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
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
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.