CHAP. I. Of the Organs of Breathing and their Vse .

IN the former Treatise having essayed to explain the reasons of every Medicine , for the most part we have toucht only upon general Medicines , namely which excite some Evacuation , or recreate and restore the fainting Spirits , or calm those which are too much raging and unquiet : The Authors purpose in the present work . But moreover there are many other Remedies , and those of several sorts , which are supposed to have respect to some peculiar part of the Body , or some particular Disease , and to be appropriated to those ends by a certain kind of specific virtue or operation . Now as concerning both the 〈◊〉 〈◊〉 〈◊〉 〈◊〉 〈◊〉 and 〈◊〉 〈◊〉 〈◊〉 〈◊〉 〈◊〉 of these , at least the chief of them , viz. whether it be really so , and for what reason it comes to pass to be so , it seems now worthy to be inquired into : And first of all we will treat of the Medicines of the Thorax , viz. those that are wont to be prescribed against the Cough , Phthisic , Catarrh , Asthma , Dyspnoea , and other Diseases of the Breast .

But since the reasons as well of these Diseases as of medicinal Operations in healing them seem very abstruse and most difficult to declare : The parts of the Thorax . therefore before I enter upon this task , something ought to be premised about the parts themselves , as well touching their uses and ordinary actions , as their sicknesses or preternatural affects . As to the first , the parts of the Thorax are either principal , as the Heart and Lungs , with the Vessels appendent unto them ; or subservient , as the Membranes and Muscles , with the Diaphragma ; as likewise the Ribs , with the Vertebra's ; the Pneumonic Vessels , with the nervous Fibres and Glandules . The consideration of the Heart and its Vessels doth not properly belong to this place , because not so much the sicknesses of the Breast alone as the general sicknesses of the whole body are usually reckoned amongst its passions . Whereas therefore the remedies appointed to cure the diseases of that region , have special respect to the Lungs , and to the other Organs of breathing serving them ; therefore first we will describe the fabrick and use of these parts , then their diseases afterwards , together with the method of cure , and remedies ; and lastly endeavour to add the reasons of all these .

The substance of the Lungs was always accounted by the Ancients , and mostly hitherto by modern Authors for flesh and a Parenchyma , like the frame of the other bowels ; which notwithstanding was accounted lighter and spongeous ( for as much as it was apt to be distended much by air pufft in , The substance of the Lungs altogether membranous . and to float upon waters . ) Moreover , whereas the Lungs taken out of an Embryo look red , and sink in water ; and the Lungs of some grown persons being boiled , appear compact enough and more solid ; almost no man doubted but they consisted really of flesh : until lately the renowned Malpighius , a most diligent Searcher of Nature , found those parts to be altogether excarneous , and meerly membranous ; and therefore he judges the bulk of the Lungs , if the Nerves and certain Vessels be separated with the branches of the Trachea , to be a certain heap of little Bladders , and those small Bladders every where stretched out and sinuous , to obtain such position and knitting together , that an entrance lies open into them from the Aspera Arteria , and so from one into another , until at length they all end in the Membrane inclosing the Lungs . And truly that it is so , he makes clear to sense by an Experiment . For let a Lung be taken out hot , and let water be so often cast by a Syringe into the Pneumatic Artery , as till the whole frame appear somewhat white , and almost transparent , the blood being clean washed out ; afterward this water being squeezed out by pressing , and the air let in by the Wind-pipe , and pen'd in , let the Lung so filled be dryed : and it does not only , whilst exposed to the light , outwardly shew transparent little Bladders ; but being inwardly cut , it presents a white heap of little Bladders to the eyes . Besides , having viewed it with a Microscope , he discovered a certain wonderful Net , binding and knitting together every one of those little Bladders ; which Net consists of the minute productions and branchings of the Artery and Vein ; which Vessels circulate the blood by the small and crooked passages , and by the many turnings of the Pipes .

The most renowned man hath found out beside these little Bladders for the most part constituting the frame of the Lungs , a new and more admirable furniture of this Bowel , Consisting of almost infinite Lobes . viz. he shews plainly the bulk of the Lungs to be blown up by almost infinite lobes girt about with their proper Membrane , which being endued with common Vessels , grow to the small twigs of the Aspera Arteria : the insertion and situation of which kind of little Lobes are manifold , as being sometimes affixt to the Basis of the Trachea , sometimes to the Ribs , or to its Cone ; also according as they end in the outward and plain superficies , or in the corners of the Lungs ; and according as they ought to have a due position , knitting and inter-spaces among themselves , rightly to fill up the frame of the Lungs . The little lobes out of which each lobe of the Lungs is made up , in the third Table are accurately and to the life expressed .

Certain inter-spaces distinguish these little lobes ( which manifestly appear in a larger Lung or in any other half boiled ) which ( as the renowned Person hath observed ) are not bare cavities or empty spaces , Their little branchings . but they have many Membranes spreading from the little lobes , some parallel , some angular , and are also covered with many Vessels , so as these inter-spaces are certain membranous little bladders , yet transparent and most thin . If you lightly open in one single lobe of the Lung one of these inter-spaces with the point of a knife , and shall blow into it by a small hole through a Pipe , presently that whole lobe will be very much extended , every interspace being pufft up ; and then if you bring this frame to the light , the inter-spaces being made transparent , do sever by great intervals every lobe very conspicuous ; and so every rank of the lobes will appear like a Polypody-leaf , and under the same figures , as Malpighius hath described , and are represented in Fig. 2. of our third Table . But when the little lobes are filled and extended by liquor easily congealing cast into the passages of the Trachea , the appearance thereof is somewhat diverse , and seems in the form of Grapes , as is expressed in Fig. 1. of the same Table . The Veins and Arteries every where accompany this production of the Aspera Arteria , and extend themselves through the whole substance of the Lungs by a certain knitting and alike branching . This is plainly perceived by a pleasant sight , in a lobe of the Lungs being emptied and turgid , Quick-silver being cast into some of the Vessels , and others filled with a coloured liquor . But in dissecting the living , another sort of Vessels , viz. Lymphaeducts are manifest to the eye to be spread through the whole Lungs : The Lymphaeducts and nervous slips . and we have in another place clearly enough shewn , both very many Nerves and nervous slips every where to be distributed through them . Besides these parts , and the primary or chief vessels of a Lung , some others , and those as it were secondary , are to be observed . For the Pneumonic Veins and Arteries are endued with other sanguiferous Vessels springing from the Aorta , moreover with Glandules , and likewise with Fibres as well nervous as moving ; and the Wind-pipe is endowed with every one of these , and cartilaginous ones besides .

Whence we may infer , that the entire frame of a Lung is meerly fistulous , The Vessels of a Lung . and compacted of Pipes of several kinds and magnitude , and variously and most intricately disposed : which although they may appear wonderfully complicated , and many ways twisted and wreathed , are yet every where continuous , and being stretched out with a mutual respect to one another , do hither and thither in good order and regularly convey and dispose the air , the blood , the Lympha , and animal Spirits for some accessary uses . To describe as it were with a Pencil this bulk of a Lung , together with the branchings , separatings , and mutual complications of all its Vessels , would be no less difficult a task than to trace the several threads of a harl of silk , and their respect one to another . Nevertheless , that both the Pathology of the Thorax , and the cure , may be duly known according to our design , it seems to be material to recite here all the Vessels of the Lungs one after another , and to deliver as well their descriptions , as their preternatural uses and diseases , to which at length the Therapeutic Method shall be subjoyned . And these are the Vessels of which the entire fabrick of the Lungs consists , the Wind-pipe , with the Bronchia and little Bladders , Arteries , Veins , Lymphaeducts , and Nerves , to which may the parts and appendices of those Vessels be added , viz. the Coats of the greater Vessels , which are endued with other sanguiferous Vessels and Glandules , and also with nervous Muscles and Fibres .

Therefore as to the chief Vessels of the Lungs , although all these , by reason of their mutual offices , communicate among themselves with a wonderful affinity ; yet the Arteries and Pneumonic Veins attend on the Trachea and its partitions the most exactly ; Wait on the Trachea . for the branches and sprigs of every one of these springing alike from their respective stocks , and stretcht out to and fro , go on every where with like pace ; so that the Trachea and its branches are always in the middle , above that the Vein , and beneath the Pneumonic Artery are carried , and all are distributed with an equal and sociable branching : and the sprigs and branches , sent from each of them , are presently applied to their like , and are interwoven like wonderful Nets , of which the texture of the Lungs is almost totally constituted . It will be impossible to describe the spreadings out and various complications among themselves of all these going on together , as to the lesser sprigs and slips ; yet if you will cast into every vessel apart Quick-silver , hot and flowing Gypsum , Wax mingled and made liquid with Oyl of Turpentine , or some such matter , which will extend all or the chief passages , and continue them stufft , then you may exactly enough represent the figure : and after that manner the frame or texture of the whole Lung may be conceived , each being described by it self and apart . Wherefore upon these and all other Vessels and parts of the Lungs we will treat in order ; and first of the Trachea or Wind-pipe .

The Wind-pipe or Aspera Arteria is a Pipe somewhat long , The description of the Trachea . consisting of Grisles and Membranes , which beginning from the Throat or lowest part of the Jaws , and leaning on the Gullet , and descending into the Lungs , is dispersed by manifold little branchings through their whole frame . It is divided into two parts by the Ancients , viz. the upper , which is called the Larynx , and the nether commonly called Bronchus ; to which a third or lowest is added , by Malpighius called Vesicularis , or the bladdery one .

The former of these , which is the beginning of the Aspera Arteria , The description of the Larynx . doth chiefly serve for vociferation or loud noise , formed of many and various Grisles , to which also are adjoyned proper Muscles ; the description and use of all which are so exactly delivered by Anatomists , that there is no need of dwelling longer on the description : we only advertise for methods sake and by way of abridgment , that the Larynx contains some greater Cartilages of divers forms , and some uniform ; the former , by reason of resemblance , bear the denomination of Epiglottis , the Buckler-like Cartilage , the Ring Grisle , and 〈◊〉 〈◊〉 〈◊〉 〈◊〉 〈◊〉 . To this last doth succeed a continual rank or row of Cartilages , fashioned altogether after the same figure and manner ; every one of which , whereas they resemble a circle , but not compleat , are disposed after such a sort , as if one so compose many wooden Rings , that there should grow up from the sides of them , by laying a good many one upon another , a certain Pipe as it were with Ribs . These circular Cartilages are equally distant one from another in their whole passage , and are knit together by the benefit of an inner Membrane ( which fills up the spaces between like the Periostium ) as with a ligament . But the hinder part of every Ring-like Grisle where it lies upon the Gullet , that it may serve better to the swallowing of meats , turns into a Membrance , which altogether is the same , and binding together those cartilaginous rings , and covering the whole hollowness of the Larynx , is always moist with an unctuous homour , by which it may as well be defended against the sucking in of sharper air , as breathing out more acrimonious vapours .

Besides this inner Membrane , Membranes encompassing the wind-pipe . also another outward , though thinner , encompasses the whole Wind-pipe , by the aid whereof both the Cartilages are more firmly knit among themselves , and the whole Pipe bound to its neighbouring parts , and descends more safely and strongly into the Breast . Besides , we judge there are some other uses and offices of either Membrane , than that it only serve to fashion or defend the sides of the Wind-pipe : for as much as we do here manisestly observe many Nerves and nervous strings every where inserted , and also the more inward Coat of the Aspera Arteria to be endued with Fibres , as well nervous as fleshy or musculous : from whence we may conclude the Wind-pipe to injoy both a certain sense and motion either in the whole , or at least in some parts . And truly it is manifest even to common observation , that its more inward passage doth excel with a most acute sense ; for as much as it is so much provoked by the smallest prejudice , that presently it is wonderfully forced into a convulsive motion , viz. a Cough : but as a sense of annoyance , and from thence very often an instinct of motion arises from this Vessel ; so we think that its Fibres do after a sort move of themselves both in breathing and coughing . Surely in respect of this it is not to be doubted , because in this inner Membrance we find two orders of muscular Fibres in that fashion disposed as in the Aorta and Intestines : to wit , there is one upper order of straight Fibres , which while they are contracted , make all the circular Cartilages to be drawn together nearer to one another , and for that cause to abbreviate the Trunk of this Vessel according to all its parts successively . Under this lies another order of circular Fibres , which ( while they are pufft up ) being contracted , the hollowness of the Wind-pipe is much narrowed . Therefore when the moving Fibres of either kind make the passage to be straitned according to all its dimensions , it is obvious enough that they conduce to the discharge of the function of breathing , and more or less to be active , as there is endeavour to breathe quicker or slower , more intensly or more remiss . These Fibres being more vehemently contracted in a Cough , in hawking , in blowing out , and certain other more strong exercises of expiration , do force the breath and other contents of the Aspera Arteria to be violently expelled . Moreover from this action sometimes either depraved or hindred , it shall be declared hereafter how an Asthma , a Dyspnoea , and some other diseases about breathing do arise .

This inner musculous Coat hath also two others , The glandulous and vasculous Coats . as if growing thereunto , to wit , one glandulous , and that full of vessels . For as in another place we have remarked about the Anatomy of the sanguiferous Artery , one may also here take notice , that the inward Pipe of the Wezand is covered with a most thick weaving of Vessels of every kind , and especially of those carrying blood , in fashion of a Net . The Arteries not springing from the Pneumonic Vessels , but from the Bronchial branch ( which the most renowned Mr. Ruisch discovered to have its rise from the Aorta ) are inserted into this same ; which the veiny slips do accompany , owing their origine to the Vena cava . The nervous sprigs meeting these two , are variously folded ; and so of all weaved together , is framed as it were a little Net , covering the whole back of the Weazand , under which folding of Vessels very small and whitish Glandules are every where strewed , or rather cleave to them ; just in the like manner , as we have in another place shewn to be in most other greater Vessels , and in all membranous Bowels : on all which the Lymphaeducts adjoyned do wait . As to the use of these , without doubt the Arteries and Veins wash through the Pipe of the Weazand with bloody stream for its nourishment ; and the Nerves carry plenty of Spirits , and the faculty of performing motions to the muscular Fibres . Afterwards whatsoever of superfluous moisture be left by the Arteries , that the Veins cannot bring back , the Glandules do receive and retain , until it may be sent back to the mass of blood through the Lymphaeducts . When they are too much filled , by reason of the Lympha more plentifully left , a humour distilling from the Glandules as well as from the Arteries into the hollowness of the Wind-pipe brings a Catarrh . All the Coats of the Aspera Arteria distinct and separated from each other are expressed in the seventh Table .

The second part of the Wind-pipe , commonly called Bronchos , Of the Bronchia : begins from the entrance of the Lungs : for near the fourth Vertebra of the Chest that great Pipe descending , is divided into two Trunks , one whereof goes towards the right side of the Lungs , the other the left : afterwards both haveing entred the Lungs , and being subdivided for the greater Lobes , distribute very many sprigs ( as for the most part in the gills of fishes ) to the Lobes or lesser Lobes through the whole frame of the Lungs . The passages of all these are furnished , even as in the Larynx , with Cartilages , but framed something in a differing manner : for in the Bronchia these are not Ring-like , but resembling a Coat of Male , so that when there is need to contract those passages , the inferiour Cartilage goes under the hollowness of the upper , almost in the same manner as it is in the joynts of the shelly Coat of a Lobster . Provision is so made by the work of God , that when the Lungs are dilated , the Bronchia are stretcht out into the greatest length ; and when they are contracted , the Bronchia are abbreviated , one part being drawn into another .

The Coats of the Bronchia , as also of the Larynx , Their Systole and Diastole . have muscular Fibres of both kinds , together with the Glandules and the Net-like twisting of Vessels : from whence we may also conclude , that all the lesser Pipes of the Aspera Arteria have their constant turns of Systole and Diastole , viz. all the Pipes are contracted while we breathe out , and relaxed while we suck in air : moreover from the same Glandules and little Net of Vessels every where continued almost within every inward recess of the Lungs , doth distil the Catarrh humour . A certain Bronchial branch of the Trachea belonging to each Lobe of the Lungs is described in the second Table H. H.

And the branched Bronchia of both sides not only constitute two or more greater Lobes ; but , as Malpighius hath observed , The Lobes of the Bronchia . many lesser or little lobes distinct among themselves ; for each Bronchial branch sends forth to and fro many little branches or twigs , every of which twigs being joyned with alike twigs of the Pneumonic Artery and Vein , from thence are parted into innumerable lesser sprigs ; all which being every where fellowed and complicated among themselves , and having got Nerves and peculiar Lymphaeducts , and ending in the outward superficies of the Lungs , represent as it were a certain private Grove ; and so the whole structure of the Lungs consists of many little branches of the aforesaid Vessels complicated , as it were of so many several Groves . The branches whereof and outmost sides of which , Their little branchings disjoyned from one the other . although they may seem mutually to touch themselves and cleave together , yet they are disjoyned one from the other , and are every one bounded within their proper limits ; far otherwise than the productions and communications of Vessels are in the Brain , where the Arteries and Veins rising up in its several corners , extend on every side , and creeping through its whole space , and mutually inosculating , do all communicate among themselves .

That former fashioning of the Vessels hath been very necessary to the uses of the Lungs ; for seeing the air ought only to enter the Lungs for that end , The use of the aforesaid frame . that it might pour out to the blood nitrous particles for its flame and vitality or life , and presently return back ; and seeing the blood doth pass through the Lungs for that cause , that it might meet the air suckt in according to all its parts ; therefore it behoves that both these , viz. the air and the blood be divided into small portions , and with these make every where distinct and short meetings . The manner of this is most elegantly perceived in the gills of fishes ; for seeing the Bronchia are as so many greater Lobes , every one of these is divided into many rundles , furnished with a complication of every kind of Vessels , as if it were into so many Lobes ; in every one of which the blood is drawn out by minute portions , as it were little rivulets , that it might throughly meet with the nitrous particles , and afterwards return into its chanel .

The Bronchial Pipes lead into the utter cavities , The uses of the little bladdery Cells . viz. into the numerous little Bladders discovered by Malpighius ; which truly are certain continued parts of the Aspera Arteria , but distinct from the former , because the Grisles are wholly wanting to them , and , which supply the turn of these , are distant one from another in larger spaces : for all the Bronchial branches send forth lesser slips from themselves every way ; whose passages , although void of Grisles , notwithstanding are straitned as it were with certain ligaments at certain intervals ; and the spaces between these being filled with air suckt in do make partly those small bladdery little Cells . In truth those passages may not unaptly be compared to the Gut Colon of a Mouse , whose continued hollowness in as much as it is girt about in divers places , seems to be divided as it were into many little purses . Moreover those bladdery passages being shorter on either side the Sinus or hollowness , have as it were particular little Bladders growing thick to them , and therefore the heap of all the Cells seems not much unlike to a bunch of Grapes . The Figures of these as much as may be are exactly represented in the third Table . Those little bladdery Cells , that they may put forth their contracting endeavours for breathing , have muscular Fibres , as is plainly seen by the Microscope . For as much as great plenty of air ought to be drawn within the Lungs , and reserved in part , lest it fail at any time ; therefore besides those upper passages which are as it were the threshold and dens , moreover more inner chambers and capacious are required , in which the air may be treasured up , and from thence be dispensed upon occasion . For it sometimes happens the external is too sharp , or otherwise disagreeable to the Lungs ; so that as it was greatly necessary that it should be suckt in more sparingly , and its vehemence presently be attempered and rebated by the air treasured within . Moreover it cannot be drawn in or inspired otherwhile in quantity great enough , as in running , singing , or much speaking , also in some crazy dispositions ; and in that case the inward air being rarified , supplies in a manner the defect of the outward .

Therefore seeing those bladdery little Cells receive a greater stock of air than that they can be bound presently to return it all by every turn of expiration ; Endued only with Muscular Fibres . therefore the grisly twigs are wanting to them , and their hollownesses are more large of themselves , that they may be more largely distended : but that they may puff out a greater quantity of air upon occasion , or throw out matter to be coughed out , being endued with muscular Fibres , they contract themselves more narrowly , and throw out what is contained within them thoroughly . For the ordinary Systole's of the Breast , which the relaxation of the Muscles do partly effect , cast out perhaps at every turn the whole air from the Trachea and Bronchus , but not from the little Bladders : for the emptying of these as often as need shall be , both the cavity of the whole Breast is very much straitned , and the small bladdery Cells themselves are straitned from their proper Fibres being drawn together .

2. The description and use of the Pneumonic Artery . The next Vessel is the Pneumonic Artery , of whose most thick branches extended every where to and fro , and with other branches twisted and complicated together , the frame of the Lungs consists . This Artery issuing from the right Sinus of the Heart , and inclining towards the Trachea , is parted into a right and left branch ; which applying themselves to the like parallel branches of the Trachea , do accompany them every where , or rather are set under them ; for they are planted beneath , and are first carried into the greater lobes of the Lungs , and afterwards into all the lesser lobes : in every of which the little branch of the Artery stretched out , sends out on either side more slips from it self , which presently are associated by other bronchial and venal slips , and are several ways complicated ; and where the outmost sprigs of the Aspera Arteria depart into circular little Cells , the Arteries being complicated with the Veins ( as is discovered by the Microscope ) do girt about those little Bladders with their thick branching , and enwrap them like Ivy : from whence we may conjecture , that it is not for nothing that the Blood-vessels that are any where in the Lungs , do curiously wait upon those of the air , and every where insinuate and intimately mingle themselves . Surely whatsoever hath been supposed by others , I shall not easily believe that this is done for the more exact mingling of the Blood and its parts , be they never so unlike . For to do that , what need would there be of so full an access of air , which in rightly making other mixtures ( the more perfect whereof are called Digestions ) we seek as much as we can to keep out ? For if the air might freely come and go , the Particles that should be mixed , would most of them flye away . And as to that which is affirmed , That the Blood in the Lungs is carried through those small , winding and extreme narrow passages only that it may be the better mixed ; I say , that its being so carried is quite contrary to such an intention : for the best mixture of any liquor ( as also of the Blood it self ) is made by fermentation ; and the liquour to be so mixed or fermented , like Wine in a Hogshead , requires a free and spacious room : but it s going through these small and narrow passages like so many strainers , serves rather for the separation than the mixture of its parts ; wherefore unless the Blood be exactly mixed in the greater Vessels , and be there rightly fermented , it does , while it passes through the Lungs , leave there the dregs and whatsoever parts are not rightly mixt , and so does stuff up and very much obstruct their passages ; as we may see in persons affected with the Green-sickness , Cachexy , and that sort of Dropsie called Leucophlegmatia , who all have a difficulty of breathing , by reason of dregs of the ill-mixt Blood that are left there . Wherefore the use of the Lungs seems to be this , That the Blood through the lesser Vessels , as so many rivulets , may as to all its parts lie open to and meet with the nitrous Particles of the Air , and be by them enlivened and accended . The Pneumonic Artery , as also the Aorta and Wind-pipe , hath a muscular Coat furnished with two ranks of Fibres , namely straight and circular ; which doubtless , when they are contracted , do make the Pneumonic Arteries to beat , and the Blood to be urged and driven still more and more forward . A great many Glandules with a Net of Vessels lie on this musculous Coat . The frame and branching of the Pnenmonic Artery in some one Lobe of the Lungs are expressed in the second Table . All the Coats of this Vessel are drawn distinct and apart from one another in the sixth Table and first Figure , and also in the fourth Table and second Figure .

The Pneumonic Vein , having its rise in the left Ventricle of the Heart , The description and use of the Pneumonic Vein . and being divided and variously subdivided first into greater branches , and then , according to the greater and lesser Lobes of the Lungs , into lesser , and lastly into the least of all , is carried above the Weazand , and as it goes on does exactly answer to the branching both of the Pneumonic Artery and the Weazand , and goes every where with them as it were cheek by joll ; and where the Weazand ends into the little Bladders , the Veins being twisted with the Arteries ( as was said before ) do make as it were a little Net wherein those little Bladders are encompassed . The Anatome of the Pneumonic Vein differs little or nothing from that of the Vena cava and its branches . All the Vessels of this kind have four Coats distinct from one another .

1. The outmost of these Coats consists of Fibres that seem to be nervous , which perhaps are after a sort muscular and are extended straight long-wise , ( though in no very regular order . ) This Coat of the pulmonary Vein is very laxe , and loose from the rest of the Vessel , insomuch that it may all of it be blown up and very much extended , as if it were a distinct Vessel : Whence one might suspect that this were a peculiar passage to carry back Lympha or Serum separated from the Blood : but it seems to be more probable , that this outmost Coat is therefore made so loose , that the passages might be much distended and widened for the return of the Blood now hot and boiling .

2. 3. Two other Coats ( common both to a Vein and Artery ) viz. the vasculous , The use of the venous and vasculous Coat . and the glandulous lie under this : the office of the vasculous is to bring nourishment to the part , and of the glandulous to receive and send away the superfluous serosities .

4. The fourth and inmost Coat is plainly muscular , having Ring sibres , The muscular Coat . as the like Coat of an Artery hath , which certainly being successively contracted after the stream of Blood , do cause its return to be hastened , and on occasion to be shortned . But here arises a doubt , wherefore , Why there is no Pulse in the Veins . seeing the Veins as well as Arteries have contracting muscular Fibres ( which in the latter are pulfifick ) and seeing both are alike joined to the Heart that beats continually , the Veins as well as the Arteries should not statedly beat according to the constant turns of the Systole's and Diastole's in the Heart ? It may easily be answered to this , first , that the Arteries have a great deal more of the moving Fibres than the Veins have ; and therefore whereas those being strongly contracted successively , do force the Blood along as if driven with a wedge , for these it sufficeth that whilst they are gently contracted behind the stream of Blood , they calmly and equally drive it forward , flowing back again of its own accord , and as it were down-hill . But besides , the reason hereof seems to depend somewhat on the unlike or rather inverted conformation of the Vessels ; for the Blood conveighed by the Arteries is driven still from wider to narrower spaces , and therefore going along it every where violently distends them , and lifting up the sides of the Vessels raises the Pulfe ; because whiles that part of the Artery that is behind the Blood is contracted by its muscular Fibres , that part which is before it , must needs beat being filled with the stream of blood gushing in : but on the contrary , the blood in the Veins returning to the Heart , runs out of less into greater spaces , or out of rivulets into a more capacious and deep chanel , and therefore glides along silently and without the fluctuating of a Pulse .

The blood in the pulmonary Veins seems as much , The disposition of the blood in the Pneumonic Veins . or more than that within the Arteries to be animated or inflamed anew by the air insinuating it self every where from the Pipes or little Bladders of the Trachea , because in those Veins 't is first changed from a black-purple to a scarlet : the reason whereof is , because the blood at the extremities of the Vessels , namely as it passes out of the Arteries into the Veins , does every where and most of all meet with the particles of the air . And for that reason it is , that if any liquour be squirted into the Pneumonic Artery , it will not so readily and quickly pass through the Lungs and return by the Vein , as it will do if you make the same experiment in any member , or part of the body besides ; yea part of the liquor so injected will sweat through into the Pipes of the Trachea , or the spaces between the little Lobes , and another part , being turned into a froth , will return very slowly by the Veins : which is a certain proof , that while it passes through the Lungs it makes a stay in the mouths of the Vessels , and is mingled with the airy particles . The Circulation of the blood through the Lungs hath something diverse from , or rather contrary to that which is made through the rest of the body ; seeing the Pneumonic Arteries contain a black-purple blood , and the Veins a scarlet , whereas in all the body besides the branches of the Aorta carry a scarlet blood , and those of the Vena cava a black-purple . Besides we may observe of the pulmonary Vein , that it does every where in its whole length want valves , except where 't is fastned to the Heart . Which appears by this , that when any liquor is injected into its trunk ( just as it is in the Artery ) it presently passes through all its branches without lett . Which ought to be so , to this end , that the blood may always , because of the violence of the passions , freely every way fluctuate and regurgitate in and about the Heart . Besides , that the left Ventricle of the Heart might never be overcharged with the blood impetuously rushing into it , by the instinct of Nature the Fibres at the root of the Vein being contracted , its course might be inverted and flow back . The description of the Pneumonic Vein as to its utmost branching is in the fourth Table and third Figure .

To these three sorts of Vessels , The Lymphaeducts added to the aforesaid Vessels . wherein the air and the blood are conveighed , the Lymphaeducts that carry forth a water are joined . A power of these dispersed through the Lungs , wait on the Arteries and Veins . All the branches tending from the surface of the Lung towards its original , unite into some greater trunks ; which , being inserted into the Wind-pipe , discharge thereinto the Lympha that is superfluous from the blood and nervous humour . Indeed there is need of a great many of this sort of Vessels in the Lungs ; because , seeing the blood is hottest of all here , is hastily circulated , and yet can exhale nothing to without by transpiration , the Veins can hardly receive all the whole mass of blood from the Arteries ; and the Glandules contain not long what is deposited in them : therefore there as need of Lymphaeducts as so many chanels , whereby the superfluous humour might continually be sent off . If these at any time happen to be obstructed or broken , there often follows a Dropsie of the Lungs or Breast , and sometimes Coughs and Phthisicks . These lymphatick Vessels of the Lungs may very well be seen , if in dissecting a live Dog you press the top of the Thoracick duct , that nothing may be poured into the subclavian Vein : for then the Lymphaeducts of the Lungs , because they cannot discharge themselves into the common Receptacle now stopt and filled , swell much and are very apparent . If such a stoppage be made for some time in a Dog that hath eat and drunk largely , a milky liquor will sweat into the Lungs out of the Thoracick duct , the Valves being unlocked : yea and the same liquor will pass through the Lymphaeducts placed far beneath the Reins , and will render them strutted with that homour , as if abounding with milk . The rough delineation of the Lymphaeducts spreading themselves in the superficies of the lobe of a Lung , is represented in the first Table .

5. The last kind of Vessels belonging to the Lungs are the Nerves and their branches , The nervous slips dispersed throughout the Lungs . whereof there are many ( as we elsewhere intimated ) dispersed every where through the Lungs . Heretofore doubting about the office of these , we were induced to think the first force , or at least instinct of breathing depended on these Nerves ; because otherwise we can hardly conceive , after what manner the motion of the Lungs in breathing , coughing , laughing , and other their actions should be always so exactly proportioned according to the several exigences of Nature . For even as the blood doth more intensly or remisly heat and boil up within the Praecordia , and as certain contents of the Trachea provoke the nervous Fibres , we breathe either quicker or slower , and oft-times , though unwillingly , we cough . But besides there doth occur another and more necessary use of these Nerves : for since it is manifest , that the Coats of those Veins and of the Trachea are every where endued with muscular or moving Fibres by which they are contracted , it is plain , that the Pneumonic Nerves do convey as well plenty of spirits , as inclinations of contraction to those Fibres . And it is very probable from those Nerves convulsively distempered , that the Palpitation of the Heart is often excited , as also the Asthma and Chin cough . We have some time since delivered the Anatomy or description of the Pneumonic Nerves in our Treatise of Nerves , viz. pag. 311. so that there is here no need to repeat or inlarge . The fivefold Vessels forementioned being mutual , and many ways accompanied in their distribution , as if divided into secret Groves with small bladders as in Trenches every where interwoven , when they are complicated and variously woven together do constitute a fleshy web , which is the very structure of the Lungs : which moreover appears like a more solid Parenchyma , in as much the Arteries and Veins being filled with blood are stufft up , and the Vessels of the Trachea and Lymphaeducts being emptied of the air as well as water , do fall together and seem to close . We shall the less admire the fleshy fabrick of this Lung wove together out of meer Vessels and little Bladders , if we consider the frame of the seminal Testicles to be nothing else than a heap composed of hollow filaments or spermatic Pipes woven together . The description of the Nerves of the Lung , and what relates to the bundle of Fibres whereof it is compact , and to the spreading of its branches , are described in the fifth Table .

The web of the Lung , as above-said , The Coats of the lungs , whereof one is smooth , and the other rough . being weaved together of Vessels and little Bladders , and divided according to their greater and lesser branchings into lobes and little lobes , a Membrane wraps them about as a common covering . Of this there are two Coats , viz. one outer and fine , which appears like a certain subtle texture or weaving together of nervous filaments ( as is apparent in most other Bowels ; ) the other more inward , which is both rough and somewhat thick , and consisting almost of meer ends of Vessels and little Bladders : and by reason of the hollownesses every where caused from these , its inward superficies resembles a Hive of Bees ; the forms of these are aptly enough described in the eighth Table . This Membrane of two Coats blown up hath very many and large Pores , insomuch that if Quick-silver be poured into the Trachial branch of one of the lesser lobes , almost filling within the whole Membrane , it will every where burst out from the Pores . Both the arterial blood and the air beating in this Membrane as against a bank , are reflected ; the former is brought back by the Veins into the left Venter of the Heart , a certain watry part being sent away through the Lymphaeducts . In the mean while the air is returned back by the same passages of the Trachea by which it flowed in . For continually fresh air ought to be suckt in , that it might supply nitrous Particles to the Blood ; to make room for which the other old air being now weak and useless , must be first breathed out . Because therefore both functions are to be performed within the same passages , it is to be done by alternate turns , first the one , then the other . While the air is drawn in , the Lungs are blown up , as if wind were forced into them ; and whilst the same is breathed out they fall down , and are narrowly squeezed together for the benefit of excluding it ; and so after the manner of Bellows discharge constant changes of the Systole and Diastole . Yet by what impulse and Organs it is accomplished , is worth our labour here to consider .

Therefore upon the whole matter it is manifest by common observation , The Systole and Diastole of a Lung . the Diastole of the Lungs perpetually succeeds the opening the Breast , and its Systole in like manner its contraction ; so that we may conclude , when the cavity of the Thorax being dilated a greater space is yielded to the expansion of the lungs , the extern air of its own accord leaps into the Trachea , whether by reason of the Pulse , or by its own Elastic force ( for it is all one ) and presently enters into its Trunk , the bronchia and all the little bladders , and blows them up ; namely for that end , that its nitrous particles may every where occur to the blood , washing all parts of the lungs : afterterwards when the breast receding from that dilatation , is straitned as to its cavity , even the lung being compress'd , falls together by its Diastole , and excludes the air even now breath'd in . But truly , because the air doth not of its own accord leap out with that plenty as it skipt in , neither the hollowness of the breast so straitly contracted , that it should mightily compress the lungs ; therefore all the passages of the Trachea are endowed with muscular fibres , which being contracted orderly while we breathe out , they may promote the expulsion of air . Wherefore , that the cause of breathing , and the manner of doing it may more plainly be made known , inquisition ought to be made after what manner , and by what Organs , that interchangeable dilatation and contraction of the breast are performed .

We cannot enough admire , It s motion mechanically unfolded . concerning these motions , the cunning artifice of the Divine Creator , evidently adapted unto Mathematical rules ; for truly in no other matter doth He more plainly appear 〈◊〉 〈◊〉 〈◊〉 〈◊〉 〈◊〉 . For when both the enlargeing and the straitening of the breast ought to be performed by some muscles ( to whose function it only belongs to contract ; ) the matter is so ordain'd , that the ribs which shape out the sides of the Thorax even as of oblong parallel lines bowed towards a Cylinder , are brought one while in a square figure with right angles for the enlargement of the breast , and afterwards into the form of a Diamond-figure with sides unequal , with acute angles for the contraction thereof . What follows from the scituation of parts so chang'd , that whenas the sides depart farthest from one another , the ends are brought nearer , and so è contra ; and for that cause the largeness of the space is wont rather to be altered than either augmented or diminished ; lest it may so happen about the cavity of the Thorax , it is so provided against by an admirable workmanship , that whilest the ribs ascend upward for enlarging the breast to a square figure , lest the ends should be shortned inward , the Diaphragma , which closes the bottom , swells downward toward the Abdomen ; so that the Thorax may be enlarged as well towards its length as to its depth : on the contrary , while the ribs beneath are brought to straiten the breast towards the figure Rhomboides , lest they should depart farther than they ought , the Diaphragma ascends upwards for that cause that the largeness of the Thorax may be straitened , while we breathe out , according to both dimensions .

What belongs to the muscles of the breast , The Muscles serving respiration . serving as well to the enlargement for sucking breath , as to the constriction for breathing out , the most wise Creator of Nature hath ordained more and sundry instruments of either function ; Therefore truly that the work of breathing being especially necessary as to life might be performed incessantly and very strongly , some of the former order of Muscles , viz. those by which the hollowness of the Thorax is opened , do raise the ribs and afterwards draw them back , even as they are bow'd and more enlarg'd ; in which number there are three muscles to the shoulder , one belonging to the loyns , and eleven intercostal outward ; and another inward muscle , viz. the Diaphragma , depresses the bottom of the breast , and enlarges its length and depth .

The aforesaid muscles , Their function as well in inspiration ; viz. the scapular , lumbar , and intercostals being also appointed with the Diaphragma for the function of breathing , are accurately enough describ'd by many Anatornists , but chiefly by Fallopius , that here seems little need to unweave this web ; especially because a more full and permanent knowledge of these parts is not wont to be acquired unless by frequent dissections and anatomical inspection . The four former muscles being of divers forms , conduce chiefly to stronger and violent inspiration ; but the exterior intercostals in regard of the ordinary actions of breathing employ their continual endeavours by turns during life , every one of these being uniform , with a fleshy and more thick basis , being rooted in the bottom of the upper rib are carried by oblique fibres , and broad towards the forepart unto the top of the rib that lyes under , and are implanted to it with a small and tendonous end ; whence it follows , those fibres being swell'd , and shortened towards their root , do lead and draw back the nether rib towards the upper ; and so while all these muscles are contracted together , all the ribs are raised upwards , and altered from oblique angles into direct ones , they render the trunk of the Thorax more large , but something shorter ; which defect that it may be helped , the Diaphragma ( which being free before from the Systole , is hidden within the cavity of the breast ) together with the ribs drawn upwards , is extended beneath ; so that the breast , as it were a Drum braced , does become most capacious ; and in the mean time the lungs , having a more ample space yielded to them , are blown up by the air rushing in wheresoever there is passage , and fill the whole hollowness of the Thorax enlarged .

Thus far touching the muscles serving to inspiration , As in expiration . which ever and anon ceasing from contraction , the ribs presently fall down from a direct position into an oblique ; and the Diaphragma also being freed from its extension , ascends into the cavity of the breast , or is rather thrust thither by the bowels of the Abdomen ; and so by reason of the position of parts so changed , viz. the breast straitened , and the lungs compressed , the act of exspiration doth succeed . Some have determin'd this to be a meer intermission of the other , and onely to proceed from the rest , or ceasing of the muscular motion ( by which breathing is performed . ) But the declination of the ribs from right angles into oblique , and the ascension of the Diaphragma , is related to be the natural position of these parts , because they are found in such a scituation in dead bodies . I think my assent not easily owing to this opinion , because sometimes the function of exspiration is performed much stronger and more violently than that of inspiration , as in coughing , singing , laughing , hollowing , and in other affects whose exercises are the more difficult labour and more earnest endeavours of the breast . Wherefore there is no reason that we should think that such vigorous exercises of expiration , should be excited by the meer rest and ceasing of the aforesaid muscles , but from the motion of others opposed to them . Moreover the Muscles now cited and opposite , and straitning the breast , seem to be required not only by reason of their violent exspiration , but for their ordinary and constant service , at least for the poising the function of respiration : for otherwise those other whose office it is to enlarge the cavity of the Thorax , being sometimes unmindfull of their task , do it either stronger or longer than is convenient ; wherefore it is necessary they be forthwith admonished by others , viz. their Antagonists subservient to Expiration , and to be restrained in their duty . But the muscles appointed for the straitning the breast , are the Sacrolumbus , the Triangular , and inward Intercostals , and some muscles of the Abdomen ; the use and descriptions of all which are delivered by many Anatomists , and most accurtely by Fallopius . The inner intercostal muscles as they obtain a contrary scituation , so a contrary function to the outer intercostals , which namely is to depress the ribs , and to straiten the cavity of the breast , by forcing it into the Rhomboidal Figure . For we are to observe , that the carneous and thicker basis of each of these is implanted in the lowest part of the nether ribs , and the moving fibres , ascending from thence obliquely and forward , and dividing cross-wise the rest of the outward intercostals , with their smaller and Tendony end are engrafted in the bottom of the upper-rib ; hence none need doubt , but that these inner muscles do depress all the ribs , or bring them downward : but whilst these ribs are so depress'd , that the trunk of the breast is rendred more strait , these inward muscles ( otherwise than the outer ) do not only incline the ribs downward , but also their gristly or cartilaginous processes . For Fallopius hath acutely described this : That the outward intercostal muscles do onely fill up the inter-spaces of the ribs and not of the gristles , but the inward fill up both spaces . The reason whereof seems to be after this manner , affording a most delightfull speculation of the Divine Architect , viz. while the ribs are brought upwards to the exercise of fetching in breath , and are withall drawn back towards the Spine , that motion commencing backward , is performed by the ribs themselves ; which being first moved together , the cartilages easily discharge their function as cords fitted to that purpose : wherefore there seems little need of the muscular aid to place these in their order ; but to put the ribs in action , not onely the intercostal muscles afore mentioned , but the four other greater ones do continually endeavour it ; but on the contrary , that the ribs may be depress'd and brought forwards together , the force taking its rise before , is performed by the cartilages as so many leading cords , most easily bending the ribs downwards as far as need requires .

Moreover to this end , that the cartilaginous appendices of the ribs may be drawn down and nearer one the other for the exercise of expiration , not onely the inward intercostal muscles fill as well the intervals of the cartilages as of the ribs , but moreover an entire triangular muscle is allotted for this function ; for this springing beneath from the bone of the Sternon , and ascending upwards obliquely , is inserted into to the lower Cartilages , which it constrains towards its head , and bends the Thorax nearer on the other side . That is worthy of consideration , which Fallopius hath remarked touching this muscle , viz. whereas it is so little and minute in a man , that it may hardly be allowed for a Muscle , it is stretched out in a Dog along the whole bone of the Breast , and reaches to all the Cartilages , even those inosculated into the Sternon of the true Ribs . Wherefore the triangular Muscle being small in a man , is stretched out through the whole bone of the breast in a Dog . The Diaphragma follows the motion of the Abdomen . The reason of which difference clearly points at the Divine Providence touching the Fabrick of Animals . For whereas this Animal is born to most swift and long running , that the blood , while it is more vehemently agitated , may duly be kindled and fan'd , as it ought swiftly and strongly to draw in the air , even so to expire it ; ( for that fresh air may be more freely suckt in , it behoves that all the old be strongly cast out and exploded ) therefore for the stronger discharge of this exercise ( of the which little use in a man ) this Muscle of a Dog is allotted a great bulk , proportionable to such a work .

Hitherto of the Muscles that straiten the Trunk of the Breast : by whose provision it is manifest enough , that the relaxation of the opposite muscles are not sufficient to this function . But that while the breast is constrained , the Diaphragma ascending upwards may shorten its hollowness , it is not enough that it is released from its contraction , but it is also necessary , that as soon as this ceases , the muscles of the Abdomen being contracted squeez together the Bowels , and press them upwards , by which the Diaphragma being relaxed , is lifted up and driven higher into the Trunk of the Thorax .

From the supposed reasons of these things we may infer , The labour of Muscles the same in exspiration as in inspiration . no less endeavours of the muscles are imployed in the exercise of expiration , than in inspiration : nay rather we may affirm them greater , after this is added , that the Pipes of the Trachea and Bronchii are endowed with muscular Fibres ( as we have shewed ) which being only contracted while we expire , do cause the air contained within to be cast out with the greater force . And truly so it ought to come to pass , because the air prevailing with an elastic force , doth of its own accord readily enter the pulmonary passages , as often as they are suffered to be open ; but from thence that again it may presently and thorowly be excluded , there needs a certain force and compression of the parts to thrust out . For although the inspiration precede in course , yet it is necessary that expiration follow immediately after , and be proportioned according to the fashion thereof ; for that it may be great , the turns or changes of this being greater are requisite . Wherefore in vehement exercise of the whole body or of the Lungs alone , that the fresh air may more plentifully be drawn in , all the old air must be moved , not only out of the Trachea and Bronchii , but also out of the farthest little Bladders every turn or change of breathing out , and expulsed most of it : whereas while we draw in the breath only the muscles of the Breast are imployed , the Lungs having respite , in strong breathing out both the opposite Muscles and the Lungs themselves labour .

Having thus explained the Organs of Breathing , The causes of the above-mentioned motions . it remains yet to be inquired into , by what instinct , being stirred up to motion , they so repeat perpetual changes of Systole and Diastole , that one while these muscles are contracted for inspiration , and another while for expiration , in the mean while the opposite muscles have a pause , and are moved by turns , that they mutually give place to themselves successively . From all this in the first place it is clear ( which likewise in another place we have abundantly declared ) that the animal Spirits , for the exercising the contractive motion of the muscles , leap from the Tendons into the fleshy Fibres , and afterwards for their relaxation they recede out of these into those . Moreover , whereas the mutual function is twofold , viz. spontaneous and meerly natural , In the animal function . we have before shewed in the former , that the Spirits are brought from the Tendons into the fleshy Fibres by approaches according to the command of appetite , and to remain within during the action , till they are dismissed by its will ; and afterwards return into the Tendons , till they are again commanded forth ; insomuch that the times of their motion and rest are unequal and uncertain , and variously determined at our pleasure .

But it is far otherwise in the natural function : And natural . because the animal Spirits are carried out from the Tendons into the flesh by perpetual turns , or constant reciprocation , and a short contraction being made , presently leap back from the flesh into the Tendons , and so alternately : after which manner the Heart it self , the Organs of the Trachea and breathing , also the fleshy Fibres of the Stomach and Guts , unless they are otherwise limited by reason of their objects , are drove on by their constant Systole and Diastole .

It will be needless to repeat here what we have already observed in another place touching these two kinds of motions , The motion of the former sort ariseth from the brain , the other from the Cerebellum . viz. that the animal spirits of the spontaneous moving function are altogether or chiefly dispensed from the brain , and the others causers of the meerly natural function are dispensed from the Cerebellum ; moreover also as the plenty of both sorts of spirits , so the very instincts of beginning those actions have their conveyance through the Nerves .

Notwithstanding here ariseth a doubt , to what kind of moving function , It is a quaere of what kind the actions of breathing are . viz. whether spontaneous , or meerly natural , the actions of breathing ought to be referred ; also of what original , viz. whether of the Brain or Cerebellum , the animal spirits appointed to that employment , are . It is manifest enough that this function is in a sort partaker of a spontaneous motion , because it is in our power one while to shorten its exercises , at other times to prolong , and otherwise diversly to alter them , yea sometimes a little to restrain them . Moreover the nerves belonging to its chief moving Organs , viz. the Diaphragma and Muscles of the breast , springing from the nerves of the Arms and Loyns , do owe their descent to the Brain , and do plainly acknowledge the spirits they contain are chiefly ordained for voluntary motions : but moreover on the contrary , this function is so far natural , that its organs do reciprocate the constant changes of Systole and Diastole in sleep , without our notice , and while we wake , we not perceiving it : Moreover although we can for some little time stop its exercise , or at our pleasure vary it , yet we deny it to be altogether or long suspended : besides , although the nerves appointed to the muscles of the breast and Diaphragma proceed from the spinal nerves , yet these latter coming from the branches belonging to the arm communicate in their progress with the slips of the intercostal nerves ; moreover , all the other nerves ( which belong to the Cerebellum ) arise from these , which are spread about through the Trachea and Lungs .

From these it plainly follows , It is concluded to be a mixt act . that the power of breathing is as it were a mixt action , and doth participate of either moving function , viz. as well of the spontaneous as natural ; and that the spirits and nerves of either Province are imployed in this duty , which proceed as well from the brain as from the Cerebellum ; and truely so it ought to come to pass according to the animal government : for although some actions of breathing necessary for the preserving life , ought to be constant and perpetual , there are yet many other motions of the breast and lungs onely occasional , and to be perform'd at our pleasure , as may be discerned in laughing , crying , singing , hollowing , whistling , and other singular offices of the lungs and wind-pipe ; in which works that they may be done strongly , the muscles conspire together , and endeavour joyntly . As in violent labours and exercises of the whole body , by which the blood being stirred up doth want the greater ventilution , the arms being vehemently moved also do force the muscles of the breast , and other pneumonic organs , into more speedy motions for a more frequent breathing . And truly for joint labour of this sort of the Arms and Diaphragma , the nerves serving this motion proceed from the nervous branches of them . Moreover , it is provided for this purpose , lest the exercises of the body might enfeeble at any time the strength of the lungs , or exceed the order of breathing ; for when its organs labour more difficultly , or begin to be weary , the nerves of the Diaphragma do warn the other nerves of the arms , plucking them and as it were admonishing of their duty to desist from an over intense motion .

For whereas the function of breathing is ordained for many uses , The nerves of the lungs some rulers of the natural motion , and others of the voluntary . whereof some are merely natural , and others spontaneous or violent ; therefore the spirits and the nerves which proceed and have their government as well from the brain as from the Cerebellum , ought to be joyned together , and to afford their social endeavours ; yet on that condition , and as it were by mutual agreement , that one give place to the other by turns for the discharging all works chiefly necessary , or convenient , and do mutually obey . From the pneumonic nerves , the instinct of ordinary breathing or meerly vital beginneth , and is presently communicated to the nerves of the Diaphragma , and from thence to all of the Thorax ; Both do alternately obey one the other , and agree in their office . so that presently all the moving parts agree together in the action , and cause the Systole and Diastole of the breast in such sort as are required to the present state of the blood ; notwithstanding on the contrary , as to other actions of breathing , whether spontaneous or violent , it seems to have them also , viz. the instinct or first force of these , beginning one while from these muscles , another while from them is presently communicated to all the other Organs ; so that it is called upon by a working consort of all together sooner than the twinkling of the eye , for the performing the designed acts of breathing .

What we have hitherto declared about the Organs of Breathing and their functions and uses , that they may more clearly be manifest , it seems to be material to expose to your view the forms of some of their chiefest parts described to the life , together with the explication of their Figures : yet it seems proper first to insert a few things concerning the Lymphaeducts and interspaces of the Lobes omitted in the former Discourse .

The most renowned Malpighius first discovered these little Lobes of the Lungs and their interspaces ; but to what uses they serve he hath not clearly enough shewed . Haply it may seem that these little places and empty spaces within the Lungs , are certain receptacles of the air ( that there may be a larger store of it . ) Notwithstanding it is evidently manifest upon experiment frequently made , that the air pufft into the Pipe of the Trachea ( which is the only entrance into the Lung ) doth not enter or blow up these interspaces of the little Lobes : The interspaces of the little Lobes have passage one into the other , and from thence into the Lymphaeducts . notwithstanding if you blow into the hole of any of these interspaces , immediately all these spaces pufft up do swell in the whole lobe of the Lungs , so that all the little lobes distinct by great interspaces , will appear with a pleasant prospect ; as is expressed in the second Figure of the third Table . Moreover the Lymphaeducts creeping through the superficies of the Lungs , seem to be every where included in little Membranes covering those interspaces , and to end in them . But as the lymphatic Vessels are all furnished with little valves , so those which appertain to the Lungs are furnished with almost infinite ; as is to be seen in the warm large lobe of an Ox , and expressed to the life in Tab. 1. d , d , d , d.

That I may dare to conjecture concerning the use of these things , Which therefore is done , that the vaporous steaming of the blood being received by the interspaces , and condensed into water in the Lymphaeducts , may be conveyed out . it is probable , that those cavities intercepting each little lobe , do receive the vapors flowing copiously every where from the blood being kindled , ( when they cannot any where else be better thrust down or separated ) which sweat through their slender Coats into these cavities out of the ends of those Vessels , and thence being forced further , they are condensed into water to be carried out of the Lungs through those appropriate Vessels : moreover lest the Lympha's caused from vapors within those passages , and so being made thick , should whirle again back into the Lungs ( which would bring great prejudice to them ) the thickest obstacles of the valves do hinder . For I have frequently admired what becomes of the vaporous steams which incessantly flow in great plenty , and sometimes most impetuously out of the blood burning ardently in the Praecordia . For although very many of them flye away through the passages of the Trachea together with the air while we breathe , notwithstanding one only way of passage or particular sluice doth not suffice to them , from every place breaking forth : wherefore these little places or empty spaces are every where placed , that they may receive those vapors shut up in the Lungs , and may drop out the same immediately condensed through the Lymphaeducts , as if through so many noses of an Alembick .

The lymphic Vessels having their passage out of the Lungs incline towards the passages of the Thorax with their numerous branches , The progress and distribution of the pulmonary Lymphaeducts . and are for the most part mingled with them ; but they climb upon the Oesophagus in their way , as also the trunks of the Trachea and the Aorta , and do lose many slips in them by a various insertion ; likely for this cause , that some of the lymphatic humor may be bestowed for making slippery the sides of those Vessels .

The Explication of the Figures .

THE first Table shews one entire lobe of the Lungs , upon whose superficies the Lymphaeducts are seen spread through every where .

A. The Orifice of the Trachea being cut lying in the midst of the Vessels . B. The Orifice of the Pneumonic Artery lying under . C. The Orifice of the Pneumonic Vein placed above it . d , d , d , d. The outer Lymphaeducts spread abroad through the superficies of the Lobe . e , e , e , e. More Lymphaeducts meeting on the back of this Lobe , from whence they pass into the Thoracick ducts .

The second Table shews one lobe of a Sheeps Lung cut in the midst , that the upper part ( wherein is the trunk of the Vein ) being removed , and the trunk of the Aspera Arteria laid by it self , the branching of the Pneumonic Artery is shewn throughout its whole frame , viz. through the small and least little Lobes . All the passages of this , viz. the slips and twigs how small soever , being filled and coloured by any liquid thing cast into them , are drawn to the life .

A , A , A , A. The nether half of the Lobe divided , containing the branching of the Pneumonic Artery . B , B , B. The Trunk of the Pneumonic Artery belonging to this Lobe . C. A hole from whence it s other branch was cut off and removed . D , D , D , D. The Trunks from which its other branches ( because they could not be expressed in this Table ) were cut off . E , E , E , E. The arterious stems thereof stretcht forward into length , the side-branches on both parts stretcht out into the right and left side . F , F , F , F. The twigs and lesser slips , which are every where intermingled with the like from the Veins and Bronchials ; and at last woven together with the Veins every where encompass the orbicular little Bladders , and bind them as it were in clusters . G , G , G , G. The Bronchial branches , which being cut from the stem of the Trachea laid aside , and entring secretly into this lobe of the Lungs , are accompanied with branches that bear blood . H , H. The stem of the Trachea appertaining to this Lobe , which lay upon the Pneumonic Artery , cut and laid aside . f , f , f , f. The stems of the Bronchial branches , which are immersed partly in this portion of Lobe described G , G , G , G , and are partly distributed in the other half cut off .

The first Figure of the third Table expresses one lobe of the Lungs , according to the branchings of the Aspera Arteria divided into lesser and less lobes , the twigs and slips of which Vessel being filled by a liquid first injected , and afterwards separated from among themselves towards the little lobes , are also drawn to the life .

A. The Trunk of the Aspera Arteria being cut from the rest of his body . B , B , B. The inner part being cut open , that as well the holes leading into all its branches , as it s straight muscular Fibres , are viewed together . a , a , a. The abve-mentioned holes leading into the every where stretched out branches . b , b , b. The straight muscular Fibres , upon which the other circular do lye . C , C. The upper part of this Tracheal stem being whole or shut , that the Ring-like Grisles might appear . D , D , D , D. The branches of the Trachea constituting the lesser lobes are whole and shut , that the Ring-like Griste may also appear in them . E , E , E , E. The like branches being cut open , that the holes and straight muscular Fibres may be seen together . F , F , F , F. The trunks from which the Tracheal branches being cut off are removed , that there may be space afforded to the rest , when cut open . G , G , G , G. The secondary little lobes hung upon the trunks of the Bronchii as grapes , which also may be divided into lesser lobes , the more inward passages of all which pass out of the Bronchii into the little bladdery Cells . h , h , h , h. The Vessels bringing blood crawling over the superficies of those little lobes .

The second Figure of the third Table expresses a part of the pulmonary lobe , wherein the membranous interspaces being blown up , all the little lobes appear in their proper figure , and do somewhat represent the leaf of Polypody .

A , A. A part of the Arteria complicated with the other Vessels , to which trunk made up of all those , the little lobes grow like leaves of a tree . b , b , b , b. The little Lobes themselves . c , c , c , c. The Vessels bringing blood creeping through them . d , d , d , d. The membranous interspaces of the little lobes , which also are covered with e , e , e , e , the Vessels bringing blood .

The fourth Table expresses as well the Vessels belonging to the Trachea as those bringing blood , separate and distinct one from another , constituting one little Lobe , as also the peculiar framing of every one of them .

The first Figure represents the separating into divers parts the Tracheal branch distributed into one little lobe , and the branching into Pipes and orbicular little bladders .

A , A , The trunk of the Aspera arteria , in the superficies whereof the ring-like gristles do appear . b , b , b , b , The lesser branches going from that trunk , wherein also little Rings appear . c , c , c , c , The passages of those branches into orbicular little bladders , which seem like the clusters of Grapes . d , d , The Vessels bringing blood , distinct from the Pneumonic which cover the Trachea , and serve to nourish it .

The second and third Figure shews distinctly the equal branchings of the Artery and Pneumonic Veins within the same little Lobe ; both which being complicated with Tracheal Vessels , do for the most part make up the texture of the pulmonary frame .

The fifth Table sets forth the pulmonary Nerve more accurately described by the aid of a Microscope ; so that it plainly appears that the Trunk is as it were a bundle of innumerable little Fibres bound together ; moreover its Trunk , while it creeps into the lungs in the likeness of Mother of Time , doth spread the various little sprigs every way .

Fig. 1. resembles a part of the nervous trunk cut away , one end whereof being opened and lookt on by a Microscope , seems to unfold it self almost into innumerable little fibres .

A , The trunk of the Nerve . a , a , a , a , The little Fibres divided from one the other about the end cut off , and spread abroad .

The second and third figure do shew some fibres as well of the trunk as of every branch , and moreover the slips of the little twigs from divers stemmes often repeated .

B. The chief trunk . b. b. b. b. The little fibres about the extremity cut off explicated . c. c. c. c. The little twigs springing from the bundles of the little fibres .

The sixth Table first sets forth the anatomy of the Artery bringing blood drawn in apt figures , which we have described in a late treatise .

The first and upper figures hereof , represent the four distinct Coats of that Vessel , viz. the nervous , muscular , glandulous , and the vasculous .

1. The first inward nervous coat , which perhaps is somewhat musculous , consisting of streight or long fibres , which being contracted shorten the Pipe of the Artery .

2. The coat properly muscular , consisting of a heap of small circular fibres , which when they are contracted successively under the stream of blood , do make its circuit to be shortened . It is from the motion of these that the arteries beat .

3. The glandulous coat , which ( like that in the guts ) being placed over the musculous coat , is weaved together of very small and most numerous glandules .

4. The outward vasculous coat , which variously folded together and wreathed , of Vessels bringing blood , and with slips and nervous fibres , seems like a certain little net .

The second and lower figures of the sixth Table , do shew the anatomy of the Vein , or its four coats expressed in fit places ; which Coats do appear entire as successively taken one part from the other ( beginning outmost . )

I. The outward coat consisting of nervous fibres ( which perhaps are somewhat muscular ) and as it were streight or stretch'd out in length , although not orderly .

II. & III. The vasculous and glandulous coat , which are the same as in an artery .

IV. The most inward muscular coat , consisting also of circular fibres , as in an artery , which being contracted behind the stream of blood , hastens its returning course .

The seventh Table expresses the distinct Coats of the aspera arteria , and separated one from the other .

The first figure shews the most inward Coat , endowed with streight or long muscular fibres .

The second figure descrbes the glandulous coat , and the third figure the vasculous coat ( which are almost the same as in the vessels bringing blood , and also in the Guts . )

4. The fourth figure expresses the outward coat ( which is partly cartilaginous , and partly muscular . ) The transverse or annular fibres hereof do fill up and weave together the interspaces of the Cartilages .

The eighth Table shews a part of the outmost pulmonary Coat covering over its whole frame , most finely and curiously described by the help of a Microscope .

The first Figure shews a portion of the above-mentioned coat , which partly by reason of the extremities of Vessels of every sort ending in it , seems pricked full of holes as it were , and partly from the complications of the vessels bringing blood , which like the twining sprigs of Vines gird about the orbicular bladders , is distinguished into many irregular Area's .

The second Figure represents a part of the outermost membrane separated from the clusters of vessels pull'd off , and without any Area , onely markt with little holes as it were with small pricks .

The third Figure expresses one singular area of the Coat above mentioned , augmented in largeness by the help of a Microscope .