nay and probably into the diaphanous humours also are not discernable but when they are preter-naturally distended in an Ophthalmia and so grow turgent and conspicuous To which we may adde that in most quick Fish though you cut a piece of their flesh off yet will no bloud be discernable though they be sanguineous Animals but the bloud is so divided by the minuteness of their Capillary Vessels or percribration through the habit of the Parts that either it has lost its redness or our eyes are not able to discover its tincture Secondly It is observable also from the former Experiments that in these minute Animals their nutritive Liquor never arises to the perfection of bloud but continually as it were remains Chyle within them for want of a higher heat to dye it into that Spirituous Liquor Nay you shall observe in perfect Sanguineous Animals a Circulation of an albugineous chylie-matter before the bloud have a being if you take Nature at the rise and critically observe her in her rudimental and obscure beginnings For view but an Egge after the second day's Incubation and you shall see the cicatricula in the Yolk dilated to the breadth of a groat or six-pence into transparent concentrical circles in the Centre whereof is a white Spot with small white threads which in futurity proves the Heart with its Veins and arteries but at present both its motion and circulation is undiscernable to the bare eye by reason of the feebleness thereof and also because both the Liquor and its Vessels were concolour to the white of the Eggs they swum in but the Heart does circulate this serous diaphanous Liquor before by a higher heat it be turned into bloud And one thing here I am tempted to annex which is a pretty and beneficial Observation of the Microscope and that is That as soon as ever you can see this red pulsing Particle appear which Doctor Harvey conceited not to be the Heart but one of its Auricles you shall most distinctly see it to be the whole Heart with both Auricles and both Ventricles the one manifestly preceding the pulse of the other which two motions the bare eye judges to be Synchronical and without any interloping perisystole at all So admirable is every Organ of this Machine of ours framed that every part within us is intirely made when the whole Organ seems too little to have any parts at all Thirdly It is peculiarly remarkable from Observation xxxi That not onely the bloud in perfect Animals and the chyle in imperfect ones but also the Animal Spirits have a Circulation which singular observation hath often provoked and entised our endeavours into a further enquiry after the Nature of these Spirits as to their Origin or Generation their activity and motion with some other eminent properties belonging to them we shall draw our thoughts together and so present them to your View I will not say that our discourse hereon shall pass for an un-controllable authentick Truth it is all my ambition if it attain but to the favourable reception of a rational Hypothesis at last A Digression of the Animal Spirits FIrst then we have not those narrow conceptions of these subtle Spirits to think that they are onely included within the Bodies of Animals or generated much less created there but we doe believe that they are universally diffused throughout all Bodies in the World and that Nature at first created this aetherial substance or subtle particles and diffused them throughout the Universe to give fermentation and concretion to Minerals vegetation and maturation to Plants life sense and motion to Animals And indeed to be the main though invisible Agent in all Natures three Kingdoms Mineral Vegetal and Animal And lest they should because of their exceeding volatility and activity be of little or no use Nature hath immersed them in grosser matter and imprisoned them in several Bodies with which she has intermixed them the better to curb the boundless activity of so thin and spirituous a substance and therefore the Spirits of all compound Bodies especially ought to be considered under a triple notion Viz. Under the state of 1. Fixation 2. Fusion 3. Volatilization First of Fixation when they are so complicated with the grosser Particles of Matter and lockt therein so fast that they can hardly be separated and dis-imprisoned as in Minerals but most especially in Gold Secondly The state of Fusion I call that when the Spirits by any kind of help have so wrought themselves towards a Liberty that they are in the middle way to Volatility as in half-concocted Minerals fermenting Vapours or Liquors and half-ripned Fruits c. Thirdly The Spirits are in their third state of Volatility when after a colluctancy with the grosser Particles they have so subjugated and overcome them that they are just upon wings and ready to fly away as in Wine when it is in the height of its fermentation and in some part of our arterial bloud alwayes Now we observe that those Bodies that relax and open the grosser composition of other Bodies do presently create a fermentation for being like so many Keys they set the imprisoned Spirits at Liberty which presently fall on working and by attenuating the grosser parts separating the Heterogeneous volatilizing some precipitating of others digesting of others expelling of others do at last mould it and work it to such a Body as the parts of it are fit to make up In all which interval of time there is a palpable and sensible heat produced Thus this Spirit being embowelled in the Earth and meeting there with convenient matter and adjuvant causes doth proceed to produce Minerals creating an actual heat wheresoever it operates as in Allum or Copperase Mines which being broken exposed and moistned will gather an actual heat and produce much more of those Minerals then else the Mine would yield as Agricola and Thurniseer do affirm and is proved by common experience The like is generally observed in Mines as Agricola Erastus and â—ibanius c. do affirm and avouch out of the dayly experience of Mineral men who affirm that in most places they find their Mines so hot as they can hardly touch them although it is likely that where they work for perfect Minerals the heat which was in fermentation whilst they were yet in breeding is now much abated the Mineral being grown to their perfection as the skilful and excellent Doctor Jordan very well infers The like heat we observe constantly to be in our Cole-Pits Nay we sometimes observe in our Brass-lumps as our Colliers call them which is a kind of Marcasite a very great heat for being exposed to the moist Air or sprinkled with water they will smoak and grow exceeding hot and if they be layd up on a heap and watered they will turn into a glowing red hot fire as I have seen them my self And it was a Casualty once terrible to our Neighbour-Town of Ealand for there one Wilson a Patient
great Mystery which here with all its consequences I shall deliver Experiment 7. THe 6. of May 1653. I took two Tubes one of 45. inches the other 35 ½ in length and of different Diameters and filling them both at the Bottom of Hallifax-Hill the Quicksilver in both came down to its wonted pitch of 29. inches thence going immediately to the top of the said Hill and repeating the Experiment again we found it there to fall more then half an inch lower then it did at the bottom or foot of the said Hill Pecquet relates That Dr. Pascal himself tryed this Experiment upon a Mountain of 500 perches high near Claramont and he found Quicksilver there at the Hill to descend lower by three inches and somewhat more then it did at the bottom so that according to the Analogy Proportion of both and some other considerable Circumstances we might not only Mechanically find out the Perpendicular height of our great Hill here at Hallifax or any other Mountain whatsoever but venture notably at the height of the Atmosphaere it self For to manage the Principles we have formerly laid down First The reason why the Quicksilver descends at all in the first Experiment is from its exceeding gravity Secondly Why it falls no lower then 29. because a Cylinder of that weight does just aequipoise the Elastick power of the Ayr without and therefore after a few vibrations up and down as is Observable in all Statick Experiments they arrive at a Counterpoise But the reason now as to our particular Mountain's Experiment why the Counterpoise should alter at the top from that at the bottom of the Hill and the descent of the Quicksilver be so unequal is not so much from any alteration in the Elastick power and virtue of that Ayr at the top from that at the bottom of the Hill as from the variation of the gravity of the Superincumbent Ayr For a longer and so consequently more weighty Columne of Ayr presses upon the vessel'd Quicksilver at the bottom of the Mountain and so makes the Quicksilver in the Tube rise higher than at the top of the Mountain which being so much nearer the top of the Atmosphaere a lesser weight of Superponderant Ayr makes a lesser quantity of Quicksilver arise in the Tube and so come the Mercurial Cylinders to vary in their Altitudes viz. from the natural Supergravitation of more or less of the Superincumbent Atmosphaere So that it is more than probable that the higher one rises in the Ayr to try this Experiment the Quicksilver in the Tube would fall down lower and if the Experiment could be try'd at the top of the Atmosphaere no Quicksilver at all would remain in the Tube but fall down to a level with that in the vessel I could wish that some of our Canary-Merchants would get this Experiment try'd at the top of the Pike of Teneriffe which is deservedly famed for the highest Hill in the world Object 1. But I see you are ready to reply and say That the inequality of the Mercurial Cylinder in the Mountain-Experiment aforesaid may every whit as rationally be supposed to proceed from a change in the Elastick property of the Ayr which may be more vigorous at the bottom and more faint and feeble at the top of the Hill and so force a greater or lesser quantity of Quicksilver up into the Tube Object 2. I know how harsh it sounds That Ayr should gravitate in its own Sphaere and we and all other Terrestrial Inhabitants be insensible of it and that which augments the improbability is That Water we experimentally know which is a fluid and dissipable Body as Ayr is does not gravitate in its own proper place for if we dive never so deep it 's so far from depressing of them lower or weighing on them that it is readier to buoy them up again And why should not we conclude the like of its next neighbouring Element the Ayr To the first Objection I answer That though I should grant that there should be some difference in the Elatery of some of the aerial particles from others yet to be so great in so small a distance as four or five furlongs 't is not so easily credible I shall answer your Second Objection with this following which may pass for the 9. Experiment FIll the Tube as in the first Experiment and drown both it and the vessel of restagnant Quicksilver by letting down all carefully with strings into a Hogshead or great Cistern of water and you shall see that the deeper you immerge the Tube the higher still will the Quicksilver in the Tube arise Let the vessel of water be of a greater or lesser plane in the surface it matters not because onely those parts of water that hang perpendicularly over the vessel'd Quicksilver do gravitate upon it We drown'd a Tube to 25. inches in depth above the Superficies of the vessel'd Quicksilver and it raised the Quicksilver in the Tube about 1 ◠4 above the stint of 29. inches at which it formerly stood just according to the fore-observed proportion 'twixt the weight of the Water and Quicksilver a Cylinder of the former of 32. foot being but aequiponderant to a Cylinder of the latter of 29. inches Of which noble Experiment we must confess the first hint was given us by those acute and singularly accomplished Gentlemen of Townley-Hall in Lancashire who were as Judicious as Honourable Spectators of these our Hydrargyral Experiments and whose Mechanical Prognosticks seldom failed but were still made good by the future event of the Experiments By which it most evincingly appears that water does gravitate in its own Sphaere as they phrase it which now we may retort upon the Second Objection and say That if water do gravitate then why not Ayr in their proper Sphaere both being fluid dissipable and co-neighbouring Elements and so consequently whether in Ayr or Water the Experiment be tryed this effect will follow That the deeper you immerge the Tube in either Element the higher will the Mercurial Cylinder rise And contrariwise As 32. foot of Superjacent water would raise up a Mercurial Cylinder of 29. inches So the same Cylinder of 29. inches is raised by a Column of the height of the whole Atmosphaere it self But we may by a far more facile and cheaper Experiment evince the gravitation of Water in its Sphaere which is observable in the common Experiment of a Syphon through which the water by Suction being first set on motion it is easily observable that the flux in the extravasated leg of the Syphon is at first most strong and proportionally decreases as the water in the vessel sinks lower and lower towards the bottom of that leg immerg'd in it which cannot proceed from any other cause imaginable but from the Supergravitation of the high parts of the water upon the lower which being thereby more strongly forced up the shorter leg of the Syphon the flux thereby is stronger in the
comes any part of it to be diffused or dispersed throughout our Elements Or if it be Why should not the aetherial particles fly all away to their proper Sphaere or be rather forced thither by the continual pressure of these heavier Bodies as we see no Ayr will abide in Water but is forc'd up into its proper region and Element above it Solut. 1. We grant that the aether pierces equally in on all sides of the Tube and so likewise on all sides of the Bladder into which it would not have entred had there been no Ayr at all which had freely open'd in its dilation to receive the coming aether into its intimate recesses Solut. 2. Why the aether hits not out again during the interim of the Ayr 's expansion may be because it has either changed its figure or it and the aërial particles may be in a new motion which may not cease till overpowred by the re-admission of new Ayr. But what 's the reason in a Bladder half-blown and held to the fire or laid in warm ashes the internal Ayr should rise and swell up the Bladder as in this Experiment If you say From the Atoms of Fire or Heat which penetrate into the Bladder the same Objection I then make to you as he there to me Why could they not hit out as well as in through the same pores The like may be said of the Ayr in a Weather-Glass upon application of any thing that is hot to the head of the Tube Solut. 3. Now why the Quicksilver does not totally descend we have told you is from the resistence of the Atmosphaerical Ayr which forces up a Cylinder of Quicksilver of that height of 28. inches but as we have since declared if the Experiment could be made at the top of the Atmosphaere which is not very high then it would totally descend and the aether there would fill the whole Tube Solut. 4. It is every whit as probable that aetherial Atoms may be interspersedly diffused through all our Elements as that Ayr may be or the Magnetical effluviums the same we have made probable by its being in Water and Quicksilver and the latter no man that knows any thing of Magnetical Operations doubts of Before we take our leave of these subtil and rare Experiments I will give you that ingenious but very difficult Experiment of Auzotius as quoted by Pecquet which shall bring up the rere in this Muster-role of our Experiments and which will confirm all we have formerly delivered Experiment 15. Of Auzotius TAke a long Tube with a Head like a Weather-Glass onely open at both ends as A B and with a Circular ledge at B to tye a Bladder about as also a little pipe G which opens into the Head thereof reverse it and into the mouth of the Head let down a hollow Cube of wood or Ivory C as large as the Head will contain which with its four corners may rest upon the neck of the Glass as in the Second Figure then take a small Cylinder of Glass of above 28. inches and set it in the middle of the Cube C and close the mouth of the Head B and the pipe G with Bladders so that no Ayr can get in then stopping the Orifice of the long Tube A with your thumb let another tunnel-in Mercury at the top of the small Glass-tube F which will first fill the Cube C and then running over and falling down the Interstices that the four Angles of the Cube C makes with the neck of the Glass shall at last come to fill both Tubes Lastly closing the Orifice of the great Tube A into the Vessel'd Quicksilver and there withdrawing your finger as in the former Experiments you shall see all the Quicksilver in the small Tube F B to fall into the Cubical Vessel C which being not able to contain it it together with all the Quicksilver in the head and neck of the great Glass-tube will come down to its wonted pitch E 29. inches of that in the Vessel Which shews the descending Quicksilver perpetually observes its Sandard-altitude from what height soever But the great business is If you open the little pipe G and let in any Ayr you shall not onely see it to depel the Mercurial Cylinder A E but to force up the Quicksilver out of the Cube C into the small Tube B F to its wonted Altitude of 29. inches and totally to expel the Mercurial Cylinder E A out of the Tube which ocularly demonstrates that it is the Atmosphaerical Ayr that in the first Experiment raises and keeps up that Cylinder of Quicksilver in the Tube of 29. inches in Altitude or thereabouts CHAP. VIII Additional Experiments made at Townley-Hall in the years 1660. and 1661. by the advice and assistance of that Heroick and Worthy Gentleman RICHARD TOVVNLEY Esq r. and those Ingenious Gentlemen M r. JOHN and M r. CHARLES TOVVNLEY and M r. GEORGE KEMP THe last year 1660. came out that excellent Tractate of Experiments of Esq r. Boyle's with his Pneumatical Engin or Ayr-pump invented and published by him wherein he has by virtue of that rare Contrivance outdone all that ever possibly could be performed by our late Mercurial and Experimental Philosophers And indeed to give a true and deserved Character of that worthy Production of his I must needs say I never read any Tractate in all my life wherein all things are so curiously and critically handled the Experiments so judiciously and accurately tried and so candidly and intelligibly delivered I no sooner read it but it rubbed up all my old dormant Notions and gave me a fresh view of all my former and almost-forgotten Mercurial Experiments Nay it had not that effect onely on me but likewise it excited and stirr'd up the noble Soul of my ever honoured Friend Mr. Townley together with me to attempt these following Experiments Experiment 1. WE took a long Glass-Tube open at both ends and put the one end into Quicksilver about one inch deep then at the upper end we poured in water by a Tunnel the effect was this as was presurmised That the water rise up to a Cylinder of 14. inches above the surface of the Quicksilver in the Vessel but then it would rise no higher but brake through the restagnant Quicksilver in the Vessel and swum upon the top thereof which is consonant to the Series and Chain of our former Experiments wherein it is proved that one inch of Quicksilver is aequiponderant to above one foot of Water and therefore there was reason that one inch of restagnant Quicksilver should support a Cylinder of 14. inches of Water but no more But as touching this proportion of Water and Quicksilver because we have formerly only given it to you upon trust from Maximius Gletaldi we will now give you an Experimental eviction of it Experiment 2. WE fill'd a Glass-Vial being first counterpoised with Mercury and then weighed it afterwards we weighed as much Water in a Glass-Vial of
upper part of it is both extenuated and extended through that seeming Vacuity 3. That by this extended film or rope as he calls it of dilated Quicksilver the rest of the Quicksilver in the Tube is suspended and kept up from falling into the Vessel 4. That this funicle or rope is exceedingly rarefied and extended by the weight of the pendent Quicksilver and will upon removal of that violent Cause which so holds it re-contract it self into its former dimensions again and so draw up what Body soever it hath hold of along with it as the effluviums of an Electrick upon its retreat plucks up straws or any other thing with it that it is able to wield 5. That Rarefaction or Condensation is perform'd without any increase or losse of quantity in the Body so chang'd 6. That this Extension of the film of Quicksilver is not indefinite but hath a certain limit beyond which it will not be stretch'd and therefore if the Tube be of an exceeding great height the Quicksilver will rather part with another film and extend that and so a third or fourth till it come to the Standard of 29. inches where it rests having not weight nor power enough to separate another film from it self Upon reliance on and encouragement from these Principles he undertakes all difficulties and engages with three great Experimental-Philosophers Torricellius Schotus and Boyle and resolves all the Phaenomena of their Engines 1. As first Why the Quicksilver in the Tube under 29. inches descends not at all Because it sticks with its uppermost surface so close to the top of the Tube that there is not weight enough to break that adhaesion the reason whereof is because there is nothing to succeed in the room of the descending Quicksilver and therefore it firmly sticks there Ne daretur vacuum 2. In longer Tubes it falls to that Standard because then the greater weight of the Quicksilver is able to break that linck of Contiguity or Adhaesion and therefore the uppermost surface of the Quicksilver being sliced off is dilated into a tenuous Column or Funicle which supplies that seeming Vacuity 3. The reason why the internal Quicksilver in the Tube does ascend upon plucking the Tube out of the restagnant Quicksilver is Because then some of the Quicksilver in the Tube falling out the Contiguity is not onely broke but the Quicksilver in the Tube being made thereby lighter the rope is able to pluck it up which it doth by retracting and shrivelling it self up to the smalness of its former dimension and thus by no violent distention but spontaneous you must perceive all the Experiments of the Weather Glass to be performed by a tenuous Funicle of Ayr and in the Pascalian-Experiment by a rope of Water and so of other Liquors where this seeming Vacuity is created By this tast of Philosophy you may easily imagine how he salves all the Mercurial Phaenomena and those of the Pneumatical Engine The Arguments by which he strives to authenticate and make good his Hypothesis are these four Negative ones by which he strives to impugn the Doctrine of those that hold the Ayr 's gravitation and Elasticity The first which is the main and Herculean-Argument is from the introsuction of the finger so observable in the Torricellian-Experiment which saith he proceeds from something that is at a stress within the Tube and from nothing that is at a full and free Liberty without this suction and attraction of the finger he proves to be not onely eminently sensible in Tubes above the Standard whether open at both ends or closed at the one but also in Tubes under the Standard of 29. inches for saith he take a small Tube under the Standard open at both ends of 20. inches supposed in length and fill it with Quicksilver stopping the lower Orifice with your thumb then closing the upper with your finger and immerging the lower into restagnant Quicksilver as in the Torricellian-Experiment you shall saith he upon removal of your thumb though no Quicksilver fall out feel a palpable suction of your finger and the Tube will stick so close to the pulp of your finger that you may quite lift it out of the Vessel and carry it with all the Quicksilver pendent in it up and down the room Therefore saith he the internal Cylinder of Quicksilver in the Tube is not held up by the preponderant Ayr without for if so whence comes so strong a suction and so firm an adhaesion of the Tube to your finger For if the external Ayr thrust the Quicksilver upwards it can never at the same time draw down the finger too His second Argument That the standing Quicksilver in the Tube is not held up there by the external Ayr is fetch'd also from another Experiment in the same Tube For saith he fill the same Tube almost full of Quicksilver leaving a little space of Ayr within it and then immerging it as before you shall see the Quicksilver to make a considerable descent in it viz. as far as that little Ayr could well be extended also a strong introsuction of your finger as before From whence he thus argues If the external Ayr cannot hold up 20. inches of Quicksilver as we here see How can it hold up 29. I pray you as in the Torricellian-Experiment This Experiment as appears by our Mercurial-Observations we made many years ago His third Argument is from the Non-gravitation of the Mercurial Cylinder For saith he the Quicksilver in that Station viz. after it has fallen to its old Standard is not all ponderous as you may perceive by your finger to the Orifice of the Tube from whence saith he 't is plain that the Quicksilver is there suspended by that tenuous but tenaceous rope in the Tube His fourth Argument is from the difficulty of Suction of Quicksilver up a Tube open at both ends of what length soever through which saith he water is easily drawn up to the mouth And why not Quicksilver Since here is nothing else required but the removal of the internal Cylinder of Ayr which is easily done saith he by Suction as is manifest by the ascension of water but cannot be performed in Quicksilver which should as easily be thrust up to 29. inches at least by the Superincumbent Atmosphaere as the water which is repugnant to Experience of the fire he concludes 'T is not the external Ayr that causes that effect neither by its Elasticity Gravitation nor both Now for the Positive Arguments to avouch his Principles by he has none at all onely what he fetches à posteriori from his commodious Solution of Difficulties and salving the Phaenomena better then others have done For read him through and you shall see he hangs so like a Tumbler by this rope that swing him which way you will you cannot get him off though I doubt not but we shall prove his cord to be a mere rope of sand and of his own twisting and Reason will Sampson-like break it
of mine having pil'd up many Cart-loads of these Brass-lumps in a Barn of his for some secret purposes of his own the Roof letting rain-rain-water fall copiously in amongst them they all began to smoak and at last to take fire and burnt like red hot Coals so that the Town was in an uproar about quenching of them and one thing further I took special notice of in this unlucky Experiment that the Water which drained from the quenching of them left little pieces and Crystals of Copperase sticking all along to the Piles of Grass that grew in the Croft it run down Thus Antimony and Sublimate being mixed together will grow so hot the one relaxing the fermenting spirit in the other that they are not to be touched Thus in the Corrosion of Mettals by Aqua fortis what a strong heat is there in the Liquor and what a steam constantly evaporates during their fermentation In the Commixtion of Oyl of Vitriol with Oyl of Tartar per deliquium what a violent heat and effervescence do presently arise besides a sharp and acrimonious vapour that strikes our nostrils Nay and we see our Subterraneous Damps do sometimes with intermixtion with the moist Air grow to that over-height of fermentation that they fire of themselves and strike down all before them Thus the Spirit of Niter mixed with Butter of Antimony grows so hot that it is ready to rise in a flame Thus certainly do all Baths receive their heat from Mineral Vapours or the Minerals themselves being in solutis Principiis and so the fermenting Spirit sets a playing in them as the Learned Doctor Jordan did most rationally conjecture This universal fermenting Spirit does not onely play these feats in the Mineral but also operates in the same manner in the Vegetable Kingdome which we ocularly behold in the Artifice of Malt where the Grains of Barly being moistned with water the parts are relaxed the internal Spirits in them are dilated and put into action and the superfluity of water being removed which might choak it and the Barly being layd up in heaps the fermentation and heat presently appears with a kind of vinous steam and effluviums which passe from it and therefore it shoots forth into Spires Thus we see in wet-Hay how the spirits work not onely to a heat but if they be not cooled and prevented by Ventilation they break out into a flame also Nay in all Vegetables there is this constant Heat though it be below our Sensation as it is in some Fishes and colder Animals also and a constant steam and transpiration of particles as we have experimentally proved in our XXV Observation And now let us pursue these Spirits into the Animal Kingdom and we shall see that they have the like effects and operations there also as is formerly observed onely being there in greater plenty and more purely refined and in a constant state of Fusion and Volatility they work nobler effects Now the Spirits that are lodged in all the meats and drinks we receive being more or less fixed therein What does the Soul but like an excellent Chymist in this internal Laboratory of Man by a fermentation of our nourishment in the stomach and guts a filtration thereof through the Lacteae a digestion in the Heart a Circulation and Rectification in the Veins and Arteries what does she I say by these several Physico-Chymical operations but strive all this while to unfix exalt and volatilize the Spirits conteined in our nutriment that so they may be transmitted to the Brain and its divarications and in that reconditory kept and reposited for her use and service So that these we now call Animal Spirits are the purest subtlest and most volatile particles and activest Atoms of the bloud which by continual pulsation of the Heart are carried with the bloud by the carotidal Arteries up into the Brain and there by that lax and boggy substance are imbibed and separated from the bloud and thence by the Spinal Marrow and Nerves transmitted to all the parts of the Body Now as the Chyle is perfected in the stomach and guts and their appendent Vessels the lacteal Veins and as the bloud is perfected in the Heart and it s annexed Vessels the Veins and Arteries so the Animal Spirits are separated preserved and perfected in the Brain with its continued trunk and branches viz. the Spinal Marrow Nerves and Fibers for the uses hereafter to be declared Now the two former Liquors the Chyle and the Bloud because of their grosser liquidity need to be conveyed in hollow Pipes and Channels viz. the Veins and Arteries but the Spirits which is the quintessence of them both can easily pass by a swift filtration through the Brain Spinal Marrow and Nerves Membranes and Fibers which are as it were the Cords Sayls and Tackling to move this Engine or Vessel we call the Body Nay though we can give you no sensible eviction of it Why may not all those long filaments of which the substance of the Brain Spinal Marrow and Nerves consists be tubulous and hollow so that the Animal-Spirits may be channelled through them as the bloud through the Veins and Arteries I am sure we see by Observation xxxi and L. what infinitely small filaments and vessels there are in Animals and yet all tubulous and perforated so that the suddain inflation of all those capillary threads or pipes may serve for Motion of the Body and the constant though flower filtration of the Spirits through their Coats and Cylindrical Membranes may serve for Sensation So that it seems this Cottage of Clay with all its Furniture within it was but made in subserviency to the Animal Spirits for the extraction separation and depuration of which the whole Body and all the Organs and Utensils therein are but instrumentally contrived and preparatorily designed Just as the Chymical Elaboratory with all its Furnaces Crucibles Stills Retorts Cucurbits Matrats Bolt-heads Pelicans c. were made for no other end by the ingenious Chymist than for the extraction and depuration of his Spirits and Quintessences which he draws from those Bodies he deals with in the obtainment of which he hath come to the ultimate design of his indeavours Now as in Minerals and Vegetables the colluctancy of these fermenting Spirits with the grosser matter does both create a constant heat and evaporation of Atoms So in Animals the like is more eminently conspicuous to wit the vital heat or calidum innatum and those fuliginous effluviums which pass constantly out of us by insensible transpiration which Sanctorius hath proved to exceed the bulk and weight of all our sensible Evacuations whatsoever Having thus demonstrated how the Soul obtains these Spirits after her several operations of Digestion Chylification Sanguification Circulation c. the like now let us see what use she makes of so pretious a substance First therefore we affirm that this thin and spirituous matter which is called the Animal Spirits is the immediate Instrument of the Soul in
partly arise from the variations of the Climates the Air being more thin and hot then ours partly from the difference and altitude of the Atmosphere here and there as shall hereafter be made more intelligible and partly from the diversity of our measures and theirs or from the club and combination of all these causes joyned together To which I may well super-add the negligence or inconsideration of those that try this Experiment for you may alter the height of the Mercurial Cylinder as you do rudely or cautiously tunnel in the Quicksilver into the Tube for I have some time with exact caution made it to rise to 30. inches in altitude from the Surface of the restagnant Quicksilver in the Vessel I set down 29. inches as its determinate height to which it will for the most mount though you use but a careless kind of carefulness in the management of the Experiment CHAP. II. That in the superiour part of the Tube there is no absolute Vacuity BEfore we proceed to any further Experiments we will first canvass the Cause of this Primitive one of Torricellius which has given occasion of trying all the rest and then we wilâ— deliver our Hypothesis which I hope will salve all the strange appearances not onely in this but in those stranger that follow Valerianus Magnus and some others are so fond to believe this deserted Cylinder to be an absolute Vacuity which is not only non-philosophical but very ridiculous 1. For the Space deserted hath both Longitude Latitude and Profundity therefore a Body for the very nature of a Body consists onely in extension which is the essential and unseparable property of all Bodies whatsoever 2. Again we have the sensible eviction of our own eyes to confute this Suppositional Vacuity for we see the whole Space to be Luminous as by Obser. Now Light must either be a Substance or else how should it subsist if a bare Quality in a Vacuity where there is nothing to support it 3. Again the Magnetical Efluxions of the Earth are diffused through that seeming Vacuity as per Experiment 4. There is some Air also interspersed in that seeming Vacuity which cannot be expelled upon any inclination of the Tube whatsoever as by Obser. is manifest 5. The most full Evidence against this pretended Vacuity is from the returgenscency of the empty Bladder suspended in this Vacuity for how should it be so full blown from nothing as is by Exp. most incomparably evinced CHAP. III. That it is not the Efluviums of Mercury that fill up that seeming Vacuity BEfore we come positively to declare what it is that supplies this seeming Vacuity let us draw some negative Conclusions and see if we can prove that it is not supplied with any Spirits Mercurial or Exhalations and this we shall most fully do by an ingenious Experiment borrowed from the Mechanical Wit of Doctor Pascal which shall passe for the second in the Bedroll of our Experiments Doctor Pascal's Experiment 2. THat the deserted part of the Tube is not filled up with any Hydrargyral emanations may be thus evinced because he hath found the same Experiment to succeed in water onely without any Quicksilver at all for he took a Tube or Lead-Pipe of 46. foot in length made close at the one end in casting of it and having filled it full of water and reversed it into a paile of water underneath about a foot deep he found the water to fall within 32. foot of that in the Vessel so that the deserted part of the Pipe was 13. foot so tall a Cylinder of that Liquor being it seems but aequi-ponderous to a Mercurial Cylinder of 28. inches Kircher and Birthius it seems also have tried the like in a Lead-Pipe of a 100. foot long and an inch diameter into which at the top was let in a short neck'd weather-glass or bolt-head and fastned so to that no Air could pierce the coement that luted the Glass and Lead-Pipe together which Lead-Pipe at the bottome was also fitted with a Turn-cock which when it was once filled with water would keep it in till they had reversed it into a Hogshead of water underneath and then by a turn of the Cock letting out the water it deserted the Bolt head and superiour part of the Tube wherein appeared this seeming Vacuity Experiment 3. BUt for a further Confirmation of this Truth let me subjoyn another Experiment which shall here pass for our third of the same Author 's Take a Glass-Syringe or Squirt of what length you please exactly fitted with a Squirt-staff stop the mouth of your Syringe close with your finger and so drown it over head and ears with hand and all in a large Vessel of water then draw back the Squirt staff and the Syringe will appear a Vacuity which will pain your finger by an Introsuction of it in at the Orifice but if then you erect the Syringe perpendicular and draw it all out of the water excepting that end closed by your finger and then open the Orifice you shall see the water suddainly arise and fill the deserted Cavity of the Syringe Both which Experiments do sufficiently prove that this seeming Vacuity may be exhibited without the help of any Quicksilver at all and therefore this imaginary Space in the Torricellian-Experiment aforesaid cannot rationally be supposed to be repleated with any Mercurial Effluviums CHAP. IV. Experiment 4. That it is not Light onely which supplies this seeming Vacuity TAke the Barrel of a long Gun about 4. foot long and Bunging up the Touch-Hole fill it easily with Mercury and reversing of it into the Vessel'd Quicksilver as before you may measure it to observe the determinate height aforesaid which you may easily perceive First By the flushing out of the Quicksilver upon removal of your finger into the Vessel where the restagnant Quicksilver receives it Secondly By the re-ascent of the Quicksilver upon tilting or plucking the Gun quite out of the restagnant Mercury as also by the forceable introsuction of your finger if you close the muzzle of the Barrel within the Vessel'd Mercury and so draw it out and reverse it as also by the plucks and shogs it will give in that action Thirdly and most perceptibly By the repletion of it with water if you draw the Tube gently out of the Quicksilver in the Vessel into a super-incumbent region of water which you first poured into the same Vessel for then if you stop the Orifice with your finger whilst it stands immers'd in the region of water and so draw it out and reverse it you shall perceive it full of water The like no doubt will succeed in Tubes of other Mettals Again if Light onely onely I say because we do not deny light to be there fill up that empty Cylinder it would be certainly far more Luminous as containing nothing but the pure Solary Atoms than the external medium and region of the Air about it which is confusedly intermixed both with
airy magnetical and coelestial particles besides the halituous effluviums of all Bodies whatsoever But this contrary to Observat CHAP. V. That the evacuated Cylinder in the Tube is not filled with Atmosphaerical Air only BY Atmosphaerical Air I understand such as we constantly breathe and live in and is a mixt Body of Luminous and Magnetical Effluviums powdred with the influential Atoms of Heaven from above and the halituous Effluxions and Aporrhoea's of this terraqueous Globe below And that no such Air fills the Superiour Cavity of the Tube take this Experiment to evince you Experiment 5. HAving filled closed and reversed the Tube AB as before into the vessel'd Quicksilver D fill up the said Vessel with water about 2. inches deep then lifting the Tube gently but perpendicularly out of the vessel'd Quicksilver into the region of water you shall see the Quicksilver and Water rise to the top of the Glass and after a short but confused intermixion the one with the other the Quicksilver will totally descend into the Vessel and the water arise and fill the whole Tube excepting a little cap of Air in the top of the Tube formerly hinted at in Obser. 14. Now if that Air in the Tube was Homogeneous to this in the Atmosphaere the water would never rise to thrust it out of its proper place or if it did it could not squeese through the Body of the Tube but we plainly see the rising water does fill up the place as likewise the Quicksilver does in the first Experiment where you tilt and incline it till it come to that particle of Air which indeed is of the same nature with ours and which we told you formerly lurked 'twixt the Concave Surface of the Tube and the Cylinder of Quicksilver and that neither the rising water nor ascending Quicksilver can or does exterminate This Truth also is manifestly evinced from the twelfth Observable annexed to the first Hydrargyral Experiment which palpably shows that it is not common Air which supplies that seeming Vacuity CHAP. VI. HAving drawn the former negative Conclusions and demonstrated That it is not Light onely not Mercurial Spirits not Atmosphaerical Ayr which is diffused through that seeming Vacuity it will be expected we should deliver something positively and demonstrate what it is Pecquet who I think follows Roberuallius therein ingeniously conceives that the whole mass of Ayr hath a Spontaneous Eleter or natural aptitude in it self to dilate and expand it self upon the removal of all circumambient obstacles which he calls the Elastical motion of that Element so that the particle of Ayr may be understood to be as many little Springs which if at liberty and not bound and squeesed up will powerfully strongly and spontaneously dilate and stretch out themselves not onely to fill up a large room but to remove great bodies So that he compares this vast Element of Air circumfused about this terraqueous Globe to a great heap of Wooll-fleeces or Sponges piled one upon another the superiour particles of the Ayr pressing the inferiour and hindring their continual tendency to a self-dilatation so that all the particles of this Atmosphaere especially the inferiour sort strive at all times to expand and dilate themselves and when the circumresistency of other contiguous Bodies to them is removed then they flye out into their desired expansion or at least will dilate so far as neighbouring Obstacles will permit Just like the Spring of a Watch which if the String be broke presently flyes out into its fullest expansion which Elastick motion in the Ayr then ceases when it comes to an aequilibration with those circumjacent Bodies that resisted it That this is not onely an Ingenious Hypothesis but that there is much of reality and truth in it I think our following Experiment will to safety of satisfaction demonstrate Onely we differ from Pecquet in the strict notion he hath of Rarefaction and Condensation which he supposeth to be performed without either intromission or exclusion of any other extraneous Body whatsoever Now how Ayr or any other Body should diminish or augment its Quantity which is the most close and essential Attribute to Bodies without change of its own Substance or at least without a reception or exclusion of some other extrinsecal Body either into or out of the Porosities thereof sounds not onely harsh to our ears but is besides an unintelligible difficulty Now though we cannot by Sensible and Mechanical Demonstration shew how any new Substance or Subtler matter than Ayr is which enters into the Tube to replenish that seeming vacuity and to fill up the aerial interstices which must needs be considerable in so great a self-dilation yet we must considering the nature of rarefaction aforesaid be forced to believe it and perhaps some happy Experimenter hereafter may come to give us a better then this Speculative and Metaphysical Evidence of it That the hollow Cylinder in the Tube is not onely fill'd up with the dilated particles of Ayr but also with a thin Aetherial Substance intermingled with them 1. Let us suppose therefore at random if you please that there is a thin subtle aetherial substance diffused throughout the Universe nay which indeed by farr the greatest thereof in which all these Luminous and Opace Bodies I mean the Starrs and Planets with their Luminous and Vaporous Sphaeres continually effluviating from them do swim at free and full Liberty 2. Let us consider that this aether is of that Subtil and Penetrative Nature that like the Magnetical Effluviums it shoots it self through all Bodies whatsoever whos 's small pores and interstices are supplyed and fill'd up with this aetherial Substance as a Sponge with water 3. Let us add to the former Considerations that the Ayr hath not onely a strong Elatery of its own by which it presses continually upon the Earth and all Bodies circuminclosed by it but it also ponderates and is heavy in its own Atmosphaere But because I am resolved you shall take nothing upon the trust and reputation of the best Authour take this Experiment to prove the Ayr 's gravitation in proprio Loco as the vulgar Philosophy cals it Experiment 6. TAke a Wind-gun which new Artifice is now common and weigh it exactly when empty then by plying the Pump-staff charge it soundly and weigh it again and you shall find it much heavier then before yea a large Bladder full blown will weigh more then its self emptied and manifest this inequality upon a ticklish pair of Scales Now though this Experiment seems onely to evince the gravitation of Ayr condens'd yet it consequentially follows that Ayr also in the Liberty of its own Sphaere is proportionally ponderous though it is a difficult point Mechanically to evince it unless we were actually above the Atmosphaere or in a Vacuity to weigh it there in a thinner medium then here we are able to do yet if I mistake not I have an Experiment in Banco which will give some Mechanical Evidence of this
longer and so faints as the bulk of the Superponderant continually decreases CHAP. VII The Reasons of all those extravagant Phaenomena which we observed in the first Experiment of Torricellius 1. BEcause the smaller weight of Quicksilver is not able to master the Elastick pressure of the external Ayr. 2. Because then the Cylinder of Quicksilver Superponderates and overpowers both the Ayr 's Elastick virtue and gravity 3. Because at that stint of 29. inches the internal Cylinder of Quicksilver comes to an aequilibration with the external Cylinder of Ayr which presses upon the vessel'd Quicksilver 4. and 5. Because that in wider and longer Tubes there is at first included a greater quantity of Quicksilver it does more strongly overpower the Elastick resistence of the Ayr and so will come though with more vehemence and swiftness to its wonted Altitude of 29. inches 6. Because by Addition or Diminution of the vessel'd Quicksilver there is a change in the Tube and Vessel but not in the Mercurial Cylinder in the Tube for that alwayes keeps at an equal Altitude from that in the Vessel 7. Because the Mercurial Cylinder is very heavy and Quicksilver in Quicksilver moves as easily as a Bucket of water in the whole Well 8. Because thereby there is onely a change in the Tube but not in the Altitude of the Mercurial Cylinder for in that Angle of Inclination the Perpendicular is still 29. inches 9. Because the Quicksilver by its long descent having acquired a greater motion than was requisite to bring it down to its determinate Altitude cannot suddenly stop there but by several vibrations up and down gradually comes back to its wonted Altitude as we see Pendents which multiply their undulations before they rest in their desired Perpendicularity 10. Because the Atoms of Fire and Heat which is alone penetrating through the Tube do expand and dilate the aetherial Ayr in that seeming Vacuity and so consequently depresse the Mercurial Cylinder or else contrariwise upon the approach of cold some aetherial Atoms pass out again through the Glass and so the Mercurial Cylinder mounts higher 11. Because it is a Medium somewhat thinner than Ayr alone is the reason of your finger's exuction may be the Elastick pressure of the external Ayr without striving either to come in it self or thrust any other Body into the Tube as also the Tendency of the aetherial Atoms within to be a free and proportional commixtion with Aerial particles without 12. Because when the Continuity of the external and internal Quicksilver is broke the Mercurial Cylinder is by the Elastick pressure of the Ayr which then prevails forced up into the top of the Tube which done then the Quicksilver by its gravity overpowring the Atmosphaerical or unexpanded Ayr falls down and gives place to the lighter Body 13. Because no Contiguity it seems in dry Bodies how close soever can exclude the interveniency of Ayr. Having in our last 9. Experiment proved sufficiently the ponderosity of Water and its gravitation upon the external Quicksilver in the Vessel we will now come to shew you likewise its gravitation upon the internal Quicksilver in the Tube Experiment 10. WE took such a like AB as in the 1. Eperiment near four foot in length and fill'd it full of Quicksilver except a Segment A of about 14. inches which we filled up with water then reversing the Tube and holding it so long in that posture till the Quicksilver and Water had exchanged their places we then drown'd it in the Vesselâ—d Quicksilver D and there withdrawing our finger as in the 1. Experiment the Quicksilver in the Tube descended an inch and more lower than the ordinary stint viz. within 2 ½ inches of that in the Vessel and this we try'd in Glass-Tubes of 40. and 45. inches in Longitude So that the Tube will be replenished with three Cylinders viz. of Quicksilver Water and Ayr. In which Experiment there are three or four remarkable Appearances which ought not to pass our Observation 1. That after inversion of the Tube into the vessel'd Quicksilver before you draw away your finger from the Orifice you may observe continual Bubbles of Ayr to pass through the Water by an Ebullition and so presently to create the little Cap of Ayr formerly observed in our 14. Observ. though in the interim the Orifice A be never so closely stopped 2. That after the removal of your finger and collapsion of the Mercury to as aforesaid the volatile bubbles of Ayr still pass through the Region of Water for a long time 3. That if the Cylinder of Quicksilver included in the Tube be not above 29. inches besides that of the Water no effect at all will follow 4. That if the Cylinder of Quicksilver included into the Tube be but one inch higher than its ordinary pitch then upon making the Experiment it will fall proportionally lower according to the weight of the Supergravitating Water This Experiment with those considerable circumstances annexed to it makes the Water's gravitation more eminently appear For since 14. inches of Water is almost aequiponderant to one inch of Quicksilver as is evident by the Statick Tables of Getaldi and the Quicksilver in the Tube being depressed by the Superincumbent Cylinder of Water of 14. inches it follows that it would necessarily depress it one inch lower than the ordinary stint But unless the Cylinder of Quicksilver be so great or at least that of Quicksilver and Water to be so powerful as that it be able to overcome the Elastick pressure of the Atmosphaere no effect at all will follow because there can be no descent of either and as for those Aerial Atoms which pass by bubbles through the Body of the Water they are those formerly observ'd for to lurk 'twixt the Contiguity of the Quicksilver and Tube nay and perchance and in the Body of the Quicksilver and Water too because they cease not after the collapsion and descent of the Mercury Thus having Mechanically evinced the gravitation of those two fluid Elements both Water and Ayr in their proper places and regions we may come to make good the second Part of our Hypothesis which is the Air 's Elastick virtue and property For the demonstrating of which take this following Experiment Experiment 11. FIll the Tube as in the former Experiment and let the Segment A of 14. inches which was formerly fill'd with Water be onely fill'd with Ayr then after you have revers'd it into the vessel'd Quicksilver D and withdrawing your finger you shall see the Quicksilver in the Vessel so to fall that it came down 16. inches lower then its wonted and determinate Altitude We fill'd the same Tube of 45. inches long within two inches of the top and then reversing it as before it descended two inches below the ordinary stint We also tunnell'd into the Tube a Cylinder of Quicksilver but of five inches in Altitude letting the Ayr supply the other Segment of 40. inches and reversing it as before it
fell down within two inches of the Quicksilver in the Vessel Observe that in these mixed Experiments of Ayr and Quicksilver or Water and Mercury or all three together that when you have revers'd the Tube you must hold it close stop'd so long perpendicular till the several Bodies have acquired their several respective and proper places To this Experiment likewise we must annex one considerable Phaenomenon First That before you withdraw your finger you shall perceive the internal Quicksilver in the Tube to press so sensibly upon your finger as if it would force an entrance out both before and after it was immerg'd in the Vessel'd Quicksilver which protrusion cannot possibly be supposed to proceed from any other cause but the Elatery of the included Ayr for the pressure was far greater than the natural gravity of the whole Tube of Quicksilver could make which upon the removal of your finger having got some Liberty to manifest it self it depells the Quicksilver so far below its determinate height Hence it appears that Ayr besides its gravity has a nobler rarefactive faculty by which it forces the Quicksilver to so considerable a descent whereas Water by its weight onely as is manifest in the precedent Experiment and no innate Elatery did depel the Succumbent Quicksilver in the Tube But because the Ayr 's Elatery is one of the chief parts of our Hypothesis we will not onely make it good by one but confirm it by many more succeeding Experiments Experiment 12. FIll any manner of Tube not above 29. inches in Length half with Quicksilver and half with Ayr and then closing your Orifice with your finger and reversing it into Vessel'd Quicksilver as in the former Experiments you shall upon removal of your finger see the Quicksilver fall an inch lower then before as being depell'd by the dilated Ayr if then you pour water upon the restagnant Quicksilver in the Vessel to about one inch deep and draw the Tube out of the Quicksilver into the region of Water above you shall see the Quicksilver hastily to arise some inches in the Tube and then the Water and it confusedly to intermingle one with the other Lastly the Quicksilver being wholly descended into the Vessel the Water will arise to fill the one half of the Tube This we tried in Glasses of 18 21 and 27 inches in Length In the first it fell 1. inch in the second it fell 3 ½ inches in the third 5 inches and more from the first point it stood at before you immers'd it in the Vessel'd Mercury This Experiment drew me on to the trial of another for I thought if Quicksilver would descend with a quantity of Ayr included with it in Tubes below the required pitch and Standard of 29. inches then probably some such like effect would follow in Water and Ayr included in any of the longer sort of Tubes though much lower then 32. foot which is found to be the Standard of Water in its Ascent in Pumps and other Instruments as is besides delivered in Exper. Experiment 13. WE therefore fill'd our Glass-Tubes of 45 inches half with Water and the rest with Ayr and afterwards invers'd it into a pail of water one or two inches deep the success was that withdrawing your finger as before the internal Water in the Tube did shoot about two inches lower then before and with such like vibrations though far shorter than those in Quicksilver Lastly if you immers'd the Tube one foot deep in the pail of water the water in the Tube would rise somewhat higher than before Note that in these two last Experiments the descent or fall of the Quicksilver or Water was most notable about the midst of the Tube viz. when it was equally fill'd with Ayr and Quicksilver or Ayr and Water Which Experiments do not onely make good what is formerly delivered of the Ayr 's Elastick pressure but also it renders Doctor Pascal's Experiment of the descent of Water to 3◠foot very creditable to those that want Instruments to try it Experiment 14. WE also tried that Experiment of Roberuallius quoted by Pecquet pag. 50. I took one of those little Bladders that are in Fishes that in the little Fish call'd with us a Graining is best and after it had been a few dayes dried I let out all the Ayr of it and tyed the mouth of it again so close that no new Ayr could re-enter then I gently wet it on the out side and dropped it down to the bottom of the Tube that it might the better stick there and not be buoyed up with the Quicksilver poured in upon it then cautiously tunnelling in the Quicksilver and reversing the Tube as in the first Experiment we found that after the Quicksilver was come down to its wonted pitch the Fish-Bladder was full blown and did swim on the top of the Quicksilver which upon the admission of the external Ayr grew instantly flavid and empty again Now what else is the reason of the Bladder's intumescences upon Collapsion of the Quicksilver to its wonted Standard but the Spontaneous Dilatation and Elastick Rarefaction of that little remnant of Ayr skulking in the rugosities thereof and then upon removal of the circumpressing Quicksilver expanding it self in the Bladder as well as that does in the Tube The reason of its flaccescency upon admission of external Ayr is because then the Elater of the external Ayr is so strong that it forces the embladder'd Ayr into its former extension and consistency again But hold Before I pass from this Experiment I must take Pecquet in hand who upon confidence of this Experiment insults highly over those that admit not of his Rarefaction but will introduce a new aetherial substance to intermingle with the dilated Ayr to fill up this seeming Vacuity Object 1. If any aetherial Substance penetrate the Glass-Tube it rushes in equally on all sides towards the Bladder pendent in the Centre and so in all probability would rather press and squeese the vesicle on all sides closer together than by an opposite motion and re-action upon it self extend and dilate it Object 2. Again Since it enters in so freely at the pores of the Bladder what should improfen it there Since the pores which gave it admittance are continually open and manifest themselves so to be when any external Ayr is admitted into the Tube for then it seems the aether flyes out indeed and the Ayr is recondensed again into its natural and ordinary Consistence Object 3. Again If the Quicksilver descending do impel the aether through the pores of the Glass to help the dilated Ayr in suppliance of that seeming Vacuity Why should not Quicksilver totally descend and fill the whole Tube with aether and so consequently Quicksilver should descend in any Tube though lower than the ordinary stint of 29. inches whatsoever contrary to Experiment Object 4. But if there be a Superaerial region of Aether as much lighter and subtiller than Ayr as Ayr is then Water How
a known weight as counterpoised the Quicksilver and then measuring the water in the Mercurial Vial aforesaid we found it to contain near 14. times as much Water as it did of Mercury Experiment 3. WE fill'd a Tube with Quicksilver as in the Torricellian-Experiment wherein much leisure and accurateness were used in filling the Tube to make a polite equal Mercurial Cylinder and after immersion thereof into the Vessel'd Quicksilver we put both the Tube and Vessel into a frame made for that purpose and let it stand perpendicular therein for certain dayes together viz. from the 15. March to the 20. April after to observe if it would vary and alter its Standard which we found it do considerably for sometimes it was half an inch higher or lower then the Mark and Standard we left it first at I think according to the variation of the Atmosphaere in its temperature and if you observe strictly you shall see that the Quicksilver in the Tube does never precisely observe the same Standard not a day together nay sometimes not an hour Experiment 4. AGain we tried the Torricellian-Experiment aforesaid in a Glas-sSyphon of 46 ½ inches in length and after immersion of both ends into two several vessels of Quicksilver the internal Quicksilver fell down to its wonted Standard of 29. inches in both shanks of the Syphon having applied warm clothes to the top of the Syphon the Quicksilver descended in either leg the breadth of two Barley corns lower than the ordinary stint We gently lifted one of the legs out of the vessel'd Quicksilver and then the Quicksilver in that leg rose violently up so that part of it passed over into the other shank then having speedily again drown'd the aforesaid leg into the Vessel we observ'd the Quicksilver in both legs to have fallen much upon the admission of that Ayr and to stand in both legs at an equal pitch and height as it did again the Second time upon admission of a little more Ayr though the Quicksilver then did not rise high enough to pass over into the other shank as before Experiment 5. WE took the same Syphon again as before and then only fill'd one of the legs with Quicksilver leaving the other full of Ayr then stopping both Orifices reversed both shanks into two several Vessels of Quicksilver as before then opening both Orifices the effect was That the Quicksilver fell in one Tube and new Quicksilver rose out of the other Vessel into the other Tube to an equal Altitude Experiment 6. WE fill'd a Tube though with much difficulty such an one as is here described with Quicksilver then invers'd it into Quicksilver as before The first effect was It fell leisurably down out of the head H and stood at D 29. inches in perpendicular from the Quicksilver in the Vessel E. The second effect was Ayr being let in 'twixt C and B the Quicksilver rose from D its former Standard to A So that from A to B and C to E for so far as C it fell upon admission of Ayr made up its wonted Standard again Experiment 7. WE took a Glass-Cruet with a small Spout and fill'd it with Water and afterwards luted the great mouth A so that no Ayr could get in then turn'd the small Spout downwards but no Water came out of the Cruet into the open Ayr inversing likewise the small Snout into Oyl no Water descended nor Oyl though a lighter Liquor ascended then filling the former Cruet with Milk though upon inversion of the Cruet none of it would fall out into the Ayr yet being inversed into Water these two Liquors changed places the Milk descending in a little still stream the Water ascending in the same manner in two constant little streams running Counter one to another in the neck of the Cruet we tinged the Water with Indico the better to distinguish their streams Experiment 8. WE fill'd the former Cruet with Quicksilver and immers'd the Snout into the Water having first well luted the mouth of the Vial but no exchange of place followed unless by much shaking of the Quicksilver you forced it little by little out and so either Water or Ayr passed up instead thereof CHAP. IX Experiment 9. APril 27. 1661. we tryed the Torricellian-Experiment in the Porch at the new Church in Pendle which standeth upon a considerable height the weather being clear fair and moderate about ten of the clock in the morning the Tube about 42. inches in length which we fill'd with very much care and diligence to make a polite Mercurial Cylinder and there we then found the Mercurial Standard to be 28 4 inches We tried the same Experiment with the like accurateness and in the same Tube at the Beakon upon the very top of Pendle-Hill on the same day betwixt twelve and one a clock the Ayr being there much colder then at bottom or at new Church aforesaid though the Sky was as clear and there the Mercurial Cylinder was lower then before at New-Church by a just inch being fallen precisely to 27 4 inches About three a clock of the same day the said trial was made with all the former circumstances at Barlow the lowest place for conveniency near the said Hill much lower then the place of the first trial the Ayr being very much hotter then at the time of the first trial and there the Cylinder of Quicksilver was equal to that in the first trial viz 28 4 inches By which it appears That if the Ayr at Barlow had remain'd of an equal temperature with that of New-Church the Quicksilver in all probability would have fallen lower then the inch we observed Experiment 10. AT the top of the said Hill we put into the same Tube which was divided into 102. equal divisions of spaces as much Quicksilver as being stop'd and inversed the Ayr remaining in the top of the Tube fill'd 50 15 or thereabout of the forementioned divisions and the Quicksilver the remaining part of the Tube The Tube being thus immers'd and the finger withdrawn the internal Ayr dilated so as to fill of the above-mentioned parts 84 75. and there remain'd in the Tube a Cylinder of Quicksilver containing in length 11 26 inches We tried the same Experiment at the bottom of the said Hill the Tubes being fill'd as above and the Ayr 50 15. dilated to 83 8. and the Cylinder was in height 11 78. inches Experiment II. WE took another Tube containing in length from the Superficies of the external Quicksilver into which we immers'd it for so we measure all our Lengths about 26. inches containing equal divisions of space 31. and about an half represented here by AB which we fill'd so with Quicksilver that being revers'd and stop'd at B there remain'd 9. divisions fill'd with Ayr from A to E then the Quicksilver being left at liberty to fall down into a dish underneath it fell near to the mark 18 to l. So that the Ayr dilated fill'd the Space A l containing of
these divisions 17 8 and then the Cylinder l B was in perpendicular height 13 86. inches We brought this Tube with the same Mountain-Ayr in it by the help of a long Tube of wood having a dish fastned to the open end of it and both full of Quicksilver into which we put our Tube AB which Instrument you have here represented and at the bottom of the Hill the Quicksilver rose up unto the mark m under the 17. division So that the Ayr dilated fill'd of the equal parts 17 35 and the Quicksilver in B was in height 14 31. inches Then we put out this Mountain-Ayr and let into the Tube the same quantity of Valley-Ayr which fill'd the part A E containing also 9. of the equal divisions aforesaid and then the end of the Tube B opened the Ayr dilated to the mark n. So that it contain'd 17 58. parts and the Quicksilver in perpendicular height 14 2. That you may at one glance behold all the varieties of these Dilatations of Ayr and height of the Mercurial Standard I have supposed the line AB to represent all the Tubes AE still represents the Ayr left in them AD the Ayr dilated BD the Quicksilver In the long Tube At the top of the Hill At the bottom of it at Barlow AE 50 15 50 15 Equal parts of Spaces Inches AD 84 75 83 8 BD 11 26 11 78 In the lesser Tube At the top of the Hill At Barlow with Ayr. At Barlow with Valley-Ayr AE 9 9 9 AD 17 8 17 35 17 58 BD 13 86 14 31 14 02 Now before we pass to any further Experiment we think it fit to make and denominate several considerable Spaces of the Tube in the Mercurial Experiments which will avoid both confusion and multiplicity of terms for the future Let AB be the Tube in which Quicksilver in case it were totally void of Ayr would stand in a perpendicular Cylinder above the Quicksilver in the Vessel from B to C. So we shall call that line or space BC The Mercurial Standard But if in the Tube there be left as much external Ayr as would fill the Tube from A to E and that then the Quicksilver would fall from C to D and the Ayr be dilated to fill the space AD then we shall call BD The Mercury CD The Mercurial Complement AE The Ayr. ED The Ayr 's Dilatation AD The Ayr Dilated Where note That the measure of the Mercurial Standard and Mercurial Complement are measured onely by their perpendicular heights over the Surface of the restagnant Quicksilver in the Vessel But Ayr the Ayr 's Dilatation and Ayr Dilated by the Spaces they fill So that here is now four Proportionals and by any three given you may strike out the fourth by Conversion Transposition and Division of them So that by these Analogies you may prognosticate the effects which follow in all Mercurial Experiments and predemonstrate them by calculation before the senses give an Experimental thereof Experiment 12. WE tried the Pascalian-Experiment in a Tin-Tube of 33. foot long made of several sheets of Tin and closely soddered up with Peuter To the upper end whereof we fastned a long Glass-Tube open at both ends then having soddered up the lower end we reared the Tube to a Turret at Townley-Hall and fill'd it with water then closing the top of the Glass-Pipe and immersing the other end of the Tin-Tube into a cistern of water a foot deep we opened the lower end and perceived the water to fall out of the Glass-Tube into the Tin but how far we could not tell onely we conjectured to be about the proportion given by Doctor Pascal viz that a Cylinder of water stood in a Tube about 32 foot high but presently our Glass-tube at the juncture to the Tin began to leak and let in Ayr so we could make no further process in the Experiment onely one thing we observed in filling of the Tube that after the water which we tunnelled in had gone down a pretty way into the Tube part of it by the rebounding Ayr was violently forced up again and shot out at the upper end of our Glass-tube two or three foot high into the open Ayr Which Experiment may be a caution to Pump-makers all Artificers that deal in Water-works that they attempt not to draw water higher then 33 foot its Standard-Altitude left they lose both their credit cost and pains in so unsuccessful a design For I remember in my Lady Bowles her new Water-work at Heath-Hall near Wakefield where the Water is raised at least 16. yards high the simple workman undertook first to do it by a single Pump but seeing his endevours were frustrated he was forced to cut his Cylinder in two Pumps and to raise it first eight yards into a Leadcistern and then by another Pump to raise it out of that other eight yards into a cistern above CHAP. X. NOw to salve all these Mercurial Phaenomena as also those mixed Experiments of Quicksilver and Water Quicksilver and Ayr Ayr and Water in single and double Tubes and Syphons of all Bores divers learned and ingenious Heads have excogitated several neat though different Hypotheses For to omit the whimsies of two Grandees that is Valerianus and Hobbs which so grosly Philosophize the former affirming the deserted space in the Tube to be an absolute Vacuity the latter to be replenished with this very Common Ayr which we breathe in which creeping up 'twixt the Contiguity of the Glass and Quicksilver fills up that conceited Vacuity To omit these exorbitant Conceits I find two or three more intelligible and rational Hypotheses The first is of Roberual and Pecquet of the Ayr 's Elasticity and Gravitation which we have formerly embrac'd onely with this addition That whereas they will have Rarefaction and Condensation to be performed without any increase or loss of quantity which can never be conceived we admit of an aetherial Substance or Matter intromitted and excluded the Bodies so chang'd as we formerly explicated The second Hypothesis is of the Vacuist's such I mean as though they hold this Spring of Ayr yet in its dilation will admit of no aether or forrain Substance to enter the pores thereof but the particles so dilated to remain so with interspersed Vacuities and this opinion hath many eminent Advocates and Avouchers Gassend Doctor Ward Doctor Charleton c. The latest Novellist that hath undertaken this Experimental Philosophy is one Linus aliâs Hall who hath excogitated a new Principle of his own whereby he not onely salves all the Phaenomena in the Torricellian-Experiments formerly delivered but also all those stranger Experiments discovered since by Gerricus and Boyl's Pneumatical Engines His Principles he thus layes down 1. That there is an inseparability of Bodies so that there can be no Vacuities in rerum natura 2. That the deserted Space of the Tube in the Torricellian-Experiment is fill'd with a small film of Quicksilver which being taken off the
easily in pieces CHAP. XI A Confutation of this Funicular Hypothesis of Linus by Henry Power M ae D r. Object 1. IF you fill a Tube of 45. inches in length as we have shewed you in Experiment 11. except 15. inches which let the Ayr supply and invert it you shall perceive a greater protrusion of your finger by the erupturient Quicksilver than can possibly be imputed to the Supergravitation of the Quicksilver included in the Tube for if the whole Tube be fill'd with Quicksilver and inverted it shall not make such a forcible pressure upon your finger as that Cylinder of Quicksilver and Ayr does which can be imputed to no other cause then the Elasticity of the included Ayr which striving to dilate it self detrudes the Quicksilver and when liberty is given it forces it down much lower than its ordinary Standard of 28. inches which shewes that there is no such thing as Attraction in the Ayr but rather a contrary power of Self-extending and Dilatation Now I confess this is but an Argument quoad sensum and therefore not so much to be insisted upon because not Mechanically demonstrable Object 2. Again this is observable in all Bodies that are capable of Extension That still as their Extension is augmented or increased so must the force or power be that extends them As for example in Ropes or Leather the first inch of their forced extension is performed by a lesser power then the second inch would be and that then the third c. Now in the third of Boyle's Experiments pag. 44. it is observed That the Sucker is as easily drawn down when it is nearer to the bottom of the Pump as when it is much farther off which is contrary to the nature of forced Extension as is before delivered Object 3. Again If according to Linus the Bladder's intumescency in Boyle's Engine did proceed from the forced extension of the Ayr in the Receiver then the first evacuation of the Pump would extend the Bladder more then the second and that than the third c. But the contrary is avouched by his fourth Experiment pag. 47. which proves against the Funicular Doctrine of Linus but neatly makes out the Elasticity of the embladder'd Ayr which gradually increases as the debilitated Ayr in the Receiver gives room for its expansion Object 4. Again Linus is refuted by the 19. Experiment in Boyle which is an Experiment of a four-foot Tube fill'd with water and inclosed in the Receiver by which he found that the water included in the Tube did not at all subside after several exsuctions till the Elasticity of the included Ayr was no longer able to support that Cylinder of water but according to Linus it should have subsided at the first exsuction as well as the Quicksilver did when the Torricellian-Experiment was included in the said Receiver Object 5. According to Linus his Principles the Mercurial Standard should be the same at the top of any eminent Hill that it is at the bottom especially if the Temperature of the Ayr be in both places alike but this is contrary to the Experiments we tried at Hallifax and Pendle-Hill as you may see in Experiment 7. pag. 19. also Experiment II. pag. 45. where the coldness of the Ayr was a disadvantage to our Experiments and yet for all that you see how considerably the Mercurial Standard did vary Which Objection Linus has ingeniously confess'd to me himself when once I had the happiness to see him that he cannot as yet answer Object 6. Take a Glass-Tube above the Standard but of a small Bore that will not admit above a great Pea or Cherry-stone let it be closed at one end and fill this with Quicksilver which you shall find no easie thing to do for I am sure we were a whole hour in filling one and still were forced to thrust the Quicksilver down into it with a small wire then reverse it very gently into a vessel of restagnant Quicksilver and after it has come down to its wonted Standard you may lift the Tube out of the vessel and carry it up and down with the Quicksilver pendent in it which will neither fall out nor rise up to the top to fill up the reputed Vacuity Now what sayes Linus to this Why does not his rope shrivel it self up and pull up this Mercurial Cylinder in this Tube as well as in all others of a larger Bore Object 7. Take a Glass-Syphon A B and having fill'd both legs with Quicksilver open the longer into the vessel'd Quicksilver B the effect is That the Quicksilver in the longer shank will fall down to C its wonted Standard but that in the short shank AD being still close stopped with your finger will remain full Now according to Linus the funicle AC exercises the same power of pulling the Mercurial Surface A as C and according to the Principles of Mechanick's If CB be heavier than AD it should pull over AD into the vessel B. And his Answer which you may read pag. 74. is nothing to the purpose for open the short end of the Syphon into the vessel D according to his Salvo no Quicksilver should still rise because it is still as closely adherent to the vessel'd Quicksilver as it was before to my finger and yet upon Experiment made the Quicksilver will rise all out of the vessel D and go over A into the vessel B. Which Experiment as it confuteth his so it clearly avouches our Principles of the Elastical pressure of the external Ayr upon the surface of the Quicksilver in the vessel D which forces it up to A and so over into the vessel B. Object 8. We took an ordinary Weather-Glass this 15. Octob. 1661. AB of about two foot in Length and carrying it to the bottom of Hallifax-Hill the water stood in the shank at C viz. 13. inches above the surface of the water in the vessel B thence carrying it thus fitted immediately to the top of the said Hill the water fell down to the point D viz. 1¼ inch lower than it was at the bottom of the said Hill which incomparably proves the natural Elasticity of the Ayr. For the internal Ayr AC which was of the same power and extension with the external at the bottom of the Hill being carried to the top did there manifest a greater Elasticity then the Mountain-Ayr there did manifest Pressure and so extended it self further by CD which it was not able to do at the bottom because the Valley-Ayr there was of equal force and resistance to it Which Experiment very neatly proves the Elasticity of the Ayr which Linus would abolish as the Torricellian-Experiment which being carried to the top of the same Hill differ'd ½ an inch did eminently prove the gravitation of the Ayr. Also about the end of January 1661. we went again to the top of Hallifax-Hill with divers Weather-Glasses of several Bores Heads and Shapes and found in them all a proportional descent of the
Water as in the former Experiment at the top of the said Hill respectively to what it was at the bottom with this Observable That in the greatest-Headed Weather-Glass which included most Ayr in it the descent of the Water was greater as being most depress'd by the greatest quantity of the included Ayr. CHAP. XII Experiments in Capillary Tubes and Syphons Experiment 1. TAke a small Capillary Glass-pipe or Tube open at both ends and dipping the one extreme perpendicular into the water you shall see the water spontaneously arise to a competent height in the Tube with a quick and smart ascent Note first That the inside of the Pipe ought to be very clean as well from dust and little bubbles as films of water which will remain in the Pipe when the water is blown or suck'd out of it Secondly It must be perfectly dry from any other Liquors which will not mingle with water as Oyl c. Thirdly If you moisten the Pipe first with water before you try the Experiment the ascent of the water will be more quick and lively Fourthly That not onely Water but Milk Wine Oil and other Liquors except Quicksilver will likewise rise to a certain height in the said Pipes Fifthly After the Water has risen to its Standard-height if you take it out of the Liquor it shall not fall out at all if you invert the Pipe the included Cylinder of water will fall down also to the other extreme also the deeper you immerge it in the vessel of water the higher still will it rise in the Pipe still keeping its Standard-Altitude above the surface of the water in the vessel also if you suck it above the Standard it will still fall back to its wonted Altitude Sixthly That not onely Water but Milk Wine Oyl and all other Liquors will spontaneously arise in the said Pipes but with this difference That the heavier the Liquors are the lower their Standard is and the slower is their Ascent to it thus you shall see Oyl of Tartar will not rise by one third so high as water nor Oyl of Vitriol by â…“ so high as it which may alter more or less according to the goodness of the said Oyls Seventhly Now if you take out a Pipe wherein in either of the said Oyls has first risen up to its wonted Standard and immerge the end thereof into a lighter Liquor as water you shall see the Oyl fall gradually out into the water and the Pipe gradually fill with water and arise to its own Standard which is higher a great deal than the Standard of either of the said Oyls as is before delivered the like will follow in Syphons Eighthly The smaller Bore that your Tube is of the higher will your Water arise yet we could never get it to arise to the height of 5. inches as Mr. Boyle mentions though we have attempted it in Tubes almost as small as Hairs or as Art could make them Ninthly If the Tubes be of the Bore of an ordinary Quill or bigger no Water at all will arise Tenthly That little or no difference of the water's ascent in the former Tubes is perceptible at the bottom or top of our Hill Experiment 2. BEnd one of these Tubes into a little Syphon which you may do by putting it into the flame of a Candle and then putting the one extreme thereof into a vessel of water you shall see it presently fall a running on its own accord Observe 1. That the perpendicular height of the flexure of the Syphon to the water's Superficies be shorter or at least exceed not that Standard-height unto which the water would rise were it a streight Pipe onely 2. That the pendent Shank hang not onely lower then the water's Superficies but by such a determinate Length for we have found that if the pendent or extravasated Leg be shorter or equal or but a little lower then the Superficies of the water in the vessel no effect at all would follow but the pendent Leg would hang full of water without any flux at all Now what this determinate length is we conceive the pendent Shank must be longer from the flexure then the Standard of the Liquor would reach and then it will run as other Syphons do which have a larger Bore so that you see the Mechanical reason which is so universally received by all men why the pendent Leg in Syphons must be longer than the other to make the Liquor run out viz. because the greater weight of water in the pendent Leg overpoises and sways down that in the shorter as in a pair of Skales is not universally true in all Syphons whatsoever 3. If to the nose of the pendent Leg you apply a wet piece of Glass the water then will begin to come out of the Pipe and run down to the lowermost edge of the Glass where gathering it self into round bubbles it would fall to the ground but then you must observe that the nose of the pendent Shank be lower than the Surface of the water in the vessel Experiment 3. LEt both Shanks of the Syphon be fill'd with water so that the pendent Leg be longer than the Superficies of the water and yet not so long neither as to set it on running then to the nose of the pendent Leg apply a vessel of Milk and you shall see that though the water would not break out of the Pipe into the open Ayr a medium far lighter and more divisible than Milk yet it did run out into the Milk and one might see it purl up again without mingling with the Milk at a little darkish hole like a Spring Observe Experiment 4. IF you lift the vessel of Milk with the pendent Leg drown'd in it higher towards the flexure of the Syphon so that the Superficies of the Milk be nearer the flexure of the Syphon than the Superficies of the Water you shall after a considerable time see the Milk rise up the pendent Leg and to drive back the Water and having fill'd the whole Syphon to fall a running into the Water-vessel with this difference to the former Experiment That whereas the Water in the former came to the top of the Milk the Milk here sunk down to the bottom of the Water in a small stream like a curl'd white thread and there setled in a Region by it self Experiment 5. NOw contrariwise if you lift the vessel of Water nearer the flexure of the Syphon than the Superficies of the Milk is then will the Water rise over the Syphon and beat out the Milk and fall a running as in the third Experiment And thus you may at pleasure change your Scene and make the Syphon fall a running either with Milk or Water which is a pleasant spectacle to behold especially if the Water be ting'd red with Scutchenel My Worthy and ever Honoured Friend Mr. Charles Townley upon confidence of these Experiments thought he had discovered that great and long sought-for Rarity amongst the Mechanicks
demonstrated of late that all the whole Earth is nothing but a great and Globular Loadstone and that all the Circles of the Armillary Sphaere are really truly and naturally inhaerent in the Earth by virtue of the transcurrent Atoms How can we conclude otherwise but with Gilbert Quis in posterum eum de facto moveri dubitabit quum ei omnia ad motum planè requisita dedit natura i. e. figuram rotundam pendulam in medio Fluido positionem omnes terminos motui Circulari inservientes polos nempè aequatorem meridianos polares circulos parallelos Lastly As for his Universal Meridian it is likewise deduced from his Anti Copernican Experiment of the Loadstone swimming in a Boat with its Poles vertically erected For saith he Since the Stone being Horizontally-placed does not shew the true Meridian but with an Angle of Variation in most if not in all places of the Earth if you set it with its Axis perpendicular as before it will after some undulations to and fro rest quietly with certain parts facing the Meridian which points must be exactly marked and through them a Circle drawn round about the Stone by help of which you may strike a true Meridian-Line when and where you please Now though we grant this Experiment to be true and probably to hold good in all Longitudes and Latitudes yet he that shall perpend how many ticklish Curiosities and nice Circumstances there are to perform this Experiment exactly will find the Invention only pleasing in the Theory but not in the Practice For 1. It is very difficult to place the Terrella in an exact perpendicular 2. When 't is so 't is as difficult to keep it invariable under the same Zenith 3. Most difficult to draw an exact Meridian-Line from it Not to mention how hard a thing it is first to find the two Polary points in a Globe-Loadstone also to keep the Boat in a Fluctuation parallel to the Horizon The end of Magnetical Experiments Subterraneous Experiments OR OBSERVATIONS About COLE-MINES BY HENRY POWER M ae D r. A The Cole-pit B The Vent-pit CC The Sow that drains all the heads from water DDD c. The Vent-head not above two yards broad EEEE The Lateral Heads which are not above two yards broad FFF The prick'd lines the Thurl-vent that is a Vent driven through the lateral heads GGGG Is Walls or Pillars of the whole Cole-Bed remaining which with us is not above two foot thick to hinder the roof of the pit for falling The Roof and Seat is the Top and Bottom of the Works wherein they get Coles which is about two foot or more distant the one from the other Experiment 1. AT the top of the Cole-pit we took the Weather-Glass AB whose shank EB was about 2 ½ foot long of a small bore and the Head AE 2 ◠◠inches in Diameter and heating the Head thereof and immerging it presently in the Glass ful of water B the water after a competent time rose up to the point C where we let it stand for a while till we saw that the External and Internal Ayr were come to the same Temper and Elasticity Then carrying the Weather-Glass so prepared in a Scoop down to the bottom of the Cole-pit which was not above 35. yards deep there the Water in the Weather-Glass did rise up to the point D viz. very near 3. Inches higher than its former Standard C. Experiment 2. THe sixth day of November 1662. we repeated the same Experiment as before in a pit of 68. yards deep and there we found that at the bottom of the said pit the water in the Weather-Glasse did rise very near four inches higher than the point C viz. one inch higher than the point D to F. Now we observ'd that in carrying down of the said Glass in a Scoop from the top to the middle of the Pit there the water did not rise so much as it did from the middle to the bottom by half an inch so that it seems the rise of the water was not proportional to the Glasse's descent in the Pit Experiment 3. WE took a very good arm'd Loadstone of an Oval figure whose poles lay in the long Diameter and at the top of the Coal-pit we loaded the North-pole of it with the greatest weight it was able to carry even to a Scruple then taking the Stone down to the bottom of the pit and hanging on the same weight again we could perceive no difference in the power of the Stone at the one place from the other for it would neither lift more nor less there than above though to try this Experiment precisely and to minute weights is very ticklish for the same Stone in any place will sometimes lift a little more and sometimes a little less Experiment 4. WE took a thread of 68. yards long which is as long as the deepest pit is with us and fastening a Brass lump of an exact pound weight to it we counterpoiz'd both it and the thread with a weight in the other Scale then fastning the other end of the thread to one of the Scales we let down the pendent weight near to the bottom and there we found it to weigh lighter by an ounce at least than it did at the top of the said pit We had tryed this with a Bladder full of water and other substances also but that our thread by often untwining broke it self Experiment 5. THe Collyers tell us That if a Pistol be shot off in a head remote from the eye of a pit it will give but a little report or rather a sudden thump like a Gun shot off at a great distance but if it be discharg'd at the eye of the pit in the bottom it will make a greater noise than if shot off above-ground But these Experiments are of a dangerous trial in our pits and the Collyers dare not attempt them by reason of the craziness of the roof of their works which often falls in of its own accord without any Concussion at all Every Cole-pit hath its Vent-pit digg'd down at a competent distance from it as 50. or 80. paces one from another They dig a Vault under-ground from one pit to another which they call the Vent-pit that the Ayr may have a free passage from the one pit to the other so that both pits with that Subterraneous intercourse or vault do exactly represent a Syphon invers'd Now the Ayr always has a Motion and runs in a stream from one pit to the other for if the Ayr should have no Motion or Vent as they call it but Restagnate then they could not work in the pits It is not requisite that the Vent-pit should be as deep as the Cole-pit Now the Vent or Current of Subterraneous Ayr is sometimes one way and sometimes another sometimes from the Vent-pit to the Cole-pit and sometimes contrariwise as the Winds above ground do alter and also weaker and stronger at sometimes than at