Fibres are not blown up but by them it is clear that if their course beâ—â— interrupted that they cannot flow into their Cavity they cannot dilate them Experience confirms this in that if you cut or tie a Nerve with a threed the Muscle which receives branches from it becomes flaccid and do what you will its Fibres do not swell The second thing needfull for the blowing up of the Fibres is the free course of the Blood through the Arteries and Veins of the Muscles For since the Tendinous Fibres cannot be dilated without straitning the Arteries and Veins and the Arteries and Veins cannot be straitned without voiding the Blood that fills them it is visible that if the Blood stop there it will hinder the Tendinous Fibres from being blown up This is so true that if you take a living Animal and tie the Aorta four Fingers below the Heart it becomes paralytick from the ligature even to the Extremities of the feet When the Fibres of a Muscle are blown up by the Animal Spirits there are two powers which concur to restore them to their first estate The first is the spring which these Fibres make For since their Pores acquire an disposition by their being blown up the Aetherial matter which does incessantly pass through them makes an effort to restore them to their former estate The second is the Effort of the Arterial Blood which being poussed by the Heart with Vigour blows up again the Arteries and Veins and at the same time straitneth the Tendinous Fibres And as the Arteries empty themselves of Blood when they are straitned by the swellling of the Fibres so the Fibres empty themselves of the Animal Spirits when they are put again into their ordinary state as well by the force of the Arterial Blood as by that of their Spunginess As to the rest the Tendons of the Muscles are ordinarly fastned to some Cartilage or to some bone Which is the Cause why the shortning of the Tendinous Fibres makes that part move to which the Tendons are fastned It is to be remarked likewise that one of the Tendons is fastned to an immovable part and the other to a moveable part from whence it follows that when the Muscle is shortned the moveable part is drawn towards the immovable But for as much as there is not almost any motion in one part which has not its opposite motion so there is not almost any Muscle which has not its opposite Muscle These Muscles which serve thus to make opposite Motions are called Antagonists It is to be observed as to the Antagonist Muscles that when the one is shortned the other is extended For since their action is opposite and that that of the one cannot subsist at the same time with that of the other the shortning of the Muscle which acts must needs produce the extending of its Antagonist But for that the shortning of one Muscle draws the Fibres of its Antagonist beyond their ordinary length they must needs spring back It is for this reason that the action of one Muscle which has been lengthned by the contracting of its Antagonist is done with ease enough For the Tendinous Fibres can be easily contracted again however they have been lengthned though there be few Animal Spirits which flow into their Cavity because the force of the Spirits is augmented by that of the spunginess of the Fibre The sixth Discourse Of the Cartilages Bones and Membranes WE find in the Body of an Animal many parts which seem to partake of the nature of a Bone and of the nature of Tendons in that they are not altogether so hard as the former and are less soft than the other They call them Cartilages The first thing which makes me conjecture that Cartilages are nothing but a composure of Tendinous Fibres which are hardned by being replenisht with Volatile Alcalies is that there is no Cartilage in which many Tendinous Fibres are not lost That which makes my conjecture probable is that we see by the eye that the substance of the Cartilages is nothing but a heap of Fibres And that which puts the thing out of doubt is that in young Animals many parts which were Tendinous become at length Cartilaginous And that we observe frequently in old Animals that certain Tendons are chang'd into Cartilages As Tendons are chang'd at length into Cartilages the Cartilages are likewise changed into Bones If therefore we have concluded the Cartilages were nothing but a composure of Tendinous Fibres for that the Tendons are sometimes chang'd into Cartilages we are obliged by the same reason to judge that Bones are nothing but a Composure of Tendinous Fibres which after having been hardned to become Cartilages are afterwards so far hardned as to make Bones The Observations which are made upon the Bones of Foetus's do demonstrate this Truth to the Eye In effect we observe there a great many Tendinous Fibres and particularly in the Scull It appears in the beginning as if it were nothing but a Membrane compos'd of Tendinous Fibres It becomes afterwards Cartilaginous and in fine is chang'd entirely into Bone After which it cannot be doubted but that Bones are a heap of Tendinous Fibres which are hardned after such a manner that they acquire the firmness of Bone Tendinous Fibres are hardned by being replenisht at length with Volatile Alcalies The Fibres of the Nerves do shed into their Cavity Animal Spirits That which is more subtile of them escapes by the Pores and the grosser remains So that at first these Fibres are filled with Volatile Alcalies and Volatile Sulphurs Whilst there are Sulphurs there they appear under the form of a Cartilage but when the Sulphurs are consumed whether by nourishing the Fibres or by escaping through the Pores or in splitting themselves they appear under the form of Bones From hence it comes that there are no parts in the whole Body of an Animal from whence we extract so much of Volatile calies as from Bones In fine we remark that Bones are all covered over with a Membrane which they call the Periostium This Membrane is so strongly fastned to the Bone that in certain places it is impossible to separate it but by cutting or renting of it When we do examine it narrowly we find three sorts of parts which enter into its composition to wit a great many Tendinous Fibres many branches of Nerves and some Arteries and Veins So that after we have duely considered all we find that the Periostium is nothing else but a Web of Tendinous Fibres of the Bone Nerves Veins and Arteries And because all the other Membranes have communication with the Bones and with the Tendons of Muscles and for that they have Tendinous Fibres Nerves Arteries and Veins we judge that all the Membranes which are observed in a living Body are nothing but a Texture of Tendinous Fibres Arteries Veins and Nerves The seventh Discourse Of the Lymphatick Vessels and of the Lympha IT is found
which we find in the Body of the Heart on its right side This Cavity is called the right Ventricle of the Heart As soon as the Ventricle is full of Blood it contracts its self and empties its self by this contraction It is here to be remarked that at the opening of the right Auricle into the right Ventricle of the Heart there are certain small Skins which they call Valves They are three in number almost of a triangular Figure whose sides are notched Their Base adheres to the opening of the Auricle and their point is plac'd within the Ventricle Their point is upheld only by small Tendinous Fibres strong and of a good Length which without being stretch'd are strongly fastned to small carneous pillars plac'd upon the concave surface of the Ventricle This disposition shews to the Eye that these Valves are so many small doors which the Blood opens of its self when it runs from the Auricle into the Ventricle and which it shuts after it is entered there Indeed as soon as the Ventricle is full of Blood it contracts its self and the Blood is prest equally on all sides by this contraction For this cause it gets under these Valves lifts up their point towards the opening of the Auricle which is thereby so exactly shut that no drop of Blood can pass that way So the Blood shuts up to its self this passage and cannot get out the way by which it has entered Nevertheless it does not stay in the right Ventricle of the Heart it goes out by another door to which the beginning of an Artery is strongly fastned This Artery is divided into many branches which distribute themselves into the Lobes of the Lungs At its passing from the right Ventricle it has in its Cavity three Valves made like Crescents and ranked each at the side of the other Their Convexity adheres to the Artery and turns towards the Ventricle and their Concavity is disengag'd and turned towards the Artery This situation shews us that they do not oppose the motion of the Blood when it comes from the Ventricle to the Artery but by rising up they stop its course if it presse from the Artery into the Ventricle After that the Blood has past from the right Ventricle into the Lungs by the Pulmonary Artery it returns from them by a Vein which is called the Pulmonary Vein This Pulmonary Vein discharges its self into a little bag fastned to the left side of the Heart which is called the left Auricle As soon as this Auricle is full it contracts its self thrusts by its Contraction the Blood into a Cavity in the substance of the Heart plac'd on its left side which is called the left Ventricle As soon as this Cavity is full of Blood it contracts its self and by this contraction throws out all the Blood which it contains That we may learn where the Blood goes when it passes from the left Ventricle of the Heart we are to take notice that at the opening of the left Auricle there are Valves situated after the same manner as at the opening of the right Ventricle Their use also is the same They permit indeed the Blood to run from the Auricle into the Ventricle but they hinder it from coming out of the Ventricle into the Auricle when the Heart contracts its self The Blood therefore takes another way Indeed it gets out of the left Ventricle by another passage which makes the beginning of the great Artery which they call the Aorta We find in the Cavity of this Artery next to the Heart three Valves made Crescent wayes disposed after the same manner as those of the Pulmonary Artery They permit the Blood to get out of the left Ventricle and to run into the Aorta but they hinder the Blood from flowing back from the Aorta into the left Ventricle There is yet an important remark to be made upon the motion of the Auricles and Ventricles of the Heart It is that the two Auricles do contract and dilate themselves at the same time and the two Ventricles in like manner With this Circumstance that at the time the Auricles contract themselves the Ventricles are dilated and when the Ventricles contract themselves the Auricles are dilated in course Which makes us conjecture that the Heart is a Muscle whose Auricles may well be reputed the Antagonist Muscles Before we enquire if this conjecture be a truth it will not be impertinent to observe that since the Auricles contract themselves at the same time they do also at the same time shed the Blood into the Ventricles of the Heart By the same reason the Ventricles of the Heart do at one time press the Blood into the Pulmonary Artery and into the Aorta When we consider the Heart narrowly we perceive that it is composed of Carneous Fibres which have all of them communication with a Membrane made of Tendinous Fibres This Membrane is plac'd at the Base of the Heart and keeps the Auricles fixt to it Which makes us judge that the Heart is a Muscle In the Heart we observe three orders of Fibres the first is of those which go in a straight line from the Basis of the Heart just to its point and they lye in a small number over the right Ventricle The second is of those which go from the Base and after they have extended themselves to the middle of the Heart ascend again and return to the Base from whence they came The third is of those which goe from the Base and come to the point describing about the Heart a spiral Line There they re-enter within the Heart and re-ascend spirally towards the Base Some of them end in the Ventricles where they make a Texture of their Tendinous Fibres which covers them on all sides Some of those also which come into the Ventricles make those little Eminencies which are called Pillars From the point of these Pillars go many Tendinous Strings which are joyned to the Teeth of the Valves that are plac'd in the opening of the Auricles All these Orders of Fibres do serve by the shortning of themselves to contract the Ventricles of the Heart The straight Fibres shorten it the circular ones straiten it and the spiral wring it The Heart cannot be thus shortned straitned and wreathed but the Ventricles must needs be contracted From whence we must conclude that the Heart is a Muscle whose action consists in straitning the Cavities which are amongst its Fibres As for the Auricles they are also composed of Carneous Fibres of which some of them are interwoven with others They are extended for the most part to the length and those of them which are interwoven seem to cross them to become Circular The shortning of the first does diminish the length of the Auricles and the shortning of the other diminisheth their breadth Which shews us that the Auricles are nothing but Cavernous Muscles whose action consists in the contraction of their Cavity
There is a communication between the Fibres of the Heart and those of the Auricles by the interposal of the Tendinous Fibres which are gathered altogether pure at the Base of the Heart We may look upon them as a Tendon common to the Heart and the Auricles The animal Spirits therefore which the Nerves distil into this Tendon do easily pass from the Fibres of the Heart into the Fibres of the Auricles and from the Fibres of the Auricles into those of the Heart If we would yet form to our selves an Idaea of the Heart as clear and distinct as may be we may consider it as a Muscle with three Bellies Each Auricle makes one and the Body of the Heart makes the third and the Membrane which is at the Base of the Heart where the Fibres of the Heart and of the Auricles do meet would be the common Tendon The Heart receives Arteries from the Aorta it sends Veins to the Cava it receives Nerves from the plexus Cardiacus and the Par Vagum In fine the Heart is shut up in a Membranous Bag which is called the Pericardium The Pericardium is strong and it is formed of a Texture of the Tendinous Fibres of the Heart of some Veins some Arteries and some Nerves It contains always a little Serosity which the small Glandules that are plac'd amongst the Fat of the Base of the Heart do distill into it From what has been said we may conclude that when the Auricles are full of Blood the Ventricles of the Heart are empty And for that the Auricles how soon they are full of Blood do contract themselves the Blood which they press into the Ventricles of the Heart being aided by the spring of their Fibres does dilate them and constrains the animal Spirits to get out of them and to run into the Auricles to accomplish their contraction But as soon as the Auricles are contracted the Blood which advances on all sides joynn'd with the force of the spring of their Fibres restores them to their former state And the Spirits passing in that moment from the Auricles to the Heart shut it up and cause its contraction It is for this Reason that the Auricles empty themselves when the Ventricles of the Heart are filled and that the Auricles fill themselves when the Ventricles are emptied The heart by its Contraction throws the Blood from its Ventricles into the Arteries But for that the Artery become still narrower the Blood cannot be thrown out impetuously without swelling them When they are thus blown up they restore themselves to their former state by the spring of their Fibres and by this mean make a part of the Blood which they have received run into the Veins of the Heart And since the Heart throws out the Blood into the Arteries by several strokes the Arteries must needs be blown up and fall again by several turns It is this motion of the Arteries which they call the Pulse concerning which it is to be remarked that the dilatation of the Arteries accompanies the contraction of the Heart and the contraction of the Arteries accompanies its dilatation Those who are satisfied with what they conceive clearly will be contented to ascribe to the Heart the office of pressing the Blood into the Arteries and of being the principal Instrument of its Circulation They may leave to those who believe that the Heart is the Organ of sanguification the satisfaction they have to be pleased with a conjecture ill founded as shall be made appear afterwards The Sixteenth Discourse Of the Lungs WE have said in the preceeding Chapter that when the Blood goes from the right Ventricle of the Heart it passes into the Pulmonary Artery This Artery is divided into many great branches which enter into the Body of the Lungs and these branches are again divided into others and these into others till at last the smallest of them are lost into the substance of the Lungs The Pulmonary Artery is not spread alone in the Lungs It is every where accompanied with the Pulmonary Vein a branch of a Nerve which comes from the Par Vagum a small Artery which goes from the Aorta and which they call the Bronchial Artery with a small Vein which is passing into the Vena Cava and which they call the Bronchial Vein and a certain Cartilaginous Conduit which they name the Bronchiae The Bronchiae are nothing but the Ramifications of a great Cartilaginous Pipe which extends its self from the bottom of the Mouth even to the Lungs It lyeth above the Oesophagus and is plac'd in the fore part of the Neck They call it the Arteria Trachaea There is at the top of the Arteria Trachaea a horny part which they name the Larinx It is made up of five Cartilages That which takes up its forepart makes that Eminence which in men they call Adams Bit. Its Figure is almost like unto that of that Buckler which amongst the Latines is called Scutum For this reason they name it the Scutiform Cartilage The second is called the Annular It is made like the Ring which the Turks make use of for drawing the Bow It is strait before and large behind It embraces the whole Larinx and is fastned into the Scutiform The third and fourth are called the Aritenoides They are the productions of the Annular placed on its hinder part and separated from one another by a small slit They make that part of the Larinx which they call the Glottis The fifth is a Cartilage fastned above the upper part of the Scutiform Cartilage They call it the Epiglottis It s Figure is Triangular and its substance softer than that of the others It s Base adheres to the Scutiform Cartilage and the rest of its Body is disengag'd from any other part It is usually lifted up This is that Cartilage which the Aliments put down in passing from the Mouth into the Oesophagus When it is down it shuts the entry of the Trachaeal Artery and thereby hinders the Aliments from going into it The Larinx is reckoned to have thirteen Muscles There are four of them which are common to it with other parts and nine which do properly appertain to it The first pair of the common ones are nam'd the Sternothyoidians They arise from the top of the Sternum lye above the Trachaeal Artery and are fastned to the inferiour part of the Scutiform Cartilage When their Fibres are contracted they draw the Scutiform downwards The second pair is made of the Hyothyroidians They arise from the Base of the os Hyoides and are fastned to the Base of the Scutiform They serve by the contraction of their Fibres to lift up the Larinx The first pair of Muscles proper to the Larinx is made of the anteriour Cricothyroidians They derive their origin from the forepart of the annular Cartilage and they end at the lower part of the same Cartilage By their action they dilate it The second is made of the Posteriour
the least resistance It finds none at the entry of the Tracheal Artery and it rencounters every where else There it enters it gets into the Bronchiae from hence it passes into the Vesicles of the Lungs It blows them up as much as is needful for them to occupy as much space as the Walls of the Breast do abandon Even as the motion which is given to the two Boards of a pair of Bellows when they are raised from one another does thrust as much Air into the Bellows as is needful to occupy the space which the Boards of the Bellows have left By this means the Muscles which serve to draw down the Ribs have their Fibres extremely stretcht to the length The Fibres of the Musculous Tunicle of the Tracheal Artery and of the Bronchiae are also greatly stretcht Both the one and the other by their spring do rebound The Nerves send some Spirits into their Cavity They are shortned By this Contraction the Ribs are forc'd downward The Cavity of the Breast is diminisht and the Cartilages of the Bronchiae do re-enter into one another So the Air which the Vesicles of the Lungs did contain is so prest that it goes out It passeth from the Vesicles into the Bronchiae from the Bronchiae into the Tracheal Artery and from thence out of the Body And it is this going out of the Air from the Lungs which is called Exspiration Since Respiration is no other thing but Inspiration immediatly followed by Exspiration and this Exspiration followed as quickly by a new Inspiration and so forward we may very well affirm that Respiration is made by means of the Muscles of the Breast of the Diaphragm of the musculous Tunicle of the Tracheal Artery and of the Bronchiae These Organs act successively And the action of the one hinders the action of the other From whence we conclude that we may in reason consider them as Antagonist Muscles All the Blood which passeth through the right Ventricle of the Heart goeth from thence into the Lungs and the Lungs receive the External Air into their Vesicles So we have ground to think that this Air produceth some change in the Blood which passeth through the Lungs We remark indeed a great difference between the Blood which enters into the Lungs and the Blood which goes out of them That which enters by the Pulmonary Artery is of a Red passably deep whereas that which returns from the Lungs by the Pulmonary Vein is of a bright and fluid Red. Behold a very considerable change which befals the Blood in passing through the Lungs This change cannot be made but by the Air which blows up their Vesicles and by this means presseth the small Arteries and the small Veins which are spread there This pressure doth mingle more exactly the Principles of Blood and does oblige it to run more quickly into the branches of the Pulmonary Vein to go from thence into the left Ventricle of the Heart But because this exact mixture of the Principles of the Blood and this passage from the Arteries into the Veins is not capable of producing the change that we have remarked it must needs be that some Principle of Air extremely subtile mingles with it This Principle may pass through the Pores of the Arteries and insinuate its self among the parts of the Blood That which makes the thing yet more probable is that the Blood which is exposed to the Air acquires a surface extremely Red and of a colour like to that of the Blood which comes from the Lungs by the Pulmonary Vein By which we see that the Air produces in the Blood a bright and florid Red by being mingled with it Since therefore the Air does produce this effect we cannot in reason doubt that the change of colour which befals the Blood in passing through the Lungs comes from the Air which swells its Vesicles All the difference which is between the Blood of the Veins and that of the Arteries is the same with that of the Blood which enters into the Lungs and of that which comes from them So we may truly affirm that this difference is made in the Lungs and not in the Ventricles of the Heart where the Blood does not receive any alteration For if you take Blood out of the Vena Cava and afterwards out of the Pulmonary Artery you shall find no difference between these two Bloods Nevertheless that which is taken out of the Pulmonary Artery has past through the right Ventricle of the Heart After this if you take of the Blood of the Pulmonary Vein and afterwards of the Aorta you shall see that these two Bloods are alike in all things though the one has been taken at its entrie into the left Ventricle of the Heart and the other at its going out It remains as yet to examine what are the principles of Air which produce the change that the Blood contracts in passing through the Lungs When we consider the Air narrowly We find amongst many principles which compose it a Nitrous Spirit spread through all its Mass There are in Physick and Chymie a prodigious number of Experiments which render the thing certain And because the Spirit of Nitre does produce in the Blood the same change with the Air we have ground to think that the change which the Air makes in the Blood as it passes through the Lungs proceeds from the Nitrous Spirit of the Air its mingling with it The Spirit of Nitre is composed of Acids and Alcalies The Alcalies do rarifie the Sulphurs of the Blood and the Acids ferment with its Volatile Alcalies The Blood becomes thereby more subtile more agitated and more ratified From all this we may conclude that the Respiration serves to make the Blood pass from the Pulmonary Artery into the Pulmonary Vein and to keep up the fermentation of it by means of the Nitrous Spirit which mingles its self with it And since this Spirit heightens the Red colour of the Blood it may be also said that the Respiration serves to maintain it and that by its means the Lympha and Chyle which do mingle with it take by degrees its Colour and Nature The ninteenth Discourse Of the Spleen WHen we follow the Blood which goes out of the left Ventricle of the Heart we find that the first Entrail of those which we have not yet examined to which it goes is the Spleen It is of a red Colour of a considerable bigness plac'd in the lower Belly on the left side and a little lower than the Liver In the Spleen there is an Artery and a Nerve which do enter into it in Company and a Vein which goes out at the same place These Arteries end in little Membranous Cells whose Figure does nearly resemble the Leaf of the Fearn The Vein derives its Origine from the same Cells This appears when we blow into the Artery or the Vein for the Breath passeth into the Cells These Cells are all filled with small Glandules
same reason that when we receive the Blood amongst hot water as soon as is comes out of the Vein there gathers about small Rods which you put into it a Mucilaginous and Glairous substance For the Alcalies spread through all the water with the Sulphurs and strike together against the Surface of the small Rods. The Alcalies never fix to them because they have not proper Particles for this but the Sulphurs insinuate into the Pores of the Wood which are opened by the heat of Water the extremities of their Branches So that finding themselves engaged they continue fixed there and the other Sulphureous parts of the Blood which swim in the Water joyn to the first so that in fine when the Water is become Cold we find the Sulphurs of the Blood upon the Surface of the Rods like to a Glaire or a Mucilage The third Discourse Of the Glandules WHen we follow the Arteries and the Veins wee find that a great number of their Branches end at certain round Bodies involved in a most delicate Coat and from which Bodies there comes a Canal and from thence flows a Liquor quite different from the Blood The Anatomists call these round Bodies Glandules There are three considerable things to be remarked in them The first that each Glandule receives a Branch of an Artery which carries the Blood to it and that there goes from it a Branch of a Vein which carries the Blood away The second that there goes a Canal from each Glandule from whence flows a Liquor different from the Blood And the thrid that the Composition of Glandules is of two sorts some are nothing but a heap of small Vessels contorted which reuniting make the Canal through which there flows a particular Liquor And others are nothing but an assemblage of little Vesicles In some places these Vesicles are angular and there is a Communication between their Cavities So that they end all into two or three whose prolongation makes the Canal from whence flows the Liquor which is different from the Blood In some others there are separated Vesicles which send each one in Particular a little Canal Those which are nothing but a heap of Contorted Vessels we shall call Vascular Glandules and those which are composed of nothing but a heap of Vesicles we shall name Vesicular Glandules If we reason upon these three things we will easily discover the nature of Glandules The arteries bring the Blood which after having watered the Vessels or Vesicles of the Glandules returns by the Veins which go from them Now the Glandules are nothing but a Composure of small Vessels or Vesicles full of a Liquor different from the Blood But for that we have not hitherto discovered any Vessel which brings any thing to the Glandules but the Arteries which carries Blood thither we may well think that this Liquor is a certain portion of Arterial Blood which has been separated from it by the Vessels or Vesicles and has been collected into their Cavity from whence it comes that this Liquor flows alwayes from the Glandule by the little Canal which comes from it and which we shall call the Excretory Canal The difference that is between this Liquor and the Blood ought not to keep us from being of this sentiment For since the Blood is composed of heterogeneous Principles a certain portion of one or many of these Principles may be separated from the Blood into the Cavity of the Vessels or Vesicles of the Glandules And for that the principles of the Blood are not to be met with there whether in number or proportion sufficient to make Blood the Liquor that results from this Assemblage must be a Liquor quit different from Blood Thus the Liquor that flows from the Glandules by their Excretory Vessels must come from the Blood But that which confirms us yet more in this Sentiment is that we can extract nothing from this Liquor by Chymie which we do not draw from Blood which is an evident enough mark that this Liquor is no other thing but an Assemblage of certain principles which have been separated from the Blood by means of the Glandule As to the Liquor which one Glandule separats from the Blood we observe that it is alwayes the same Nevertheless we must not for this imagine that all Glandu es separate the same Liquor Experience makes appear to us most considerable differences between the Liquors which proceed from different Glandules Which abundantly shews that for the most part diverse Glandules separate different principles from the masse of Blood But as this does not entirely satisfie the mind it will not perhaps be impertinent to enquire into the manner how the Glandules do separate from the Blood the Liquors which flow from them That wee may succeed in this enquiry I remark that the Arteries bring the Blood into the Body of the Glandule that the Blood is a Composure of heterogeneous parts that some of these heterogeneous parts go out of the Cavity of the Arteries and gather into the Cavity of the Vessels or Vesicles which compose the Glandule From whence I conclude that there are passages from the Cavity of the Arteries into the Cavity of the Vessels or Vesicles of the Glandules and such Passages as that no other principle of the Blood can pass thither but these which are absolutely necessary for making up the Liquor which flows from each Glandule in particular We shall call these sorts of Holes or Passages Pores To the end that the thing be thus done these Pores must be proportioned to the Magnitude and Figure of the parts which are separated from the Blood that they may be gathered into the Vessels or Vesicles of the Glandules whiles parts of another Magnitude and Figure cannot pass through them For then the Blood coming to run in the Arteries which are spread through the substance of the Vessels or Vesicles of the Glandules those of its parts which can pass through the Pores when they come thither are engaged in them And for that the Blood continues to move in the Arteries the parts which are engaged in the Pores through which they can pass are thrust forward and being followed by others which have the same fate they are in fine press'd foreward into the Cavity of the Vessels or Vesicles of the Glandules There they mingle with many others which are come thither after the same manner and compose with them the Liquor which flows from the Glandule through its Excretory Vessel But for that the Liquor which runs from one Glandule is made up of Heterogeneous parts it must needs be that the Pores of each Artery are not all equal So that according as the Liquor of one Glandule is composed of Sulphurs Alcalies or Phlegms there must be proportionably in the Arteries of that Glandule Pores fitted to let Alcalies Sulphurs or Phlegms pass through them We may even affirm that not only the Pores of the Arteries of Glandules are not all equal amongst themselves
but also that those of the Arteries of one Glandule are sometimes entirely different from those of the Arteries of another The reason is that there comes sometimes from one Glandule a Liquor entirely different from that which flows from another After this it is to be observed that there are Glandules to be met with alone without being joyned to any other These are called Conglobated Glandules because they are considered as little Globes which separate a Liquor from the Blood But when there is an assemblage of them and that they are all folded up within one Coat and that all their Excretory Vessels are united in one and so compose one Canal through which the Liquor runs which they have all with one accord separated from the Blood they are called Conglomerated Glandules The greatest part of the Conglomerated Glandules are Vascular and the most part of the Conglobated are Vesicular As those may see who will give themselves the trouble to make the enquiry And sometimes there are Conglobated Glandules which are Vascular in some Animals and Vesicular in others The Fourth Discourse Of the Nerves THe Surface of the Brain and of the Cerebellum as well as the inner part of the Marrow of the Back-bone are made up of nothing but a heap of small round Bodies It is observed that they receive Arteries they send off Veins and there goes from them a small white Fibre The Arteries do bring them Blood after that it has watered them it returns by the Veins But since it is not found in the Veins with the same qualities which it had in the Arteries we may well conjecture that it has left something in these round Bodies which occasions all this Change In effect this Change does not befall the Blood but either by the Addition of some new matter or the loss of some of its parts It will easily appear that it is not from the addition of any new matter if we consider that these little round Bodies receive nothing but from the Arteries For if they made this alteration in the Blood by communicating unto it any new Liquor they should receive it elsewhere The reason is that the Blood passes continually through these round Bodies and is also continually changed So they must incessantly Communicate unto it this Liquor which cannot be if they do not receive it from some inexhaustible source Since therefore this source is not known we may reasonably think that this Change does not befall the Blood by the addition of any new matter It must needs then be occasioned by the loss of some of its parts And because this change is sensible it cannot fall out but by the loss of a considerable number of its parts which since they cannot stay in these round Bodies because they are perpetually parting from the Blood they must needs go through some passage to be carried elsewhere When we examine narrowly these round Bodies we find nothing in each of them but Arteries Veins and a small white Fibre The parts which are separated from the Blood do not go by the Artery since it is by the Artery that the Blood comes to the round Body neither do they go by the Vein for if this were there would be no difference between the Blood of the Artery and that of the Vein It remains therefore that they pass through the small white Fibre And thus we find that the Surface of the Brain is nothing but a composure of small Glandules which do receive Blood from the Arteries which send it off by the Veins and which have their Excretory Vessels from whence the the Liquor flows which they have separated from the Blood There are two sorts of Substance taken notice of in the Brain the Cerebellum and the Spinal Marrow The first is that Glandulous Substance which making the Surface of the Brain and Cerebellum is called their Cortical Substance In the Spinal Marrow it is found in the middle covered with the other Substance And the other which is a white Substance more firm than it is nothing but the assemblage of the Excretory Vessels of the Glandulous Substance They call it in the Brain and Cerebellum the Callous Body or the Marrowie Substance And in the Back-bone it has no Name The Vessels which compose the Callous Body of the Brain and Cerebellum are so interwoven that they resemble a Net It has not as yet been discovered whether they are Inosculated or if the Nets be made only by their passing one over another In fine they gather into little Bundles which are found shut up into Membranous sheaths According as they advance into the Body of the Animal they are divided into many small branches and after this manner spread themselves through all So that there are very few parts in the Body of an Animal which does not receive its portion of them In the Nerves the Excretory Vessels of which they are composed have no Communication even it is not remarked that they are Interwoven But they extend themselves in length coucht one above another as if they were small Bundles of little Cords I say this falls out in the Nerves that it may be observed that it is quite otherwise in certain Tumours fastned to the Nerves which are called Olive Bodies or Ganglions For these Olive Bodies are not formed but by the interweaving of the Nervous Vessels Even as the threed of which a sling is made seems to take up more room in the Body of the sling where the Stone is plac'd than in the strings which are on either side Many Nerves meet together in diverse places of the Body of an Animal and are so interlaced one with another that the Anatomists call these assemblages Plexus They part afterwards from these Plexus and spread round about It must carefully be observed that when many Nerves meet in one there is not an Anastomosis of the Vessels that Compose them but only of their Coats And when a Nerve is divided into many branches its particular Vessels are not branched into many but the division is only in their cover and the Vessels which are in one Bundle are parted into many Bundles In fine the use of the Nerves is to distribute the Liquor which runs into the Fibres into all the parts where they terminate As to this Liquor it must needs be composed of the most subtile and most Volatile parts of the Blood It is look'd upon as a very subtile wind which passes through the Fibres of the Nerves and that not without reason For since it escapes our eyes and that the best Microscopes are not capable to make us see it we may well think that it is the most subtile of all the Liquors which are separated from the Blood through the Glandules of the Body of an Animal This Liquor is called the Animal Spirits because of its great subtility and because it is the Soul which makes Animals to live Though nothing of this Liquor can be gathered to
examine its nature by mingling it with Acids and Alcalies yet we are enclined to think that the Volatile Alcalie prevails in it with an extremely Volatile Sulphur The reason is that all Volatile Alcali's taken inwardly do encrease the Animal Spirits the Volatile Sulphurs do almost the same thing and there is nothing which does so much encrease their quantity as Sulphureous Volatile Alcalies as all Volatile Alcalies Aromatiz'd are The effect of Alcalies upon Sulphurs confirms us in this Sentiment For Alcalies do dissolve Sulphurs by separating their parts one from another and by this means hinder their branches from grapling together For this cause the Interstices or Intervals of the branches are replenisht with Aetherial matter as well as the Pores which remain between the Sulphurs and the Alcalies which being larger than if the Liquor were simply Alcaline or Sulphureous do also contain within them much more of Aetherial matter And for as much as this Aetherial matter is highly agitated it moves with much force all the parts of this Liquor which contributes not a little to its activity and its subtility The fifth Discourse Of the Muscles WHen we follow the Nerves and Arteries we find that the most part of their branches do lose themselves into Carneous Bodies which are covered over with a most delicate Membrane and are called Muscles Three sorts of parts do enter into their Composition 1. We discover in them a great many Arteries and Veins 2 Nerves and in fine small Fibres which are neither Arteries Veins nor Nerves but which are certain small long Filaments most delicate and yet very strong The manner after which they are ranked in the Muscles has something in it very remarkable At first we find them all gathered together and then they resemble a string Afterwards they separate from one another and receive amongst them diverse branches of Arteries Veins In fine they unite together and make again a Cord The first and the second Cords are called Tendons or the Head and Tail of the Muscle And that part which is plac'd between the Head and the Tail and which is the place where the Fibres of the Tendons separate from one another and where they receive the Veins and Arteries amongst them is called the Belly of the Muscle These Fibres are all parallel both in the Tendons and in the Belly In the Tendons some of them are longer than others and in the Belly all are of the same length By the order they are plac'd in they make an Obliquangular Parallelogram in the Belly of the Muscle And they are so closely prest together in the Tendons that they resemble two Strings which draw the Obliquangular Parallelogram by its opposite sides as may be seen in this Figure A. B. represents a Tendon or the head of a Muscle B. C. the Belly and C. D. the other Tendon or the Tail The Arteries and Veins which are spread through the muscle are not to be found but in its Belly if they be found sometimes in the Tendons they are so few that they are not to be regarded So the Tendons are nothing but the Assemblage of the simple Fibres which for this wee shall call the Tendinous Fibres whereas the Interstices which are amongst them in the Belly of the muscle are all replenisht with Veins and Arteries From hence comes the difference which we observe between the colour of the Tendons and that of the Belly of the muscles The Tendons are Brown and the Belly is Red. And it is this part of Animals composed of Tendinous Fibres and of Veins and Arteries which wee call Flesh Therefore we must not imagine that Flesh is Red of its self no more than we are to beleive that a Glass full of red Wine is red of its self But rather as the Glass appears Red because the Liquor that is within it is of that colour even so Flesh and all the other parts of the Body of an Animal appear Red only because of the Redness of the Blood which is contain'd in the Veins and Arteries of these sorts of parts This truth is demonstrated by an Experiment which renders it Incontestable That is if you make Injections of warm water into the Arteries which spread their Banches through the Flesh after you have repeated frequently the Injection the Flesh becomes of the colour of the Tendons The Muscles are not only composed of Arteries Veins and Tendinous Fibres but the Nerves also make one of their parts They march first upon their Coat and pierce it When they have pierced it they divide themselves in most delicate Branches which are mosculated with the Tendinous Fibres Sometimes the Nerves enter into the Tendons and sometimes into the Belly of the Muscles But in what part soever they enter we find alwayes the extremites of their Branches to end at the Tendinous Fibres All these Tendinons Fibres have a Cavity that goes through them like unto a Tube or Pipe Indeed this Cavity cannnot be seen by the eye but there is an Experiment which abundantly shews the necessity of it that it cannot be Contradicted by those who will hearken to reason The Experiment is that alwayes when a Muscle acts its Fibres are considerably shortned and in the mean time they swell bigger Nevertheless we cannot conceive how flexible Fibres can swell bigger and be shortn'd at the same time but by the means of some Liquor which fills a Cavity that pierces them from one end to the other After this it will not be very hard to discover how all these things must act Each Tendinous Fibre receives a Branch of a Nerve and each branch of the Nerve sheds animal Spirits into the Cavity of the Tendinous Fibre The Animal Sprits are the most subtil and the most agitated parts of the Blood When they enter into the Cavity of the Tendinous Fibres they blow them up and shorten them Even as the Air which is blown into a bladder swells it and shortens it at the same time If we consider after this that the Belly of the Muscle is stuff'd throughout with Arteries and Veins we will grant that the Tendinous Fibres cannot be blown up without diminishing the Cavities of the Arteries and Veins from whence if follows that the Blood is driven out of them It is for this that in some Animals the Muscles become white alwayes when the Animal Spirits do dilate the Tendinous Fibres If in fine we take notice that when the Blood stops in the Arteries and Veins the Tendinous Fibres do not receive enough or motion from the Animal Spirits to thrust forward that Bloud which stayes amongst them From hence it follows that in such rencounters they cannot dilate nor become shorter From hence we may conclude that there are two things absolutly necessary for the blowing up of the Tendinous Fibres of the Muscles the first is that the Animal Spirits must have their free course through the Nerve which goes to the Muscle For since the Tendinous
that from all the Parts of an Animal certain small Vessels do proceed which the Anatomists call Lymphatick because they are full of a clear and transparent Liquor which they name Lympha The Membranes which compose them are so delicate that they are invisible when they are not replenisht They are inosculated into one another and so compose big enough Trunks which are inserted into the Veins Those which come from the Head and from the Neck are inserted in the Subclavian or in the Jugulars And the most part of those which derive their Origine from the Inferiour parts and from the Viscera of the lower Belly do discharge themselves into one Cistern plac'd upon the Vertebra's of the Loins from whence there goes a Vessel which after having passed over the Vertebra's of the Thorax does void its Lympha into the Subclavian Vein This Cistern is called the Reservatory of the Chyle because the Chyle which is formed in the Stomach by the Digestion of the Meat comes thither and the Vessel which goes from this Reservatory is called Canalis Thoracicus because it is found coucht upon the Vertebra's of the Thorax That which is most remarkable in these Vessels is a great quantity of little Valves which are placed at very small distances from one another They are so disposed as that they permit the Lympha easily to run towards the Veins but they hinder it from coming back again and from flowing towards the parts from whence the Lymphatick Vessels do proceed From whence we may certainly conclude that the Lympha does not come from the Veins but from the parts from whence the Limphatick Vessels do derive their Origine Which agrees perfectly with experience for if you tie with a threed any Lymphatick Vessel the Limpha does so abound between the Ligature and the part from whence the Vessel comes that it blows it up prodigiously and is so emptied between the Ligature and the Veins whether it is going to discharge its self that there it becomes invisible From whence it follows that the use of the Lymphatick Vessels is to carry into the Veins the Limpha which they have received from all the parts of the living Body Wee have not hitherto discovered any Vessel which brings any thing to the parts of the living Body but Arteries and Nerves The Arteries bring Blood and the Nerves Animal Spirits It must needs therefore be that the Lympha comes either from the Arteries alone or from the Nerves alone or from the Arteries and Nerves together It does not seem to come from the Arteries alone for if you cut the Nerves which go to one part there does not flow so much Lympha in the beginning and diminishing by little and little in fine it ceases entirely Neither does it come from the Nerves alone since if you tie the Arteries which carry the Blood to one part it ceases by little and little to furnish Lympha It must needs be therefore that the Lympha come partly from the Arteries and partly from the Nerves And consequently it must be composed of a part of the Arterial Blood and of the Animal Spirits The Lymphatick parts which come from the Blood pass after the same manner as the particles of the Liquors which flow from the Glandules For as these pass from the Blood by being engaged in certain Pores of the Arteries even so the Lymphatick particles finding in the Arteries small Holes through which they may pass they are engaged in them But because they are followed by others which press them forwards they get out and pass into the Fibres of the parts from whence the Lymphatick Vessels come These which come from the Nerves do not get out by this Artifice The Nerves insert their Filaments into the Tendinous Fibres of one part and shed the Animal Spirits into their Cavity The Fibres have Pores through which they escape and mingle themselves with what runs from the Arteries to compose the Lympha by their mixture Since we have establisht in the discourse of Nerves that the Animal Spirits are no thing but a Sulphureous Alcalie we may well think that the Lympha is nothing but a Composure of Volatile Sulphurs Volatile Alcalies and a little Phlegm The Volatile Sulphurs and Volatile Alcalies are the Animal Spirits which enter into its composition and the Phlegm with the fixt Sulphurs are those of its parts which come from the Blood by the Pores of the Arteries An Experiment which succeeds always confirms this Sentiment That is if you gather of the Lympha in a Silver Spoon and place the Spoon on the Fire as soon as it begins to warm there goes from the Lympha a small Vapour and then it hardens like the white of an Egg that is boil'd I say this Experiment confirms that the Lympha is nothing but a Composure of a great deal of Fixt Sulphur a little of Volatile a little of Phlegme and much Volatile Alcalie For the Lympha is fluid whilst the Volatile Alcalies keep its Sulphurs dissolved and it hardens like the white of an Egg how soon the Fire has exhal'd them For then the Fixt Sulphurs being alone do so entangle their branches one with another that they cannot move after the manner that is needful to compose a Liquor As to the Volatile Sulphur and the Phlegme it cannot be denied but there is of them in the Lympha for that the Animal Spirits which compose a part of it are made up of them and the Vapours going from the Lympha when set on the Fire do sufficiently resemble the Vapours of Water We conclude from this that the use of the Lympha is to nourish the parts between the Fibres of which it flows As will appear plainly enough after what we are going to say of Nutrition It is a truth well enough known that many Particles of our Bodies are separated and do exhale and because these parts go out by the Pores of the Skin as if it were a most subtile Wind they call this Transpiration The parts which pass from our Bodies by Transpiration are ordinarily Salts dissolved in Phlegmes with which there are some Sulphurs mingled They are separated from the Blood by the means of an infinite number of small Glandules which are situated under the Skin and whose excretory Vessels end at small Holes which are on the Surface of the Body and which we call Pores These Glandules which we shall call Subcutaneous do receive Arteries send forth Veins and have some Filaments of Nerves So that judging of them by others we may well think that their use is to separate from the Masse of Blood the Saline parts which are formed thereby the Conjunction of the Acids and Alcalies Which makes us conclude that the parts which pass away by Transpiration are parts of the Humours of the living Body and not Particles of its solid parts The Acids which are mingled with the Humours pass away not only when they are joyn'd with the Alcalies but also when they
likewise four other great streams which empty themselves into it They discharge themselves of a sweet and Transparent Water in which there is some Viscosity remarkable This Liquor is called the Spittie We find within the Mouth two small Holes the one on the Right the other on the Left side They peirce the Checks towards the Molar Teeth or Grinders And because we find them alwayes wet we make no doubt but they are the opening of two streams of Spittle And indeed if we put into them a Bodkin we find that it goes without difficulty into a small Membranous Pipe which extends its self alongst the Cheeks and is divided into many small Branches when it approaches below the Ear. This Vessel is always found full of Spittle and the small Branches which are at its rise do lose themselves into a heap of Vascular Glandules These Glandules are placed about the Inner-part of the Ear they are called Parotides So that the small Excretory Vessels which go from each Glandule coming to be inosculated together make up Vessels somewhat larger These larger Vessels joyning together do compose a greater which encreaseth according as it approacheth the Mouth where it empties the Spittle which the Parotides have separated from the Blood Moreover the Parotides do receive their Arteries from the Carotides and send Veins to the External Jugulars there are amongst them many Branches of Nerves which come from the hard portion of the seventh pair The opening of the two other streams which do discharge the Spittle into the Mouth is to be seen under the point of the Tongue towards the incisive Teeth They are so small that they cannot admit a Hogs Bristle They appear at the end of two fleshy Papillae which serve them for small Sphincters They extend themselves alongst the Tongue and when they come near its root they are divided into many Branches which lose themselves in a heap of Glandules which are called the Maxillar Glandules They are placed within the under Jaw and they extend themselves from the root of the Tongue even to the Chin. The part of this Conglomerated Glandule which comes nearest unto the Parotides is grosser and more red than the rest As it advanceth towards the Chin it diminisheth so that it becomes by little and little more narrow and slender There is remarked towards its middle part a little strait which joyns its fore part to the hinder And afterwards after having encreased considerably it extends its self even to the Chin under the Figure of a Quince All the Glandules which compose it are nothing but a Convolution of Vessels which are Inosculated in one another to make by their Concourse two considerable Canals These Canals extend themselves on each side on the side of the Tongue and end at the two Papillae fastned to the Gums near the two incisive Teeth within the Mouth The Maxillar Glandules receive their Arteries from the Carotides they send Veins to the Jugulars their Nerves come cheifly from the third fourth and seventh pair They separate from the Blood the spittle and the Vessels of which wee have been speaking do empty it in the Mouth Besides the four streams of spittle we remark also many small Rivulets of it which are within the under Lip and alongst the Gum on the inside of the Mouth It comes from some Glandules which are found engaged amongst the Carneous Fibres of these parts and whose Excretory Vessels pour into the Mouth the Liquor which they have separated from the Blood The little Viscosity that is remarked in the Spittle makes us think that it is composed of some Sulphurs some acids and much Phlegms with which there are some Salts It mingles with the Aliments in the Mouth and facilitates the Chewing by Moistning of them It renders them more fluid and by consequent fitter to pass through the Conduits which must carry them elsewhere It may be said also that by its acids and salts it opens their small parts and makes the beginning of a dissolution The Sulphurs enwrap its acids by a marvellous precaution of the Author of the Animal Oeconomy to the end they may not corrode the parts which must be watered with Spittle The necessity of the mixture of Spittle with the Aliments appears in that all concurs to make it The Aliments press the Palate and so oblige the Spittle which its Glandules contain to run into the Mouth by the little Excretory Vessels which peirce its Membrane The Crotaphite Muscle and the Masseters by straitning and dilating themselves press the Parotides and through their Vessels make two little streams of Spittle to run which enter on the right and left Side into the Mouth The Digastrick by its contraction and dilatation agitates the Maxillar Glandules and presses the Spittle out of them which runs through their Excretory Vessels like two little streams which discharge themselves into the Mouth And whereas in the time of chewing all these parts play together after the manner we have said it must needs be granted that this mixture of the Spittle with the Aliments is most necessary In fine we must examine the Tongue which is a peice of Flesh almost of a Conical Figure It s Basis is fastned unto the bottom of the Mouth by a little Bone which they call Os Hyoides And from its Basis even to the middle it is fastned by its under part to the Muscles which fill the Cavity of the Under-Jaw so that its point is free and does not cleave to any part Under the free part of the Tongue there is a small Line made of small Tendinous Fibres which reach from one end even to the place where the Tongue ceaseth to cleave to the parts which fill the Cavity of the Under Jaw This small Line is called the Bridle The Hyoides Bone is plac'd in the bottom of the Mouth at the Basis of the Tongue It has the Figure of a very open Fork whose Arms cleave to an heap of Cartilages which they call the Larynx It is composed of many little Bones which are joyn'd by Cartilaginous knots Sometimes there are but three of them and at other times they reckon thirteen to wit six on each side As for the Bone in the midst to which the Tongue is fastned it is big in compare with the rest which are very slender It is likewise somewhat broad bunching towards the Tongue and hollow towards the Larynx On its raised side it has two small appendages which are ordinarily Cartilaginous They call them the Horns of the Bone Hyoides There are five pairs of Muscles which do make it move with the Tongue The first is the Genthoidien which has its rise from within the Chin and reaches to the Basis of the Bone Hyoides These Muscles serve to raise it by the shortning of their Fibres The second is the Sternohoïdien It comes from the top of the Sternum ascends alongst the Arteria Trachaea and is fastned to the Basis of the Os Hyoides This pair
the small Intestines All the Intestines are made up of three Tunicles as the Oesophagus of the Stomach The inner is a Texture of Tendinous Fibres diversly interlac'd the middle has two Orders of Carneous Fibres of which the one are Circular and the other Longitudinal And the outer is a Texture of Tendinous Fibres These Tunicles serve to make the Peristaltick motion of the Intestines after the same manner that it is done in the Oesophagus and the Stomach This Vermicular motion serves to make that which is in the Intestines to pass even to the Fundament that it may be thrown out of the Body as useless Besides the three Tunicles of which we have spoken we remark in the substance of the small Intestines a heap of little Glandules which send their Excretory Vessels into the Cavity of the Intestines and Distill there a clear and transparent Liquor We shall tell its use when we speak of the changes which the Chyle receives in passing into the Intestines Moreover the Chyle is not very Liquid when it comes out of the Stomach It resembles somewhat the Paste which is made by the Boiling of Meal with Water It is even like to it of a grayish colour and has much ot Viscosity But it does not continue long in that state It has no sooner past the Duodenum but a yellow and extremely bitter Liquor which they call the Bile comes to mingle with it The twelfth Discourse Of the Bile and of the Liver WHen we enquire by Chymistry what are the Elements of the Bile we find that it is composed of much of fixt Alcalie a little Volatile a little of Sulphur yet less of Earth and much of Phlegme From whence we may conclude that the Bile mingling its self with the Chyle receives in its Alcalies both fixt and Volatile a part of the Acids which hold its Sulphurs united together and thereby keep up the Viscosity which it has in the Duodenum So that the Sulphurs of the Chyle are after this more at liberty and more separated one from another Wherefore they receive amongst their parts the Phlegme of the Bile which dilate the whole Masse and give it a greater fluidity The Bile is discharged into the Cavity of the Guts at the end of the Duodenum by a small Hole round about which is observed a small Spongious edge If you put a Probe into this small Hole it passes into a Membranous Conduit which reacheth to the Liver This Conduit is always full of Bile It is therefore called Canalis Cholidochus The Insertion of this Vessel into the Intestines is singular enough At first it creeps above the hinder part of the Duodenum and then peirces its outer Coat Afterwards it peirces its middle Tunicle after having descended for some space between that and the outer Coat And in fine after having made some way between the middle Tunicle and the inner it pierces the inner at the place where we have observed the little Hole through which the Bile flows into the Intestines The Obliquity of this Insertion serves to make the Bile run into the Intestines And the spongious edge which environs the little Hole hinders the Bile from returning from the Intestines into the Ductus Cholidochus For the spongious edge is a small Sphincter which keeps the little Hole shut when the Bile does not keep it open by flowing into the Guts And the Peristaltick motion of the Intestines passing towards the little Hole serves successively that part of the Ductus Cholidochus which creeps amongst the Membranes of the Duodenum and thereby obliges all the Bile that is in this part of the Ductus Cholidochus to run into the Cavity of the Guts After having considered all this exactly I follow the Ductus Cholidochus towards the liver and I perceive that it is forked there and that one of its branches goes to a Bladder situated besides the concave part of the Liver whilest the other goes to the Liver They call the branch which goes to the Bladder Ductus Cysticus and that which goes to the Liver Ductus Hepaticus and the Trunck which arises from the joyning of both these which is inserted into the end of the Duodenum Ductus Communis The Hepatick Conduit enters into the Liver accompanied with two Arteries two Nerves and the Vena Porta All these Vessels are shut up in a Membranous sheath which they call Glisson's Capsula As soon as they enter into the Liver they are divided into many branches and these branches into others and thus they continue to divide till they be spread through all the substance of the Liver It is here to be remarked that all these Vessels continue still to be shut up in Glisson's Capsula It accompanies them thro' all and follows all their ramifications So that wherever there is a branch of an Artery there is there also a branch of the Vena Porta and one of the Ductus Cholidochus and the whole is shut up in a branch of the Capsula As for the Nerves they follow also the ramification of the other Vessels for some space and in fine they form a small net which enfolds the Arterys From this by the way we may conclude that the Vena Porta does not beat in the Liver as some Authors have imagined but that the beating of the Capsula proceeds from the beating of the Arteries which are shut up in it All these Vessels enter into small Lobes the Assemblage whereof makes up the Liver Each Lobe is shut up in a very delicate Membrane which divides it from all the rest Nevertheless it ceases not to adhere to them by small Tendinous Fibres The Membrane which enfolds each Lobe degenerates into a part of the Capsula enfolding all the Vessels which enter into the Lobe So that Glisson's Capsula is nothing but the continuation and re-union of all the Membranes which encompasse the small Lobes of the Liver All these Lobes are made up of little Vascular Glandules which touch one another Each Glandule receives a branch of an Artery and of the Vena Porta and there goes from it a branch of the Ductus Cholidochus which is nothing but a continuation of the Vessel of the Glandule They are fastned to these small Vessels as Raisins to the Trunk of the Grape There goes also from each Glandule a branch of the Hepatick Vein which being united make up a considerable Trunk which goes from the Liver at its convex part and enters into the ascending Vena Cava The Vena Porta and the Arteries bring the Blood to the Glandules of the small Lobes the branches of the Hepatick Vein carry it away again into the Vena Cava and the Ductus Cholidochus transports into the end of the Duodenum the Bile which the Glandules of the small Lobes have separated from the Blood This is what we have discovered in following the Ramifications of the Hepatick Conduit Let us now trace the Ductus Cysticus I remark first that it
Lacteal Veins These Excrements do afterwards pass into the Ilium where in divers places they receive again of the Glandulous Juyce which doth produce the same effect as formerly In fine after they are entirely freed of their Chylous parts they pass into the greater Intestines They are then composed of parts which the Ferment of the Stomach could not dissolve and of salts which are formed by the union of Alcalies of the Bile of the pancreatick Juyce and of the Glandulous Juyce with the Acids which were engaged amongst the parts of the Chyle The fourteenth Discourse Of the Mesentery the Lacteal Veins Pecquets Reservatory and the Thoracick Conduit THe Intestines adhere to the Circumference of a Membranous Ruffe which they call the Mesentery The middle of it is so strongly fastned to the Vertebraes of the Loins that it cannot be separated from them unless you tear a part of it or cut it It is composed of two Membranes of which the upper is a continuation of the Peritonaeum and the inferiour a Texture of Tendinous Fibres which come from the Vertebraes of the Loins The Mesenterick Arterie spreads many branches amongst the Membranes of the Mesentery one part of which goes to the Intestines and the other is spread amongst the Fibres of the Membranes which compose it The Veins which come from the Intestines are likewise spread between the Membranes of the Mesentery and many small Veins which come from amongst their Fibres go thither They are called the Mesaraick Veins They go to the Vena Porta Many Nerves which arise from the Vertebraes of the Loins and from the Intercostal are so interwoven one with another upon the Mesentery that they form a Plexus which is called the Mesenterick Plexus Many Nervous Fibres go from it which are spread amongst the Fibres of the Membranes of the Mesentery and a part of which passes even to the Intestines The middle between the Membranes of the Mesentery is replenisht with Far. It appears cheifly about the Mesaraick Veins In the midst of it we find a large Glandule and sometimes two three or four In Oxen and some other Animals there are many more and they are plac'd towards the small Intestines The knowledge of the structure of these Glandules does admirably serve to explain their uses They are a heap of angular Vesicles There is a communication between their Cavites This is found by blowing into them after you have thrust out all that fills them The Air passes from one Vesicle to another and makes them appear such as we have described them In fine we discover between the Membranes of the Mesentery certain small Vessels which come from the Intestines and pass into the Glandules of which we have spoken These Vessels are ordinarly full of Lympha and sometimes we find them full of Liquor like to Milk which is the reason why they call them the Lacteal Veins This Milk is nothing but the pure Chyle which has past from the Cavity of the small Intestines into that of the Lacteal Veins There are four Experiments which confirm us in this Opinion The first is that the Milk which runs into the Lacteal Veins comes from the Intestines this truth appears to the Eye when the Lacteal Veins are prest with the Fingers They empty themselves of the Milk and we see it come afterwards from the side of the Intestines to fill the Vein which has been emptied The second is that Milk is not to be found in the Lacteal Veins but some Hours after the Animal has eaten The third is that we find the Jejunum almost alwayes empty because of the great number of Lacteal Veins which goe from it Moreover the Lacteal Veins have many Valves plac'd very near one another They are so disposed that they permit the Chyle to run easily into the Lacteal Veins in going from the Intestines to the Glandules of the Mesentery but they hinder its return They go from the Intestines in great number and they are Inosculated many of them together accordding as they advance By this means they make up some greater Vessels which empty the Chyle that they carry into the Vesicles of the Glandules of the Mesentery The Chyle goes into the Vesicles of these Glandules to receive there Animal Spirits which come thither in abundance by many Nerves which proceed from the Mesenterick Plexus These Spirits render the Chyle more subtile and fluid by their Volatile Alcalie and if there be any acidity in it they correct it by receiving it into their Alcalies and changing it into Salt After that the Chyle has past through the Vesicles of the Mesaraick Glandules it discharges its self into two or three Conduits which arise from under them They end afterwards in a Membranous bag situated above the Vertebras of the Loins they call it the Reservatory of the Chyle The Reservatory is the same thing with the Cistern of the Lympha of which we have spoken before In this place the Chyle is mingled with much Lympha with which the Reservatory is alwayes full It dilates it and renders it more Liquid that it may run the more easily In fine there goes from the Reservatory of the Chyle a Conduit which is called the Thoracick Conduit for that it goes alongst the Vertebraes of the Thorax Sometimes this Conduit is forked and its branches unite again sometimes it is altogether simple The Thoracick Conduit is inserted into the Subclavian Vein above its Insertion there is a Valve which like a small Vault covers it So that the Blood which runs through the Subclavian Vein runs by without hindring the entry of the Chyle When we blow in the Thoracick Conduit we perceive many Valves in its Cavity They are plac'd at very small distances from one another and are so disposed that they permit the Chyle easily to run towards the Subclavian Vein but they hinder it from descending into Pecquets Reservatory From whence we may conclude that the Chyle runs from its Reservatory by the Thoracick Conduit into the left Subclavian Vein There it mingles with the Blood Whose course it follows and goes into the Vena Cava which carries it into the right Auricle of the Heart The Auricle discharges it into the right Ventricle And whereas the Chyle makes then a part of the Blood it follows its course and circulats with it through all the Body The fifteenth Discourse Of the Heart WHen the Chyle is once entered into the Subclavian Vein it mingles its self with the Blood and follows its course We must therefore follow the Blood if we could know what becomes of the Chyle The circulation of the Blood shews us that it runs from the Subclavian Vein into the Vena Cava and from the Vena Cava it passes into a bag adhering to the right side of the Heart This little bag they call the right Auricle of the Heart When this Auricle is full of Blood it contracts its self and in contracting its self sheds it into a Cavity
heaped upon one another like the Raisins of a Cluster of Grapes These Glandules receive small Branches of Arteries from the Trunck of the Splenical Artery and Nervous Filaments from the Nerve which enters with the Artery into the Spleen From each heap of these Glandules there goes a root of a Vein which being united together do compose the Splenick Vein On the Surface of the Spleen we perceive many Lymphatick Vessels which do empty their Lympha into Pecquet's Resesvatory By all that we have said it appears that nothing enters into the Spleen but the Animal Spirits which come by the Nerves and the Blood which comes thither by the Arteries There goes nothing out also but the Lympha which runs by the Lymphatick Vessels into the Reservatory of the Chyle and the Blood which goes by the Splenical Vein The Lympha is nothing but the Remains of the Nutritive Juyce of the Spleen and it appears not to have any other quality in this place than what it has every where else As for the Blood it has the same colour and consistence which we observe in other Veins These Observations do extremely perplex us as to the use of the Spleen For if the Arteries do bring unto it Blood it may be said that this is but to nourish it and if the Nerves do bring thither Animal Spirits this is but to give unto the Nutritive Juyce the fluidity that is needful So that we find nothing yet but what simply serves to the Nourishment of this part Yet we cannot say that it is entirely useless For what appearance is there that an useless part should alwayes be found in the Animal Body ever of the same frame and in the same situation Nature it is like would not have been so exact in this matter if it served for nothing So that it is probable it has in the Animal Occonomy some use which we do not know But for that on such occasions we must be satisfied with conjectures till we find better we may suppose that a ferment distils from the Vesicles of the Glandules and that it mingles with the Blood which passeth through the Spleen That the nature of this ferment is such that it disentangleth from the other parts of the Blood the parts which are proper to compose the Bile The reason which makes us of this opinion is that all the Blood which goes from the Spleen passes into the Vena Porta and from thence goes to the Liver where we know it rids it selfe of those parts which are fittest to compose the Bile But this sentiment though the most probable has many difficulties All know that an Animal can live many years after the taking out of the Spleen but this sayes nothing as to its use or Inutility since the cutting out of the Pancreas whose uses are known and which is acknowledged to be most necessary for the maintaining of the Animal Oeconomy does not hinder a Dog from living many years The Twentieth Discourse Of the Reins and the Vreters THere are in the lower Belly two Bodies made like to French beans plac'd upon the loins on the two sides of the descending Aorta and the ascending Vena Cava These Bodies receive Arteries from the Aorta they call them Emulgent Arteries and they send Veins to the Vena Cava They call these Veins the Emulgent Veins And these Bodies are called the Reins We find them first wrapt up in a Tunicle which covers the whole Cavity of the lower Belly Next to this there is another Tunicle which does immediatly cover them And in fine when we have taken off these two Tunicles we discover the surface of the Reins upon which we have the pleasure to observe an agreable ramification of Sanguineous Vessels These Sanguineous Vessels do enter into the Reins upon there Concave side which looks towards the Aorta and the Vena Cava Many small Nerves go from the Plexus Renalis and bear them faithful Company They are all shut up in a small Membranous Cover and the Nerves are lost in its substance Afterwards these Vessels are spread through the outer substance of the Reins and enter into small Glandules of which this whole outer substance is composed These Glandules are fastned to the Vessels as the Grapes to the Trunk of the Cluster By this means they make small Lobes wrapt up into a particular Tunicle This Tunicle enters partly into the Capsula and partly into the Cavity of the Reins which they call the Bassin All these small Lobes do adhere to the one or the other of these by small Tendinous Filaments From each Glandule there goes an Excretory Vessel They descend in a straight line to the Bassin being coucht one beside another When they come near to peirce the Tunicle which makes its inward Cover many of them joyn together and make up a great Pipe This Pipe has an opening by which it communicate with the Bassine about which opening we remark a little Rising which they call a Papilla The Cavity of the Bassin is Covered with a very thick Tunicle It is formed of the Expansion of the small Pipes which pierce it It is afterwards so much contracted towards the Concave side of the Reins that it takes the forme of a Vessel of the bigness of a Goose feather It descends in the form of an S. and goes into a Bag placed in the lower part of the Abdomen under the Pecton They call this Bag the Bladder of the Urine These Vessels they call the Ureters They are wrapt up in the Peritonaeum and in a proper Tunicle which communicates with that which does immediately cover the Reins Their Substance is Membranous and very Thick Their Fibres are so variously interwoven that they keep no order The use of the Reins is to separate a Saltish Serosity from the Blood which passeth from the Glandules into the Bassins and from thence runs by the Ureters into the Bladder This Liquor they call Vrine The twentieth and first Discourse Of the Bladder and of the Vrine THe Bladder is a Bag into which all the Urine goes which the Reins do separate from the Blood Its Figure is like to that of a Pear It is so Situated that its wider part which they call the Bladder is alwayes turned upwards and its more narrow part which they call the neck of the Bladder is ever turned downwards It is held in this Situation by two considerable Ligaments The first goes from its bottom to the Navel It hinders it from falling downwards The second is very short In Men it keeps it fixt upon the Rectum in Women upon the Matrix so that the Bladder cannot turn either to the left or right Hand The first is inserted in its fore part and the second in its hinder part The Bladder is made up of three Tunicles The first is nothing but a production of the Peritonaeum which enwraps it outwardly It is composed of Tendinous Fibres variously interwoven The middle Tunicle is made of
is straitned by a small Fibrous Ring at its Insertion into the Vesicle of the Bile So that this Fibrous Ring performs the office of a small Sphincter which shuts the entry of the Vesicle and hinders the Bile which usually fills it from getting out unless it be forced Afterwards I consider the Vesicula Fellis It has the figure of a small Pear and it receives Arteries from the Caeliack which are called the Cystick Arteries It is made up of two Tunicles between which there are a prodigious number of small Vesicular Glandules which receive branches from the Cystick Arteries The Excretory Vessels of these little Glandules do peirce its inner Coat and make within its Cavity a small Down from whence there flows a very clear and Transparent Bile in form of a Dew This Bile differs from that which flows from the Hepatick Conduit in this that the former is of a deeper colour and abounds more in a fixt Alcalie whereas this is more fluid and has more of a Volatile Alcalie than the other All the Bile which is found in the Vesicula Fellis does not come only from the Vesicular Glandules situated between its Tunicles but a great part of it comes from the Lobes of the Liver which are about the Vesicle They discharge themselves into its Cavity by two or three Ductus Cholidoci which are inserted into that part of it that adheres to the Liver Amongst the rest there is one considerable enough which peirces the Tunicles of the Vesicula Fellis near the Fibrous Ring The mouth of this Vessel is encompassed with a small Spongious border which serves it for a Sphincter There goes a great number of Lymphatick Vessels both from the concave part of the Liver and from the Vesicle which enter into the Reservatory that is placed above the Vertebrae of the Loins In fine the Liver has three Ligaments which keep it in its situation The first keeps it strongly fastned to the Diaphragme and it peirces into the substance of the Liver even to Glisson's Capsula The second is of a good length it is fastned to the Liver near the Bladder of the Gall and it goes to the Navel The third is slack but strong and large It derives its Origine from the Membrane which encompasses the whole Liver and which is a production of the Peritonaeum and it goes from thence to the Xiphoid Cartilage It s upper part is Convex and it s under Concave is divided into three or four great Lobes and by its under part it embraces a part of the Stomach So that when the Stomach is full of Meat the Bladder of the Gall being then prest the Bile goes out by the Cystick Channel and runs in abundance into the Duodenum to dissolve the Chyle according as it comes from the Stomach From all this therefore we may conclude that the use of the Liver is to separate the Bile from the Blood to perfect the Chyle in the Intestines by dissolving its Sulphurs by its Alcalies and by diluting it with its Phlegme The Thirteenth Discourse Of the Changes which the Chyle receives in the Intestines BEsides the Bile which is discharged into the Duodenum there is also another Liquor Clear and Transparent as Water which advances thither and which they call the Pancreatick Juyce This Pancreatick Juyce is somewhat of the same nature with the Lympha that is that it is composed of Sulphurs Phlegms and Volatile Alcalies As soon as it falls into the Intestins it mingles with the Chyle If it rencounters any Acids in the Chyle which keep its Sulphurs united its Volatile Alcalie charges its self with them which frees the Sulphurs from the other Principles The Sulphurs which are in the Pancreatick Juyce thrust themselves amongst the parts of the Chyle They moderate the Fermentation of the Alcalies with the Acids and hinder it from being done with too much Violence which would occasion much disorder And the Phlegme make way to the Alcalies and Sulphurs and they mingle more exactly with all the parts of the Chyle From all this it follows clearly enough that the Pancreatick Juyce perfects the Chyle and renders it more Liquid In men the Pancreatick Juyce and the Bile do enter into the Intestine at the same Hole And in the most part of other Animals the Pancreatick Conduit is inserted into the Jejunum two Inches below the Insertion of the Ductus Cholidochus We remark in this Insertion of the Pancreatick Conduit almost the same circumstances which have been observed in the Insertion of the Ductus Cholidochus About the little Hole from whence the Pancreatick Juyce flows into the Cavity of the Intestines there is a little Fibrous edge which serves it for a Sphincter and hinders any thing from passing from the Intestines into the Pancreatick Conduit This Conduit is made of many others which spread through a Glandulous Body which they call the Pancreas The Glandules which compose it are Vascular of a reasonable bigness There goes from each a small Conduit which is Inosculated into the Pancreatick Conduit and sheds into its Cavity the Liquor which the Glandule has separated from the Blood The whole Pancreas is covered with one Tunicle It receives Arteries from the Caeliack it sends Veins to the Splenick and some Ramifications of the Intercostal come thither and spread through all its Body It is so needfull for the conservation of of the Animal that the Chyle should be freed of its Acids that the Author of nature has plac'd many heaps of Vesicular Glandules between the Tunicles of the small Intestines They distill into these places a Liquor like unto the pancreatick Juyce By its mixture with the Chyle is finisheth what the Bile and the pancreatick Juyce had so well begun These small heaps of Glandules are of different bignesses There are of them which contain more than two hundred Glandules and there are of them again which have not thirty Sometimes there are four of them sometimes five and sometimes six Sometimes there are two of them in the Jejunum sometimes three and sometimes but one we find alwayes two or three such heaps in the Ilium All the parts of the Chyle are not fit to Pass into the small Vessels which are called the Lacteal Veins Some of them too gross and these are they which are called the gross Excrements The Chyle abounds in parts fit to pass into the Lacteal Veins after that it has been prepared by the Bile and the pancreatick Juyce It is for this that its masse doth diminish so much in the Jejune Intestines for that its more subtile parts get out and pass into the Lacteal Veins So it is observed that there are more Lacteal Veins of the Jejunum than of all the other Intestines At the end of the Jejunum some Excrements are found mingled with many Chylous parts The Glandulous juyce mingles with them and dissolves the Sulphurs from the Chylous parts which are there What has thus been prepared passes likewise into the