ways but that I may render what I have to say upon it as perspicuous and intelligible as I can I think it very convenient we should take a special notice of the vessels that come into the Tooth and of their respective Functions The first and chiefest whereof is an Artery whose Office is to bring directly from the heart that hot and spirituous blood out of which although it is not the general Opinion the Tooth is at first made as well as the rest of the whole body and ever after preserved and repaired by the supply of nourishment and vital principles it affords continually To this effect the whole Artery divides it self into an infinity of small branches which being disseminated throughout the whole substance of the Tooth distribute to each part as much of their blood as is necessary to make up the incessant loss they are subject to and the rest is returned through innumerable hair-like veins into the great ones and thence to the heart again but in two different manners for the superfluous part of that portion of the blood that is carried by the Capillary Arteries to that part of the Tooth standing above the Gums is sent back again through some Capillary veins towards the middle of the Tooth where uniting together they make but a single channel and this is it we commonly call the vein of the Tooth which we shall here take for its second vessel But the remainder of the blood that goes to the relief of that part of the Tooth that is within the Gums passing quite through the substance of the Tooth is carried by the Capillary veins to the veins of the Gums Checks and Lips and hence it is that whatever pain is at any time occasioned in any of those parts either by bruise excessive heat or cold c. comes to be soon after communicated to the Teeth The Third and Last Vessel of the Teeth is a Nerve one of the extremities whereof is expanded through the Membrane that invests the cavity of the Tooth and that that contains its Vessels and the other is rooted in the Brain from whence it takes its Origine and where the Animal Spirits being elaborated are thence sent by the Nerves to all the parts of the body to administer sense and the cause of motion to them c. although in some as the Teeth the faculty of motion is not exercised From this consideration of the Vessels of the Tooth we may gather the following reasons of its Dolour As first that if either through the too great quantity or ebulition of the blood the Artery is so dilated and swoln that it fills up the hole at the end of the stumps where it enters the Tooth and consequently so compresses the vein going out the same way that the circulation of the Blood is thereby hindred the continual flowing in of the blood will extremely puff up and distend the membrane that contains the vessels and consequently cause a great pain in the Tooth which will last till either the preternatural state of the Blood be changed or that the Arteriols which we have said to pass quite through the rooty part of the Tooth be so stretched and widened that by them the Blood may be discharged into the Gums Cheeks and Lips where it will then cause a swelling greater or lesser according to the quantity of the superfluous Blood And if at the beginning of this disorder when the Vein is first impeded in its Function the motion of the Blood is so rapid and its influx into the Tooth so impetuous that before it can make its way through the small Arterial Twigs into the Gums it does extremely extend the coats of the Artery the Interstices between their Fibres will thereby become wide enough to give passage to some of the thinnest parts of the Blood which gathering at the end of the root between the outside of the Artery and the common Coat investing all the Vessels will there putrifie and cause a great and very lasting pain in the Tooth during which if the Tooth be drawn the said gathering will appear at the end of its stump like a little Bladder You shall know this sort of Tooth-Ake by the high beating of your Pulse the fulness of the Veins and an often beating in the affected Tooth with a continual tho not very extreme pain And then for the Cure of it you must first bleed the Gums and sometimes open a Vein in the Arm also and wash your mouth with Rose-water and Vinegar of each equal quantities mixt together putting a little Cotton dipt in Oyl of Box into the Tooth if it be hollow Furthermore if that portion of the Blood which is diffused through the substance of the Brain for the production of the Animal Spirits is so depraved that all the sifting it receives through the hidden meanders and recesses of the Brain cannot clear it from its impurities and that notwithstanding all the contrivances of Nature it is deposited into the ventricles of the Brain tho under another form yet still impregnated with its ill qualities such sort of Animal Spirits being compounded of Heterogeneous parts if not timely discharged of their malignant and offensive Corpuscles through the usual Emunctories will either by their fermentation in the Ventricles of the Brain cause an Head-ake or by the oppilation of its pores cause a giddiness or else passing out of the Brain into the Nerves will by their irregular motion and preternatural extention of the coats of the Nerves and other Tunicles breed a disturbance in all the parts they go to but more particularly in the Teeth in which they always excite very great pains For discharging the peccant humour between the membrane that invests the inside of the Tooth and that that incloses its vessels it occasions a perpetual torment in them till it be expelled from thence by transpiration This second kind of Tooth-ake will be known by a disturbance in the head which precedes it most commonly a soreness in the joynts and a certain drousiness and lingring pain all over the body as if one were inclined to an Ague with a sharp and very excessive pain in the distempered Tooth which comes by fits soon ceasing and often beginning a-new As for its Cure it may be effected by Sternutation the friction of the nape of the Neck with warm clothes and the application of aperitive Remedies to open the pores of the Tooth and if it be hollow you shall put in 't a drop of Oyl of Camphire whereinto has been infused some Henbane-root These are the two general causes of the Tooth-ake all the rest proceeding from them some few excepted There is what I had a mind to say at this present concerning the Tooth-ake But you must note further that as it is not enough for one that intends to travel a Countrey over to understand the Map of that Countrey but he must also inquire often of the people he meets with as he goes
the right to the left intersecting thus one another obliquely as they go from the heart to the anastomosis whereby they form a sort of Net or Sieve-like-woof upon the outside of the Artery At their coming out of the heart they are knitted together by a cartilagineous substance that incompasses the root of the Artery round about as an iron-ring does the end of a handle from the circumference of which cartilagineous Ring they run Helix-wise upon the superficies of the artery at the extremity of which being arriv'd they insert themselves into the tendinous small ring or anastomosis These spiral Fibres are tied so loosely on the body of the artery and so slightly between themselves at the places where they intersect one another that they may run very easily to and fro upon the artery The second thing conducive to the production of those stated turns of Systole's and Diastole's of the artery is that the bloud contains a certain subtil matter or vital spirit which can move it self and pass between its parts very easily And in fine that the bloud coming out of the heart where it acquires an extreme agitation into the arteria magna expands it self with great violence and strongly dilates that part of the said artery that lies contiguous to the heart forcing in the same time the bloud to advance from the heart towards the extremity whereby the spiral Fibres being necessarily drawn towards the dilating place do compress the artery round about all along so squeeze the subtil matter from between the parts of the compressed bloud into that which is not forcing it thus to pass from the extremity towards the heart which makes the ebbing or systole of the artery And then the spiral Fibres having been extended violently and on a sudden upon the dilatation of the artery do by the Elastick faculty of some of their parts come back again and restitute themselves into their former situation and state forcing thereby the subtil matter to fly through the bloud from the dilated place of the great Artery towards the extremity of the capillary ones c. which makes the flowing or Diastole of the Artery THE EXPLICATION WE have already supposed the Artery to be of a right Conical figure let us further for greater evidence imagine it to be mentally divided into four parts of equal capacity so that as much as the first shall exceed the second in bredth the second will exceed the first in length c. Let besides the places of the suppos'd divisions be marked with several letters as A B C and let A denote the first division proceeding from the heart to the extremity B the second and C the third let us also mark the Basis of the Cylindrical artery which is inserted into the basis of the heart by X and its capillary end inserted into the circumference of the annular anastomosis by Y. And now suppose that a certain portion of bloud as a dram for example passes out of the heart into the aorta where it swells and dilates it self very considerably by reason of a very intense degree of heat it acquires in the ventricles of the heart and of its being mixed therein with a certain leaven or fermentative juice it being the residue of that portion of bloud that had past immediately before through the heart which necessarily causes a great commotion and strife amongst its parts it must follow according to true Philosophy that the said portion of bloud coming out of the heart does in the same time thrust the bloud already in the artery forwards and dilates that part of the artery that lies contiguous to the heart It thrusts the bloud I say towards the extremity because that it must occupy a space in the artery equal to its natural bulk neither greater nor smaller by reason that a like quantity of the bloud to that that comes out of the heart into the artery is poured out of the vein into the heart so that there is only room left in the vein to admit just as much bloud as comes out of the heart at each Diastole And if we suppose the space X A to contain a dram of bloud whether more or less makes no matter here as we have also supposed that the same quantity comes out of the heart at every Diastole or Systole as some would have it it is an invincible truth that this bloud coming out of the heart must exactly occupy the space X A and that therefore it thrusts in the same time the bloud that occupied it before into the space A B that in A B into the space B C that in the space B C into the space C Y and that in C Y into the capillary end of the vein c. And altho according to our Hypothesis the passage from the artery into the vein be much smaller than that of the heart into the artery yet if the motion of the bloud through the anastomosis is to the motion of the bloud at the orifice of the heart as the orifice of the heart is to the anastomosis that is as X is to Y as it may easily be so altho it is naturally otherwise the rest of the anastomoses from which we have abstracted here being together at least as capacious as the orifice of the heart it is plain that a dram of bloud will as soon pass from the artery into the vein as another shall from the heart into the artery And as the bloud coming out of the heart into the great artery cannot possibly occupy a greater space than such as is adequate to its volume in a condensed state and that nevertheless it dilates it self it must necessarily extend and dilate X A the part of the artery that contains it as much beyond its natural tone or reach as the rarefaction of the bloud increases its volume which cannot come to pass but these two things must necessarily follow First that when the bloud dilates it self it leaves some intervals between its parts which intervals because there is no vacuum in nature must in the same time be filled up with some other fluid matter which ought to be thinner than the bloud for otherwise it cou'd not pass between its parts And as this subtil matter can't come from the heart because that then it 's empty and that besides its orifice is shut close by its three valves it can neither come through the coats of the artery by reason of their thickness and close texture neither is there any such matter about them It remains then only that it must come from the bloud contained in the artery Secondly that the spiral Fibres must be drawn towards the dilated place and the rest of the artery made as much narrower than ordinary as X A becomes wider than it uses to be Whereby the artery being compressed round about the vital spirit is squeezed from between the compressed parts of the bloud and forced to advance towards the dilated place
in such manner that as much of the spirit as is necessary to fill up the spaces left between the parts of the dilated bloud is sent thither from between the parts of that which is compressed the remnant of the spirit being equally distributed through the rest of the artery so that if every one of the four parts or divisions of the artery contains a certain quantity of vital spirit distinguished into three parts and that three of those parts do pass from A B into X A two of them will in the same instant pass from B C into A B and one from C Y into B C in which action consists the ebbing or systole of the artery And as a rope or more sensibly a gut-string which is fixed to any place being pulled with a jerk will draw back again him that drew it at first so likewise the spiral Fibres being extended violently and on a sudden upon the dilatation of the artery do come back again instantaneously by reason that some of the parts of each Fibre being strongly thrusted towards its middle and somewhat bent from its circumference towards its centre do presently spring back again extending themselves according to the bredth of the Fibre whereby the said Fibre is necessarily as much shortned as it had been stretch'd before and restitute themselves into their former situation tone which they are facilitated to do by the extenuation of that extraordinary agitation of the bloud which it communicates in an instant to the yielding sides of the artery forcing thereby three parts of the vital spirit or subtil matter to repass from X A to A B and the two parts that were already in A B to pass into B C from whence another will pass into C Y c. which makes the flowing or Diastole of the artery I foresee an Objection that some may make against what we have said that that portion of the bloud that comes out of the heart in its Diastole is dilated and yet occupies no more of the artery than if it were condensed only that part of the artery which contains it is a little more extended than the rest for they will say this supposes that both the artery and the vein are always full of bloud being certain that if the bloud in coming out of the heart into the great artery did find there any empty space where it might expand it self freely it would start forwards into it and then it wou'd not dilate the artery nor by consequence draw the spiral Fibres and therefore there wou'd neither be Systole nor Diastole in the artery But it is most certain they will continue that men have sometimes more and sometimes less bloud in their bodies and that if a man has for example fifteen ounces of bloud drawn it will follow that there being a vacuity in the Sanguiducts till the same quantity of bloud be regenerated a-new the Beating of the Pulse must also cease till then which being contradicted by daily experience they will conclude that the motion of the spiral Fibres with whatever else we have taught concerning the Beating of the Pulse is altogether chimerical To which I answer in few words that for the Beating of the Pulse and Circulation of the Bloud it matters not at all whether or no the artery and vein be quite full of bloud since that as the bloud decreases in them the muscles of the limbs and other adjacent parts do proportionably compress them round about so that their internal superficies touches the bloud continually every way which has the same effect as if the artery and vein were exactly full of bloud for the bloud coming out of the heart and finding as much difficulty in lifting up the adjacent parts as to drive on the bloud of the artery and vein when they are full on 't it 's forced to keep the same order and method in that case as it does in this concerning its dilatation and place in the artery Now these being the true and genuine reasons of the Diastole and Systole of the arteries it 's very easy thereby to explain all the Phenomena relating to Galen's experiment For the Quill being put into the artery and left there without being tied the artery will nevertheless beat still above and below the Quill as it did before because that the spiral Fibres can still play to and fro from one end of the artery to the other without impediment But if you bind the sides of the artery upon the Quill the motion of the same spiral Fibres will be intercopted by the ligature so that it must necessarily follow by the foregoing reasons that the artery being not alternatively compressed and dilated betwixt the said ligature and the extremity the Pulse must also cease in that part of the said artery c. Many things may easily be explained by this Doctrine tho impossible to be interpreted any otherwise which therefore become as many proofs of its verity as namely the difference which is between the arterial and venal bloud For having demonstrated above that when the bloud advances in the great artery from the heart towards the anastomosis and from thence into the vein the vital spirit goes in the very same time from the anastomosis towards the heart whereby the said spirit is necessarily kept within the artery it is certain that this disparity proceeds from the want of spirit in the venal to keep its parts in agitation which abounding in the arterial keeps it in a continual effervency c. I cou'd add many other things to authorize what we have said concerning the Beating of the Pulse and Circulation of the Bloud but I hope this will suffice to rational men and such as are of a Mechanical Genius As for those that attribute all things to final causes and have recourse upon every occasion to the designs and intentions of Nature as when they say that the Eye-brows are made to hinder the Sweat from falling into the eyes c. if notwithstanding all that we can do they remain still insensible to our reasons it matters not much and in my opinion such persons had a great deal better study Astrology or if they are big with devotion go and comment upon Job or Paraphrase some Psalms than meddle with Physical matters FINIS THE CONTENTS Section I. Of the Nature of the Teeth Page 7 Sect. II. Of the Alteration of the Teeth p. 11 Sect. III. Of the Corruption of the Teeth with their Remedies p. 15 The Description and Vse of the Polican p. 17 Sect. IV. Of the Restauration of the Teeth p. 19 Sect. V. Of the Tooth-ake Looseness of the Teeth and decay of the Gums with their Remedies p. 22 Sect. VI. Of Childrens Teeth p. 31 Sect. VII Of the Acceleration of the Teeth p. 37 Advertisement to the Readers p. 44 A Physical Dicourse concerning the Beating of the Pulse and Circulation of the Bloud p. 45 The Explication p. 52
of what we shall say So that although this Tractate will be imperfect as wanting many things yet what it shall contain will be as useful and advantageous as if it were accompanied with all the rest However according to the method we have prescribed our selves here we are to proceed next to the consideration of the Structure and constitution or nature of the Tooth In Analysing the Tooth its substance is not found to be uniform every where but manifestly distinguishable into two different sorts of make one of them being harder whiter and of a finer texture and the other softer more obscure and of a courser composition The first makes up the head of the Tooth or that part of it that stands out naked above the Gums and the other its stump or that part on 't which is hidden within the said Gums The exposed part of the Tooth consists also of two different Parts To wit its stony Cover or Case and its inward substance the first is as it were an hard Periosteum that invests the head of the Tooth on all sides lying on it much after the same manner that Enamel does upon Gold or any other thing This natural Enamel which I call the gloss of the Tooth is of a far harder whiter more dense and lucid nature than the inward substance lying under it which for its several uses may properly be compared to the Cuticula or Scarf-skin for like unto this it is bloodless and altogether destitute of sense serving to cover and defend the extremities of the Vessels contained within the inward substance from external injuries and to render the Tooth more beautiful and strong It has pores for the perspiration of the excrements of the Tooth which pores are not always of the same figure nor magnitude but vary almost in every body The said gloss or stony substance is likewise very various in point of thickness from which differences do arise the diversity of its colour in several men The inward part of the head of the Tooth though inferior to its cover or gloss in brightness and solidity yet its substance is nevertheless much more compact and clearer than that of the stump and contains two several sorts of pores or small channels both of a conical figure having their Bases in the concave superficies of the Tooth and their Apexes in the convex superficies of the inward substance immediately under its glassy integument Through some of which channels the blood is carried by many and very small Arterial Sprigs from the middle of the Tooth to its extremity and through the others the same blood is sent back again from the said extremity towards its middle by some capillary veins as shall be said hereafter As to the root or stump of the Tooth it is the darkest most soft and porous portion of its whole substance and yet is closer and harder than any other bone of the body having also two sorts of channels but of different situation from one another for some of them have their Bases like those above described towards the cavity of the Tooth and contain the branches of the Artery that carry the blood quite through the substance of the Tooth to the Gums as shall be explained in its place but the others contrary to any of those already mentioned have their Bases towards the external superficies of the Tooth the use of which last conduits is to transmit to the Gums the blood that is returned to the heart from the membrane that invests the cavity of the Tooth This rooty part of the Tooth consists in the small Teeth of a single body and in the big ones is divided into two three or four branches called roots or fangs along the middle of each of these fangs there is a little channel that goes up to the head of the Tooth where they are united together and make but a single cavity whereinto are carried the vessels of the Tooth passing first through the hollowness of the stumps Every Tooth has its particular cell or socket within the Mandible distinct from all the rest by a thin production of the jaw-bone passing between the Teeth from one side of the said bone to the other wherein most of its stump is comprehended the rest being incompassed about with the Gums SECT II. Of the Alteration of the Teeth with their Remedies FRom the consideration of the nature of the Teeth let us now pass to that of the first step of their degenerating or mutation For the better understanding of which we shall take notice that as our body is so made by nature that it wasts continually by the dissipation of some Particles separating themselves from its Mass without intermission transpiring for the most part through the pores of the skin and that if these particles which being divided from the whole become Excrementitious are kept too long within the body by reason of the Opilation of the said pores it causes Fevors and great disorders in our blood and vital as well as animal Functions So likewise from the substance of the Teeth are emitted certain Effluviums through their pores the transpiration of which being hindred by the obstruction of those invisible passages the Teeth become liable to all those infirmities hereafter to be mentioned The substance of the Tooth being rigid and inflexible it cannot be Opilated by contraction or astriction as the skin usually is but only by the intrusion of some extraneous matter into its pores or the incrustation of some slimy stuff upon its superficies which is done when we eat any thing of a glutinous nature for then some of its most viscous parts do stick and cleave about the Teeth and by the mixture of some tartarious particles coming from the Lungs the heat of the mouth and a certain petrifick juice distilling into the mouth out of the Salival Ducts is turned into a stone-like substance commonly called the scales or scurf of the Teeth these scales grow thicker and thicker continually and if let alone will cover the Teeth all over except just at the top were they grind one against another Having thus taken notice of the production of those scales let us now consider of what ill consequences they may be to the Teeth The first whereof is the Opilation of their pores from whence proceed all the rest for by that the exit of those Excrementitious particles before mentitioned being hindred it causes them to stagnate within the body of the Tooth and there corrupting do corrode it by degrees beginning first by the alteration of its colour from white to yellow and from yellow to black and then follows the real decay of its substance c. The said humor is not only destructive to the Teeth but extends also its malignity to the Gums some of its particles being subtil enough after a due fermentation to pass through the scales and thence sliding between the Gums and the Teeth they eat clear away the ligaments that tye them together dividing
besides that the Gums are more sinewy and membranous about them than any where else and therefore much more difficult to penetrate That part of the Jaw-bone that contains them is likewise much thicker and stronger than any other and consequently harder to be divided by the included Teeth which being incapable of making their way through it are forced to stay therein till such time that Nature having perfected our growth the bloud becomes hotter stronger and its energy more powerful by the firmness of the Heart which is the Sun of our Microcosm or little-world and other principal parts and increase of those particles that were wont to be imployed in making up and augmenting the body most of which remain then in the mass of the Bloud whereby the said bloud being able to surmount the resistance of the Jaw and Gums forces the said Teeth to come out of their cells and grow up To the efficacy of this new strength of the Bloud upon the arrival of Nature to its highest Period may be attributed the causes of those alterations that usually happen in mens bodies about that time many looking pale and being troubled with divers infirmities till then of which they are afterwards delivered But leaving off Digressions let us return to our Subject We have already observed that the Novel-Teeth in Children and Dentes Supientiae in Men cou'd not arrive to their perfection nor therefore become serviceable to us without a long time and a great Effort of Nature It remains now that pursuant to our design as we have declar'd it at the beginning of this Section we indeavor to find out some means whereby we may remedy those defects in facilitating Nature's work and rendring those tardy Teeth above-mentioned serviceable to us as soon as we can And as I find none more proper and expeditious than the Rarifaction and Dilatation of the Gums so that they may lose their greatest stubbornness and become more yielding to the Teeth I conclude that all the difficulty lies in knowing how such an effect can be produced which after a due consideration I think may be performed after this manner In the first place there is need of an Instrument made of Gold or Silver about a foot long as big as a Tobacco-pipe and like a Syringe being so bored that a perfectly Cilindrical embolus or sucker may fill exactly nine inches of its Cavity the rest being made a good deal smaller and bow'd like the Blowing-pipe of Watch-makers which ought to end into an head resembling the cup of an Acorn and so contriv'd that it may imbrace the Gums exactly Your Instrument being ready if you have a mind to perform the Operation you must in the next place concerning the Dentes Sapientiae tie all the Teeth together which may be done without any trouble so that the two foremost of them may draw the last of all towards the fore-part of the mouth By this the included Teeth will be freed from being compressed between the others and the extremity of the Jaw-bone And then the Gums being prepar'd by Emollients and relaxing things apply the end of your Syringe close upon the Gums under which the imperfect Tooth lies and then draw the Embolus and the top of the Gums will follow and rise within the little Acorn-cup-like end of the Pipe as the flesh usually doth under Cupping-Glasses Keep it a while so and then take away the Syringe and scarifie that part of the Gums that was drawn within the Pipe in several places reiterating the same Operation twice a day for about a fortnight omitting only the Scarification which is to be used the first time only By this means it appears probable to me that the Gums yielding the force of the Blood will compel the fibres or minute parts of the imperfect Tooth to advance according to their natural order and situation and so cause the said Tooth to grow As to the Novel-Teeth you shall follow the same method and use the same means in facilitating their coming out that you have done to the others omitting only the tying of the Teeth which would be superfluous here Note that every thing is not capable of the same perfection and that as there is no rule without some exception so when I have asserted such and such things to be improvable to such a degree it is to be understood for the most part and in general not denying but that it may happen otherwise in some particular cases but I shall always deal candidly with every body never undertaking any thing but what I shall be able to do according to agreement And if any one will be pleased to come to my Chamber he may have my Advice concerning any thing that belongs to my Profession gratis at any time ADVERTISEMENT TO THE READERS GENTLEMEN ALthough I have offered nothing in this Paper but what is according to my own Experience and the best of my knowledge yet I will not say but that I have been deficient in many things and have committed a great many Errors in the management of my Subject but if you consider that I am the first as far as I know that ever wrote any thing of this nature and withal what is to be expected from one in my Circumstances I hope you will be the more ready to excuse my faults However if what I have done be acceptable to you I intend in a second Impression of this small Treatise to Correct Illustrate and augment it to its full proportion In the mean while I would advise you to make use of what is here presented you by Your very Humble Servant CHARLES ALLEN Printed in the Year 1686. A Physical Discourse WHEREIN The Reasons of the Beating of the PULSE or Pulsation of the Arteries Together with those of the Circulation of the Bloud are Mechanically Explain'd Which was never done before THe Beating of the Pulse being one of those Phenomena that deserve mans consideration the best it has excited the most Learned in all Ages to search out what might be the cause of it The best Physitians and greatest Philosophers of former times being ignorant of the Circulation of the Bloud did ascribe it to their occult qualities and unknown powers Galen an Eminent Physitian searching the natural cause of the Beating of the Pulse thought upon the making of that famous Experiment of his by which having put a Quill into an Artery and tied the Artery upon it he found that the said Artery ceased from beating betwixt the ligature and the extremity tho it continued still beating betwixt the same ligature and the heart And then seeing also that the Artery being untied from about the Quill the Pulse would immediately pass beyond the place where the ligature had been made and beat all along the Artery altho the capacity of the Quill remained still the same he concluded that the Pulse was caused by a Pulsisick faculty residing in the coats of the Artery Gassendus a Modern and most Learned
Philosopher attributed the said effect to the Pulsifick Faculty of the heart which in his opinion communicates it self to the Arteries Both which opinions altho propos'd by extraordinary men yet are so inconsiderable that they need no refutation The most Learned and most Profound Cartesius was of opinion that the Beating of the Pulse proceeded from the motion of the Bloud which coming out of the lest Ventricle of the Heart into the Aorta in a tumultuous manner extends it self forcibly and thereby drives all the mass of the Bloud from the heart to the heart again according to the Circulation of the Bloud After which this great Man who would always give natural and intelligible reasons for every thing as he has done for most coming at the instigation of a Physitian of Louvaine to examine Galen's Experiment he attributed the cessation of the Pulse that happens below the ligature to the narrowness of the passage of the Bloud through the Quill which Bloud according to the principles of the Philotopher coming out of the said Quill into a wider space cannot communicate its action to the sides of the Artery but is disposed to imploy the force of its motion forwards according to the length of the Artery But the said Physitian alledging against this that if one takes an Artery without Quill or any Incision and ties its sides so close together that there be left a far smaller passage for the Bloud in that place than in the Quill the Artery will nevertheless continue still to Beat on both sides of the ligature as it did before the contrary of which wou'd necessarily follow if it were so that the straitness of the passage of the Bloud did occasion the loss of the Pulse Cartesius was here forced to recede somewhat from his former Sentiment and to confess that the motion of the Arteries depends partly upon the free continuation of their coats which totally overthrows his opinion For let the power of the said continuation be what it will supposing as the Philosopher did that its action may be stopt by the compression of the sides of the Artery It is certain that altho the Quill in the Artery were of equal or if you will greater capacity than the Artery yet if the said Artery were tied upon it the Pulse would notwithstanding all that cease below the ligature But Cartesius said that such a Quill as that we were speaking of just now being in an Artery either tied or untied wou'd never hinder any part of the Artery from Beating And therefore c. Doctor Lower says after many Disquisitions on this Subject that the knowledge of those things was left to God alone Doctor Willis ascribes the Beating of the Pulse to the contraction of the circular Fibres of the muscular coat of the Artery But it is absurd to think so for its impossible to imagine that those Fibres cou'd contract themselves of their own accord neither does the Doctor give any reason for what he says Besides he 's inconsistent with himself when he ascribes the same motions to the circular Fibres of the muscular coat of the veins which are notwithstanding wholly destitute of any Pulsation c. All which considering and how these and other great men had through the difficulty of the thing and not out of any insufficiency in them fallen into so gross and so erroneous opinions concerning the Point in Question I concluded that it was as good as impossible ever to solve the difficulty Yet recollecting my self and seeing that the said Effect must have a cause whatever it be which probably cannot reside any where else but either in the Heart Bloud or coats of the Artery or finally in them all together I made a resolution to examine carefully each one of these things separately as possibly containing alone the cause sought after and then all together as being possibly Coadjutors in the production of the known Effect And after as exact an Inquiry into the matter as I am capable of my Reasons which wou'd be too tedious to tell you now perswade me that all the Mystery consists in the three following things The First is the Structure of the Artery which is made up of four Coats We shall examine in another place how they are generated at first The first of them which contains the Bloud immediately seems to be nervous and made of strait Fibres which take their Origine from the heart or rather are a continuation of those that immediately invest the cavity of the heart As soon as they are arriv'd at the orifice of the heart they rank themselves by one another forming a certain Cartilagineous Ring from the circumference of which they run almost parallel along the Artery but yet with such an inclination towards one another that going from the heart to the extreme parts they form a kind of Cone for that we may render our Discourse more intelligible we shall consider here one of the trunks of the great Artery suppose the ascending one as a continued right Conical Pipe abstracting from all its divisions and branches to every one of which may easily be apply'd what we are going to say of one of them a little below the Apex of which those Fibres unite themselves together and do compose a little tendinous ring called Anastomosis to which is affix'd the extremity of the vena cava which vein we shall suppose here to be a single conical channel or pipe disposed as we have taken the Artery to be Within this Anastomosis there is a little Valve so dispos'd that it permits the bloud to pass from the Artery into the vein but hinders it from returning back again from the vein into the Artery Between every one of those nervous Fibres there is a thin membrane that joyns them together as the skin in a Goose'sfoot ties its toes to one another which permits the said Fibres to open and go further from one another when the Artery is dilated And which do continually increase in breath as they go from the Anastomosis to the basis of the Artery so that they become so conspicuous near the heart that Doctor Willis took them for some large fleshy Fibres to which he assign'd the faculty of shortning the Artery in order to promote the circulation of the Bloud The second coat is the Muscular and the third the Glandulous but the consideration of these middle coats being not necessary to our present purpose we shall speak of them another time As to the fourth or outmost Coat it is that which we have most need to take notice of here as being the principal Instrument of the Systole and Diastole of the Artery This Coat is made up of two orders or ranks of spiral Fibres which proceed from the oblique Fibres of the heart from whence they go twisting and winding themselves about the body of the Artery as Ivy does about Trees some running upon it from the left to the right and the others from