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
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
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
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
ESSAYES OF ANATOMY In which the Construction of the ORGANS AND THEIR MECHANICAL OPERATIONS Are clearly Explained according to the new HYPOTHESES By ****** Dr. in Medicine Written Originally in French EDINBURGH Printed by George Mosman and are to be Sold at his Shop in the Parliament Close Anno Domini 1691 TO THE RIGHT HONOURABLE The VISCOUNT of TARBET My LORD THe following Treatise receiving the Approbation of a most Ingenious Peice it has encouraged the making and publishing this Translation to supply the scarcity of French Copies and to satisfy the Curious who do not understand that Language And because the Author of the Essayes has both the Honour of Your Lordships Acquaintance and also the Favour of Your good Opinion Therefore Your Lordships Patronage and Protection is Humbly desired to this Translation which will be found a just enough Representation of the Author Thoughts and Sentiments And the Publisher hath presumed to prefix Your Lordships Name to this that He may testify his Duty to Your Lordship and likewise because of Your Lordships readiness to encourage all Ingenious Studies and Enterprises The STATIONERS ADVERTISMENT TO THE READER THose who Judge of a Book by the Title are Discouraged when a Title is Simple and on the contrary believe that a Work is Excellent when Men have the Art to give a great Idaea of it by an ingeniously invented Title we might doubt of their acceptance of this little Treatise if many others which have appeared with the same Modesty and have nevertheless had a great Success had not favourably disposed the Reader for the word Essayes Since those of the Famous Montaigne how many others have appeared in Physick and in Morality which have been the Admiration of all the Learned I hope therefore that they will not be prejudiced against this present Treatise because it promiseth nothing but Essayes and that they will have the Patience to see what it sayes After which I am perswaded they will be satisfied I shall say no more to recommend my Marchandize THE PREFACE THe knowledge of the Living Body is extremly necessary for Physicians Without it they do nothing but at adventure This is a Flambeau which gives them Light in the Causes of Diseases and in the Choice of Remedies And all they who understand nothing in it can be reasonably concluded no other then Charletons The most part of Judicious and Ingenious Men have alwayes acknowledged this Truth It is for this that they have ever cultivated Anatomy with much application In the past Ages they thought they knew all that could be Learned of it And in this they have found to the shame of Physicians that they have made but a very small advance in this Science The preoccupation in which they were in past Ages in favour of the Antients was the Cause why they did not apply themselves to Learn but what these had discovered Hippocrates and Galen only were then studied They sought in their Writings all that they were obliged to know to render them Learned Men. They imagin'd they knew all and took those for Visionairs who pretended to know more than these Thus the past Ages have been extreamely barren in Discoveries But Thanks to the Penetration of an excellent Philosopher of this Age it has been discovered that the Living Body is nothing but a Machine Men have applied their Minds to discover its Springs In this Harvey and Pecquet have been successful The Circulation of the Blood has Immortaliz'd the one and the Reservatory of the Chyle and the Thoracick Conduit has given the other a Reputation which will never end Their Example has animated all the Anatomists They found they had made small progress in the knowledge of this Machine They were perswaded that they needed but search to make Discoveries In effect the Bartholin's the Wharton's the Steno's the Willis's the Glisson's the Lower's the des Graaf's c. And above all the Malphigis have searched very deep into the Structure of the Living Body The Discoveries which they have made do give us an Idaea of an Animal altogether different from what the Antients had of it It might seem that after them there remained nothing to be Discovered Nevertheless there are Treatises frequently published which contain some new thing and I doubt not but an hundred years hence they may make some new Discovery The Contrivance of the Body is necessary for explaining the Office and Function of its Parts and if what we fancy to to be the Contrivance is not sufficient for the Explication of the Operations of the Body nor the Effects of its Particular Members and Parts we may therefore conclude that there is something of this Contrivance yet to be Discovered The best Anatomists do ingenuously acknowledge that they fail in many Particulars there are therefore many Discoveries yet to be made Some of them will be found in these Essays and to me they seem Important enough to make me believe that they will not be unacceptable I do not conceive the same hopes of my Sentiments concerning the nature and use of the Liquors which are found in the Living Body To those who are prejudiced the Novelty of the most part of them will make them seem extravagant But I hope those who do not condemn an Opinion without having examined it will do me the favour to believe that if they find them Erroneous I was not hastily mistaken without good and probable inducements I shall only beg of them to Read the first Treatise of these Essays before they read the rest It gives the Idaea which I make to my self of the Elements and without it they will not conceive so distinctly what is contain'd in the rest There is a great Connexion between all the Treatises of these Essays Those who would understand them well will not do ill to read them in Order The Order which I give them will seem Fantastical to those who are accustomed to read Courses of Anatomy written according to the Ordinary Method But they who shall observe that each Treatise serveth for the understanding of that which followeth will acknowledge that I have given them a Natural Order Perhaps it may be thought strange that I make no mention of Authors in the places where I set down their Discoveries They may even think that I do it on Design to attribute to my self the Glory of them In this they would do me a great Injury I am not so base as to acquire Reputation at the Expence of that of others But I have not nam'd those who have made the Discoveries because every Body knows them and it would serve nothing for the understanding of these Essays There is an excellent Anatomist at Montpellier who is called Monsieur Chirac The first reason which has made me wave the Names of others has no place as to him Nevertheless I have not Nam'd him any where But I 'le do him Justice here It is he who has written to me that all the Glandules were
conclude that the Fire does not produce any changes in the Elements which are extracted from Bodies by the means of Chymie And since many different Liquors are to be found in Animals which are composed of divers Elements we shall make use of the Chymie to separate them from one another and to examine them apart that we may know the nature of each in particular After this we shall easily see what may be their uses in the animal Oeconomy and what effects do depend upon them The second Discourse Of the Blood WHen I strike a Lance into any outward part of a living Animal I remark that there comes from the wound I have made a red Liquor which I call Blood I imagine that it is very important to know the nature of it aright for I find it so spread through all the Body that there is no part which is not watered with it Which obliges me to gather a little of it in a Vessel and to know if it be not some of our Elements or if it be not a composition of them I mingle it first with Acids and I find that they co-agulate it in such a manner notwithstanding that they co-agulate but a part of it and that remains another very Liquid and Transparent which we call Serosity In the second place I take the Serosity and mingle it with Acids and I find that there is made by this mixture a little Fermentation From hence I conclude that there are in the Blood much Sulphur and some Alcali that the Sulphurs are that which has been co-agulated by the Acids and that the Alcalies are that which ferments with the Acids which we mingled with the Serosity I do not satisfy my self with this I take Alcalies and mingle them with the Blood to confirm what I conjecture by some new Experiment And it falls out that the Blood is extremely dissolved by this mixture And as I know that the effect of Alcalies on Sulphurs is Dissolution I am confirmed the more in the opinion I have that in the Blood there is a great deal of Sulphur The small Fermentation which the Acids have excited in the Serosity makes me think that there is in the Serosity something more than Alcalies and by consequent that there is through all the Blood some other Principle than Sulphurs and Alcalies To know therefore the truth of the matter I take a considerable quantity of Blood I put it in a Cucurbite I place my Cucurbite in a Furnace to distil some part of it by Sand. I adapt a Head to my Cucurbite and to the Pipe of the Head I apply a Recipient I take care to lute the Junctures well and give it a little Fire at first and augmenting it afterwards by degrees I dry gently all the Blood which I had put in my Cucurbite Whilst the Blood is thus drying there arise some Vapours in the Alembic which gathering in its concave Surface run in drops of Water through the Pipe into the Recipient I take this water and try it by putting it on my Tongue A little favour that it excites there makes me judge that it is not pure Phlegme I mingle Alcalies with it and I remark no Fermentation Which makes me think that what is in this Water is not Acid. I mingle afterwards Acids with it and I perceive by the light Fermentation that arises from this mixture that there are Alcaline parts extremely Volatile mingled with much Phlegme I take out after this that which is dryed in my Cucurbite and I put it in a Retort which I place on a Furnace proper for this I give it Fire by degrees and there comes out of my Retort a stinking Oyl which is the Sulphureous part of the Blood With the stinking Oyl there comes out a great quantity of whitish Particles which stick to the neck of the Cornute and to the concave Surface of the Recipient as if it were a most delicate hoar Frost I examine the stinking Oyl by the mixture of Acids and Alcalies The Acids Co-agulate it the Alcalies Liquify it which will not let me doubt that it is a true Sulphur I do the same with the whitish Particles which I rub off from the neck of the Cornute and the sides of the Recipient and I learn by the great Fermentation they make with Acids that it is nothing but an Alcalie which rising by a moderate heat is very Volatile I have therefore three Volatile Principles which compose the Blood viz. A most considerable quantity of Phlegme much of a Volatile Sulphur and yet more of a Volatile Alcalie That I may know now what remains in the the bottom of the Cornute I put it in a Crucible and Calcine it by a wheel Fire There is some small matter that yet Exhales And in fine after the whole have been well Calcin'd I make a Lixivium of it which I filter I make a part of the Water to evaporate which makes up the Lixivium I put the rest in a cool place and there Chrystallizes somewhat about my Vessel in form of a Salt I take this Salt and mingle it with Alcalies and Acids The Alcalies do not move it but the Acids excite a Fermentation yet less than what they do with the Volatile Alcali of Blood Which makes me think that it is a Fixt Alcalie with which there may be some Acid mingled I perceive after this that there remains some Terrestreity in the Paper through which I filtered the Lixivium from whence I had extracted the Fixt Alcalie So that after having examin'd all I find that the Blood is a Composure of Volatile Alcalie Fixt Alcalie Volatile Sulphur Phlegme Earth and it may be some little Acid mingled with the Fixt Alcalie So that it abounds more in Sulphur in Volatile Alcalie and in Phlegme than in any other Principle For there is little of Fixt Salt and almost no Terrestreity We may easily understand by this the reason why through a Microscop there are to be seen in the Blood many small red Globules which swim in a Chrystalline Liquor while the Blood is put into small Pipes of Glass The Sulphurs which are more disposed to keep themselves united to one another because their branches are embarrassed do swim in a Liquor compos'd of Phlegmes and Alcalies The Phlegmes by their motion press those branched Particles one against another and oblige them to form small Sulphureous Globules after the same manner that the Air makes the drops of water Sphaerical And the Alcalies make the smalness of these Globules and oblige the Sulphureous parts of the Blood to assemble in small Bodies by keeping them separated one from another We see also the reason wherefore curdled Blood after having been washed in cold water seems all Fibrous For cold water dissolves the Alcalies and carries them away Afterwards it assembles the Sulphurs which fall down to the bottom of the Vessel like a Glairous matter and composed of small Fibres like Glue It is also for the
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
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
Carneous Fibres Of these they reckon three Orders The first is of some great Fibres coucht on the fore-part of the Bladder which come in a straight line from its bottom even to its neck The second is of Fibres which do enwrap the Bladder Circularly They may be called Circular Fibres And the third coucht under the Circular is of Fibres which cross the former obliquely going from the left to the right Hand from the bottom of the Bladder even to its neck We shall call them Transverse Fibres In fine the inner Tunicle is composed of Tendinous Fibres of such a Textures as has not been yet discovered When the Bladder is not blown up it is all wrinkled and within it is alwayes covered with a Mucilage At the neck of the Bladder there is a Muscle made of strong and Circular Fibres It is a Sphincter which keeps it alwayes shut From all this we may conclude that the Bladder is a Concave Muscle whose outer and inner Tunicles are Tendons and the middle Tunicle the Belly The Insertion of the Ureters into the Bladder shewes evidently enough that its use is to be the Reservatory of the Urine and that all we have remarked in its frame tends to no other end but to keep the Urine in its Cavity and to thrust it forth when it is therewith filled I say that the Bladder is the Reservatory of the Urine for that the Ureters are inserted into its Cavity after such a manner as that the Urine can easily enter there but cannot return again into the Ureters They creep for some space between the outter and middle Tunicles afterwards they peirce the middle Tunicle and creep a little farther between it and the inner which they peirce towards the neck of the Bladder So the Urine can pass without much difficulty from the Ureters into the Bladder But as the Bladder swells by the abundance of Urine it straittens the ends of the Ureters which creep amongst its Tunicles so that the Urine in the Bladder cannot enter there The Sphincter of the Bladder is the cause that the Urine makes some stay in its Cavity And least in staying there its salts should prick the inner Tunicle nature has conveyed thither the Mucilage which anoints it on all sides The Longitudinal Fibres shorten the Body of the Bladder when the Animal Spirits do contract them The Circular and the Transverse do by their action straitten it So when the Fibres are filled with Spirits the Bladder is Lessened in all respects And if then there be Urine in its Cavity it makes its passage maugre the resistance of the Sphincter and gets out of the Body by a small Pipe which they call the Vrethra This Pipe is nothing but the Continuation of the Inner Tunicle of the Bladder In Women its opening is in the Pudendum and in Men it extends its self into the Body of the Wand and terminates in the end of the Balanus By all that has been said we see that the Reins the Ureters the Bladder and the Vrethra have been made to separate the Urine from the Blood and to convey it out of the Body not only as useless but even as hurtful to the maintaining of the Animal Oeconomie To understand these truths aright it is to be observed that the Urine is almost composed of nothing but Phlegms and Volatile Salts having but very little of Sulphur Earth and fixt Salt The Nitrous Spirit which mingles with the Blood in the Lungs is composed of Acids and Alcalies Its Acids coming to joyn with the Alcalies of the Blood do make a Salt And for that the most part of the Alcaline parts of the Blood are Volatile the Salt which is made of them is also Volatile These Volatile Salts might diminish the natural Fermentation of the Blood and stop its Course To prevent this mischeif the Author of Nature has plac'd the Reins into the Bodies of Animals which do separate these Saline parts from the Masse of the Blood And for that also a too great abundance of Phlegm would make the Blood too slow and hinder the Spirits from acting the Reins do not only separate the Salts but also the Phlegms which are the two Principles whose too great abundance would be capable of chocking the ordinary Fermentation of the Humours upon which the life of Animals depends Moreover it is remarked that when the Urine abounds in Alcalies that is to say when its Salts are not strongly charged with Acids it is thick and troubled And when it has a deal of Acids that is when its Salts are well furnisht with them it is more clear and Transparent And when there is much Salt in a little Phlegm the Urine is of a reddish Colour And when there is much Phlegm and little Salt it is clear and is very near unto the ordinary Colour of Water There is remarked in the Urine a little Cloud which is formed of some parts of the Mucilage which we have said is in the Bladder The Salts of the Urine detatch them by little and little and carry them along with them This Cloud appears when the Urine begins to cool because the coolness doth condense it and by this mean renders it more visible FINIS