an explication as really and in truth consists not with it as we shall see hereafter This being therefore the state of the Notion of Rarefaction and Condensation in its true explication we are to consider what bodies or motions in bodies are such as are applicable to the Argument in hand The special Instances that I shall use are these 1. The Rarefaction or Condensation of bodies by Transmutation thus Water by Rarefaction is sometimes changed into Air which hath thereby a greater extension than it had before by about 900 times and Air by Condensation is changed into Water and thereby loseth by contraction a like proportion of space than it had before Thus Aristotle in 4. Phys cap. 9. and the great Verulam in Historia Densi Rari pag. 88. 2. The Rarefaction that is caused by external violence as in the Air-Pump in the Cacabus Evacuatorius and the Magdeburg Engin this is a Rarefaction by Tension whereby the Air is dilated not only in its external Bulk but in all the parts of it and in its internal as well as external parts and dimensions And thus Mersennus and others tell us Air may be dilated to near 70 times its former and natural extent 3. The Condensation that is made by Compression Some there are that think Water is thus contractible and condensible by compression The same Verulam ubi supra pag. 99. tells us that taking a Leaden hollow Globe and fill it with Water and then strongly stop the Orifice which took in the Water and compress the Globe in a strong Presser whereby it may be reduced to an eighth part of its former dimension the Water will sustain that contraction but if it be pressed farther the Water will discharge it self through the Globe ad modum parvi imbris It is not impossible but it might do so from its first compression though the streams by reason of their exility were imperceptible to the Eye as the emanation of effluvia through the pores of the bodies of Animals electrical effluxes or the Odors of Herbs for Water though fluid seems very impatient of Condensation by compression yet it is not impossible if under a very strong pressure but to the very eye it appears capable of dilatation by Tension in its discharge of it self by Bubbles upon a strong Tension But howsoever it is with Water it is apparent that Air is capable of condensation and contraction by compression this appears visibly in the compression of the Air by Wind-Guns and the careful injection of water by a well ordered Syringe in an empty Aeolipile so that Air by these means may be contracted into a seventh nay possibly a seventieth part of its natural space or dimension 4. The Rarefaction and consequential dilatation of Bodies by Heat or Fire Thus Water it self is rarefied and extended into Vapours by Heat The Lord Verulam ubi supra pag. 28. gives us a notable Instance by taking a Vial-Glass holding an ounce filling it half full of Spirit of Wine then taking an empty Bladder that held about 8 pints and tying it about the neck of the Vial strictly the Spirit of Wine heated upon the Coals the Aura Spiritus Vini filled the Bladder and yet only six penny weight of the Spirit of Wine spent which did not amount to the 40th part of a pint yet filled the Bladder of 8 pints with its rarified Air. And although this Instance be in the Spirit of Wine which is fuller of subtil Matter than the like quantity of Water yet it will hold its proportion with the Fumes or Vapours of Water And of the like kind is the Rarefaction by Ignition in the Gunpowder where a grain of Gunpowder fired will expand above a thousand times its former dimension and more But that which is most obvious to Sense and most apposite to my purpose and therefore will be the Subject of most of my ensuing applications is the Rarefaction of Air by heat whereby it may gain an expansion of above 70 times its natural size and dimension as is easily found by the strong heating of a strong Brass concave Globe which if the included Air have no vent will break it and if it have a vent and after it is strongly heated cast into a Vessel of Water it will soon discover the proportion of its dilatation by the contraction that it receives from the cold Water and by the quantity of Water it sucks in upon that contraction 5. The Condensation and consequential contraction that the Air receives by the constipation of it by Cold especially after a strong dilatation but although there be no such preceding dilatation or expansion of the Air by heat yet it is visible in Weather-Glasses and other Engines of that nature that the Air is contracted in its dimension by the ambient Cold from what it usually hath at other times CHAP. V. Concerning the Phaenomena of Rarefaction and Condensation apparent to Sense TO pursue all the Phaenomena of Condensation and Rarefaction in its full Latitude were too long a business and not so much conducible to my purpose I shall therefore take up those Phaenomena that are apparently evident to Sense in the Rarefaction and Condensation of Air for the due discussion of that single Subject will give an estimate and explication of other Rarefactions and Condensations 1. It is evident to our very Senses that a smaller portion of Air suppose a Cubique Foot in a Vessel being ratified by heat will take up a far greater space than it did before such application and the like will be when it is done by Tension as in the Air-Pump and the Magdeburg-Engin for when a great part of the Air is driven out by Heat in the one Instance and drawn out by Traction in the other yet it is evident to Sense that the Receiver or other Vessel remains full of a very rare and extended Air for sensibly no other Substance supplies it 2. It is evident to Sense that this distension of the Air is not only in the Extima Superficies but in all the very internal parts of it for it is apparent to our Sense that it hath a visible effect as well upon the Birds Water or other Body placed in the middle of the Cavity of the Receiver as in those that are conterminous to the Sides of it as appears in those many Instances given by Mr. B. especially in 21 22 c. Experiments And unless the whole Body were extended every where and every way it were impossible that a little portion of Air included in a Bladder should encrease its bulk by Heat to ten times its extension as it will do and is apparent to our Sight by the ample distention of the Bladder 3. It is apparent to our Sense that if the Air be rarified by Heat in any close Vessel as the Heat which is the cause of its Rarefaction decays so the Air endeavours its contraction to gain its primitive size which it then attains when the Heat is
perfectly gone out if it be not impeded by the closeness of the Vessel This is visible in Weather-Glasses of 22 inches long whereby when for the purpose the Water riseth to ten Inches and leaves twelve inches of Air in the Head of the Glass the warm hand laid upon the Head of the Glass will depress the Water by expanding the included Air two or three inches but the Hand being removed the Air will contract it self to its former Staple and so the Water will rise to ten as before 4. It is evident to Sense that the Air contracting it self doth by that which is called by some Motus nexus lay hold of the inward sides of a close Vessel containing and strictly imprisoning it and if they be otherwise severable yet the strong contraction of the filaments of the Air holds them together as appears abundantly by the Instance of the Magdeburg Hemispheres mentioned at large in the 18th Chapter of the Observations upon the Toricellian Experiment and other Instances of the like Nature given in that Book 5. It is evident to Sense that in that strong cohesion of the Filaments of the Air to the sides of the Vessel when by the decay of Heat it contracts it self with a motus or conatus of restitution and with it the ambient Vessel by a motus nexus yet if a small degree of Heat be moved to the Vessel that contraction is relaxed and the Vessels fall asunder and the like is done by the smallest admission of the free or solute Air though through a Pin-hole for by the Heat the included Air is again dilated left lax as before it grew cold and by the admission of foreign Air the included Air is relieved gradually to that expansion as is natural to it and as it had before its Rarefaction or Condensation 6. It is evident to Sense that upon the smallest Pin-hole made in the Vessel where the Air is that thus contracts and endeavours its restitution either upon Tension or upon growing cold after Rarefaction the Air thus tensed or contracting it self will greedily suck in the foreign Air yea or Water for its relief against that Tension that it is under 7. In Condensation of Air especially by compression it is apparent that the Air takes up or may take up a far less room than is natural to it as appears in Wind-guns or Aeolipiles 8. It is also apparent to Sense that the compressed Air in those Instances endeavours with great strength and force its relaxation from this compression in so much as if it can get liberty it will cast out a Bullet with great force in Wind-guns and in Aeolipiles well made and well charged with Water by a Syringe it will throw up the Water above twenty foot high These Phaenomena are as evident to our Sense of Sight and Touch as any thing we see or feel and though there is difference among the Learned in the solution or manner of explication of these Phaenomena yet the effects themselves are plain and sensible and do give a sensible demonstration that surely there is some alteration of the state of this Body of the Air or of its Texture or Fabrick under these various Appearances which are usually called Rarefaction and Condensation But whether they are really such or how made or ordered will be the Subject of farther Enquiry CHAP. VI. Concerning the various Solutions of Condensation and Rarefaction and first of that which is by supposed interspersed Vacuities RArity and Density of Bodies although it terminate in a greater or lesser dimension or extent which properly respects Quantity yet they seem in themselves to be but various Passions Affections or Qualities of Bodies arising from their different Textures either more crass or more subtil And Rarefaction or Condensation of Bodies seems to be those several Motions towards these Qualities of Rarity or Density caused for the most part by some external or adventitious Agent which changeth and altereth the Texture of any Body whereby it assumes those Qualities of Rarity or Density different from its own natural constitution and sutable to the variety of the Texture they do for the time undergo There have been various Solutions or Explications of these apparent Phaenomena of Condensation and Rarefaction which I shall in the next place consider holding my self to that of the Air either by compression in case of Condensation or by expansion by Heat or by Tension by force in case of Rarefaction because this Instance of Rarefaction and Condensation of the Air is most obvious to Sense and doth in a great measure explain the Rarefaction or Condensation or other Bodies capable of those Affections These Methods of Solutions of Explications of Rarefaction or Condensation that have been taken up by several parties are principally three 1. Of those that suppose the same to be performed by reason of interspersed Vacuities Porosities or Spaces empty of all body interposed between aery particles which in cases of Rarefaction are made wider by a kind of divulsion or greater apertures of the particles of Air or other bodies rarified whereby the Interstitia of the aerie Particles are greater and those empty interspersed Vacuities made larger and in case of Condensation the aerie Particles are crouded closer together and those empty spaces or Interstitia made less by reception of those particles of Air into those Vacuities in a closer posture or conjunction than they were before such compression constipation or condensation and this I call the Epicurean Solution 2. Of those that admit no Vacuities at all in the Universe but that all places or spaces are full of some body or other but that in the Rarefaction of the Air whether by Heat which I call simple Rarefection or Expansion or by a forcible distraction or divulsion of the particles of such rarefied or expanded body by force which I call Tension those particles of the extended or rarefied body are removed to a greater distance one from another and as they are so removed other more subtil corporeal particles do interpose gradually and fill up those Interstitia and in case of Condensation the more subtil parts with which all bodies are furnished but especially the Air are driven out by compression and take up a temporary residence at least in the conterminous Air. And this I call the Cartesian Solution though this as shall be shewn have some variation in the manner of its explication But though these methods differ in the application to the matter in hand yet they both much agree in this that the first material Principles of Bodies are certain minute Corpuscles or Atoms which though they are really bodies and therefore Mathematically divisible yet they are so minute that physically and actually they are indivisible and therefore in themselves hard and unfrangible into lesser portions This I shall examine hereafter in the seventh and eighth Chapters 3. The third Solution is that of the ancient Philosophers and some other of the Modern which suppose
their particles without any Interstitia of vacuous spaces or of other Matter to fill them up and all this arising from the various textures of those bodies so the same body by a various texture acquired by accidental emergencies either of heat tension or compression may acquire a greater or less expansion according to those varieties of acquired textures yet without any new accession of substance or deperdition of any its included particles but still remaining individually the very same Matter For if several bodies of various textures may be some more rare and some more dense from their very Make and texture and yet as well those that are more rare as suppose Air or Water may as exactly fill all the spaces within the compass of their extension without the subsidiary help of vacuities or other interspersed bodies as well as those of a more condense consistency suppose Gold Lead or Mercury the very same reason doth enforce that the same body if its texture be either by force or accident altered to a greater Rarity or Density than it had before may alter its space and yet be entirely and exactly commensurate to a greater or lesser space according to such alteration of its texture as well as those several bodies that had primitively the like variety of texture constant to their nature For Matter or material substance is of it self equally susceptive of a laxer or crasser a rarer or denser consistence or texture of parts only when it is lax or rare the same portion of Matter takes up more space when it is crass or dense it takes up less space For instance in Distillation we will suppose that first by some moderate Heat the distillatory Vessels the Vessel wherein the Roses for the purpose are placed to be distilled the Head of the Still and the Recipient to be as much evacuated of Air or the included Air attenuated as much as may be and then the Vessels closely luted one to another the moist Matter of the Roses by gentle heat is resolved first into a subtil Fume or Vapour and so rarefied from what it was in the Rose-Leaves Then again these Fumes or Vapors partly by the coldness of the Head of the Still partly by the collection and aggregation of the Vapors themselves resolve into drops of water and so discharge themselves into the Receivers Here the very same body by the change of its texture namely the watry or moist substance of the Roses is first dilated into Fumes or Vapors and then contracted into Water and the first receive a dilatation or expansion into Vapors where it takes up a larger dimension in all its parts as well as in its ambient Superficies and then a contraction into a narrower compass when resolved into Water and yet continues still the same body but by variation of its textures assumes a larger or narrower dimension in all its parts without reception of new foreign particles to dilate it or emission of some of its substance in contraction or condensation Which Instance explains what I intend namely that the same individual body according to the variety of its textures may acquire a larger or less space and yet continue the same body though altered in the textures of Rarity or Density as Air hath a larger expansion than Water so if Water be converted into Air and thereby its texture altered into a more subtil expansive body it takes up the same dimension as if it had been never Water but alwayes Air. And if Air again be converted into Water it takes up the same contracted dimension as if it had ever been Water And this method of solution of Condensation and Rarefaction answers all the evident apparent and sensible Phaenomena in Rarefaction and Condensation above delivered and that without any difficulty or strained supposition For instance In Rarefaction by Heat or by tension of a Cubical Foot of Air in a Vessel it is visible that the Air and every particle of it gains a larger extent every way for it will break the Vessel unless it have vent which it could not do unless the entire body were extended and not barely the Superficies because unless the whole Moles were every way expanded it would have room enough within it self for its reception without breaking the Vessel that contains it Again when the Heat decays and consequently the Air relaxed from that extent it endeavours its own contraction to its just and natural size and texture which it lost for the time by the foreign violence of expansion by Heat or Tension and this by a natural motion of restitution to its natural texture and because it cannot gain its relaxation to its former texture by contraction by reason of the vacuity that would thereupon follow it doth as much as it may and lays hold on the internal sides of the Vessels wherein it is imprisoned and pulls them together but as soon as it gains a relaxation by the admission of foreign Air into it the very same portion of expanded Air that under its expansion filled a Cube of a Foot square will subside into a space of less than six inches square which was its true natural space resulting from the texture it then had by that admission of foreign Air. Again in Condensation a portion of Air suppose a Cubique Foot in its just and natural texture entirely fills all the space within that Cubical Foot for its texture is suited to such a space but being compressed forcibly into a Wind-gun or Aeolipile the texture is changed by this violence and it takes up perchance not the twentieth part of that space The difference of its extension ariseth from the alteration of its texture by this external compressive force used upon it and hereupon it gains an Elasticity which is nothing else but a natural motion or conatus to be restored to its former just and natural texture and consequently to that just extent and Liberty and position of space that belongs naturally to it as a Stick or Branch of a Tree or Spring of Steel being bent beyond or against its just position hath its motion of restitution to its former position with a force or resilition For the Air in its natural constitution hath a certain determinate texture belonging to it and consequently a just and natural extension proportionate to that texture And this it greedily endeavours to keep and when disturbed from it to re-acquire which is the motion of restitution which I often express by the natural and spontaneous contraction of a Lute-string after an extention beyond its proper texture And this is the genuine and true cause of that strong and violent explosion that happens in those Pneumatical Engins of various sorts So that in these and all other Phaenomena of Rarefaction and Condensation this plain and common and ancient Solution squares exactly with them as might be instanced in infinite more Particulars if it were needful And with this agree the best Philosophers both Ancient and
that Rarity and Density are really natural Affections or Qualities of Physical bodies and that Rarefaction is a real expansion of the very entire Moles of the body truly rarefied and Condensation is a real contraction of the whole dimension of the body condensed namely where it is truly and formally a true Rarefaction or Condensation as the Question is above stated in the beginning of the Fourth Chapter And this I call the Aristotelian Solution and seems to me the truest in the manner hereafter dedescribed First therefore Touching the first of these Solutions by interspersed Vacuities This though it doth in truth take away the true Notion of Rarefaction and Condensation as it is before stated for still the same body holds but the same quantity of space though in different position or ubication of its parts yet I must needs say were the supposition of interspersed Vacuities true would in a great measure though not altogether salve many of the Phaenomena of Rarefaction and Condensation But there are these two grand Objections that I think render this Solution impossible to be true 1. It seems to me utterly untrue that there are any such interspersed Vacuities wholly destitute of Body either in the Air or any other Body and herein the Cartesians and I agree And that which renders this Supposition untrue is that excellent demonstration improved by Sir K. Digby in his History of Bodies If there were such interspersed Vacuities it must necessarily follow that those Bodies of an equal Superficies that are more rare must have more or greater interspersions of such Vacuities than such as are more dense or which is all one the same Moles of body that is more dense must needs have more of matter or body in it than that which is more rare or which seems to be equally consequential that where the body is more weighty the same external Moles of the more weighty body must needs have more of body and less of interspersed Vacuities than that which is more light where the external Moles of either is equal And therefore a Cubique Foot of Gold must have more of Body and less of interspersed Vacuities than the like Cubique Foot of Silver and that than the like Cubique Foot of Water and that than the like Cubique Foot of Air. The Lord Verulam in his Historia Densi Rari pag. 8 9 by an exact computation gives us the Estimate of the disproportion of Weight of the same extrinsick Moles of several bodies whereby he finds that a portion of pure Gold reduced into a Cubical Figure or Moles weighed 20 d weight and the like Moles of of Mercury 19 d weight and 9 grains the like Moles of Silver weighed 10 d weight and 21 grains and the like Moles of Water weighed 1 d weight and 3 grains and upon a like trial pag. 20. found that the heavier any solid body is and more united its parts are the lighter was the same body reduced into Dust though closely compressed together in comparison to the weight of the same body before its pulverization His Experiment goes not so far as the disproportion between the weight or denseness of Air or Water but Mersennus and some others that have been curious in this Computation tell us that the same extrinsick Moles of Water is about 14 times lighter than the like Moles of Mercury and the same Moles of Air is at least 900 times others say 1300 times lighter than the like Moles of Water The consequence whereof is that if we should suppose a Cubick inch or foot of Mercury to be entirely full without interspersed Vacuities or other Matter in it which yet upon the account given wants much it must follow that in one Cubique inch or foot or other Moles of Air for one particle of body there must be 11699 parts of empty space each of these spaces equal to the space that the real body of the Air takes up such is the disproportion of the weight between the like quantity or Moles of Air to that of like Moles of Mercury viz. as 1 to 11700. The consequence whereof would be that yet the Cubique foot or inch or other measure or a Vessel containing nothing but Air might receive a quantity of Mercury that bears proportion as 11699 to 1 and a quantity of Water as bears the proportion of 899 to 1 without extruding any part of the included Air or overfilling or breaking the Vessel wherein it is included And if we should suppose that in the common Air we breath in there should be but 891 parts of Vacuities for one part of true substantial Air as there must be upon this supposition all respiration would presently be obstructed and indeed all that Motion which we see especially in Meteors But as this is prodigiously incredible so it is apparently untrue For take a Tube full of Air and stop it at one end immerse the open end into Water and press it down as low as may be yet not one half of the Tube will be filled with Water nay take an Aeolipile of Brass with a Syringe to drive in the Water it will with great difficulty receive into it ¾ parts of Water and thereby the Air contracted into a quarter of its former room and with great pains and force it may be into a much less room but never any pretended it could be compressed into the 899 th part of its former room and yet thus it may be and with great ease because here are 899 empty spaces which may receive the water with as much ease as if the Bottle or vessel were not empty only of Water or Air but perfectly empty of any other body abating only 1 900 of the room to receive the Air. 2. The Second difficulty in this Supposition seems to be this that it doth not answer the Phaenomena especially in condensation of Air by pressure as in Wind-Guns and Aeolipiles which visibly with a great force endeavours its restitution as appears in the explosion of the Air in Wind-guns and ejection of Water pressed into Aeolipiles for the Air upon this Supposition hath a free room far more than sufficient for its reception and therefore hath no need of any such violence in its motion of restitution it having 899 empty cavities whereas it hath need but of 1 900 part thereof for its reception and more vacuity can contribute nothing either to resist compression or to cause a sensible force of restitution because nothing can have no activity or motion 3. Again if Air or Water be strongly rarefied by Heat we see it takes up a larger extention than before it had and that with such an energy and force that it will break a strong Vessel inclosing it which it could never do were there any considerable interspersions of Vacuities because the body of the Air would with much more ease break into those vacua Interstitia which have no resistance against it than it would or could force its room upon
the ambient Vessel that containes it and resists its dilatation with all the strength it hath And this very reason doth as effectually conclude against the second Solution of Rarefaction by the admission of Materia Subtilis into the supposed Interstitia if duly considered CHAP. VII Concerning the Second Solution of Rarefaction and Condensation and its insufficiency I Come in the next place to consider the Second Solution above offered which supposeth these things 1. That there is no empty space or interspersed vacuity in the Air or any part of the Universe with which I agree 2. That the Principles of compounded bodies are certain minute Atomical Corpuscles physically indivisible and yet for all this these very minute bodies are some grosser like little Globuli ground to as small a magnitude as is naturally possible and yet the Ramenta or Filings of these Globuli are smaller than the former and make that Constituent or Principle which they call Materia subtilis which interposeth between other grosser Atoms or Corpuscles and filleth up the Interstitia between them this Supposition I deny and shall shew my Reasons against it 3. That in Rarefaction or Tension of the Air or other Bodies capable of Rarefaction there is only a separation or disjunction of the parts thereof to a greater distance one from another which doth not at all encrease its extension but only varies the position or vicinity of its parts and hereupon to fill the Interstitia between the parts thus divulsed there is immitted into those Interstitia subtil matter or those subtil Filings of the Globuli that fill those spaces which are therefore borrowed from the subtil matter of the other parts of circumjacent Air or finally from the Aether which seems to be the subtilest matter in Nature 4. That in Condensation of the Air c. by compression that Subtilissima Materia that resided before within the body of that portion of Air is by compression squeezed out and driven into the conterminous Air whereby that which we call the condensed portion of Air and its parts come closer together and take up less room or space than it seemed to have before namely in the external bulk or Superficies though in truth and reality the Air it self thus seemingly condensed and its particles take up really as much room or space as before though the figure and position and ubication of that space that it takes up now is only altered by its secession into the spaces wherein the subtilissima materia now flown away did formerly reside This Solution of Rarefaction and Condensation I think is neither true nor doth it in any measure answer the Phaenomena in Rarefaction or Condensation First therefore I think the very Supposition it self of these solute Atoms is but imaginary and the creature of the Brain and therefore I think may deserve the Title of Idolum Epicureum or Cartesianum never intended by the latter as any real Truth but only as a Supposition Engin or Medium to explicate the Phaenomena of Nature though now unwarily enough taken up by many Virtuosi as a Truth 1. It robs all bodies of any real or possible continuity without a miracle or the substitution of some cementing matter differing from Atoms or solute bodies to hold the parts of the Universe together for how can really separate bodies such as the very least of Atoms are supposed to be have any continuity or so much as mutual cohesion barely by contiguity For as to the Atomi hamatae they savour too rankly of fiction and invention and the Polar Magnetism and difference of Sexes of Atoms seems as vain 2. We see in many bodies not only a continuity but a strong texture whereby they will not readily be broken that yet at first arise from a thin watry substance or concrement as the Nerves of Animals the Wood of Trees the Barks of Trees and Plants as Withy Flax Nettles nay the very Spiders Web hath besides its continuity a certain tenaciousness so hath Water it self as appears by the traction of the water in the longer Leg of a Siphon this tenaciousness glutinousness and strong cohesion of parts of bodies one to another could never be by the apposition of solute particles one to another though never so small but from a kind of intrinsick contexture of the bodies themselves 2. Upon this Supposition it were necessary that all bodies should be equally hard and equally weighty and equally dense Those Atoms even those that are the most minute that are the Constituents of the Materia subtilissima are yet supposed to be bodies and essentially divisible though not divided nor indeed divisible physically by any force and therefore hard and unfrangible and therefore if we should take a Vessel of a foot square filled with Air this Moles though we call it of Air is yet really made up of those hard particles and then how is it possible it should be soft to the touch any more than Brass or Steel For the softness of dust of Gold or other solid Bodies is not from the dust it self but from the numerous interspersed particles of Air. Again this Cubique Vessel full of Air is entirely full of body or not if it be not then this supposition must necessarily admit interspersed Vacuities the thing that the whole Supposition of the Cartesians deny But if it be full of body in every imaginable space thereof why should not this Cubique Moles of Air thus constipated with a plenitude of body be as weighty as the like Cube of water yea or Gold for as to solidity the Atomical bodies themselves in both are of the same consistence and all spaces are supposed full both in the Cubique foot of Air and Water for excess of weight is but the effect of excess of Matter or bodily substance 4. Again It is most certain that the smallest Atoms or Particles of matter even the Ramenta that are supposed the Constituents of the Materia subtilissima are yet bodies and consequently have their Trina Dimensio and variety of configurations some spherical some cubical some triangular be these never so little yet it is impossible they can exactly touch one another in all parts of their Superficies a spherical body cannot be in all its Superficies contiguous to another spherical or cubical body and consequently there must be some real though small Intervals between these minute Particles and then the Cartesians to make good their Supposition must have yet another matter more subtil than that which they yet call subtilissima to fill those Chinks Et quis custodiet ipsos Custodes And it is not enough to say these fissures between the minutest Particles are inconsiderable For if they be at all it spoiles the Supposition but besides that certainly he that holds this Supposition must yet admit that in the Cubique Foot of Air the Interstitia must needs be greater than in Water or Mercury of the like Moles for certainly otherwise the weight of Mercury Water and
Air would be all one and so they fall in with the Vacuists Therefore upon the whole Matter it seems more agreeable both to Nature Sense and Reason that in the first production of bodies homogeneal whether by Creation by Almighty God or by Generation according to his instituted Law of Nature the consistency of things and their several textures to be the immediate effect of their first production and that they consist of parts in union and not separated till actual separation and that these parts are of the like consistence and texture with the whole in bodies homogeneal as in Air and in Water and not of parts or principles quite of another consistence and frame from the whole all the parts of the Air to be Air but yet some Air or Airs at some times more subtil than others and so for Water And therefore all this Apparatus of Atoms and Globuli and minute particles are not of things that ever really existed but only the creatures and fictions of the Brain But if we should admit of any one common material principle of physical bodies it is most consonant both to the Doctrine of the Scriptures and to some of the ancient Philosophers that it should be Water 1. Thus it is declared in that admirable Narrative of the Creation the first distinct body we find mentioned is the Water 2. This was the opinion of the Learned Thales Milesius and others of the Ancients Ex Aqua omnia 3. The accommodation of Water to the production of other bodies by the transmutation of its texture speaks much for it to be the common principle of material bodies 1. It is productive of Consistences rarer and more subtil than it self as Vapours Fumes yea and of the very Air it self by the means of activity of Heat 2. It is productive of things more crass and solid than it self as Leaves Fruit Wood Shells Stones which we see arise from certain concretions singly of water 3. It is productive of consistences that have greater tenaciousness and connexion than it self as we see in the production of the Nerves Tunicles Tendons Muscles of Animals which are at first but certain waterish concrements digested by the Animal heat into those Ligaments and in the tough and strong barks and filaments of Vegetables in their trunks rinds c. which are at first but a kind of limpid juice or water sucked up into the bodies of Vegetables and that even where it hath no other visible nutriment but simple Water 4. In the dissolution of bodies either artificially or naturally they seem most readily to reassume a waterish Consistence Water therefore seems more accommodate to be the common material principle much rather than these imaginable Atoms though I take not upon me positively to determine it CHAP. VIII Further Considerations concerning the deficiency of this second Solution in relation to Rarefaction and Condensation and the Supplements that have been devised to enforce or supply it IN the last Chapter I have considered the improbability of the Supposition in general I shall now set down those Reasons and Evidences which render the whole Supposition utterly inapplicable to the Phaenomena of Rarefaction and Condensation 1. As to Rarefaction the intromission of these foreign particles of Matter to supply the supposed separation of the particles of the Air or other body rarefied it is not possibly consistent with that motion which rarefied bodies have in the time of their rarefaction which is most apparently expulsive of any foreign Matter and not receptive of it Take a Corn of Gunpowder and give it fire it turns in a moment to a body of flame above 1000 times larger than it self it drives away the conterminous Air from it and if it be a good quantity of Powder it will break the Windows Walls and Contignations next to it and this done in a moment and in the moment of its expansion Is it imaginable to any man that thinks twice that in that moment of its expansion when it drives all before it and from it this Subtilissima Materia which is so subtil and delicate should have admission and admission in that moment to make good an expansion of such an extent nature and quality Again When Air in a Vessel is brought near the fire and warmed by this Heat the Air is expanded and a great part of it driven out of the Vessel and if the Vessel be close it will break from the dilatation within so that in all this rarefaction the Air and all the particles of it and within it have a pressure outward not any motion of receptiveness of any thing from without and therefore must necessarily drive away those gentle particles of Materia subtilissima and can never admit them in the act of rarefaction done by Heat 2. It is a very hard supposal that the subtil Matter should pass through the most impervious bodies as Glass Brass yea Gold it self for the supplying of the Interstitia of tense or rarefied bodies as it must according to this Supposition But 3. It is not only difficult to believe it but the contrary thereof is most apparently evident to the very Sense especially in the Magdeburg Hemispheres described cap. 18. Nugarum If you take the two Brass Hemispheres there described and by heat rarefie the Air in them then clap them together in the manner there described when the included heat is spent they will cohere so strong together that 30 l. weight will not sever them but let them receive a moderate heat again from the fire or let there be a hole no bigger than the point of a Needle to let in any foreign Air they will be quickly severed for the tension which the included particles of Air do gain by their motion of restitution and Motus nexus is thereby relaxed And it is observable that these Hemispheres if they are kept from heat or perforation they will remain in this posture of cohesion an hour nay possibly a day or week or more Now if this subtil matter which must be the means of Rarefaction or extension according to the Cartesian Supposition pervades the Vessel so easily how comes it to pass that it is kept in this straight prison without avolation through the Brass Hemispheres Or rather why doth not a greater quantity thereof pervade the Brass Hemisphere all this while and release the Air from its hard tension by separating thereby the Hemispheres and so restoring the Air in all parts to its just and natural texture and position And certainly if the Spirit of Nature or Hylarchical Principle had any thing to do in matters of this Nature or were effective in it here were a proper business and exercise for it But we see that without perforation or accession of Heat nothing of such relaxation is effected notwitstanding the great stress that the Air is under in the Hemispheres and which yet would be inevitably relaxed if a considerable portion of subtil Matter did penetrate through the Hemispheres
and mix it self with the included rarefied Air as well as if a little Air were let into it through a Pin-hole 4. In the Instance last given and many other of like nature that might be given where the filaments of the Air in their relaxation from heat have a motion of contraction in themselves per viam restitutionis and a consequential attraction on the Vessel including them per modum nexus it is impossible this can be salved by the Supposition of the Cartesians and Lucretians which suppose the Air to consist of minute particles only joyned together by contiguity for where there is only contiguity without continuity of parts that body can never draw another body per modum tractionis it will be really less tenacious than a Rope of Sand so that such an intromission of particles thus solute as they state most bodies to be by a bare contiguity of Atoms could never explicate this visible Phaenomenon that ensues upon tension of the Air or after the avolation or extinguishment of Heat that first expanded it 5. And as this Supposition by no means salves the Phaenomena of Rarefaction of the Air and what ensues thereupon so it as little salves that of Condensation or Constipation of Air by compression as we see in Wind-Guns and other Engines which upon a Discharge or a Motion of that compression do with a force explode or discharge themselves and press very hard upon bodies that are in their way so that a Wind-Gun will drive a Bullet through a pretty thick piece of Wood which could never be if this Solution of Rarefaction and Condensation were true 1. If the Air it self and also this subsidiary Materia subtilissima were but a collection of minute bodies joyned only in contiguity one to another all the compression in the world would give it no more elasticity or that explosive motion than if a portion of Calice-Sand were forced into a Gun or other Vessel with all the compression imaginable 2. But again in that elastical explosion by the Air compressed into a narrower room what is it that actually exerciseth that explosive Elasticity Is it the subtil matter that was mingled with the included compressed Air Surely no for according to this Supposition that is squeezed out and permeated through the Barrel or Trunk of the Wind-gun Or is it the grosser Particles of the Air that is yet left in the Gun and cannot get out till the Obturaculum be removed But there is no reason for that to have any Elasticity for by the avolation of the subtil Matter there is room enough left for it and under that narrow dimension that now it hath yet hath it as much room as before for the avolation of the Materia subtilis hath made a perfect room for it and left it a space exactly commensurate to its corporeal Moles But it may be that the Materia subtilis that was driven out by the compression now upon the aperture of the Obturaculum pervades the substance of the Gun with that force that it gives the explosion But it is apparent that neither this can help it for it doth appear that the Motion of the Subtil Matter into the Orifice of the Wind-gun upon the removal of the Obturaculum must needs run counter to the explosion of the Air and obstruct it Again it is apparent that the subtil Matter is driven out gradually and with iterated force and it cannot pervade the Iron sides of the Gun but gradually and with great straining and to imagine that in a moment the moment of a Motion of the Obturaculum the whole body of that removed Matter should pervade the strong and close Metal in an instant to give that strong and forcible explosion exceeds all reason sense and credibility And therefore it was but necessary for those that will maintain this Assertion to substitute a Spirit of Nature or an Hylarchical Principle which for the preservation of Bodies in their due natural state and position should act little less than miraculously to supply all these Difficulties which yet notwithstanding must be supposed according to this Supposition to act in contradiction to it self and Nature also For when in Rarefaction of Bodies this Spiritus Naturae sends supplies of subtil Matter to fill the Interstitia it must necessarily rob other parts of the Air of some of that subtil Matter that properly belonged to its texture and natural constitution and so when one portion of Matter is gratified another is impoverished of what belongs to it which seems wholly unsutable to the office which this vicarious Spirit of Nature according to this new Supposition is substituted to exercise CHAP. IX Touching the Third Supposition of the Method of Rarefaction and Condensation according to the Ancient Philosophy and seems to be the truest HAving examined the two former Suppositions and as near as I can discovered their insufficiency I now come to the Third which I think to be true viz. as to that kind of Rarefaction and Condensation which before in the 4 th Chapter is stated to be the true Matter of the Question for in Rarefaction of a Body suppose Air either by Heat or Tension there is a real expansion or dilatation of the same Moles of Matter of the Air and all its parts to a larger space extent or dimension than it had before and in Condensation by Cold but more evidently by compression the same Moles of Matter and all its parts have a narrower or less space or expansion than before I suppose therefore that although Rarefaction and Condensation of any Body from its natural size and dimension belonging to it is for the most part if not alwayes by the agency or efficiency of some external cause yet under such circumstances Rarity and Density are but natural affections or rather Passions Qualities or Modes of such Bodies arising from their very texture and make and are as naturally belonging to them as Heat or Cold Humidity or Driness Smoothness or Roughness or other tangible Qualities to other Bodies that are more gross and corporeal 2. I do suppose that whatever men have talkt or wrote concerning Spatia imaginaria without relation to any Bodies to fill it yet as time or successive duration is a kind of Attendant upon successive Motion so space is a kind of Entity relative to Bodies and dependent upon them 3. To make way to what I have to say herein It seems to me no kind of repugnancy in Nature but altogether consonant thereunto and that it is equally possible and reasonable that a Body that is much more rare than another and having in it less of solid corporeity and consequently of weight than another yet may as entirely fill the whole space within the compass of its external Superficies as a body of a denser consistence so that although Gold be 18000 times bulk for bulk heavier than Air and near 20 times heavier than Water and although Water be near 14 times lighter than Mercury
yet it is no way repugnant but highly consonant to Nature that all the particles of a Tube of Air may be as closely united one to another and as entirely fill that Cubical space as the like Cubical body of Water or Mercury or Gold And that although it is inherent in the very nature of a rare body not to have so firm a consistency as that which is more crass and solid yet such a rare body may be wholly destitute of Pores or Interstitia between its parts as the most solid body imaginable for porosity or distance of parts is not an effect necessarily resulting from Rarity For it would be a strange position that no Body that were not summè solidum or crassum could have been created that had all its parts commensurate to all the space within the external dimensions or extima Superficies of such body and yet this must necessarily follow if such a commensuration ex natura rei were contradictory to and inconsistent with any body that is not summè solidum or crassum whereof possibly there is no instance that is or can be made for Gold it self is not summè crassum or solidum for one piece of Gold may be solider and have more of crass Matter than another which appears by the Disparity of weight between two several kinds of Gold of the same bulk Nay upon a strict search it may be found de facto true that some kinds of Wood or Metals that are more crass and consequently more weighty than others may yet be more porous than some Woods or Metals that are lighter and of a greater tenuity yea Glass or Crystal that is lighter and less crass than some other bodies may be less porous than such as are heavier and crasser or if comparison be made between it and common Iron-Ore the like between Calice-Sand and yellow Wax and many more whereof the Table of the Lord Verulam in his Historia Densi Rari may yield us many Instances Again we have no better measure of the Rarity or Density in Bodies than their difference of weight Quod Rarum leve quod Densum grave Let us resume the Instance given supra cap. 6. Wherein it appears that Air is at least 12000 times lighter and consequently rarer than Mercury Now if we should suppose the Air in a Cubique Vessel of a Foot square should fill but 1 12000 of that space and the rest viz. 11999 parts of that space must be either totally empty or supplied with another kind of Heterogeneous subtil Matter differing from Air This must be the consequence of the Supposition that the Moles aeris is not commensurate to all the spaces within the Cavity of that Cube and yet it is so evidently against Sense that it is not possible to be admitted or almost conceivable by any that duly thinks of it Water is subtiler than Mercury by 14 times Air is subtiler than Water by 900 times and possibly the Aether above the Atmosphere or the Elementa Stellarum is as much subtiler than common Air of our lower Atmosphere It were a wild conceit to think that every given portion of the Ethereal world must necessarily have forty thousand equal portions either of Vacuity or of subtil Matter more refined than Aether and that no one given portion of Ethereal Matter suppose a Cubique Foot could be exactly commensurate to all the space within that Cubique Foot but must have forty thousand interspersed pores either wholly vacant or filled with another more subtil Matter than it self I conclude therefore it is equally consonant to the nature of Bodies that a more rare or subtil Body may be and is equally commensurate to all the spaces within the extent of its Ubication as the crassest body in the World The thing I drive at is this real Truth viz. that a Body though never so rare may be entirely commensurate to all the space within the compass of its external Superficies as well as the densest or crassest Body that is or can be in Nature and consequently that the same Body if it have at several times several textures may in these several seasons entirely possess spaces answering such textures as if Water gain the texture of Air it may be commensurate to all spaces within its Superficies 4. It seems to me that although some particles of Air included in the common Body of the Air may possibly be more subtil than others yet as to point of extension or contraction all the parts thereof even the minutest parts thereof as to the quality of Rarity and Tenuity and the motion of Rarefaction and Condensation are of the same nature and perfectly homogeneal and the like for Water and although some imaginable parts thereof may be rarer others crasser yet they are perfectly mingled together as common Constituents of the same Body we call Air and therefore to suppose the first Constituent minute particles of Air or Water are hard or of any other nature than the whole Body is a precarious inevident and unreasonable Supposition 5. I do suppose it as a certain evident truth that the actual existence of parts or particles of continued Bodies as most evidently Water and Air are are but only potentially or by the operations of the Understanding in such Bodies and not really existing as parts or as divided till a real and actual separation of them with integral parts though they may be bigger or less according to the method of their separation yet 1. Still remain Bodies 2. Cannot be indivisible no not physically 3. Are of the very same nature texture or make with the whole Body out of which they are cancelled and therefore when the external Superficies of the whole bulk in Rarefaction is expanded or in Condensation is contracted the like expansion and contraction happens in proportion in every particle thereof in a true and proper Rarefaction or Condensation whereof the Question is stated 6. I do not think that corporeity or bodily consistence is the same thing with quantity or trina dimensio but that this is but an affection or consequence of it for otherwise all Bodies that have an equal trina dimensio must needs have the same Density or an equal mass of Matter or Corporeal Moles which is contrary to Experience for a Cubique Foot of Water hath less of Matter than a Cubique Foot of Mercury as appears by the disparity of their weight the best indication of the disparity of the Moles of Matter These things being thus premised I now proceed to declare my thoughts touching Rarefaction and Condensation holding my self singly to it as it is stated to be the Question in the 4 th Chapter and principally applying my self to those Bodies that are most Pneumatical or Spirital I say not Spiritual It seems therefore to me that as several Bodies of the same external extent or Superficies as suppose a Cubical Foot of Air Water Mercury or Gold may have and have yet a close continuity of all
Modern Aristotle that great Priest of Nature in 4 Physicor cap. 9. wherein he answers the Objections brought by others to prove Vacuities from the Phaenomena in Rarefaction and Condensation tells us that Rarity and Density properly so called are not by accession of new Matter or loss of any of the old but from the potentiality of Matter it self to undergo several textures and consequently several extensions Si factus est Aer ex Aqua eadem materia facta est Aer nulla re insuper alia assumpta sed quod erat potentia id tandem facta est actu simili modo si orta est Aqua ex Aere eadem namque materia nunc in magnam ex parva nunc in parvam ex magna vertitur molem c. Qua re ipsa Moles sensibilis non ideo extenditur aut constringitur quia materiae aliquid insuper adjicit aut objicit sed quia ipsa Materies utrumque subire potest quo sit ut idem sit rarum densum utriusque Materia una atqui densum est grave rarum autem leve Again the Lord Verulam a great inquisitor into Nature and not very friendly to Aristotle in his Historia Densi Rari after several Instances of Pseudo-rarefactions when he speaks of Rarefaction of Air by Heat pag. 43. tells us Aer per calorem dilatatur simpliciter neque enim separatur quippiam aut emittitur ut in tangibilibus sed simpliciter fit expansio This Rarefaction is not therefore by the distraction of the particles of Air one from another to a greater distance and interposing porosities or interstitia either of perfect empty spaces as the Vacuists would have it or filled with adventitious subtil Matter as the Cartesians would have it neither in Condensation are any parts of Air or included in Air drawn out and thereby the remaining particles rendred into a closer order and contiguity one to another But in the former the extension of the whole portion of Air and of every particle is thereof quaquaversum enlarged and in Condensation the entire extension of the Air and every part thereof is quaquaversum contracted and this variation is no other but a common affection or rather position or quantity of Matter necessarily arising from the various textures that it successively acquires And therefore the great Objections that are made against this Method of the Ancients in their accounts of Rarefaction and Condensation fall to just nothing as for instance 1. That in Rarefaction of the Air it must be softer to the touch and in Condensation harder I would gladly hear of that man that ever knew de facto Air condensed but to its 100 th part yet if it were condensed 900 times it would not be so dense as Water or what disproportion to the touch he can find between Smoke and Air and yet the former is far more dense for it is conspicuous to the view so that he had need be a man of exquisite sense to make any conclusion from his touch touching the Rarity and Density of a Pneumatical Body Again if the Atomical Hypothesis were admitted it is not conceptible but that all bodies whether in their natural texture or under the motions of Rarefaction and Condensation must be hard and equally hard because consisting of a plenitude of Atoms which are all supposed to be hard and infrangible CHAP. X. A farther Consideration of Rarefaction and Condensation and of the Supposition of the penetrability or impenetrability of Bodies Material Substances Quantity Extension c. THe principal Objection against the method of Rarefaction and Condensation propounded in the former Chapter is this That it is impossible the same Moles of Matter can assume a larger space and dimension as in Rarefaction without a division of one part from another and thereby leaving certain vacant Interstitia between the parts separated or without a supposition of a pre-existent penetration of the parts of Matter while in its former more condensed consistence and in Rarefaction thrusting out those parts that formerly penetrated one another being unfettered in Rarefaction or by admission of new porosities made in the rarefied Matter and reception therein of other foreign Matter Again Condensation of the same portion of Matter cannot be without supposition of vacant empty Spatiola which are closed up by the strict coalition of parts or by supposing a penetrability and penetration of the parts of the same portion of Matter in its new acquired state of Condensation or by driving out from that portion of Matter some of its more subtil parts whereby the remaining parts are fewer and take up less room or space than before such Condensation The first is the first way propounded by the Vacuists and is rejected The second is in effect the way propounded by me in the former Chapter but is said to be inconsistent in nature because penetrability of bodies or of extension of Material Substance is rejected by almost all Philosophers therefore the last which is the middle way contended against in the 8 th Chapter must be the true Method of Rarefaction and Condensation I answer It is true I have laid aside and that justly the Opinion of the Vacuists in the 7 th Chapter and likewise the Opinion of acquest of new Matter and expulsion of part of the old in the 8 th Chapter and have entertain'd the Opinion of the Ancient and some of the Modern Philosophers in the 9 th Chapter And it is true that this Opinion thus by me entertained cannot well be supported without a supposition of the penetrability of material Substances or somewhat analogal thereunto viz. Contraction and Dilatation And it is true that although I think that this penetrability of Material Substance be a great truth yet it is some difficulty to explain it which nevertheless I shall endeavour to do and in doing of it the Answer to the Objection will evidence it self And I shall choose to do it this way namely by explication of Terms and Words and rendring my apprehensions sutable to those Explications though it may be in a different manner from the usual or Scholastick expressions 1. Concerning Penetrability and Impenetrability 2. Concerning Material Substance 3. Concerning Body and wherein it differs from the Notion of Substance 4. Concerning Quantity 5. Concerning Rarity and Density 6. Concerning Extension or Dimension 7. Concerning Penetrability how it is or is not applicable to the former Subjects First Penetrability or Penetration of Matter or Bodies c. is of three sorts viz. 1. The permeation or penetration of one Body into or through another by porosities of the penetrated Body either found or made by the penetrating Body this is common almost to all Bodies and is not the Penetrability in question 2. The separation distraction or division of the parts of a penetrated Body by the force and energy of another Body as the Arrow through the Air or the Bullet through the sides of a Ship this is also
usual and is not the penetration or penetrability in question 3. When one part or particle of Matter is taken into another portion of Matter by a kind of contraction and swallowed up and drowned as it were in another portion of Matter by a stricter union than it had before whereby the same numerical portion of Matter hath a less extension and space than it had before and yet continues the same portion of Matter without diminution or encrease of substance and this is that which is the Subject of the Question in hand And this penetration of Matter or Bodies may be considered two ways 1. When two distinct divided bodies or portions of Matter are said thus to penetrate each other 2. When the united parts of the same portion of Matter do penetrate and swallow each other as is supposed to be done in Condensation and though the former be considerable yet this latter is that kind of penetration touching which the Question grows Secondly Matter or Material Substance is the Substratum of Bodies and although it is not possible for it to exist one moment without a determinate extent and determination into some Body compleated in Esse Corporeo yet it is of it self indifferent to any particular extension or bodily Concrement This is that Materia Prima the Subject of all Generation and Corruption yet it self ingenerable and incorruptible that Proteus which in various successions is capable of various Forms Extensions and Variety of Bodies as we see in a piece of Wood thrown into the Fire that same material substance which but now was Wood assumes several Natures and Extensions some more fixed than the Wood as its Salts some more lax as Ashes and Smoke and accordingly undergoes Varieties of Extensions different from what the very same portion of Matter had before the very same individual supposed portion of Matter is capable of being determined into Air Water or some other Body and if determined into Water it may be the supposed portion of Matter would make up a Cubical Body of an inch square but if determined into Air it would make a Cubical body of above 1000 times that extension and yet the individual portion of Matter simply the same and neither more nor less under those different textures and extensions for Material Substance is naturally susceptive successively of various textures and consistences from whence do necessarily result successively various extents or diminutions of that one individual particle of Matter under those various consistences Thirdly Body is nothing else but Matter determined into a Body of this or that Nature Figure Texture Plexus Quality and Dimension these are superadditions to Matter and being added to it determine it into Body and when this Body by the power of the Agent assumes another distinct consistence then is that Body either essentially changed into another kind of Body or else accidentally altered in figure dimension texture or otherwise and yet the Matter continues entirely the same as in some Bodies the very same Cubique inch of Bees-Wax may be moulded into a Globe a Cone a Trigone c. and yet continues the same numerical and individual piece of Wax Fourthly Quantity and herein I shall take the Liberty to use this word according to my own sense abstracted from others acceptation I call therefore Quantity that Habitude whereby a Material Substance under any determination is denominated more or less and is a kind of proper inseparable Accident if we will call it so of Material Substance and intrinsick to it and really differs from Extension or Dimension For instance a Cubique inch of Water is rarefied into 1000 Cubique inches of Air or a Cubique Foot of Air is by heat rarified into five cubique Feet of Air here is variety of Extension and yet the same quantity of Matter in the cubique inch of Water and in the cubique foot of Air as is after Rarefaction in the 1000 cubique inches of Air and 5 cubique feet of Air Quantity being closely knit to Material Substance but this or that particular extension variable though the quantity i. e. the Moles the muchness of Substance be the same And herein among other things it differs from Extension that Extension is measured by artificial measures of Inches Palms Feet Cubits but Quantity in my acceptation is measured by weight which gives the discrimination of Quantity or Muchness of Matter where it may be the extent is equal as a cubique foot of water is equal in dimension to a cubique foot of Mercury but there is 14 times more weight and consequently more Matter and Material quantity in the latter than in the former Fifthly Density and Rarity are various Qualities both of Bodies and Material Substance and they are equally susceptive of those qualities as they are of Colour Figure variety of Texture or the like namely in successive portions of Time or Duration and hence it is infallibly true that the same Material Substance that is now actually rare is potentially dense or that which now is actually dense is potentially rare without any admission of new Substance or deperdition of any of the old And as several portions of Material Substance are susceptive of or actually under several degrees of Rarity or Density as Gold Iron Wax Water Air so the same portion of Material Substance may in successive portions of times be susceptive of several degrees of Rarity or Density for as I said they are but several qualities or if you will modes of Matter The Motion to Rarity or Density is that which is usually called Rarefaction or Condensation and though Matter or Body be susceptive of it some more easily some more difficultly yet it is most ordinarily the effect of an extrinsecal Agent as Fire Tension Constipation Compression The Method whereby the alteration from Rarity to Density or to a less degree of Density and e converso is effected is the alteration of the texture of the Body so rarefied or condensed into a more dilate or contracted consistence And this Alteration is sometimes so great that it alters the very nature or Species of the Body as when Air is condensed into Water or Water into Air sometimes it only alters the texture without altering the nature as when Air is compressed into a narrower compass in Wind-guns or dilated by heat in Aeolipiles it remains Air still though under differing texture from what it had before The effects of Rarefaction and Condensation are neither increase nor diminution of the Substance thus condensed or rarefied nor of its quantity or muchness If a cubique inch of Brass were condensed into Gold indeed the Moles would be less in extent but there would be the very same individual portion of material substance in both and the very same weight that the cubique inch of Brass had would the portion of Gold have upon such a condensation For weight and not extent is the best measure of equality or disparity of material substance But indeed
as to Extension the measures would differ the same Moles of Matter condensed might not take up half the extent it did before and being rarefied might take up ten times its extension or dimension Sixthly Dimension or Extension Though as Quantity imports much or little it be inseparable from the notion of material Substance yet actual Extension in this or that determinate measure or degree is but purely accidental to Material Substance for it may have one extension one hour and the next hour have another as its texture is altered For variety of extension is consequential and necessarily consequential upon alteration of texture There are certain distinctions to be observed touching Extension viz. 1. An actual and an habitual aptitudinary and potential extension although de facto every portion of matter is under some actual extension yet as I said this or that actual extension is not intrinsecal or essential to Matter for as it is capable of a variation of its texture so it is capable of a change variation and alteration of its dimension But that habitual aptitudinary and potential extension whereby it must necessarily be at some time or moment under some determinate extension or other is intrinsick to it though it be successively alterable as its texture is alterable Again 2. We must distinguish between the extension in the superficial and external dimension and that which is the whole portion of Matter the former may be without the true and real encrease of extent or dimension for possibly by the distraction and separation of the more interior parts of Matter and the production thereby of porosities the external superficial extent may be enlarged and yet the whole extent continues the same but only with a diversified ubication of the more interior parts of Matter but that extension which is intended by me in Rarefaction is an entire extension of the whole Matter and all its parts without which there is no true and adequate extension and that contraction or penetration of Material Substance to Condensation is the contraction of the whole triple dimension length breadth and thickness of the whole Body and every part yet retaining the same quantity or muchness of Substance And as I have shewed that in several portions of Material Substance it is not only consistent with the Laws of Nature but evidently true in fact that a portion of rarefied Matter suppose it Air may be and is co-extended to all the spaces within the compass of that Matter and fills them as entirely as a most dense Body or portion of Matter fills all the spaces within its superficial dimension as suppose it Water or even Mercury or Gold it self so the same portion of compacted Matter suppose it Water or Mercury being rarefied into a more dilated and expanded consistence as into Air or Fumes may upon the very same account fill all the spaces within the extent of that dilated extension without any hiatus or interstitia of empty spaces or the acquest of any additional Matter because the texture of that portion of Matter is only changed and a greater extension or dimension is necessarily consequential upon or concomitant with the variation of the texture of that very same portion of Matter to a greater expansion in Rarefaction Seventhly The Contraction or Evolution and Expansion of a Spirit or Spiritual Substance which is commonly called Penetration is incident to Spirits and Spiritual Substances that are void of Matter but this doth not at all impeach that natural penetration of Material Substance whereof I have spoken for they differ toto coelo one from another 1. In the principle of each Penetration In Material Substance it always or at least commonly proceeds from an external efficient or force as in Contraction or Penetration of Material Substances by compression or by constipations from without but the penetration or contraction or dilatation of a Spiritual Substance is from an internal principle possibly the determination of the will of such a Spirit to contraction or evolution 2. In the Consequent or rather Concomitant of such Penetration or Expansion In Material Substance upon contraction or penetration the Matter is necessarily thereupon more dense and in evolution or expansion more rare for it cannot be one or other without the acquest of a new texture of its parts viz. more lax in Rarefaction more close and compact in Condensation but in the contraction or evolution of a Spirit there is no alteration in the texture or Rarity or Density of a spiritual substance For Rarity and Density are Qualities and Affections competible only to Bodies and Material Substances not to Spirits or Substances purely immaterial therefore I do dismiss the Penetrability of Spirits as a thing wholly unapplicable to the Matter in Question and no way applicable to the Argument in hand Eighthly Now to apply the business of Penetrability or Impenetrability to what hath been formerly delivered First In case of several Bodies that are under several actual dimensions and not united one to another by continuation this concerns not the present Question which is touching one common portion of Matter whose parts are united one to another and so in a state of union yet whether that a Body may not be of so high a rectified purity and tenuity that it may penetrate the dimensions of a grosser Body without porosities for its transition either found or made in that penetrated Body may be difficult to determine because we are unacquainted with the highest degrees of subtilty of Bodies and consequently of those Energies that are consequential thereupon Only if Light be a Body or if the Magnetical effusion be corporeal effluxes as some of the late Philosophers assert it seems to favour such a penetrability of such subtil Bodies for Light will pervade every part of the Diaphanum and Magnetical Effluxes will pervade the solidest Bodies even Gold it self as Experience shews us without making porosities for its transition But I dismiss this as not to the Question in hand and possibly the Supposition that Light or Magnetical Effluxes are Bodies is untrue Secondly As to portions of Matter Bodies and Extensions thereof where its parts are united in one common continuity as in the case of proper Rarefaction and Condensation it seems that such a penetration of actual dimensions or of Bodies determined in or under actual dimensions such a penetration either of Bodies or actual dimensions or extensions is impossible and contradictory in it self so long as such actual dimensions continue unaltered by an alteration of the texture of such Body and consequentially of such actual dimensions for a cubique Body of 12 inches cannot be more or less in extension than it is so long as it is a cubique Body of 12 inches This is that penetration of Bodies and Dimensions that we do reject under that name Thirdly But in as much as the very same portion of Material Substance is successively capable of several textures and consequently of several dimensions there
is nothing in Nature or Reason that prohibits a successive penetration of Material Substances under such a mutation of textures and actual dimensions so that one and the very same numerical portion of Matter that this moment is under a texture accommodate to the nature of the most subtil Air being condensed into a degree of Air less subtil or condensed into Water its parts will be constipated and contracted into a closer posture and take up less space according to the degree of its Condensation which contraction or constipation of its parts may not improperly be called penetration of material Substance but is not properly a penetration of Bodies or extension actually determined and remaining unaltered in its texture And this gives the difference between 1. Penetration of actual Dimensions and 2. Penetration of Bodies 3. Penetration of Material Substance The two former are impossible without an alteration of the dimension or texture of the Body The third is not only possible but necessary and necessarily consequential upon the alteration of the texture of the Body into a more rare or dense consistency And the evidence of the Truth hereof is because the same numerical portion of Substance material in a state of Rarity is as commensurate to all the particles of Space within the compass of its external Superficies and hath as perfect and undivided continuation of its parts one to another as when it is condensed into a consistence that bears not the 100 th part or 1000 th part of the same superficial dimension for otherwise it were not possible to conceive but that in the whole Body of Air and Aether for one portion of Material Substance there must be 1000 portions of empty spaces or nothings which is against Nature And this Sentiment though not warily enough examined and considered by some Philosophical Heads hath made them run on with one common cry against all penetration of Material Substances under the name of penetration of Bodies and Extensions as a great absurdity But of latter times some more considerate and inquisitive persons have searched more freely and impartially into this business and though they do reject that impossible and contradictory penetration of Bodies and actual Extensions or Dimension remaining unaltered in the sense before given yet do not only allow as possible but also assert as natural and necessary penetration of the parts of the same individual portion of Material Substance consisting in a State of union and under an alteration of textures and consequently a change of extensions as any man may see in the Learned Treatise of Bodies of Sir K. Digby pag. The large Dispute of Guarinus Guarini Disputatione 4to Expensione 2. De Rarefactione Condensatione And our Learned Countrey-man Dr. Glisson in his Tractate De Natura Substantiae Energetica cap. 27 28. Wherein among other clear Explications of this Matter of Penetrability of Material Substances he hath these Passages namely the prejudice that men have taken up against penetrability of Matter is Quod ab incunte aetate consuevimus cogitare dicere non dari penetrationem Corporum aut dimensionum quodque simul pro concesso habuimus penetrationem Corporum Substantiarum idem sonare Again Impossibile est ut manente eadem Extensione mutetur Densitas aut ut hac mutata illa non mutetur mutata dimensione ut in Condensatione Materia partes aliquas sui quasi absorbet in seipsam And again Sola terminata extensio est quae materiam durante eadem terminatione non diutius impenetrabilem prâ—stat Neither is this any Novel Doctrine but the very Natural Sense of Aristotle in 4 to Physicorum cap. 9. before cited and those expressions of the potentiality of the very same portion of Matter to become rare or dense and thereby the Extension altered without any diminution of its Matter in Condensation or acquisition of new Matter in Rarefaction though it mention not Penetrability in express words yet asserts the thing as it is above declared Upon the whole Matter therefore it seems 1. There is no necessity of a Supposition of a penetration of Dimensions on Condensation neither is it indeed possible where the Dimensions continue the same but would be a kind of contradiction And 2. Consequently where the Dimensions continue the same without alteration it is impossible there should be a penetration of Bodies or Material Substances remaining under the same actual dimension unaltered 3. But there is not only a possibility of the change of Extension but the same will necessarily follow upon the change of the texture of the Body or Matter under such Extension And 4. Consequently the Extension there remaines not the same but is changed And 5. Under such a change of Dimension or Extension or together with it there may be and will follow that which is called a penetration of Matter or Material Substance for that which was the impediment thereof namely the actual Extension or Dimension is not only changeable but now changed And 6. Therefore it seems no absurdity in Nature or Reason to suppose such a penetration of Material Substances in the case of Condensation and is the most reasonable Solution of it And thus I have given an Accompt of what seems probable to me touching this dark and intricate Enquiry touching Rarefaction and Condensation and therefore I have been the longer in it because I would be understood and because in the ensuing Remarks it is often urged against the Solution offered of the Phaenomena of the Torricellian Experiment and I shall remit the Answer of the Remarks of that kind to this Preliminary Discourse which though possibly it may not satisfie every Reader yet it will at least render it evident that the Objections made upon these obscure and intricate Suppositions of impenetrability of Material Substance are not so effectual nor indeed proper to evince or prove unless we had a clearer Discovery of the Nature and Affections of Bodies than we have yet attained And therefore Objections made from this Topique lose their use in as much as the Medium is more obscure than the very thing contended about And now I shall proceed to the Remarks themselves REMARKS upon the Essay touching GRAVITATION of FLUIDS REMARK I. Upon the Second CHAPTER THis Remark fiercely and in the first greeting chargeth the Second Chapter of the Essay with contradiction in that in some places thereof it is said That Gravity is a quality whereby heavy Bodies tend to the Center and yet in other places it is said That Gravitation is but Nisus or Conatus ad Motum and therefore that it is not improper to say that Bodies that have a Nisus or Conatus ad Motum verticalem do gravitate upward which the Remarker thinks to have been more properly expressed by Levitation and to call it Gravitation is repugnant and contradictory to what is said of the quality of Gravity But to avoid a frivolous contention of Words it might have been fairly and
easily observed that in truth all kind of Gravitation is but Motion or Conatus ad Motum But in that Conatus or Nisus ad Motum we are necessarily to consider two things 1. The Principium Motivum 2. The Terminus Motus or Conatus ad Motum The Principium Motivum may be various and tending to various terminations it may be extrinsecal and accidental as when I throw a Stone into a Bucket of Water the motion of the Water is thereby caused upward and raiseth its Superficies and the motion of the Water upward is not altogether improperly called Gravitation upward coming from an external force Again The Principle of the Motion or Conatus ad Motum may be intrinsick and from that intrinsick Principle may have a motion or Conatus ad Motum downward which I call the intrinsick quality of Gravity this intrinsick quality governs and enclines the Motion and Conatus ad Motum to a central termination when it hath no collateral impediment Any man with half an eye may see here is a Conatus ad Motum of the heavy Body to a central motion which is its Gravitation and yet the Principle that impresseth this kind of termination of its Motion is that which I call and call truly the Quality of Gravity in the heavy Body In the very Instance of the Motion of Water in relation to the Rundle of Wood specifically lighter than Water we may observe both these Gravitations or Motions the Water presseth downward from its intrinsecal Principle or Quality of Gravity and thereby undermines and gets below the Rundle and then by a relative occasional or accidental motion in relation to the Rundle of Wood it presseth upward and drives up the Rundle of Wood with a force and kind of gravitation or motion upward to the Superficies of the Water The same Water hath these various terminations one downward from its own intrinsick quality of Gravity though the exercise thereof be suspended till it find a lighter Body within its dimension to exert it the other upward in relation to the Rundle of Wood which by circumpulsion it drives upward And therefore the kind consequences that I hold there is nothing but mobility in Bodies and that I use the phrase of Gravity according to the vulgar acceptation and as Idolum fori or that the actual descent of Water or other heavy Body is from a distinct Being as is inferred in the first second and sixth Sections of that Chapter are but mistaken Collections and have no concession from me or any thing I have therein asserted nor are at all true as I think As to the 4 th and 5 th Illation in that Remark where it is said The Water hath no Nisus ad motum upward into the Tube immersed and stopped at the lower end till opened that in the Sequel of this Enquiry will appear not to be altogether true But if it were never so true yet it impugnes not what is above by me delivered for the Water is driven up into the Tube by the weight of the body of the Water in the Bucket upon the Cavity of the Tube filled only with Air and so the rising of the Water into the Tube is by the pressure of an accidental Position and the fluidity of the ascending Water meeting with an Element in the Tube lighter than the Water We see in a pair of Scales a weight of two pound in one Scale makes the weight of one pound in the other Scale to ascend though both are heavy Bodies and this by Mechanique and Statique Principles So in the Siphon A B Water poured into the Leg A raiseth the water in the other Leg to an equal Superficies upon necessary statique grounds without calling in any subsidiary Spirit of Nature to effect the ascent for rhe Siphon is a kind of natural Libra And so when the Tube stopped with the Finger beneath is immersed into a Bucket of Water and then opened the circumjacent water being both fluid and heavy is driven up into the vacant Tube till it come to an equal Superficies with the rest of the water in the Bucket by a kind of due Equipondium And all this is most regularly and necessarily effected according to the common Mechanism of Statique Principles without any help from the supposed Spirit of Nature to fetch out the Air out of the Tube or to raise the Water into it There be many accidental causes of the motion of water vertically upward which yet consist with its intrinsecal principle or quality which I call Gravity or Conatus to a central motion For instance 1. It is moved upward by casting into it a heavier Body which takes up some of its room as throwing a Stone into a Bucket of water 2. It is moved upward by attraction as in Pumps and Syringes 3. It is moved upward when within its own dimension it meets with a lighter body than it self as in the instance of the Tube of Air immersed and then unstopped at the bottom or where a Rundle of lighter Wood is immersed in it it is apparent the water raiseth it and casteth it to the Superficies with a kind of Force so that it will leap above the Superficies of the water when it comes thither But these accidental vertical Motions do not at all take away the intrinsick principle of its Gravity but consist with it and therefore it is no contradiction to say that Gravitation is but Conatus ad Motum be the motion lateral or vertical or central and yet at the same time to say that Gravity is a quality in heavy bodies that specificates and determines their Conatus ad Motum to be central or perpendicular REMARK II. Descent of Bodies THis Remark would surely have have been spared if the Author had been pleased to have read the next Page where it is affirmed that Water powred through the Air hath a direct central Direction and Gravitation Pag. 14. of the Essay REMARK III. Touching the Gravitation of Parts of Solid Bodies one upon another THat every part of a Solid Body hath its common quality of heaviness and would in a state of Separation descend and that every part contributes to the weight of the whole is no where questioned only when the Body is in continuity and of an equal consistence that there is a suspension of actual Gravitation of one part upon another is that which is affirmed But where they are of different Consistencies there many times happens actual and sensible Gravitation of one part of a Solid Body upon another This is observed in the Third Chapter of the Nugae pag. 1. And had it been observed the Remark I suppose would have been spared REMARK IV V VI VII Upon the Fourth CHAPTER FOr the rendring my Thoughts more intelligible touching Gravitation of FLUIDS and to make my Approaches to it the more easie and fair I give in that Chapter Instances of solute solid Bodies and how the pressure of their parts are refracted I
bodies naturally to a central direction though it may be some time accidentally impeded and ordinarily impeded by the fluidity of a fluid body REMARK XII XVI XVIII THat the parts of Water when in conjunction one with another are only contiguous I do admit by way of Argument but I no where admit it by way of Concession for if I should I think I should grant that which is by no means true I only therefore in that place argue that were the parts of water solute and only contiguous yet even there the actual gravitation of them would be suspended as well as in Sand. And because the business of continuity and contiguity often occurs in the Remark and great endeavours are therein used to prove the particles of Water and Air only contiguous I shall here once for all make some Observations touching Continuity and Contiguity that I may avoid Repetition We learn both from the Ancient and Modern Philosophy that Contigua sunt quorum ultima sunt simul in situ non est possibile quod inter ea cadat aliquid quod habet situm Continuum autem illud cujus natura est quod inter partes ejus reperitur unus terminus communis or quorum ultima sunt unum in actu which is a little clearer explained by the Moderns that Continua sunt quando ex pluribus quantis fiat unum totum nulla sensibili commissura inter partes remanente or implicatio incorporatio partium unitarum so that they as it were run one into another without any sensible discrimination of their Moles or Situs Although in grosser Bodies there is more required than contiguity to make them continuous yet in Liquids especially perfectly homogeneal as Water and Water Air and Air Mercury and Mercury there ariseth a continuity of parts meerly upon their contiguity or contingency for thereupon they presently incorporate implicate and mingle so one with another that there remaines no possible distinction of the parts united one drop of water touching another one portion of Air touching another one little globule of Mercury touching another become perfectly continued bodies without more ado though they were before divided by their distance and interposition of another Body this is apparent to our very Sense that these are undistinguishably united incorporated and implicated one in another by their very contact as closely though not so firmly as Lead Iron or Gold after Hammering or Fusion In all Bodies that are in continuity as there is a unity of Existence so ordinarily though not alwayes follows a unity of motion It doth not alwayes follow because there may intervene something that may disorder or break it But in things barely contiguous as they are not in themselves united so regularly ad motum unius non sequitur motus alterius unless united by alligation as in Chains of several Links by some other accidental intervention as in the cohesion of distinct contiguous bodies for the avoiding of Vacuity as in polished Marble c. And herein we may easily observe the continuity of Water Take a Siphon and fill it with water stopping both Legs with your finger till the shorter Leg be immersed into a Vessel of water the water will be entirely drawn out of the Vessel by a Funiculus of continued water ascending and descending from the first immersion as is shewed in the Additions to the Nugae But fill the Siphon with the finest Powder or Sand that traction will never follow upon its immersion into a Vessel of the same or the like Sand or Powder for in the former there is a traction by the continued Body of Water But in the latter the particles are solute and only contiguous and will not cohere but gives us the Proverb of a Rope of Sand. And what is here observed touching the continuity of Water and the traction wrought in the virtue of that continuity is observable touching the Air and the traction wrought by its filaments as appears most evidently in the Magdeburg Hemispheres in the 18th Chapter of the Difficiles Nugae and in the raising and holding up of water in the heated Tube or Glass described in the 16th Chapter which could never be effected did the Air consist only of contiguous and solute particles unless we should dream they were fastened together by Hooks or Chains And upon what hath been said it is most apparent that neither the softness of the Air nor its easie divisibility or separability by a Feather or a Cobweb nor the attenuation of the particles of water into vapors by the heat of the Sun are so much as tolerable Reasons against their continuity for although the disjunction and separation of the parts interrupt the continuity between the parts when actually separated yet the separability or easiness of separability of the parts of it are not so much as a shadow of Argument against their continuity till such an actual separation be made No man that thinks twice can imagine that Lead in fusion is less a continued Body than when it was solid or that Gold beaten into Leaf is less continued than when in the Ingot and yet the separability of its parts much more facile than before And therefore the Fancy of contiguity only of fluid Bodies is the effect of that Idolum Democraticum or Cartesianum which with his imaginary Globuli and their Ramenta the Materia Subtilis hath disordered mens Sentiments as in many other things so in this touching Continuity and Ratio Continui REMARK XIII I Am very well contented to be rectified touching the Nature of the Principium Hylarchicum of the Learned Remarker I must confess when I found so much of a Spiritual Nature attributed to it and that great and ready accommodation of it to the solving of most of the admirable Phaenomena in Nature whether Mechanical or Vital I thought it had been some intelligent Spirit or Intelligence but now I understand that it is only plastick and vital not intelligent and doubtful whether sentient or not But of whatever nature it be supposed to be it seems necessary to prove its very existence by such instances as are not meerly Mechanical otherwise I fear more is asserted than proved REMARK XIV XIX XX. IN these Remarks lies most of the Elixir of the precedent Remarks And besides they offer at somewhat of experimental proof of what they assert besides bare Notions but how far these proofs are sufficient or effectual we shall see hereafter And therefore I shall insist somewhat larger upon them and the Observations that are to be made upon them Archimedes in his Third Proposition De Insidentibus Humido tells us that if solid Bodies having a Bulk or Moles be equally heavy to the Water wherein they are placed being let down into the Water are so immersed that nothing of the Superficies of the Water is above them yet they are not pressed downward And in the Sixth Proposition he tells that a Solid Body lighter than the Water
being forced down into the Water is driven up with such a force as the Water having an equal Moles to that immersed Body is heavier than that Body And this driving upward of the lighter Body is by that circumpulsion of a heavier fluid Body upon another Body lighter than it self which will if it can take up the place that the lighter Body hath invaded within its Dimensions and the Limits of its Province And the truth is the reason of the motion of a Ballance or Libra Artificialis in the Air wherein a heavier weight in one Scale lifts up a lighter weight in the other Scale is in effect the same with this natural libration between the heavier Body of the Water and the lighter Body of the Wood only here it seems like a Ballance inverted wherein the counterpoise of the Moles of Water being greater and more than the like Moles of a lighter solid Body must needs overweigh it and if it be possible get below and under it as in this Scheme Suppose A be a Cube of Wood of 6 inches square immersed towards the bottom of the Cubical Vessel of Water C D and lighter than the like Moles of water this Cube takes up the room of 234 square inches which were not the Cube there would be in a great measure taken up by the Water The Cube of wood is environed with a quantity of water equal in Moles to this Cube of wood but exceeding it considerably in weight the weight of the water must necessarily preponderate the Cube of wood and consequently must thrust it upward that it may possess the place the Cube of wood hath invaded and so in this Libra Naturalis the heavier Moles of water must necessarily drive up the lighter Moles of wood as in the artificial Scale the heavier Scale raiseth the lighter And hence it is that without the aid of an Hylarchical Principle the Water bears and carries up the Rundle of light wood in the Instance so often magnified by the Remarker For unless the Rundle were so closely fastned to the Base either by some glutinous matter or by its strict jointing and adhesion to the sides or Base of the Vessel as would be too strong for the water to displace it it is hardly possible by any art whatsoever to make the Rundle so close to the Base of the Vessel but the subtil particles of water will creep between the Rundle and the Base and throw it up in spite of the imaginary Column of water commensurate to the Rundle that is supposed to keep it down and herein as I before observed the water hath accidentally and upon this occasion a motion upward which yet is but the Consequent of its motion downward below the Rundle And upon the same account it is if you take a hollow Cane suppose one inch diameter 12 inches long let the Base thereof be filled with a quantity of Lead for about an inch then let there be powred in 6 inches of water and then there will remain 5 inches of Air in the upper part of the Cane although the Lead be heavier than so much water and the water in the Cane equal in specifical weight to so much water yet as long as the whole weight of the Cane thus compounded doth not equal the weight of a like Moles of water this Cane immersed into a Vessel of water 12 inches deep will not subside or rest at the bottom of the Vessel but will be driven up to that height in the water that the parts of the Cane subsiding in the water will countervail a Moles of water equal to the weight of the whole Cane and there it will swim erect Experience and the very Reason of the thing makes the truth hereof apparent Stevin that next to Archimedes hath written best of Hydrostatiques in his 5 th Book Prop. 2. supposeth nevertheless that if this Rundle cover a hole in the bottom of the Vessel it will not rise but will be kept down by the impending Column of water commensurate to the Base of the Rundle Albert Girard the Commentator denies this unless the Rundle be of equal or greater weight than the like quantity of water But the truth lies between them both for the Rundle lighter than the water will be undermined in the Rims and Edges and so the water will get out do what the Artist can if the Rundle be lighter than the like Moles of water But then when the water hath thus gotten a passage to pass through the Orifice into the free Air upon which it hath been shewn the Moles of water commensurate to the passage it hath now presseth with its full swing and if it meets with the Rundle in the way of its motion so long as it stands in its way it will gravitate upon it till the water hath wholly discharged it self through the Orifice And therefore the reason is obvious why there is some impediment in the ascent of the Rundle when it is thus placed upon an Orifice without calling in any other principle than the natural pressure of the water upon that Orifice now giving it an access to an Element that it can press upon viz. the Air below the Orifice Just as we see in our Kettles and Brewing Furnaces when they have a small Leak the Servant throws in a handful of Bran which though perchance it would not so readily sink much less sink to the Leak yet the motion of the water to the Leak will carry those light and small particles thither which being crouded in by the weight of that Column of water that is commensurate to the Orifice of the Leak stops it And the like is done upon a Leak in a Ship where a light Fardel thrown out into the Sea will be carried down to the Leak and crowded into it by the water sometimes stop the Leak And therefore touching the gravitation of the Column of Water upon the Rundle of light wood where there is a hole under it in the Base which I add as an exception pag. 57. and is no more than what Stevin tells us in the 5 th Book of his Practical Hydrostatiques both He and I must be understood where any little water passeth under the Rundle to the Hole and therefore to clear that Experiment and the reason of it I made exact trials concerning it as followeth Then oyling the Base and Rundle as before and uniting them I filled the Bucket with water which by reason of the glutinous Oyl did not pass nor sever the Rundle from the Base Then fixing the Rundle as before to a Scale I tried what weight was sufficient to sever the Rundle from the Base being under the supposed pressure of that imaginary Colum of water of 5 inches deep and I found that very near the same weight would sever it from the Base under water as did sever it when it lay dry and though in several trials there was some little disparity which might arise from the unequal
so heavy as the like Globe or Cube of water weighing for the purpose 13 pound and be immersed into a Vessel of water ten or twenty foot square which is filled with water only to two inches deep though this water be of an intrinsick double weight to the Cube or Globe of wood and extrinsecally it may be above forty times more weighty than that Cube or Globe of wood yet that Cube or Globe of wood will subside to the Base of the Vessel or rest there in contiguity to it without any swimming or bearing up above the Base of the Vessel And the reason is because the strength of the pressure of water is alwayes secundum altitudinem vel profunditatem and not at all secundum latitudinem vel amplitudinem and the water in the Vessel rising but two inches high doth not equal the half weight of the Cube or Globe which requires somewhat more than three inches of water to overmatch the extrinsecal weight of the Cube of wood without which it will not be moved by the preponderation of the water but the wood will preponderate the energy of that expanded water or at least be in aequilibrio with it and so not moved from the Base of the Vessel 6. But if in the Instance last given a Globe of wood of six inches diameter and six pounds weight being but of half the weight of the like Globe of six inches diameter of water weighing therefore 12 pound be immersed into a cylindrous Vessel of water of 7 or 8 inches diameter and of such a depth as may hold 7 or 8 pound of water without being forced over by the immission of the wooden Globe into it and let there be but 7 or 8 pound of water powred into it and then let the Globe of wood of half the intrinsick weight of the water be put into it or let the wooden Cube be first put in and then the 7 pound of water here the water between the Base of the wooden Globe and the Base of the Vessel it may be will not be an inch deep but the water in the sides of the cylindrous Vessel may rise four five or six inches higher In this Instance this wooden Globe will swim and the reason is plain 1. Because the water in the Vessel is not only intrinsecally but also extrinsecally heavier than the Globe of wood this weighing only 6 pounds and the water in the Vessel 7 or 8 pounds but that over-weight of water alone would not be sufficient to bear up the Globe of wood as is shewed in the next precedent Observation Therefore 2. The immediate reason thereof is because the ambient or lateral water between the Globe and the Vessel riseth to above half the diameter of the wooden Globe and presseth secundum altitudinem upon the little portion of water next the Base of the Vessel as a weight of water of near 7 or 8 pound and so exceeds the whole weight of the Globe of wood But if by reason of the amplitude of the Vessel the lateral water encircling the Globe of wood had risen but an inch or two above the Base of the Globe of wood that would never raise the Globe of wood from the Base of the Vessel but there it would stand contiguous to the Base of the Vessel or if the Globe of wood were put into such a Vessel of water it would sink to the bottom for it preponderates the weight of the water in such a position these Figures will explain it In the lesser Vessel A B where the 7 or 8 pound of water riseth never so little above the diameter of the wooden Globe C the wooden Globe of six inches diameter and 6 pound weight will swim But in the greater Vessel or where by reason of its amplitude the lateral water doth not arise above the diameter of the Globe the Globe will not swim but rest contiguous to the bottom though the water in that Vessel were 20 or 40 pound weight REMARK XXI THis Remark is sufficiently answered before where I say that heaviness in bodies is an intrinsick quality that it is not mobility at large but a special or specifick mobility whereby its Gravitation is naturally determined to be central That mobility upward in heavy Bodies is occasional and accidental and not purely natural as a heavy body I must confess I do not understand what the Remark means when it says that Water hath no tendency to motion downward but when it is out of its place what is meant by the place of Water Is it a place determinate with relation to the position of the Vniverse If so we find no place in Nature but the Water will descend from it unless it be in the very indivisible Center which though it be the termination of its motion was surely never intended for its place because never ample or capable to receive it let the water be in the Ocean or in the middle Region of the Air or in the Bowels of the Earth it will still as a heavier Body descend if it be not impeded Or is the place of it that place where any portion of water is placed suppose in a Vessel upon my Table or upon the top of my House or on the top of a Steeple yet there this water will still descend if it be not impeded Or is it that the Water having gotten into any place in its fluid consistence it is now become its natural place per occupationem and all other Bodies invading that place are intruders and put it out of its place and so give it a Nisus downward But the Water it self when I remove a Vessel of it out of the River into a Boat or upon the Shore invades the place that the Air before had and so cannot be the proper place of the Water So that upon the whole account the Water unless otherwise impeded must necessarily move downward in all positions though sometimes it hath an accidental or consequential motion upwards and by reason of its fluidity a lateral motion therefore I confess I am to seek what is meant when it is said that the Nisus of Water downward is occasional and pro re nata as well as upward namely when it is out of its place REMARK XXII XXIII XXIV XXV XXVI XXVII XXVIII I Answer to the Demand the Mobility of the Water downward is natural being thereunto as a heavy Body determined by the Principle thereof viz. intrinsick Gravity but the other Motions are either from its fluidity or occasional Though it be not pertinent to the Debate yet it is plain that at the same time Water may have an occasional motion upward or laterally and yet a natural motion downward The Bucket of Water weighing 12 pound will weigh as much when a Tube stopped below and immersed and then opened below gives an occasional motion to part of the Water upward into the Tube And the same is apparent when it drives up a light Rundle of Wood
from the Base to the Superficies The rest of the Remark is principally levelled against Continuity of Water the contrary whereof is here affirmed to be proved in the former Remarks Indeed I find this often said but without any proof that I can find And indeed it requires a very evident proof for its Continuity is affirmed by all others that I know of and is evident to some Concerning the motion and pressure of Sand I have said enough only where it is said that an Animal is not damnified under a high heap of Sand may have some such reason as the suspension of Fluids I freely agree herein for as I take it the Animal is protected in both by the Mechanism of the incumbent parts but not by such Hylarchical Principle as the Author supposeth REMARK XXIX XXX THat the natural gravitation downward is not inconsistent with an occasional gravitation lateral yea and in some cases vertical is most evident by what hath been said upon the last Remark And therefore those other actual gravitations are not bare imaginations but may be as real effects in Nature as when a Bullet is shot out of a Gun in a horizontal Line at the same time there is a conatus ad motum Horizontalem Centralem for otherwise the Bullet could never sink from a straight Line the former is conatus ad motum violentum and the latter ad motum naturalem But as to the distinction that I make between the fluid Water in the Bucket and the Bucket containing an entire Cylinder constituted both of the Bucket and Water in it and that the latter hath one simple motion downward as a heavy Body or as a Keg of Ice but the fluid water in the Bucket had as a fluid Body those various motions which in this Chapter I assign unto it I must confess when I wrote it I thought and still think it so plain and intelligible and evident that I wonder it should not be understood or should be thought a repugnancy in Nature The Water in the Bucket is perfectly a fluid Body and hath its perpendicular motion downward which is simply natural to it as a heavy Body and its lateral motion belonging to it as a fluid Body by which it would drive out the sides of the Bucket near the top especially were it not well fenced and though by the strong gards of the Bucket it be kept in that it cannot effect what it endeavours yet it hath still its conatus ad motum lateralem but that conatus is still kept in by the strong sides and bottom of the Bucket But the Bucket of Water is now one entire aggregate Body consisting of Wood formed into a Cylindraceous form and Water contained within it and so presseth simply centrally as if the Water were congealed into Ice or as if Water and Earth were mingled together into one solid Mass in which Instances the Bucket of Water presseth not as a fluid Body of Water but as a common solid aggregate Body And now if you ask But why doth not the Bucket of Water press laterally as well as the Water in the Bucket The Answer offers it self even before the Question asked because the sides of the Bucket are solid and not fluid and can no more press laterally upon the circumjacent Air than if they were empty of Water the Water within the Bucket presseth upon the interior sides and cavity of the Bucket but is restrained from pressing farther by the contignation of the Bucket but the convexity of the sides of the Bucket do not cannot press upon the ambient Air and so the whole weight is discharged from it in a central direction as in truth it doth alwayes in a solid Body And the consequence that would be drawn from hence that then Water congealed should be heavier than the same Water solute is the vainest inference imaginable for the Water as one common Body had the same and possibly a little more weight before its congealing than after and though its congealing hinder the various motions of it as a fluid Body it doth not encrease nor considerably impair its weight upon the Scale as a heavy Body Methinks the Reasoning of the Remarker in this Case is just as if a ship were sayling from North to South a man should say it were unconceptible that a Passenger should walk upon the Deck from South to North for then he should be moved with two contrary motions and of contrary terminations at the same time and yet is apparently true that at the same time he is moved ad motum Navis from North to South and ad motum proprium from South to North so the same Vessel of water as it is one entire heavy bulk hath simply its central termination yet the several included fluid parts in their fluid consistence have and may have various terminations as well lateral or inclining as perpendicular or central But to put a period to this Debate when I speak of the various motions of fluids as fluids I speak of the motions of the parts of that common body which is fluid and those are horizontal per declive lateral and central But when I speak of its motion as one common body then it is true the motion is central which is its motion of natural gravitation upon the Scale and therefore 12 pound of water without relation to the Vessel wherein it is will weigh still 12 pound upon the Scale and yet its parts have those several motions before described which abate not the weight of the whole Mass but correct the particular pressures of it and the several parts thereof while in fluore And by way of illustration of what I say take these few Instances a Barrel of new Wine or Beer suppose it weigh 100 pound after a little time it will gain a motion of fermentation which by reason it proceeds from heat is principally upward towards the Superficies yet notwithstanding this motion the Barrel of Beer or Wine will as a heavy body weigh as much as before the excitation of thaâ— motion unless some of the Liquor bâ— spent at a vent or break the Barrel In Animals there is a great variety of the motions not only of the Spirits but of the Blood the Chyle the Lympha and most considerably upward towards the Head and superioâ— parts of the Body whereupon it waâ— supposed by some Learned men thaâ— the Body of a dead Animal that by such death had lost none of his blood should weigh more than the same body living but upon strict trials it hath been found that the weight continues the same upon the Scale so that the various motions of the Blood Humors Chyle and Lympha which are of a different yea and in many respects of a contrary termination to that of natural gravity doth not only consist with the proper motion of gravity of the whole Moles Corporea but doth not so much as abate it yet these particular partial motions of the
Blood Humors Chyle and Latex may one correct the other And the same I say of Water though there be particular motions of its parts as a fluid body and those correct and refract one another yet the motion of the entire Moles Corporea as constituting one entire body retains its entire weight upon the Scale viz. 12 pound and this without any repugnancy to or diminution of the Laws of Nature in relation to the descent of heavy bodies to the Center Take a Ballance and charge one Scale with 3 pound weight the other with 2 pound weight the preponderation of the Scale with 3 pound weight will raise up the Scale with 2 pound weight so that in a relative consideration between the weights the latter hath no sensible gravitation and yet the hand that holds the Ballance will sustain and feel in both Scales together the weight of 5 pound and it were an unreasonable way of argumentation to urge that because the lighter weight hath lost its actual gravitation in relation to the heavier weight therefore the weight of both should be but 3 pound which is the preponderating weight of the heavier Scale 1. That notwithstanding this aequipondium in this Instance between the 2 pound and 4 pound whereby the relative weight of each is abated yet the entire Engin with its weights will weigh 6 pound besides the weight of the Engin. 2. That by the declivity of the motion of D it loseth half of that weight that it would have in a direct descent from C to B and so this accidental interposition of a motion per declive corrects that natural gravitation that is truly central and perpendicular 3. But yet it doth not wholly remove or take it away only the declive termination or direction takes off one half of the actual perpendicular or central gravitation And this Instance explicates and in a great measure proves what I have said and evinceth that these 29 30 Remarks are not of that moment as the Remarker takes them to be So that upon the whole Matter though a Tun of Water in a Vessel weigh 2000 pound weight and that a man being laid upon his back in the bottom of that Vessel be subjected to a Pile or Column of Water equal in Base to the half of that Tun of Water yet the man shall not be pressed with 1000 pound weight of Water nor the 1000 th part thereof and yet the whole Vessel of Water or the whole water in the Vessel shall nevertheless weigh 2000 pound upon the Reasons given in the 7 th and 8 th Chapters of the Essay without the help of an Hylarchical Spirit whether intelligent sentient or plastick only And thus I have done with the Remarks upon the Pamphlet called An ESSAY touching the Gravitation of Fluids The Brief of what I have herein and there delivered are as followeth I. That there seems to me a double Reason of the Non-gravitation of Fluids upon Bodies within them of a narrower Base at least than the Base of the whole Moles of the Water incumbent upon them namely 1. Mechanical which is principally sustinendo the inferior parts of the Water sustaining and bearing up the superior as analogical to the sustentation of the superior parts of Sands or other minute Bodies by the inferior 2. Natural premendo which is the motion of the parts of Water it self as a fluid though withal a heavy Body which being per declive and very near horizontal corrects the central gravitation II. That although the Moles of Water considered as one common Mass or Moles moves as a heavy Body in a central termination yet the Water and its parts considered in their fluid consistency have differing motions as a fluid body and with various terminations viz. central lateral and per declive which check and refract the pressure of each other so that the entire pressure of the parts of water is not all one way because a fluid Body though as one entire Moles it press with one single central termination as a heavy body yet the parts thereof in their common consistency have various motions or Conatus ad motum III. That although the various Conatus ad motum of the parts of water in fluore do correct the motions of water in relation to their terminations as a fluid body whereby Divers Urinatores are not pressed to death yet these motions of its parts as a fluid body do not abate or alter the common motion of the whole Moles when in one collection in its central termination as a heavy body IV. That besides these motions incident to Water as a heavy or a fluid body there are or may be certain accidental motions ab extrinseco which may give water a vertical ascending motion of pressure by an external force as that motion which ariseth by circumpulsion where it meets with a lighter body below the Superficies as in that of the Rundle of a lighter body as a Rundle of Wood the rising up of Water into a Tube full of Air the instance of the value given in the ensuing Remarks all which though they partly happen from the fluidity of water yet they are effected from an accidental interposition and most ordinarily are consequential upon a descent of the Water first all which motions of parts of fluids arising either ab extrinseco or from its fluidity yet are consistent with its intrinsecal quality of a heavy body and the motion or Conatus ad motum of the entire Moles thereof in a central termination or motion towards the Center which I usually express by a central motion or termination Touching the REMARKS upon Difficiles Nugae REMARK I. I Now come to the Second Course of Remarks upon Difficiles Nugae and begin with the first In this Remark the Learned Author hath fallen upon one of the subtillest Subjects in Philosophy and such as would require more than a small Treatise to give a tolerable accompt touching it namely Rarefaction and Condensation I have more largely given an account of my thoughts touching it in the beginning of this Book whereby it will appear whether the Principles I take up are unproved or whether they or the Remarkers Principles be or can be proved by any Experiment or Reason in Nature or whether his Principles or mine are such as are repugnant to Reason and absurd if we closely canvass them and more considerately search into them It was not in that place here remarked upon necessary to prove them but to suppose them the proof was therefore there omitted I having therefore now in the beginning supplied that defect in some measure REMARK II. THe Learned Remarker mistakes the Scope of the Assertion it is true that the conjunction of solid heavy bodies contribute to their weight and consequently to the motion of the whole solid body downward But the actual gravitation of one part upon another is suspended by their continuity the lower parts receiving and sustaining and so de facto suspending the actual
gravitation of the upper parts upon the lower so that although the superior parts contribute to the total weight yet they do not superately and actually gravitate upon the lower parts REMARK III. I Must confess the substiturion of an Hylarchical Principle to perform all the Phaenomena of motions in Natural Bodies is a compendious and easie way for the answering of all difficulties But he that but observes the Instance here endeavoured to be confuted will find as in many others that I shall hereafter mention they do not stand in need of such a help for it is meerly Mechanical from the various Librations of the Water and Oyl at various immersions by a kind of inverted natural Ballance between the Water and Oyl in these various positions therefore I shall refer the truth of the Solution to the Readers trial and what hath been before said upon the former Remarks REMARK IV. IT is cautiously said that in a manner I acknowledge what is endeavoured to be proved in the first Remark For in the Atmosphear the Air is more compounded than above it and yet all are connexed together by continuity and so in a manner I do not acknowledge it also Touching the continuity of the Air it is said by the Author to be sufficiently disproved but it is only said so And I think the continuity of the Air is sufficiently proved and in it self most evident if no proof were offered of it REMARK V. THe exclusion of innate Gravity because the parts compressed will sensibly gravitate but do not sensibly gravitate before compression seems to me as strange a consequence as if a man should say a Feather hath no sensible gravitation but a peck of Feathers put together have a sensible gravitation therefore there is no such thing as intrinsick gravity in the Feather REMARK VI. ANd I have before noted that Continuity consists not in the facility or difficulty of separation of parts which yet till such separation are in continuity and when that separation is past may grow together into continuity again by the first contact of the separated parts as the Air and Water do upon removing of what separates their parts REMARK VII IN the 4 th Chapter pag. 64. of the Nugae I have given an account touching the various pressure of solute and included water namely that in a Siphon there described the Water in the open Air poured into the longer Leg being 24 inches depressed the Mercury 2 inches and ¼ and drove it out of the short Leg but the solute water in an open Tube incumbent upon the shorter Leg drove back only one inch the longer Leg being empty Now if the impelling down of 2 inches and ¼ of Mercury by the 24 inches of Water in the longer Leg be no more than the pressing down of one inch of Mercury by the solute Water of 24 inches deep in the shorter Leg the Remarker is in the right and I was in the wrong but if these be differing pressures and the pressing down of one inch of the Mercury by the solute Water leaning upon the short Leg be less than the pressing of two inches and ¼ by the 24 inches of Water included in the longer Leg then I was not mistaken and a little Arithmetick will serve to discover it The Remark gives this Answer to this part of the Experiment That more was impelled up by the solute Water because the shorter Leg was wider and so required more Mercury in the other Leg to counterpoise it But to give the Remark satisfaction herein I have made a most exact scrutiny into this part of the Experiment and to the Objection I give these Answers 1. The Cavity of the Siphon in the shorter Leg was ⅛ parts of an inch or ¼ of half an inch the breadth of the Cavity of the longer Leg was not the 40 th part of an inch less than the shorter which is so small a disproportion that it could scarce be sensible and this upon an exact admeasurement And again when the Mercury in the shorter tube was depressed an inch by the solute Water incumbent upon it there was not any visible difference between the extent of the Mercury driven up in the longer and depressed in the shorter Leg both being indistinguishably the same viz. an inch subsiding in the shorter and an inch only rising in the longer Leg which evidenceth the imperceptibleness of the difference 2. If it gave an advantage of raising of the Mercury it must be to the shorter Leg because it had a greater Moles of Mercury in it and of Water upon it 3. But the truth is the pressure of Water or Mercury in an inverted Siphon is equal though the amplitude of the Legs differ for Fluids in that Instance press secundum altitudinem or longitudinem not secundum amplitudinem A Siphon inverted having one Leg of 6 inches diameter and the other but of an inch diameter filled with Water or Mercury will have their Superficies of equal heights notwithstanding the disproportion of their amplitude This part of the Experiment therefore stands unshaken by the Remark and therefore surely the Experiment it self nor the Collection thereupon made by the Remark gives little countenance to the magnified demonstration mentioned in the Remark but concludes effectually against it Indeed as to the second Instance or Trial which I call the double Trial pag. 66. it hath reasonably given a just cause of exception yet not without some Mistake in the Remark because it was tried when two inches and more of the Mercury was first driven out of the Siphon by the Water poured into the longer Leg and therefore I lay no weight upon it yet even there there is a disparity in the pressure of the solute and enclosed water there being a greater height of water pressing upon the Mercury in the shorter Leg than in the longer But because this second trial is less evident I lay it aside yet howsoever this doth not impeach the former trial nor the Conclusion which I lay upon it viz. that the force of the same Column of water contracted in the longer Leg of the Siphon and having no other Base but the Mercury it self is of greater force than the like Column of solute Water in the open Vessel impending upon the shorter Leg especially since in the one case and the other the open Air gives the most fair trial to the energy of both and therefore the disparity of the pressure of enclosed and solute water which the Remarker is pleasantly disposed to call the Masonry of the water is not hereby impeached nor the notable demonstration in the Enchiridion Metaphysicum by the Rundle of wood any way relieved And for evidence of the truth of the pressure of water secundum altitudinem and not secundum amplitudinem and also the disparity of pressure of solute water and water under a constriction to a narrow Basis I have observed that if a Tube of half an inch diameter and 4 foot high
with a Lumen of a quarter of an inch diameter in the side near the Base be filled with water the parabolical Line that the water will make out of that Vessel in its first exsilition will be as long yea and somewhat longer than the like parabolical Line made in the first exsilition by the like Lumen out of a Vessel of six inches diameter and the same height which must needs proceed from the greater pressure by that Column of water that hath an equal height but a Base of more equality to the Lumen according to the subjoined Figure REMARK VIII IX THe true reason of the rising of the Rundle of wood is neither from the Spirit of Nature nor from an Hylarchical Principle but from the plain common known Rules of Hydrostaticks whereby necessarily a fluid Body drives up a solid Body lighter than it self to the Superficies if it can by any means in the least proportion insinuate it self between the Rundle and the Base of the Vessel and this is done by circumpulsion But as touching Stevinus his Experiment of the Rundle covering a pertuse or hole in the Basis of the Vessel I must needs say Stevinus delivers it in his Observations upon the 10 th Proposition of his Hydrostatiques from whence I transcribe it pag. 94. of the Nugae I have said enough touching this Business before upon Remark 19 20. upon the Essay I shall therefore shortly collect somewhat of what is there more fully delivered If the Rundle of Wood be specifically lighter than a portion of water equal to its Moles and the Rundle be pressed down as contiguous as may be to the plain Basis of the Vessel yet it will rise for by reason of the porosities and chamfers of the wood all the industry imaginable will not press it so close but there will be some interstitia between the Rundle and the Basis or bottom of the Vessel into which the Water will creep and so undermine and drive up the Rundle to the Superficies of the Water by an ascending pressure of the Water which ascending pressure is nevertheless wrought and effected first by a descent of the water round the sides of the Rundle and so by a kind of Ballance overweighing the Rundle of wood and thereupon necessarily weighing it up 2. If the Rundle be closely fixed to the bottom by a viscous or glutinous or thick Oylie matter that the water cannot get under it the Rundle will not rise upon this double account 1. Because that adhering Oyl by the mutual adhesion to the Rundle and Base renders the Rundle consequentially and effectively and extrinsecally heavier by its adhesion than the like Moles of Water whereby the Water cannot raise it But 2. and principally Because the interposed viscous Oyl doth obstruct the migration or insinuation of the Water between the Rundle and Basis or bottom of the Vessel and so it cannot get under it to drive it up but stands now as one common fixed Base of the Vessel united to the true Base thereof 3. If there be a hole in the bottom of the Vessel suppose of two inches diameter and the Rundle of light wood be 4 inches diameter and so overlap the Orifice the Rundle will not rise because the Water notwithstanding all the care imaginable will creep under the sides of the Rundle and discharge it self gradually through the hole for the water having never so little passage through the pertuse or hole though not commensurate to the 40th part of its amplitude will contend and press that way and so gravitate upon the Rundle that lies in its way by its Conatus ad motum to that Orifice where it finds never so little vent that it may discharge it self for the water pressing upon and through the Orifice doth necessarily press upon the interposed Rundle 4. And if the Rundle of wood could be kept so close to the bottom either by its own exquisite smoothness which is hardly possible or by any viscous Oyl or by any fixation to the bottom or Base of the Vessel now it stands as one common Base to the water as the rest of the bottom of the Vessel doth and is of no use to explicate the Phaenomenon for it is all one as if it were one continued solid Base to the Vessel unmoved and unmoveable by the water And this upon more than one trial I find true and when duly weighed it makes nothing in favour of the Remarkers Hypothesis or to the disadvantage of my Supposition in the Essay though I confess it doth more distinctly and clearly explicate the Phaenomenon REMARK X. THe adequate Reason is truly given by me if the Glass were excessively strong or if it were filled with water it would not break because the internal water bears as strongly against the external pressure of the external water as that can downward against it As we see in making new Cuts and Rivers if there be a River with a small or weak bank on its South side and another Cut of Water be made on the South side of that slender Bank the water in the River will not break the Bank for the adjacent Cut filled with water strengthens the Bank by its renitence but if the Cutt be empty of water the Bank of the River will break because the conterminous Air is not of strength enough to balance it The sides of the Glass-Bottles of themselves being too weak to protect them and the included Air capable of compression by the heavier Element of water it wants strength to protect it and so breaks But as for the Air being out of its place when under water I have observed enough before of the vanity of that Reason and the ensuing Remarks will give me occasion to re-inforce it REMARK XI IF the Remarker had been pleased to take notice of what is so often mentioned in both the Tracts upon which he remarks and is of infallible truth that the pressure of water in this Instance and divers others is never secundum amplitudinem but secundum altitudinem Much of this Remark might have been spared and the censure of absurdity would have been reserved to better purpose for the water in the Pipe of one quarter of an inch diameter must be counterpoised with a Cylinder of external water of equal height and length to that in the Tube And if the height be less though the amplitude of the Water be more it will not counterpoise it in this motion REMARK XII XIII I Come to the Instance which I call the Valve he calls the Obturaculum I have given my reason of that Phaenomenon why the Obturaculum will not subside in such an immersion into water this is the Subject of Cap. 6. Nugarum pag. 102 c. and in the Observation upon the Remark which is this in effect When the whole Tube with its Valve closed is counterpoised with a portion of water of greater or at least equal weight to the whole instrument and of equal
Bulk to so much thereof as is immersed in the water the whole Engin must necessarily swim for it is in aequilibrio with or preponderated by so much water which it displaceth by its immersion And it is in effect no other than if a Cylindrical Body suppose a Cane were of two inches diameter and of two foot long the bottom filled about an inch with Lead and then 11 inches with Water and the rest with Air and suppose the whole Cane were lighter than the like Bulk of Water so that a Moles of water countervailing 12 inches of this Cylinder would counterpoise it it is absolutely necessary that this Cylinder must swim perpendiculary and erect in the water at an immersion of twelve inches for the water bearing against its Basis must necessarily sustain it at that height And perfectly the same reason is that which keeps up the Obturaculum by pressing against it at the bottom which now is as it were one common piece of the whole Latin Cylinder or Valve And this aequilibrium is the true Cause of its sustentation But the Remarker hath given us another kind of Solution which if I understand aright is to this purpose that in this Instance the Air is out of its place being in the Latin Cube below the Superficies of the Water and that the Spirit of Nature or the Principium Hylarchicum to rescue it from this inconvenience draws up the Air and drives down the contiguous water and therewith draws and drives up the Obturaculum which by the Abituriency as it is called of the Air is sustained And as a strong proof hereof it is said both in the Remark and in the Enchiridion Metaphysicum that if the Tube be stopped near the Sucker or Obturaculum it will by no means be sustained because now the Obturaculum is not concerned in the abiturience of the Air thus separated from it by the interposed obstruction This I call an obscure Solution and had I then searched into it as I have done since I should have stiled it a mistaken Solution for so it is 1. I do not understand how the Air is out of its place when it fills the Tube below the Superficies of the Water any more than if the Vessel were placed upon a Steeple the Air on either side reaching below the fund of the Vessel it may be 40 yards were out of his place because the Bucket of Water stands above it 2. Neither do I understand how the Spirit of Nature is concerned to fetch up the Air out of the Tube or to bring the water into the Tube but it is performed by a plain statical necessity and the relative pressure of the Water upon the Basis of the Tube being lighter than the like Moles of Water 3. Be it in his place or out of his place if the instance given by the Remarker of the falling off of the Valve or Obturaculum when another Obturaculum is interposed were as true as it is confidently affirmed there might have some relief thereby been given to the Solution which I called obscure But most plainly it is not true and by frequent trials I have found that notwithstanding that interposed stopping a little above the Sucker or Obturaculum the Obturaculum will continue suspended as well as if there were no such interposed stoppage I took a Latin Tube of two foot five inches long and one inch and a quarter diameter with its Valve and Obturaculum closely fitted each to other but so as with its own weight the Obturaculum would subside in the open Air the weight of the whole Engin weighed 12 ounces and a half and 9 d weight I stopped the Tube within less than ah inch above the Obturaculum with Cork so every way encompassed with a strong Cement that all possible intercourse between the superior Air and the lower brazen Obturaculum was entirely stopped The Valve or Obturaculum being put up and the Tube immersed into a full Vessel of Water subsided to 18 inches depth and thereby drave over a portion of Water equal in weight to the weight of the Engin and equal in Bulk or Moles to the 18 inches of the Engin immersed in the Water and all this while the Obturaculum stuck fast I therefore gently raised the Engin till it came within 5 or 6 inches of the Superficies of the Water and yet it continued sustained till it was raised to such a height as the weight of the Obturaculum counterpoised a Column of Water commensurate in weight unto it and so long the Obturaculum continued suspended but when the Tube was lifted higher so that the aequipondium between the Obturaculum and the like Moles of Water was lost then the Obturaculum fell down as in the instance of the Valve that had no such interposed obstruction This was the event of this Experiment often made and will doubtless fall out upon any other mans Trial if it be carefully and soberly put in ure Only this must be remembred if the Obturaculum be not very true and exact but that the water comes in considerably between the Obturaculum and the Valve the Obturaculum will fall off after a little while at least as well in this as in the unstopped Tube described in the Fifth Chapter of the Nugae partly by reason of the laxness of its adhesion and partly by reason of the additional weight of water getting in above the lower Obturaculum And yet it must be remembred also that though there be the greatest care imaginable used if the Obturaculum be so lax as to fall from the Valve in the open Air though it be so close as to stick together in the Water the Water will creep between the Fissures of the Obturaculum and the Valve with a force if it have any room to receive it And whether even that very pressure of the water upwards through that Fissure may for a while contribute to the bearing up of the Valve as in the instance of the Rundles of Wood covering the Orifice in the Base it contributes to the keeping down of the Rundle may be considerable But howsoever if it receive too much water it presseth the Obturaculum the more downward and thereby in time weakens the adhesion thereof And now what part hath this Spiritus Naturae to act in this case I shall therefore conclude this Remark upon which so great a stress is laid to prove the Hylarchical Principle and the manner of its sustaining the Obturaculum by evocating the Air and its ready obsequious abituriency to be not so much an obscure as a mistaken Solution and bottomed upon a mistaken Experiment REMARK XIV IN this Remark the Author is pleasant with his Hylarchical Principle attributing to it a pretty kind of Intelligence only where he sayes that it is the Pulp not the Skin of the Finger that feels the monition of the Hylarchical Principle it is certainly both for the Pulp cannot be attracted unless the intervening Skin be attracted
than once answered which I think is done in my Observations upon Remark 17 c. Then he proceeds to the Argument touching Rarefaction and the inconvenience of the penetration of dimensions and so endeavours to prove repugnancies in what is said by a Problem that deserves more discussion than the Argument in hand as hath been shewed in the beginning of this Book wherein I have nevertheless expressed my thoughts touching it I cannot tell what the Remarker imagines or conceives against the cohesion of grosser Bodies by the tension of lighter bodies but I can tell what is evident to my sense and so may any that will give his Senses leave freely to determin without stifling them by Notions namely that there is as plain a cohesion in the Magdeburgh Hemispheres yea and in the Torricellian Engin as there is between things fastned each to other by a string And therefore I cannot so over-readily change the conviction of my Senses for a Notion or Conception asserted and magnified but not proved But to infer that because Water which is above 900 times crasser than Air is not compressible to a sensible smaller room by a great weight therefore a portion of subtil Matter cannot be extracted out of it or Mercury with so small a weight as the Mercurial Cylinder or that the effluvia of Water or Mercury which are as subtil as Air cannot be expanded by a less weight than Water compressed into a sensible narrower room seem hard illations and very inconsequential for we see the heat of a mans hand will expand Air in Weather-Glasses to near a double extension REMARK XXXIV I Do prove the attraction of tensed Bodies by the plain evidence of Sense and I assign the preservation of the continuity of the Universe as the end thereof and the supream efficient cause thereof to be the most wise and powerful Creator of all things and the immediate effective cause that instituted Law that he hath placed in things natural the immediate instrumental cause in many motions that are not primitive in their Subjects to be from the singular disposition of the part of the Universe their admirable mechanical adaptation each to other And as to the vicarious Spirit of Nature as a distinct incorporeal subsistence when the Author hath given us better proofs thereof than the suspending of Mercury in the Torricellian Experiment the driving up a Rundle of light wood by the Water and potentia attractiva of the Embolus of the Air-Pump and such like petty Instances together with his bare Notion touching it It may possibly obtain a better entertainment than yet I find it doth at least with me REMARK XXXV THis Instance in the Bladder and Cupping-Glasses is passed over in this Remark very lightly and it was necessary so to be dealt with because too troublesome to be explicated otherwise than by Tension and Attraction and it would require an admirable process in the Hylarchical Principle to effect this and some proof besides single Notions and Conceptions of such explication by such a principle REMARK XXXVI THe Instance here given hath put the Remarker to a great deal of pains to find a solution for it and the consequences of it for the Hypothesis of Attraction is confidently said to be fully confuted though it be only so said but not so done But yet the Hylarchical Principle is at length furnished with an Hylostatical Libration and Hylostatical power of union of the several parts of Water Air and Glass And at this rate I confess there will never want a ready solution to any difficulty for it is but asserting that the Spirit of Nature is furnished with that effectual power and the knot is untied or cut though there be not a Syllable of proof offered for it but it is only graffed on to the Hypothesis of the Spirit of Nature by the wit of the Assertor to accommodate the Hypothesis REMARK XXXVII I Refer my self to what is said before in the first Chapter of this Book and upon the same Remark there need not be said more The Laws of Nature were the Laws of God imprinted upon the nature of Physical Beings by his Almighty Fiat and though as to particular Beings he hath substituted particular active principles usually called Essential and Vital Forms yet as to the Universe it self it seems to be too great an Empire to be put into the vicariat hands of that which is here called the Spirit of Nature The great God that gave the Laws of Nature is sufficient without such a Substitute and is only sufficient for the regiment of so great an Empire and this may serve also to Remark 38. We are not disputing whether such a Spirit of Nature be possible to be but whether de facto it be or not or that it is necessary that it should be at least as to those motions which have so evident explication from other principles REMARK XXXIX HErein we differ not as to the rejecting of the great Elasticity of the Air. REMARK XL. I Confess when I read the beginning of this Remark I hoped to meet with such a Solution to the Instance remarked upon as would be close and clear because this Instance bears so hard against most of what the Remarker hath before affirmed but I was deceived herein In this Instance of the Magdeburg Hemispheres these things are most evident to any mans Sense 1. That the included Air is certainly expanded and rarefied by the heat beyond its natural size 2. That while they are so hot and the Air so expanded and lax they do not at all cohere 3. That as they grow cold they do most evidently cohere so that they will not be divulsed without a considerable strength 4. That most necessarily as the included Air grows cold and the heat which was the cause of its expansion decayes so the Air must needs endeavour its restitution to its natural dimension by contracting it self inward to its natural size 5. And yet if it have such a degree of heat as again gives a more lax state to the included Air the cohesion will cease and the Hemispheres fall asunder 6. And as the Remarker confesseth and the most clear evidence of Sense evinceth those Phaenomena are not wrought nor indeed possible to be wrought either by the weight pressure or elasticity of the external Air as the Elaterists would have it The Consequence of all which is that certainly as far as Sense can lead us the Air is rarefied by the Heat and as the Heat decayes the Air endeavours its own contraction and there necessarily follows even to our Sense an attraction upon the sides of the Hemispheres whereby they cohere and that cohesion will continue till relaxed by another accession of Heat or admission of more Air. But now what doth the Remark propound in this Instance Marry an Hylostatical Spirit which pro re nata works these various Phaenomena which is only a conjecture and hath no evidence to prove it
besides Notion or Imagination but the method of the effecting it by this Hylostatical Spirit is more admirable though it is pleasantly offered that thereby all goes off glibly And it is to this effect as I take it The Hylostatical Spirit finding the subtilty of Matter imprisoned in an undue place between the Hemispheres presently makes up an occasional Gravitation or Elasticity in the ambient Air to squeeze out the included subtil Matter and give it liberty and thereby presseth the Hemispheres together And so in this glib Hypothesis the Remark doth two things viz. 1. It creates a weight or elasticity in the ambient Air pro re nata which as it is in effect contrary to all that he hath before delivered against the weight or elasticity of the Air so it hath this disadvantage as is proposed by the Remark that it is infinitely more incredible than the common Supposition of the Elaterists and indeed little less than miraculous And 2. It is a Conatus of this Hylostatical Spirit to no purpose at all and meerly frustraneous unless by such an admirable condensation of the ambient Air it could break the brazen Ribs whereas indeed it makes the Prison the stronger I must confess this Fetch goes not down so easily with me nor I believe with many more REMARK XLI I Come to the Remarks upon the Phaenomena of the Glass-Pump wherein I attribute the raising of the Water in the Glass to the traction made by the tensed Air in the Shank of the Pump and the dilatation of the Air in the top of the Glass by the extraction of the Water And the reason why after iterated evacuations of the Water by that suction or traction no more will rise to be because the Air in the Bottle hath undergone as great a tension or dilatation as a Pump of that length can give it These things I must observe touching this Pump 1. The length of the Shank or Pump if self above the Glass was not much above fourteen inches and the Embolus proportionable thereunto if it had been longer the attractive force must have been greater and would probably have given a stronger traction and consequently a greater expansion tension or rarefaction to the Air in the upper part of the Glass 2. That in this Instance here is no misplacing of the Air or Water upon which the Author builds much of the activity of his Hylarchical Principle in divers of his Remarks for the Air in the Bottle and in the Shank of the Pump are both above the scituation of the Water in the Bottle And here the Author after some recourse to the impossibility of penetration of dimensions which he so often inculcates gives us his Solution returns to the activity of the Hylostatical Principle which because the subtil Matter misplaced invigorates the external Air to do something in this business but tells us not expresly what or how in this place We shall hereafter it may be find what is meant Only he tells us two things 1. That it is impossible so heavy a Body as Water should rise so high into so extream a thin Body in the Glass and that without fresh Air succeeding 2. That the Embolus that at the first pumping overcame the consistence of the Air should as reasonably overcome it still As to the first It seems he is now pleased to admit an intrinsick Gravity in the Water which renders it unwilling to ascend but besides according to the Authors Assertion in his Remarks the more subtil parts of the Air will pervade the Glass if that were true there would be supplemental subtil Air at least to supply the evacuation of the Water to the last drop As to the Second There is nothing more plain to our very Sense than that any extendible or tensible Body till it be broken doth more easily yield to the first attempts of its extension which yet with more difficulty succeeds afterward as is evident in the Air-Pump and a Lute-string which is an Instance I frequently use I confess but it explains my meaning so that this Remark concludes nothing against what I have delivered in relation to my Glass-Pump nor to evidence the interposition therein of the supposed Hylarchical Principle REMARK XLIII XLIV XLV XLVI BEfore I come to my Observations upon these Remarks it may be convenient to give an explication of the dimensions of the Glass-Pump that I made use of referring my self to the Figure thereof described in the Nugae Fig. 21. The whole length from the upper end of the Embolus to the bottom of the Glass-Globe was near 21 Inches whereof the Embolus reaching to D near as low as H where the Water was to be pumped out was about 8 inches from H to the upper Surface of the Glass near 4 inches from the upper Surface of the Glass to the bottom of it about 9 inches which was the diameter of the globular Glass the continued Pipe of the Pump being less running into the Glass about 7 inches and so at E opening and ending about 2 inches from the bottom of the globular Glass consequently from the lower end of the Sucker at D to the middle of the globular Glass about 8 inches and a half or 9 inches the cavity of the Pump it self near two inches diameter or thereabouts so that the Air between the bottom of the Embolus and the top of the Glass might be a Cylinder of near 2 inches diameter and about 4 inches long by the tension whereof the Water in half the Glass is by me supposed to be attracted and raised The other and upper half of the Glass contains the other half of the Globe and is filled with Air which contained about 5 pints which was more than twenty times the quantity of Air contained in the Pump between the lower end of the Embolus and the top of the Water I say by iterated pumpings I drew out a quart of Water which made the water subside in the lower half of the Bottle above an inch and an half and consequently the Air in the upper half of the Bottle expanded so that now it contained about 7 pints of Air after which it was not capable of a greater expansion by my small Pump The Engin it self is more punctually described in the 19 th Chapter of the Nugae but the dimensions not so fully mentioned there as here This Instance I use as an evidence to prove the attraction of the Water by the tension of that little portion of Air in the cavity of the Pump and the sequaciousness of the Water to relieve that tension and to preserve the continuity of the Mundana Materia which in these Remarks is opposed by my learned Antagonist And the Instance is opposed upon this account that the Air in the Glass is tended from 7 to 5 whereas the Air in the Pump is tended from 1 to 5 spaces at least which is said is an evidence that there is no such tension for if
there were the Air in the Glass would receive a greater tension than from 5 to 7 when the Air in the Pump is supposed to be tended from 1 to 5 which is ever proportionate to the tension of the Air in the Glass But surely this is an Objection of no force for apparent Reasons Though the expansion of 5 to 7 is not in proportion the same with the expansion from 1 to 5 yet such a proportion need not nor indeed is possible in this case for as the Body of the Air in the Glass is above 20 times the quantity of the Body of the Air in the Pump so such an expansion serves its turn as may make good the space that is left by the evacuated water which being no more but one quart the Air in the Glass can receive no greater amplitude of expansion than one quart of space more than it had before The measure of the extension of the Air not being governed by the bare proportion which happens in another distinct portion of Air and that of a less dimension But by the room or space that is left by its next contiguous Body that must be supplied by its expansion In the 45th Remark that which was before wanting seems now to be supplied viz. The method which the Hylostatical Spirit useth in raising the Water in this and in other Pumps viz. by a circular pressure and gravitation of the Air and Water incumbent upon the Superficies of the Water that the bottom of the Pump is on which jointly gravitates upwards in regard of that subtil Element in the top of the Tube that there may be no bare subtil Matter in the Pump which gravitation and circulation is carried on by the Hylostatical Principle that there may be no misplacing of the Elements of the Universe whereof the Materia Subtilis is one This is the Solution in substance and very near the words of the Learned Author This Solution in my understanding is not only wonderful inevident but also very improper 1. Here is granted an occasional Elasticity of the Air and of the Water also though supposed to be effected by the Spirit of Nature or Principium Hylarchicum which Elasticity I had thought the Author would not have granted to Air much less to Water 2. But the Supposition of this Circulation encounters it self For either the Materia Subtilis which is supposed subtil enough to pervade the Glass though the crasser parts of the Air cannot is either a distinct Element of it self not incorporated with the Air but of a distinct consistence or else is part of the aery concretion of the Air the subtil part thereof and mingled with the Air as one constituent part thereof though in some cases severable from it which way soever we take it the difficulties of the Authors Supposition are unanswerable It is plain the Air in the upper part of the Glass upon the exsuction of a quart of Water takes up a quart more of room or space than it had before If this be caused by the perforation of the Glass by the Materia Subtilis as a distinct Element and so uniting it self to the Air in the Glass then this Materia Subtilis which in respect of its purity must needs have its proper place rather above the place of the Air by the Laws of Nature and not below it is called down by the Spirit of Nature from its proper position into the cavity of the Glass and so the natural Order Position and Taxis of the parts of the Universe disordered and discomposed Again if the Materia Subtilis be but a constituent part of the Air then is the fas ter external Air robbed of part of its constitution and impoverished of what naturally belongs to it to supply the space in the Glass derelicted by the exhausted Water and that portion of Air in the Glass furnished with a greater portion of the Materia Subtilis then belongs to it and all this done by the Spirit of Nature which is supposed to be an active plastick principle to conserve the order of the Universe and not to disorder it which according to the Learned Authors supposition must yet be the necessary consequence of this imaginary transposition of the Materia Subtilis in this Circulation 3. Again in this Circulation and circular pressure we shall find the Chain broken and the Circulation interrupted or a worse inconvenience the Air in the Glass moves upon the Water and that again presseth upward and moves upon the subtilized Air in the Pump and then it is thrown out in the open external Air and so moves upon that It remains therefore for the compleating of the Circle that now at last by ther interposition of the Hylostatical Principle the external Air must circulate by a pressure upon the Air in the upper part of the Glass and so the Dance is finished But 1. We must note that even the Author himself agrees that the grosser parts of the Air cannot pervade the Glass but it must be the Materia Subtilis I demand therefore whether this Materia Subtilis pervades the Glass and is united to the Air in the top of the Glass or not If it do not surely the Circle is broken and with it the circular pressure or gravitation If it do pervade the Glass and be united to the Air included in the Bottle these insuperable difficulties ensue 1. The Hylostatical Spirit whose Office it seems is to keep the Universe in its due Libration and to preserve the Air it self in its just size and consistency of gross and subtil Matter as is above observed breaks that order that it is placed there to conserve for it takes too great a proportion of subtil Matter from the common external Air which is due to it and crowds it into the Air in the top of the Glass which hath already more or at least as much as belongs to it 2. It would follow that by such a Current of subtil Matter through the Pores of the Glass that the Water should rise into the Pump even to the last drop for here is a perpetual spring and supply of subtil Matter strained every where through the Glass into the Air or aery space that was in the head of the Glass and no fear of any Vacuum to ensue by the passing away of the Water so that it may to use the Authors word as glibly pass to the last drop as at the first which is evidently contrary to experience This Circular Gravitation therefore is but a supplemental Invention to help the Flaws that arise from the Hypothesis of the Interposition of the Hylarchical Principle as the true cause of this Phaenomenon REMARK XLVII I Shall not need say any thing upon this Remark for herein we are very much agreed and he useth me and my Book with much Civility and is pleased to contribute his own Learned Observations in favour of it THE CONCLUSION I Shall not spend many words touching the Conclusion