Year or two before who is not near so exact as Monsieur du Verney The other Parts of the Head and Neck wherein the Old Anatomy was the most defective were the Tongue as to its internal Texture and the Glands of the Mouth Jaws and Throat The Texture of the Tongue was but guessed at which occasioned great Disputes concerning the Nature of its Substance some thinking it to be glandulous some muscular and some of a peculiar Nature not to be matched in any other part of the Body This therefore Malpighius examined with his Glasses and discovered that it was cloathed with a double Memorane that in the inner Membrane there are Abundance of small Papillae which have extremities of Nerves inserted into them by which the Tongue discerns Tasts and that under that Membrane it is of a muscular Nature consisting of numberless Heaps of Fibres which run all manner of Ways over one another like a Mat. The general Uses of the Glands of the Mouth Jaws and Neck were anciently known it was visible that the Mouth was moistend by them and the Mass of the Spittle supplied from them and then having named them from the Places near which they lie as the Palate the Jaws the Tongue the Ears the Neck they went no further and there was little if any thing more done till Dr. Wharton and Nicolaus Steno examined these Glands And upon an exact Enquiry Four several Salival Ducts have been discovered which from several Glands discharge the Spittle into the Mouth The First was described by Dr. Wharton near Forty Years ago it comes from the conglomerate Glands that lie close to the inner side of the lower Jaw and discharges it self near the middle of the Chin into the Mouth The Second was found out by Steno who published his Observations in 1662 this comes from those Glands that lie near the Ears in the inside of the Cheek and the outside of the upper-Jaw The Third was found out by Thomas Bartholin who gave an Account of it in 1682 and about the same Time by one Rivinus a German It arises from the Glands under the Tongue and going in a distinct Canal to the Mouth of Wharton's Duct there for the most Part by a common Orifice opens into the Mouth The Fourth was discovered by Monsieur Nuck he found a Gland within the Orbit of the Eye from which not far from the Mouth of Steno's Duct Spittle is supplied to the Mouth by a peculiar Canal Besides these the same Monsieur Nuck found some smaller Glands near the last but lower down which by Four distinct Pipes carry some Spittle into the Mouth so careful has Nature been to provide so many Passages for that necessary and noble Juice that if some should fail others might supply their Want CHAP. XVIII Of the Circulation of the Blood FRom the Head we are to look into the Thorax and there to consider the Heart and the Lungs The Lungs as most of the other Viscera were believed to be of a Parenchymous Substance till Malpighius found by his Glasses that they consist of innumerable small Bladders that open into each other as far as the outermost which are covered by the outer Membrane that incloses the whole Body of the Lungs And that the small Branches of the Wind-Pipe are all inserted into these Bladders about every one of which the Veins and Arteries are entwined in an unconceivable Number of Nets and Mazes that so the inspired Air may press upon or mix with the Mass of Blood in such small Parcels as the Ancients had no Notion of The Wind-Pipe also it self is nourished by an Artery that creeps up the Back-side and accompanies it in all its Branchings Which was first found out by Frederic Ruysch a Dutch Professor of Anatomy at Leyden about Thirty Years ago But the great Discovery that has been made of the Lungs is That the whole Mass of Blood is carried out of the Right Ventricle of the Heart by the Arteria Pulmonaris called anciently Vena Arteriosa through all the small Bladders of the Lungs into the Vena Pulmonaris or Arteria Venosa and from thence into the Left Ventricle of the Heart again So that the Heart is a strong Pump which throws the Blood let in from the Veins into the Lungs and from the Lungs afterwards into the Arteries and this by a constant rapid Motion whereby the Blood is driven round in a very few Minutes This Discovery first made perfectly intelligible by Dr. Harvey is of so very great Importance to shew the Communication of all the Humours of the Body each with other that as soon as Men were perfectly satisfied that it was not to be contested which they were in a few Years a great many put in for the Prize unwilling that Dr. Harvey should go away with all the Glory Vander Linden who published a most exact Edition of Hippocrates in Holland about Thirty Years ago has taken a great deal of Pains to prove that Hippocrates knew the Circulation of the Blood and that Dr. Harvey only revived it The Substance of what has been said in this Matter is this that Hippocrates speaks in one Place of the Usual and Constant Motion of the Blood That in another Place he calls the Veins and Arteries the Fountains of Humane Nature the Rivers that water the whole Body that convey Life and which if they be dried up the Man dies That in a Third Place he says That the Blood-Vessels which are dispersed over the whole Body give Spirit Moisture and Motion and all spring from one which one Blood-Vessel has no Beginning nor no End that I can find for where there is a Circle there is no Beginning These are the clearest Passages that are produced to prove that Hippocrates knew the Circulation of the Blood and it is plain from them that he did believe it as an Hypothesis that is in plain English that he did suppose the Blood to be carried round the Body by a constant accustomed Motion But that he did not know what this constant accustomed Motion was and that he had not found that Course which in our Age Dr. Harvey first clearly demonstrated will appear evident from the following Considerations 1. He says nothing of the Circulation of the Blood in his Discourse of the Heart where he Anatomizes it as well as he could and speaks of the Ventricles and the Valves which are the immediate Instruments by which the Work is done 2. He believes that the Auricles of the Heart are like Bellows which receive the Air to cool the Heart Now there are other Uses of them certainly known since they assist the Heart in the Receiving of the Blood from the Vena Cava and the Vena Pulmonaris This cannot be unknown to any Man that knows how the Blood circulates and accordingly would have been mentioned by Hippocrates had he known of it 3. Hippocrates speaks of Veins as
receiving Blood from the Heart and going from it Which also was the constant Way of Speaking of Galen and all the Ancients Now no Man that can express himself properly will ever say That any Liquors are carried away from any Cistern as from a Fountain or Source through those Canals which to his Knowledge convey Liquors to that Cistern 4. Hippocrates says the Blood is carried into the Lungs from the Heart for the Nourishment of the Lungs without assigning any other Reason These seem to be positive Arguments that Hippocrates knew nothing of this Matter and accordingly all his Commentators Ancient and Modern before Dr. Harvey never interpreted the former Passages of the Circulation of the Blood Neither would Vander Linden in all probability if Dr. Harvey had not helped him to the Notion which he was then resolved to find in Hippocrates whom he supposed not the Father only but the Finisher also of the whole Medical Art It is pretended to by none of the Ancients or rather their Admirers for them after Hippocrates As for Galen any Man that reads what he says of the Heart and Lungs in the 6th Book of his De Usu Partium must own that he does not discourse as if he were acquainted with Modern Discoveries and therefore it is not so much as pretended that he knew this Recurrent Motion of the Blood Which also further shews that if Hippocrates did know it he explained himself so obscurely that Galen could not understand him who in all probability understood Hippocrates's Text as well as any of his Commentators who have written since the Greek Tongue and much more since the Ionic Dialect has ceased to be a living Language Since the Ancients have no Right to so noble a Discovery it may be worth while to enquire to whom of the Moderns the Glory of it is due for this is also exceedingly contested The first Step that was made towards it was the finding that the whole Mass of the Blood passes through the Lungs by the Pulmonary Artery and Vein The first that I could ever find who had a distinct Idea of this Matter was Michael Servetus a Spanish Physician who was burnt for Arianism at Geneva near 140 Years ago Well had it been for the Church of Christ if he had wholly confined himself to his own Profession His Sagacity in this Particular before so much in the dark gives us great Reason to believe that the World might then have had just Cause to have blessed his Memory In a Book of his intituled Christianismi Restitutio printed in the Year MDLIII he clearly asserts that the Blood passes through the Lungs from the Left to the Right Ventricle of the Heart and not through the Partition which divides the two Ventricles as was at that Time commonly believed How he introduces it or in which of the Six Discourses into which Servetus divides his Book it is to be found I know not having never seen the Book my self Mr. Charles Bernard a very learned and eminent Chirurgeon of London who did me the Favour to communicate this Passage to me set down at length in the Margin which was transcribed out of Servetus could inform me no further only that he had it from a learned Friend of his who had himself copied it from Servetus Realdus Columbus of Cremona was the next that said any thing of it in his Anatomy printed at Venice 1559. in Folio and at Paris in 1572. in Octavo and afterwards elsewhere There he asserts the same Circulation through the Lungs that Servetus had done before but says that no Man had ever taken notice of it before him or had written any Thing about it Which shews that he did not copy from Servetus unless one should say that he stole the Notion without mentioning Servetus's Name which is injurious since in these Matters the same Thing may be and very often is observed by several Persons who never acquainted each other with their Discoveries But Columbus is much more particular for he says That the Veins lodge the whole Mass of the Blood in the Vena Cava which carries it into the Heart whence it cannot return the same Way that it went from the Right Ventricle it is thrown into the Lungs by the Pulmonary Artery where the Valves are so placed as to hinder its Return that Way into the Heart and so it is thrown into the Left Ventricle and by the Aorta again when enliven'd by the Air diffused through the whole Body Some Years after appeared Andreas Caesalpinus who printed his Peripatetical Questions at Venice in Quarto in 1571. And afterwards with his Medical Questions at the same Place in 1593. He is rather more particular than Columbus especially in examining how Arteries and Veins joyn at their Extremities which he supposes to be by opening their Mouths into each other And he uses the Word Circulation in his Peripatetical Questions which had never been used in that Sence before He also takes notice that the Blood swells below the Ligature in veins and urges that in Confirmation of his Opinion At last Dr. William Harvey printed a Discourse on purpose upon this Subject at Francfort in 1628. This Notion had only been occasionally and slightly treated of by Columbus and Caesalpinus who themselves in all probability did not know the Consequence of what they asserted and therefore it was never applied to other Purposes either to shew the Uses of the other Viscera or to explain the Natures of Diseases Neither for any Thing that appears at this Day had they made any Numbers of Experiments which were necessary to explain their Doctrine and to clear it from Opposition All this Dr. Harvey undertook to do and with indefatigable Pains traced the visible Veins and Arteries throughout the Body in their whole Journey from and to the Heart so as to demonstrate even to the most incredulous not only that the Blood circulates through the Lungs and Heart but the very Manner how and the Time in which that great Work is performed When he had once proved that the Motion of the Blood was so rapid as we now find it is then he drew such Consequences from it as shewed that he throughly understood his Argument and would leave little at least as little as he could to future Industry to discover in that particular Part of Anatomy This gave him a just Title to the Honour of so noble a Discovery since what his Predecessors had said before him was not enough understood to form just Notions from their Words One may also observe how gradually this Discovery as all abstruse Truths of Humane Disquisition was explained to the World Hippocrates first talked of the Usual Motion of the Blood Plato said That the Heart was the Original of the Veins and of the Blood that was carried about every Member of the Body Aristotle also somewhere speaks of a Recurrent Motion of the Blood Still all this was only Opinion and Belief It
was rational and became Men of their Genius's but not having as yet been made evident by Experiments it might as easily be denied as affirmed Servetus first saw that the Blood passes through the Lungs Columbus went further and shew'd the Uses of the Valves or Trap-doors of the Heart which let the Blood in and out of their Respective Vessels but not the self same Road Thus the Way was just open when Dr. Harvey came who built upon the First Foundations to make his Work yet the easier the Valves of the Veins which were discovered by F. Paul the Venetian had not long before been explained by Fabricius ab Aqua pendente whence the Circulation was yet more clearly demonstrated There was one thing still wanting to compleat this Theory and that was the Knowledge how the Veins received that Blood which the Arteries discharged first it was believed that the Mouths of each sort of Vessels joined into one another that Opinion was soon laid aside because it was found that the capillary Vessels were so extremely small that it was impossible with the naked Eye to trace them This put them upon imagining that the Blood ouzes out of the Arteries and is absorbed by the Veins whose small Orifices receive it as it lies in the Fibres of the Muscles or in the Parenchyma's of the Bowels Which Opinion has been generally received by most Anatomists since Dr. Harvey's Time But Monsieur Leeuwenhoek has lately found in several sorts of Fishes which were more manageable by his Glasses than other Animals That Arteries and Veins are really continued Syphons variously wound about each other towards their Extremities in numberless Mazes over all the Body and others have found what he says to be very true in a Water Newt So that this Discovery has passed uncontested And since it has been constantly found that Nature follows like Methods in all sorts of Animals where she uses the same sorts of Instruments it will always be believed That the Blood circulates in Men after the same Manner as it does in Eels Perches Pikes Carps Bats and some other Creatures in which Monsieur Leeuwenhoek tried it Though the Ways how it may be visible to the Eye in Men have not that I know of been yet discovered However this visible Circulation of the Blood in these Creatures effectually removes Sir William Temple's Scruple who seems unwilling to believe the Circulation of the Blood because he could not see it His Words are these Nay it is disputed whether Harvey 's Circulation of the Blood be true or no for though Reason may seem to favour it more than the contrary Opinion yet Sense can very hardly allow it and to satisfie Mankind both these must concurr Sense therefore here allows it and that this Sense might the sooner concurr Monsieur Leeuwenhoek describes the Method how this Experiment may be tried in his 66 th Letter The Inferences that may be made from this Noble Discovery are obvious and so I shall not stay to mention them CHAP. XIX Further Reflections upon Ancient and Modern Anatomy IF after this long Enquiry into the First Discovery of the Circulation of the Blood it should be found that the Anatomy of the Heart was but slightly known to the Ancients it will not I suppose be a Matter of any great Wonder The First Opinion which we have of the Texture of the Heart was that of Hippocrates that it is a very strong Muscle this tho' true was rejected afterwards for want of knowing its true Use its internal Divisions its Valves and larger visible Fibres were well known and distinctly described by the Ancients only they were mistaken in thinking that there is a Communication between the Ventricles through the Septum which is now generally known to be an Errour The Order of the Muscular Fibres of the Heart was not known before Dr. Lower who discovered them to be Spiral like a Snale-Shell as if several Skains of Threads of differing Lengths had been wound up into a Bottom of such a Shape hollow and divided within By all these Discoveries Alphonsus Borellus was enabled to give such a Solution of all the Appearances of the Motion of the Heart and of the Blood in the Arteries upon Mathematical and Mechanical Principles as will give a more satisfactory Account of the wonderful Methods of Nature in dispensing Life and Nourishment to every Part of the Body than all that had ever been written upon these Subjects before those things were found out Below the Midriff are several very noble Viscera The Stomach the Liver the Pancreas or Sweet-Bread the Spleen the Reins the Intestines the Glands of the Mesentery and the Instruments of Generation of both Sexes in the Anatomical Knowledge of all which Parts the Ancients were exceedingly defective The Coats of the Stomach have been separated and the several Fibres of the middle Coat examined by Dr. Willis with more Exactness than formerly he also has been very nice in tracing the Blood-Vessels and Nerves that run amongst the Coats has evidently shewn that its Inside is covered with a glandulous Coat whose Glands separate that Mucilage which both preserves the Fibres from being injured by the Aliments which the Stomach receives and concurrs with the Spittle to further the Digestion there performed and has given a very particular Account of all those several Rows of Fibres which compose the musculous Coat To which if we add Steno's Discovery of the Fibres of the musculous Coat of the Gullet that they are spiral in a double Order one ascending the other descending which run contrary Courses and mutually cross each other in every Winding with Dr. Cole's Discovery of the Nature of the Fibres of the Intestines that they also move spirally though not perhaps in a contrary Order from the beginning of the Duodenum to the end of the streight Gut the Anatomy of those parts seems to be almost compleat The great Use of the Stomach and the Guts is to prepare the Chyle and then to transmit it through the Glands of the Mesentery into the Blood this the Ancients knew very well the Manner how it was done they knew not Galen held that the Mesaraick Veins as also those which go from the Stomach to the Liver carry the Chyle thither which by the Warmth of the Liver is put into a Heat whereby the Faeculencies are separated from the more spirituous Parts and by their Weight sink to the Bottom the purer Parts go into the Vena Cava The Dregs which are of two sorts Choler and Melancholy go into several Receptacles the Choler is lodged in the Gall-Bladder and Porus Bilarius Melancholy is carried off by the Spleen The Original of all these Notions was Ignorance of the Anatomy of all these Parts as also of the constant Motion of the Blood through the Lungs and Heart Herophilus who is commended as the ablest Anatomist of Antiquity found out that there were veins dispersed
quite through the Mesentery as far as the small Guts reach which carried the Chyle from the Intestines into several Glandulous Bodies and there lodged them These are the Milky Veins again discovered by Asellius about Fifty Years ago and those Glands which Herophilus spoke of are probably that great Collection of Glands in the Mesentery that is commonly called the Pancreas Asellii After Herophilus none of the Ancients had the Luck to trace the Motions of the Chyle any further and so these milky Veins were confounded with the Mesaraicks and it was commonly believed That because all Mesaraicks carry the Blood from the Intestines into the Liver therefore they carried Chyle also when there was any Chyle to carry and hence probably it was that the Liver was believed to be the common Work-House of the Blood But when Asellius had traced the Chyle as far as the great Gland of the Mesentery it was soon found not to lie there And Pecquet about Forty Years since discovered the common Receptacle of the Chyle whither it is all brought Thence he also found that it is carried by particular Vessels through the Thorax almost as high as the Left-Shoulder and there thrown into the Left Subclavian Vein and so directly carried to the Heart It has also been discovered that in his Canal usually called Ductus Thoracicus there are numerous Valves which hinder the Return of the Chyle to the common Receptacle so that it can be moved forwards but not backwards Since this Passage of the Chyle has been discovered it has been by some believed that the Milk is conveyed into the Breasts by little Vessels from the Ductus Thoracicus The whole Oeconomy of that Affair has been particularly described very lately by Mr. Nuck before whose Time it was but imperfectly known He says therefore that the Breasts are Heaps of Glands supplied with Blood by innumerable Ramifications of the Axillary and Thoracick Arteries some of which passing through the Breast-bone unite with the Vessels of the opposite Side These Arteries which are unconceivably small part with the Milk in those small Glands into small Pipes four or five of which meeting together make one small Trunk of these small Trunks the large Pipes which terminate in the Nipple are made up though before they arrive thither they straiten into so small a Compass that a stiff Hair will just pass through The Nipple which is a Fibrous Body has seven or eight or more Holes through which every Pipe emits its Milk upon Suction and lest any one of them being stopped the Milk should stagnate they all have cross Passages into each other at the Bottom of the Nipple where it joyns to the Breast The fore-mentioned Discovery of the Passage of the Chyle obliged Men to re-examine the Notions which till then had generally obtained concerning the Nature and Uses of the Liver Hitherto it had been generally believed that the Blood was made there and so dispersed into several Parts for the Uses of the Body by the Vena Cava Erasistratus indeed supposed that its principal Use was to separate the Bile and to lodge it in its proper Vessels But for want of further Light his Notion could not then be sufficiently proved and so it presently fell and was never revived till Asellius's and Pecquet's Discoveries put it out of doubt Till Malpighius discovered its Texture by his Glasses its Nature was very obscure But he has found out 1. That the Substance of the Liver is framed of innumerable Lobules which are very often of a Cubical Figure and consist of several little Glands like the Stones of Raisins so that they look like Bunches of Grapes and are each of them cloathed with a distinct Membrane 2. That the whole Bulk of the Liver consists of these Grape-stone-like Glands and of divers sorts of Vessels 3. That the small Branches of the Cava Porta and Porus Bilarius run through all even the least of these Lobules in an equal Number and that the Branches of the Porta are as Arteries that convey the Blood to and the Branches of the Cava are the Veins which carry the Blood from all these little Grape-stone-like Glands From whence it is plain that the Liver is a Glandulous Body with its proper Excretory Vessels which carry away the Gall that lay before in the Mass of the Blood Near the Liver lies the Pancreas which Galen believed to be a Pillow to support the Divisions of the Veins as they go out of the Liver and for what appears at present the Ancients do not seem to have concerned themselves any further about it Since it has been found to be a Glandulous Body wherein a distinct Juice is separated from the Blood which by a peculiar Canal first discovered by Georgius Wirtsungus a Paduan Physician is carried into the Duodenum where meeting with the Bile and the Aliment just thrown out of the Stomach assists and promotes the Business of Digestion The Spleen was as little understood as the Pancreas and for the same Reasons Its Anatomy was unknown and its Bulk made it very remarkable something therefore was to be said about it And what no Body could positively dis-prove might the easier be either received or contradicted The most general Opinion was that the grosser Excrements of the Chyle and Blood were carried off from the Liver by the Ramus Splenicus and lodged in the Spleen as in a common Cistern But since the Circulation of the Blood has been known it has been found that the Blood can go from the Spleen to the Liver but that nothing can return back again into the Spleen And as for its Texture Malpighius has discovered that the Substance of the Spleen deducting the numerous Blood-Vessels and Nerves as also the Fibres which arise from its Second Membrane and which support the other Parts is made up of innumerable little Cells like Honey-Combs in which there are vast Numbers of small Glandules which resemble Bunches of Grapes and that these hang upon the Fibres and are fed by Twigs of Arteries and Nerves and send forth the Blood there purged into the Ramus Splenicus which carries it into the Liver to what purpose not yet certainly discovered The Use of the Reins is so very conspicuous that from Hippocrates's Time downwards no Man ever mistook it But the Mechanism of those wonderful Strainers was wholly unknown till the so often mentioned Malpighius found it out He therefore by his Glasses discovered that the Kidneys are not one uniform Substance but consist of several small Globules which are all like so many several Kidneys bound about with one common Membrane and that every Globule has small Twigs from the emulgent Arteries that carry Blood to it Glands in which the Urine is strained from it Veins by which the purified Blood is carried off to the Emulgent Veins thence to go into the Cava a Pipe to convey the Urine into the great Basin in the middle of the Kidney
and a Nipple towards which several of those small Pipes tend and through which the Urine ouzes out of them into the Basin This clear Use of the Structure of the Reins has effectually confuted several Notions that Men had entertained of some Secundary Uses of those Parts since hereby it appears that every Part of the Kidneys is immediately and wholly subservient to that single Use of Freeing the Blood from its superfluous Serum What has been done by Modern Anatomists towards the Compleating of the Knowledge of the remaining Parts I shall omit That the Ancients likewise took Pains about them is evident from the Writings of Hippocrates Aristotle and Galen The Discoveries which have since been made are so great that they are in a manner undisputed And the Books which treat of them are so well known that it will not be suspected that I decline to enlarge upon them out of a Dread of giving up more to the Ancients in this Particular than I have done all along The Discoveries hitherto mentioned have been of those Parts of Humours of the Body whose Existence was well enough known to the Ancients But besides them other Humours with Vessels to separate contain and carry them to several Parts of the Body have been taken notice of of which in strictness the Ancients cannot be said to have any sort of Knowledge These are the Lympha or Colourless Juice which is carried to the Chyle and Blood from separate Parts of the Body And the Mucilage of the Joints which lubricates them and the Muscles in their Motions The Discovery of the Lympha which was made about Forty Years ago is contended for by several Persons Thomas Bartholine a Dane and Olaus Rudbeck a Suede published their Observations about the same Time And Dr. Jolliffe an English-Man shewed the same to several of his Friends but without publishing any Thing concerning them The Discoveries being undoubted and all Three working upon the same Materials there seems no Reason to deny any of them the Glory of their Inventions The Thing which they found was that there are innumerable small clear Vessels in many Parts of the Body chiefly in the Lower Belly which convey a Colourless Juice either into the common Receptacle of the Chyle or else into the Veins there to mix with the Blood The Valves which Frederic Ruysch found and demonstrated in them about the same Time manifestly shewed that this is its Road because they prove that the Lympha can go forwards from the Liver Spleen Lungs Glands of the Loins and Neck or any other Place whence they arise towards some Chyliferous Duct or Vein but cannot go back from those Chyliferous Ducts or Veins to the Place of their Origination What this Origination is was long uncertain it not being easie to trace the several Canals up to their several Sources Steno and Malpighius did with infinite Labour find that Abundance of Lympheducts passed through those numerous Conglobate Glands that are dispersed in the Abdomen and Thorax which made them think that the Arterious Blood was there purged of its Lympha that was from thence carried off into its proper Place by a Vessel of its own But Mr. Nuck has since found that the Lympheducts arise immediately from Arteries themselves and that many of them are percolated through those Conglobate Glands in their Way to the Receptacle of the Chyle or those Veins which receive them By these and innumerable other Observations the Uses of the Glands of the Body have been found out all agreeing in this one Thing namely that they separate the several Juices that are discernable in the Body from the Mass of the Blood wherein they lay before From their Texture they have of late been divided into Conglomerate and Conglobate The Conglomerate Glands consist of many smaller Glands which lie near one another covered with one common Membrane with one or more common Canals into which the separated Juice is poured by little Pipes coming from every smaller Glandule as in the Liver the Kidneys the Pancreas and Salival Glands of the Mouth The Conglobate Glands are single often without an Excretory Duct of their own only perforated by the Lympheducts Of all which Things as essential to the Nature of Glands the Ancient Anatomists had no sort of Notion The Mucilage of the Joints and Muscles was found out by Dr. Havers He discovered in every Joint particular Glands out of which issues a Mucilaginous Substance whose Nature he examined by numerous Experiments which with the Marrow supplied by the Bones always serves to oil the Wheels that so our Joints and Muscles might answer those Ends of Motion for which Nature designed them This was a very useful Discovery since it makes Abundance of Things that were very obscure in that Part of Anatomy very plain and facile to be understood And among other Things it shews the Use of that excellent Oil which is contained in our Bones and there separated by proper Strainers from the Mass of the Blood especially since by a nice Examination of the true inward Texture of all the Bones and Cartilages of the Body he shew'd how this Oil is communicated to the Mucilage and so united as to perform their Office And if one compares what Dr. Havers says of Bones and Cartilages with what had been said concerning them before him his Observations about their Frame may well be added to some of the noblest of all the former Discoveries These are some of the most remarkable Instances how far the Knowledge of the Frame of our Bodies has been carried in our Age. Several Observations may be made concerning them which will be of Use to the present Question 1. It is evident that only the most visible Things were anciently known such only as might be discovered without great Nicety Muscles and Bones are easily separable their Length is soon traced and their Origination easily known The same may be truly said of large Blood-Vessels and Nerves But when they come to be exquisitely sub-divided when their Smalness will not suffer the Eye much less the Hand to follow them then the Ancients were constantly at a Loss For which Reason they understood none of the Viscera to any tolerable Degree 2. One may perceive that every new Discovery strengthens what went before otherwise the World would soon have heard of it and the erroneous Theories of such Pretenders to new Things would have been exploded and forgotten unless by here and there a curious Man that pleases himself with reading Obsolete Books Nullius in verba is not only the Motto of the ROYAL SOCIETY but a received Principle among all the Philosophers of the present Age And therefore when once any new Discoveries have been examined and received we have more Reason to acquiesce in them than there was formerly This is evident in the Circulation of the Blood Several Veins and Arteries have been found at least more exactly traced since than they were in Dr.
Harvey's Time Not one of these Discoveries has ever shown a single Instance of any Artery going to or of any Vein coming from the Heart Ligatures have been made of infinite Numbers of Vessels and the Course of all the Animal Juices in all manner of living Creatures has thereby been made visible to the naked Eye and yet not one of these has ever weakned Dr. Harvey's Doctrine The Pleasure of Destroying in Matters of this Kind is not much less than the Pleasure of Building And therefore when we see that those Books which have been written against some of the eminentest of these Discoveries though but a few Years ago comparatively speaking are so far dead that it is already become a Piece of Learning even to know their Titles we have sufficient Assurance that these Discoverers whose Writings out-live Opposition neither deceive themselves nor others So that whatsoever it might be formerly yet in this Age general Consent in Physiological Matters especially after a long Canvass of the Things consented to is an almost infallible Sign of Truth 3. The more Ways are made use of to arrive at any one particular Part of Knowledge the surer that Knowledge is when it appears that these different Methods lend Help each to other If Malpighius's or Leeuwenhoek's Glasses had made such Discoveries as Men's Reason could not have agreed to if Objects had appeared confused and disorderly in their Microscopes if their Observations had contradicted what the naked Eye reveals then their Verdict had been little worth But when the Discoveries made by the Knife and the Microscope disagree only as Twi-light and Noon-day then a Man is satisfied that the Knowledge which each affords to us differs only in Degree not in Sort. 4. It can signifie nothing in the present Controversie to pretend that Books are lost or to say that for ought we know Herophilus might anciently have made this Discovery or Erasistratus that their Reasonings demonstrate the Extent of their Knowledge as convincingly as if we had a Thousand old Systems of Ancient Anatomy extant 5. In judging of Modern Discoveries one is nicely to distinguish between Hypothesis and Theory The Anatomy of the Nerves holds good whether the Nerves carry a Nutritious Juice to the several Parts of the Body or no. The Pancreas sends a Juice into the Duodenum which mixes there with the Bile let the Nature of that Juice be what it will Yet here a nice Judge may observe that every Discovery has mended the Hypotheses of the Modern Anatomists and so it will always do till the Theories of every Part and every Juice be as entire as Experiments and Observations can make them As these Discoveries have made the Frame of our own Bodies a much more intelligible Thing than it was before though there is yet a great deal unknown so the same Discoveries having been applied to and found in almost all sorts of known Animals have made the Anatomy of Brutes Birds Fishes and Insects much more perfect than it could possibly be in former Ages Most of the Rules which Galen lays down in his Anatomical Administrations are concerning the Dissection of Apes If he had been now to write besides those tedious Advices how to part the Muscles from the Membranes and to observe their several Insertions and Originations the Jointings of the Bones and the like he would have taught the World how to make Ligatures of all sorts of Vessels in their proper Places what Liquors had been most convenient to make Injections with thereby to discern the Courses of Veins Arteries Chyle-Vessels or Lympheducts how to unravel the Testicles how to use Microscopes to the best Advantage He would have taught his Disciples when and where to look for such and such Vessels or Glands where Chymical Trials were useful and what the Processes were by which he made his Experiments or found out his Theories Which Things fill up every Page in the Writings of later Dissectors This he would have done as well as what he did had these Ways of making Anatomical Discoveries been then known and practised The World might then have expected such Anatomies of Brutes as Dr. Tyson has given of the Rattle-Snake or Dr. Moulin of the Elephant Such Dissections of Fishes as Dr. Tyson's of the Porpesse and Steno's of the Shark Such of Insects as Malpighius's of a Silk-Worm Swammerdam's of the Ephemeron Dr. Lister's of a Snail and the same Dr. Tyson's of Long and Round Body-Worms All which shew Skill and Industry not conceivable by a Man that is not a little versed in these Matters To this Anatomy of Bodies that have Sensitive Life we ought to add the Anatomy of Vegetables begun and brought to great Perfection in Italy and England at the same Time by Malpighius and Dr. Grew By their Glasses they have been able to give an Account of the different Textures of all the Parts of Trees Shrubs and Herbs to trace the several Vessels which carry Air Lympha Milk Rosin and Turpentine in those Plants which afford them to describe the whole Process of Vegetation from Seed to Seed and in a Word though they have left a great deal to be admired because it was to them incomprehensible yet they have discovered a great deal to be admired because of its being known by their Means CHAP. XX. Of Ancient and Modern Natural Histories of Elementary Bodies and Minerals HAving now finished my Comparison of Ancient and Modern Anatomy with as much Exactness as my little Insight into these Things would give me Leave I am sensible that most Men will think that I have been too tedious But besides that I had not any where found it carefully done to my Hands though it is probable that it has in Books which have escaped my Notice I thought that it would be a very effectual Instance how little the Ancients may have been presumed to have perfected any one Part of Natural Knowledge when their own Bodies which they carried about with them and which of any Thing they were the nearliest concerned to know were comparatively speaking so very imperfectly traced However in the remaining Parts of my Parallel I shall be much shorter which I hope may be some Amends for my too great Length in this From those Instruments or Mechanical Arts whether Ancient or Modern by which Knowledge has been advanced I am now to go to the Knowledge it self According to the Method already proposed I am to begin with Natural History in its usual Acceptation as it takes in the Knowledge of the several Kinds of Elementary Bodies Minerals Insects Plants Beasts Birds and Fishes The Usefulness and the Pleasure of this Part of Learning is too well known to need any Proof And besides it is a Study about which the greatest Men of all Ages have employed themselves Of the very few lost Books that are mentioned in the Old Testament one was an History of Plants written by the wisest of Men and he a King So that there is
certainly shew that he did not understand the true Texture of those Parts because where his Anatomy did not fail him his Ratiocinations are generally speaking exact Wherefore in this particular his Mistakes instruct us as effectually in the Ancients Ignorance as his true Notions do in their Knowledge This will appear at large hereafter where it will be of mighty use to prove That the Ancients cannot be supposed to have known many of the most eminent Modern Discoveries since if they had known them they would not have assigned such Uses to those Parts as are not reconcilable to those Discoveries If Galen had known that the Pancreas had been a Heap of small Glands which all emit into one common Canal a particular Juice carried afterwards through that Canal into the Guts which there meeting with the Bile goes forwards and assists it in the making of the Chyle he would never have said that Nature made it for a Pillow to support the Veins which go out of the Liver in that Place where they divide into several Branches lest if they had been without a Rest they should have been hurt by the violent Eruption of the Blood and this too without the assigning any other Use for it By Anatomy there is seldom any thing understood but the Art of laying open the several Parts of the Body with a Knife that so the Relation which they severally bear each to other may be clearly discerned This is generally understood of the containing Parts Skin Flesh Bones Membranes Veins Arteries Muscles Tendons Ligaments Cartilages Glands Bowels wherein only the Ancients busied themselves As for the Examination of the Nature and particular Texture of the contained Parts Blood Chyle Urine Bile Serum Fat Juices of the Pancreas Spleen and Nerves Lympha Spittle Marrow of the Bones Mucilages of the Joints and the like they made very few Experiments and those too for want of Chymistry very imperfect The Discoveries therefore which have been made in that nobler part which are numerous and considerable are in a manner wholly owing to later Ages In the other a great deal was anciently done though a great deal more was left for Posterity to do I shall begin with the Body in general It is certain that all the great Divisions of the Bones Muscles Veins and Arteries most of the visible Cartilages Tendons and Ligaments were very exactly known in Galen's Time the Positions of the Muscles their several Originations the Insertions of their Tendons and investing Membranes were for the most part traced with great Nicety and Truth the more conspicuous pairs of Nerves which arise either from the Brain or Spinal Marrow were very well known and carefully followed most of the great Branches of the Veins and Arteries almost all the Bones and Cartilages with very many Muscles have still old Greek Names imposed upon them by the Old Anatomists or Latin Names translated from the Greek ones So that not only the easie things and such as are discernable at first Sight were throughly known but even several particulars especially in the Anatomy of Nerves were discovered which are not obvious without great Care and a good deal of practical Skill in diffecting So much in general from which it is evident that as far as Anatomy is peculiarly useful to a Chirurgeon to inform him how the Bones Muscles Blood-Vessels Cartilages Tendons Ligaments and Membranes lie in the Limbs and more conspicuous Parts of the Body so far the Ancients went And here there is very little that the Moderns have any Right to pretend to as their own Discoveries though any Man that understands these things must own That these are the first things which offer themselves to an Anatomist's View Here I shall beg Leave to descend to Particulars because I have not seen any Comparison made between Ancient and Modern Anatomy wherein I could acquiesce whilst some as Mr. Glanvile and some others who seem to have copied from him have allowed the Ancients less than was their Due others as Vander Linden and Almeloveen have attributed more to them than came to their Share especially since though perhaps it may be a little tedious yet it cannot be called a Digression Hippocrates took the Brain to be a Gland His Opinion was nearer to the Truth than any of his Successors but he seems to have thought it to be a similar Substance which it evidently is not And therefore when several Parts of it were discovered not to be glandulous his Opinion was rejected Plato took it to be Marrow such as nourishes the Bones but its Weight and Texture soon destroyed his Notion since it sinks in Water wherein Marrow swims and is hardned by Fire by which the other is melted Galen saw a little farther and he asserts it to be of a nervous Substance only something softer than the Nerves in the Body Still they believed that the Brain was an uniform Substance and as long as they did so they were not like to go very far The first Anatomist who discovered the true Texture of the Brain was Archangelus Piccolhomineus an Italian who lived in the last Age. He found that the Brain properly so called and Cerebellum consist of Two distinct Substances an outer Ash-coloured Substance through which the Blood-Vessels which lie under the Pia Mater in innumerable Folds and Windings are disseminated and an inner every where united to it of a nervous Nature that joins this Bark as it is usually called to the Medulla Oblongata which is the Original of all the Pairs of Nerves that issue from the Brain and of the Spinal Marrow and lies under the Brain and Cerebellum After him Dr. Willis was so very exact that he traced this medullar Substance through all its Insertions into the Cortical and the Medulla Oblongata and examined the Rises of all the Nerves and went along with them into every Part of the Body with wonderful Curiosity Hereby not only the Brain was demonstrably proved to be the Fountain of Sense and Motion but also by the Courses of the Nerves the Manner how every Part of the Body conspires with any others to procure any one particular Motion was clearly shewn and thereby it was made plain even to Sense that where-ever many parts joined at once to cause the same Motion that Motion is caused by Nerves that go into every one of those Parts which are all struck together And though Vieussens and du Verney have in many things corrected Dr. Willis's Anatomy of the Nerves yet they have strengthened his general Hypothesis even at the Time when they discovered his Mistakes which is the same thing to our present purpose Galen indeed had a right Notion of this matter but he traced only the larger Pairs of Nerves such as could not escape a good Anatomist But the manner of the forming of the Animal Spirit in the Brain was wholly unknown In Order to the Discovery whereof Malpighius by his
Microscopes found that the Cortical Part of the Brain consists of an innumerable Company of very small Glandules which are all supplied with Blood by Capillary Arteries and that the Animal Spirit which is separated from the Mass of the Blood in these Glandules is carried from them into the Medulla Oblongata through little Pipes whereof one belongs to every Gland whose other End is inserted into the Medulla Oblongata and that these Numberless Pipes which in the Brain of some Fishes look like the Teeth of a small Ivory Comb are properly that which all Anatomists after Piccolhomineus have called the Corpus callosum or the Medullar Part of the Brain This Discovery destroys the Ancient Notions of the Uses of the Ventricles of the Brain and makes it very probable that those Cavities are only Sinks to carry off excrementitious Humours and not Store-Houses of the Animal Spirit It shews likewise how little they knew of the Brain who believed that it was an uniform Substance Some of the Ancients disputed whether the Brain were not made to cool the Heart Now though these are ridiculed by Galen so that their Opinions are not imputable to those who never held them yet they shew that these famous Men had examined these things very superficially For no Man makes himself ridiculous if he can help it and now that Mankind are satisfied by ocular Demonstration that the Brain is the Original of the Nerves and the Principle of Sense and Motion he would be thought out of his Wits that should doubt of this Primary use of the Brain though formerly when things had not been so experimentally proved Men might talk in the dark and assign such Reasons as they could think of without the Suspicion of being ignorant or impertinent The Eye is so very remarkable a Member and has so many Parts peculiar to its self that the Ancients took great Notice of it They found its Humours the watry crystalline and glassy and all its Tunicles and gave a good Description of them but the Optick Nerve the aqueous Ducts which supply the watry Humour and the Vessels which carry Tears were not enough examined The first was done by Dr. Briggs who has found that in the Tunica Retiformis which is contiguous to the glassy Humour the Filaments of the Optick Nerve there expanded lie in a most exact and regular Order all parallel one to another which when they are united afterwards in the Nerve are not shuffled confusedly together but still preserve the same Order till they come to the Brain The crystalline Humour had already been discovered to be of a Double-Convex Figure made of Two unequal Segments of Spheres and not perfectly spherical as the Ancients thought So that this further Discovery made by Dr. Briggs shews evidently why all the Parts of the Image are so distinctly carried to the Brain since every Ray strikes upon a several Filament of the Optick Nerve and all those strings so struck are moved equably at the same Time For want of knowing the Nature and Laws of Refraction which have been exactly stated by Modern Mathematicians the Ancients discoursed very lamely of Vision This made Galen think that the crystalline Humour was the Seat of Vision whose only Use is to refract the Rays as the known Experiment of a dark Room with one only Hole to let in Light through which a most exact Land-skip of every thing without will be represented in its proper Colours Heights and Distances upon a Paper placed in the Focus of the Convex Glass in the Hole which Experiment is to be found in almost every Book of Opticks does plainly prove Since the same thing will appear if the crystalline Humour taken out of an Ox's or a Man's Eye be placed in the Hole instead of the Glass The Way how the watry Humour of the Eye when by Accident lost may be and is constantly supplied was first found out and described by Monsieur Nuck who discovered a particular Canal of Water arising from the internal Carotidal Artery which creeping along the Sclerotic Coat of the Eye perforates the Cornea near the Pupil and then branching its self curiously about the Iris enters and supplies the watry Humour As to the Vessels which moisten the Eye that it may move freely in its Orbit the Ancients knew in general that there were Two Glands in the Corners of the Eyes but the Lympheducts through which the Moisture is conveyed from those Glands were not fully traced till Steno and Briggs described them so that there is just the same Difference between our Knowledge and the Ancients in this particular as there is between his Knowledge who is sure there is some Road or other from this Place to that and his who knows the whole Course and all the Turnings of the Road and can describe it on a Map The Instruments by which Sounds are conveyed from the Drum to the Auditory Nerves in the inner Cavities of the Ear were very little if at all known to the Ancients In the First Cavity there are Four small Bones the Hammer the Anvil the Stirrup and a small flattish Bone just in the Articulation of the Anvil and the Stirrup It is now certainly known that when the Drum is struck upon by the external Air these little Bones which are as big in an Infant as in adult Persons move each other the Drum moves the Hammer That the Anvil That the Stirrup which opens the oval Entrance into the Second Cavity None of these Bones were ever mentioned by the Ancients who only talked of Windings and Turnings within the Os Petrosum that were covered by the large Membrane of the Drum Jacobus Carpus one of the first Restorers of Anatomy in the last Age found out the Hammer and the Anvil Realdus Columbus discovered the Stirrup and Franciscus Sylvius the little flattish Bone by him called Os Orbiculare but mistook its Position He thought it had been placed Sideways of the Head of the Stirrup whereas Monsieur du Verney finds that it lies in the Head of the Stirrup between that and the Anvil The other inner Cavities were not better understood the spiral Bones of the Cochlea that are divided into Two distinct Cavities like Two pair of Winding-Stairs parallel to one another which turn round the same Axis with the Three semicircular Canals of the Labyrinthus into which the inner Air enters and strikes upon the small Twigs of the Auditory Nerves inserted into those small Bones were things that they knew so little of that they had no Names for them and indeed till Monsieur du Verney came those Mazes were but negligently at least unsuccessfully examined by Moderns as well as Ancients it being impossible so much as to form an Idea of what any former Anatomists asserted of the wonderful Mechanism of those little Bones before he wrote if we set aside Monsieur Perrault's Anatomy of those Parts which came out a