at length carried off by the Veins and remixt with the whole Mass thereof must of necessity more or less pollute it But if we convert the Eyes of our Curiosity upon the Effects of this febrile Ferment and consider the manner and process of its acting upon the Blood we shall soon find that what hath been said of the narcotic and fixative Power of it will be sufficiently consentaneous and evident to engage our Belief For from thence it will appear by what reason and way the Ferment is wont to exert its forces and exercise its tyranny upon the Vital Spirits in the divers times of a Paroxysm or fit of a Fever viz. in the begining or invasion in the augment or increase in the vigor or Achme and in the declination I say then that before the actual invasion of a Paroxysm the febrile Ferment is already diffused through the Blood and united with the vital Spirits Upon this it of necessity comes to pass that the Spirits being clogg'd and as it were inviscated by the pendulous clamminess thereof remit somewhat of their vigor and endevor to expansion and consequently with less briskness irritate the Ears and Ventricles of the Heart and Arteries conjoyned to them to contract themselves in order to the distribution of the Blood Hence it comes that the free transpiration of the halitus or steams of the Blood is more or less checkt and render'd more slow and weak than it ought to be And this makes the first insult or surprise of the Cold Fit which though scarcely perceptible in the beginning comes creeping on more and more till the Eclipse it brings upon the vital Spirits be manifest from the weakness and languid Motion of the Pulse and from the chilness of the whole Body and dead paleness of the Face c. A little after the Pulse is more retracted and languid and the Eclipse increasing the Nayles of the Fingers become pale and of a leaden Blew the extreme parts grow sensibly cold and all the other symptoms grow more strong and vexatious so that the Patient is now compell'd to feel the Attacque his Enemy is making upon the Guards of his Life And this is the second step of the cold Fit Which ceases not yet but is continued a good while after its first sensible Invasion the depression of the vital Spirits the retraction of the Pulse and the consequent diminution of Heat still by degrees increasing Nevertheless soon after the beginning the irritation of the vital Spirits to rise up and oppose their intestine Enimy and to repell it by their spontaneous expansion begins For first they strive to resist oppression by the clamminess of the febrile Ferment and to shake off the Clogg by their natural agility Then the Mass of Blood being slowly and heavily diffused into the parts of the Body doth in some degree stagnate in the Avenues of the Heart and by its resistence burden the Heart and Arteries and so incite them to make more frequent Pulses to discharge it Then the Effluvia of the Blood being by intercepted transpiration retained and by the Veins returned to the Heart serve somewhat to excite the Spirits and to discuss a little of the clammy Ferment repressing them But yet these three irritations conjoyned are not from the beginning of so great Moment as quickly to hinder the increase of the Cold or farther depression of the vital Motion only they so far avail as to hinder the influent Life from being wholly eclipsed And at this time it is that the first certain Signs of actual Fermentation of the Blood shew themselves to Physicians accurately observing them For so soon as the certain Signs of an universal oppression of the vital Spirits appear we may from that time date the commencement of the Fermentation immediately consequent thereunto because they declare that the Ferment hath already actually begun its Work These Signs and Symptoms then are as I have said first retraction of the Pulse chilness paleness and sometimes blewness of the extreme Parts chiefly of the Nayls tipp of the Nose and Lips and some light constriction of the whole Skin Because at that time there happens some oppression of the vital Heat which governs the Pulse renders all parts actually hot gives a vivid and grateful tincture of red to all and plumps up the Skin that otherwise would shrink itself up Secondly a troublesom Sense of Cold accompanied with a Horror trembling shivering or shaking All from the difficult passage of the Blood through the habit of the Parts For the Blood being but weakly emitted from the Heart and passing slowly through the substance of the muscular Parts hurts and offends them by vellication or attrition Thirdly a weak and quivering Voice and shortness of Breath for the most part trembling and unequal which seem to arise
matter For whatsoever is superadded to the first rudiments of the parts ought certainly to be of the very same substance with what was praeexistent and so must consist ex congenere materia their renovation as well as first corporation being effected by Aggeneration or superstruction i. e. per Epigenesin So that from all these reasons put together it is constant that Nutrition is nothing else but Generation continued and as necessary to the conservation of every individual Animal yea every individual Plant also as Generation it self is to the conservation of the Universe Which our most sagacious Sr. G. Ent well understanding recommends to the belief of his Readers in these few but memorable words in Antidiatribae pag. 40. Nutritio sane videtur esse veluti continuata quaedam generatio quae est opus ideale ad exemplar primitivum actiones suas dirigens c. That I may both illustrate and confirm this Theorem give me leave to represent to you in a few lines the method and process of Nature in the formation of a Chick out of an Egg according to the most accurate Observations of Malpighius the summe of which is this From those Observations containing eight several acts of the Formative power it is highly probable 1. That the Spirit Plastic Virtue or Archeus call it by what name you please of the Egg lies dormant as it were and unactive for some time after the Egg hath been laied as if it expected the incubation of the Hen or some other warmth equivalent thereto to help it to exsert its power and begin the great work of building for it self a house according to the idea or modell prescrib'd by the Divine Architect whose instrument it is and that having obtain'd that requisite aid it soon acts upon the genital humor in which it is lodged by way of attenuation or eliquation that so the Matter may be made more fluid and obedient to its energy Which seems to be the first Act. 2. That this Spirit having drawn the first lines or threds of the solid parts of the Embryo and dispos'd them into their proper seats doth immediately after design certain wayes or passages by which those slender and delicate Stamina may be commodiously supplied with vital and nutritive liquors for their enlivening and nutrition and to that end mark out and appoint three Fountains as it were in the now more fluid Colliquamentum and thence deduce as many Canales or rivulets two of which are from their origine united and therefore somewhat greater one out of the first rudiments of each ventricle of the Heart not yet conspicuous because not coagulate but pellucid and a third consisting of many smaller rills flowing from the like rudiments of the Brain So that we may thence collect that the two former of these Canales are made to bring in the vital humor from the Heart the third to bring in the Succus Nutritius from the Brain to the first rudiments of the Chick and that in process of time those are turn'd into the Aorta and arteria Pulmonaris these into pairs of Nerves And this I take to be the whole work of the second Act. 3. Lest these so necessary fountains should by exhaustion fail the same Architect directed by divine instinct provides also for their perpetual supply To irrigate the Brain Rivulets are brought thither from the trunc of the grand canale of the Heart and to feed the current of the Heart three new streams are deriv'd to it one from the interior Lake or Colliquamentum a second from the exterior by the wayes of the Navill and a third from the yolk of the Egg by veins that by all these importing conduit-pipes fresh liquors may be continually deduced from the parts nourished into the Heart Which pipes are soon after compacted into veins either such as are design'd to bring back the Bloud or such as are ordain'd to convey the Chyle or the Lympha And this may be call'd the third Act. 4. 'T is evident that the same invisible Agent advances in the next place to distribute the vessels derived from the rudiments of the Heart viz. the Arteria Pulmonaris and Aorta first whole then divided and subdivided into branches still smaller and smaller till at last they dwindle into Capillaries and on the contrary to collect and by degrees unite all the rivulets that return from the Stamina of the solid parts to the Heart till they all meet and make a confluens in the single trunc of either the vena portae or vena cava For even common sense teaches us to call that the original or sourse of a Canale from whence the liquor which it conveys flows as every River is truely said to begin from its head or spring And Malpighius hath by the help of Microscopes observ'd and in his sixteenth and eighteenth Figures faithfully as I believe represented certain varicose veins lying in the Umbilical area or space not yet extended to either the Heart or Liver and therefore also not the Heart but the Stamina of the parts circumjacent ought to be reputed the Origin of the veins And this distribution of one sort of Canales and collection of another completes the fourth Act. 5. No less evident it is that from the beginning the Vital Nectar is clear and transparent and so remains till somewhat of the Yolk hath been mix'd with it For not only Malpighius but our equally curiose Dr. Glisson de ventriculo intestinis cap. 20. num 67. expresly affirms that he had seen bloud of a rusty colour in the coats involving the Embryo of a Chick before any the least signe of bloud could be discern'd in or about the Heart But this so early beginning of bloud may be ascrib'd either to the speedy excitation of the Spirits by the incubation of the Hen to whose heat those veins are somewhat nearer than the Heart is or to this that perhaps somewhat of a yolky tincture had preceded and caus'd that rusty or dark red However this beginning of Change in the Vital liquor from transparency to redness seems to be the fifth Act. 6. All the Canales just now describ'd being fix'd and open'd and the vital liquor exalted some degrees nearer to perfection the Plastic Spirit proceeds to finish the whole body so regulating its operations as to augment those parts first which ought to be first used and then to add to the dimensions of others whose use may be longer wanted without detriment And this slower work of accomplishing all parts by way of Nutrition and Augmentation may be accounted the sixth Act. 7. The same Architectonic Spirit as it spinns the first Stamina of all the solid parts so doth it gradually augment and complete them all out of one and the same homogeneous liquor viz. the Colliquamentum or spermatic humor clarified by Eliquation and this by transmuting the same into as many several forms as there are different kinds of similar Spermatic parts in the whole body
namely into bones cartilages ligaments tendons membranes fibres c. So that all the Organs are at length compos'd of dissimilar parts by wonderful artifice context without the least of confusion or incongruity Which deserves to be reckon'd the seventh Act. 8. In that work of Organization 't is credible the inimitable Artist divides without section only by terminating the parts and unites without glew or cement only by continuing them to the common term or bounds which depends more upon union of matter than upon union of nature By these admirable artifices of Division and Unition the Plastic Spirit perforates separates conjoins cements the yet fluid at least soft Stamina of the parts where how and as often as need requires it deduces and runns out their Rivulets terminated in the fluid matter as by chanels it preserves from confusion the two different Colliquamenta and the Yolk divided as it were by partitions it so distinguishes and disterminates even contiguous and semblable parts that they may be diversly moved at the same time without interfering or impediment and each yield to other when occasion requires and thus almost all fibres very many membranes and in many sorts of Animals the Lobes of the Lungs and Liver and the Cartilages mutually touching each other in the joints c. are divided among themselves In a word by these wayes and degrees here by me from Malpighius his Microscopical Observations collected and rudely described it seems most probable that the Embryo is form'd augmented and finish'd in an Egg. Now therefore that we may accommodate this Epitome to our present Argument if this be the method and process that Nature uses in the Generation of Oviparous Animals and if she uses the like in the production of Viviparous also as Dr. Harvies observations and our own assure us that she doth we may safely conclude that Human Embryons are in like manner form'd augmented and finish'd by one and the same Plastic Spirit out of one and the same matter the Colliquamentum Quod er at probandum I add that the same Plastic Spirit remaining and working within us through the whole course of our life from our very first formation to our death doth in the same manner perpetually regenerate us out of a liquor analogous to the white of an Egg by transmuting the same into the substance of the solid parts of our body For as I said before Nutrition is necessary to all Animals not only in respect of the Augmentation of their parts while they are little Embryons but also in respect of their Conservation after during life because their bodies being in a natural consumption or exhaustion would inevitably be soon resolv'd into their first elements unless the providence of Nature had ordain'd a continual renovation or reparation of the parts by substitution and assimilation of fresh matter in the room of those particles dispers'd and consum'd Having therefore to some degree of probability explain'd the former necessity of Nutrition and the causes of it my next business must be to inquire into the Later Which that I may the more effectually do I find my self obliged to begin my scrutiny from the Causes of the perpetual Decay or Depredation of the substance of our bodies viz. the Efficient or Depraedator and the Matter or substance thereby consum'd and the Manner how The Depraedator then or Efficient cause of the perpetual consumtion of our bodies seems to be what all Philosophers unanimously hold it to be the Vital Heat of the bloud therein first kindled by the Plastic Spirit continually renew'd by the Vital Spirit and by the arteries diffus'd to all parts of the body that they may thereby be warm'd cherish'd and enliven'd This Lar familiaris or Vital Heat continually glowing within us and principally in the Ventricles of the Heart call'd by Hippocrates 〈◊〉 〈◊〉 〈◊〉 〈◊〉 〈◊〉 ingenitus ignis by Aristotle 〈◊〉 〈◊〉 〈◊〉 〈◊〉 〈◊〉 accensio animae in corde and flamma Biolychnii the flame of the Lamp of Life by others and by others again ignea pars Animae Sensitivae is what Physicians generally have heretofore understood by Calidum innatum tho' they seem to have had but an obscure and inadaequate notion of the thing it self as I hope to evince when I shall come to inquire what life is and upon what it chiefly depends Meanwhile supposing it to be an Actual Heat consisting in a certain motion of the various particles of the bloud and in some degree analogous to fire or flame I cannot conceive how 't is possible for it to subsist or continue for so much as one moment of time unless it be maintain'd by convenient fewel which is thereby uncessantly fed upon and by degrees consum'd for it is of the nature of all fire how gentle or mild soever to generate and conserve it self only by preying upon and destroying the matter in which it is generated This Vital Heat therefore without intermission agitating dissolving and consuming the minute and most easily exsoluble particles of the body must be the Depraedator here sought after So that in truth we have one and the same cause both of our life and of our death or to speak more properly our very life is nothing but a continual death and we live because we die For we live so long as while this internal Vestal Heat is kept glowing in the bloud and when it ceases to glow either from want of convenient sustenance or by violent suffocation life is instantly extinguish'd So true even in this natural sense is that Distich of Euripides Quis novit autem an vivere hoc sit emori An emori hoc sit quod vocamus vivere The Matter consum'd I humbly conceive to be for the greatest part the fluid parts of the body chiefly the bloud and spirits which are most easily exsoluble and somewhat tho' but little of the substance also of the solid parts For Experience teaches that divers Animals Bears Dormice Swallows c. sleep the whole Winter without receiving any supply of aliment and yet have all the solid parts of their bodies as large and firm when they awake again in the Spring as when they first betook themselves to their dens or dormitories and the Reason hereof seems to be this that their Vital Heat being all that time calm and gentle consumes their bloud and spirits but slowly and very little of their solid parts as a lamp burns long when the oyl that feeds it is much and the flame but little and calm We have Examples also of Leucophlegmatic Virgins who from a gradual decay of Appetite have fall'n at length into an absolute aversion from all food and endur'd long abstinence without either miracle or imposture and yet notwithstanding have not been emaciated in proportion to the time of their fasting Whence 't is probable that in our bodies there is not so rapid and profuse an expense or exhaustion of the substance of the solid parts as heretofore many learn'd Physicians
may be inferr'd from hence that there are some perfect Muscles particularly those of the Forehead the Temples Bladder the fundament c. In the composition of which neither Tendon nor Ligament is to be found But because there is in some parts to be moved by reason of their greater Gravity a greater resistance to Motion than the musculous Flesh in respect of its softness and tenderness is of itself able to overcome chiefly in some positions 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 more firmly conjoyn it to the Bones so as to inable it to overpower that resistance Hence it is that some Muscles especially such as are destined to bear great stress in surmounting the weight of great Members or in strong Motions are furnished with Ligaments as well for their better firmation to the Bones as for augmentation of their strength All which Galen de usu partium lib. 12. cap. 2. de motu muscul lib. 1. cap. 2. intimates in these few words Vinculo enim tuto quodam opus erat musculis cum osse ab ipsis movendo nec erat aliud ad hoc aptius Ligamento But this necessity not extending to all Muscles and a ligament being of it self immoveable and insensible and the Nerves being in respect of the softness and laxity of their Substance not sufficiently strong to pull great and heavy Bones without some accession of strength it was requisite there should be of both those parts composed a Third that might be firmer and stronger than a Nerve but softer and weaker than a Ligament Such is a Tendon which in Sense and Aptitude to Motion much exceed's a ligament and in strength a Nerve and is therefore made a part of many Muscles I say of many Muscles not of all because some have no need of Tendons as the Muscles of the Tongue of the Testicles of the Penis Lipps Forehead and all Sphincters but those only that are framed for Motions either strong or continual Those that were destined to the motion of Bones do all end in Tendons greater or less and are inserted not into the Syntax or conjunction of two Bones nor into the end of the same Bone from which they arise but near to the Head of another which they are to move Those which are to be kept long in Motion have likewise need of Tendons both to corroborate and facilitate their Motions as is most evident in the Muscles of the Eye all which are furnished with Tendons Hence we come to understand why Tendons are by Nature conferr'd upon all Muscles designed to perform strong Motions in Hexion in extension and in that which holding a part in a stiff and steady Posture is termed Motus Tonicus as in the Arms and Leggs and in the Back for erection of the Spine c. and why other Muscles are made up without Tendons being as in their Originals so likewise in their ends only Fibrose That these four parts of a Muscle namely Flesh Nerve Ligament and Tendon might not want either Covering or Combination Nature has providently invested and bound them together with a proper Membrane or Coat which seems to have these two farther Uses to cause Muscles touching or incumbent upon each other to slip up and down smoothly easily and without interfering and to unite the force of all the Fibres when they act And finally because the whole Organ requires to be continually supplied with Life as being Pars Corporis Vivens therefore is it copiously furnished with Arteries and Veins those to bring in Blood by whose vital Heat all parts are impregnated with influent Life these to return the same Blood to the Heart after it hath performed that Office And this may be sufficient to explain the Constitution of a Muscle upon which if we reflect we may conveniently enough define a Muscle to be an organical part of an Animal participant of Life composed always of Flesh and a Nerve and many times also of a Tendon and Ligament covered with its proper Membrane and so framed to be the proxime instrument of voluntary Motion ¶ As for the SECOND general to be considered namely the DIFFERENCES observed among various Muscles these are many as being desumed from their diversity in Substance Quantity Figure Position Origination Insertion Parts Actions and Uses all which I will run over lightly In respect of Substance some Muscles are mostly Carnose as all the Sphincters the Muscles of the Tongue c. others mostly nervose or membraneous as the fascia lata abducing the Tibia the Quadratus call'd by Galen 〈◊〉 〈◊〉 〈◊〉 〈◊〉 〈◊〉 musculosa expansio by others Distortor oris because it is first contracted involuntarily in that Convulsion named Spasmus Cynicus and some others In respect of Quantity which comprehends all the three dimensions of Longitude Latitude and Profundity some are Long as the Rectus abdominis the Longissimus dorsi the Sartorius in the Thigh c. Others short as the Pyramidales in the bottom of the Belly Surrogates of the oblique ascendent Muscles and by a peculiar right conducing to compression of the Bladder of Urine when we make Water Others broad as the Oblique and Transverse Muscles of the Abdomen the Latissimus dorsi depressing the Arm c. Others narrow as those of the Fingers and Toes Others thick and bulky as the two Vasti of the Thigh the Glutei of the Buttocks c. Others thin and slender as the Gracilis bending the Legg c. In respect of Figure some are Triangular some Square some Pentagonal some Pyramidal some Round some of other Shapes as is exemplified in the Deltoides Rhomboides Scalenus Trapezius c. In respect of the Position or course of their Fibres some are Oblique some Transverse some above some below some before some behind some on the Right others on the Left Side Where we may observe in the general that all oblique Muscles serve to oblique Motions all Right to direct flection or extension all internal to flection all External to extention In respect of their Origination some arise from Bones and that either from the Heads of them as most of the greater Muscles do or a little below or from some Glene some Sinus or small cavity in the Bone some only from one Bone some from two or three others from Cartilages or Gristles as the Muscles proper to the Larynx others from the Membrane inshrouding the Tendons as the Musculi Vermiculares sive I umbricales in the Hands and Feet and others again from other Parts as the Sphincters In respect of their Insertion some are inserted into Bones some into Cartilages as the Muscles of the Eyelids and of the Larynx others into a Membrane as the Muscles moving the Eye others into the Skin as those of the Lips some arising from divers parts are inserted into one and on the contrary others single in