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TAke a Glass-Tube of above 29 inches in length, as AB, closed at the end B, and open at A: fill it full of Quicksilver, and so close the end A, exactly with the thumb (as with a stoppel;) then reverse it, and putting it and your finger together into the wooden vessel D, fill'd about two inches deep with Quicksilver, erect it per∣pendicularly therein; then drawing away your finger from the orifice, your shall see a great part of the
Quicksilver in the Tube to make a quick and smart de∣scent into the external Quicksilver in the vessel; and after it hath, by several vibrations up and down, found out a certain point or degree, there to stand still and im∣moveable: so that all the upper part of the Tube (which the Mercury has deserted) viz. from E to B, will seem to be a vacuity.
The first Inventor of this noble Experiment, was Torricellius the eminent Mathematician, and deserved Successour to the famous Gallilaeo, to whom all the Common-wealth of Learning are exceedingly oblieg'd, because thereby he has excited the greatest modern Wits to higher and nobler Experiments.
In this Torricellian Experiment (for so we shall al∣wayes hereafter call it) let me give you notice of these rare Observables:
1. If the Tube be not longer then 29. inches, the Quicksilver will not at all descend: this we have tryed in several Tubes of 18, 21, and 26 ½ inches long.
2. In Tubes of a greater length then 29. inches, the Quicksilver will descend.
3. The Quicksilver will not descend lower then 29. inches, or thereabouts; that is, the Cylinder of Mercury in the Tube will alwayes be 29. inches in height above the superficies of the restagnant Mercury in the vessel.
4. The Quicksilver descends neither more nor less in Tubes of a greater or lesser Bore, provided they ex∣ceed the length of 29. inches.
5. How long soever the Tube be, the Quicksilver will fall down to its wonted pitch and stint of 29. inches or thereabouts; as we have tryed in Tubes of 32, 35 ½, 37, 45, and 50 inches in Longitude, and all of dif∣ferent Diameters and Bores.
6. If you add any more Quicksilver to that in the ves∣sel, then, that in the Tube rises proportionally the higher: and contrariwise, if you take any Quicksilver out of the vessel, that in the Tube descends lower; and so consequently, the internal Quicksilver in the Tube keeps alwayes the same height of that in the vessel.
7. That you may with great facility move the Tube to and fro in the vessel'd Quicksilver, but not draw it up towards the superficies of the external Quicksilver in the vessel without some reluctancy.
8. That if you tilt or incline the Glass-Tube, you shall see the Quicksilver gradually to ascend till it al∣most totally fill the Tube, at which Angle of Inclination the atletus or perpendicular will be equal to 29. inches, let the Tube be of what length soever.
9. That upon removal of your finger from the ori∣fice, you shall see the Quicksilver to make a very Quick and Smart descent six inches at least below the stan∣dard of its Altitude in the Glass of 45. inches long, and in others more or less; and after a few vibrations up and down, to settle at its wonted pitch and altitude of 29. inches, or thereabouts.
10. That if any thing, considerably hot or cold, be ap∣plyed to the Superiour part of the Tube, the Quicksilver therein will more or less ascend or descend, as the water in a Weather-glass, though with farr feebler and more insensible effects: So that any time of the year it will not much desert nor surmount the determinate height and pitch aforesaid of 29. inches.
11. That this seeming vacuity in the Tube would be judged by any one that came in at an adventure, to be nothing but such like illuminated ayr as this we breathe in.
12. If you dip your thumb into the vessel'd Mercury, and close the orifice of the Tube therin, and so gently re∣verse it, you shal see the Quicksilver in the Tube to move more swiftly (though not without resistance, and ebulli∣tions) through that seeming vacuity; and the Mercury will pass with such shoggs towards the depressed ex∣treme of the Tube, as will make you apprehend that the Tube will be either beaten out of your hand or broken: none of which Phaenomena will appear, if you let in the outward ayr into the cavity unpossessed by the Mercury. In which Interim of Motion, your thumb will be drawn and suck'd into the orifice of the Tube, not without some considerable pain.
13. If before the removal of your thumb you reim∣merge it again into the vessel'd Quicksilver as before, & then draw the Tube perpendicularly quite out of the vessell'd Quicksilver, the Quicksilver in the Tube will rise to the top of the Glass with such a violence as will indanger the knocking out of the head of the Glass, and then the ayr will pass by a speedy ebullition through the Quicksilver, and it will totally descend into the vessel. I once brake a Glass-tube of near forty inches long, by plucking it suddenly out of the vessel'd Mercury.
14. That you cannot so cautiously perform this Experiment in any Glass Tube whatsoever, but some little Air will be seen in the top of the Tube, when re∣versed, and before the removal of your Thumb, like the little Cap of Air in the obtuse end of an Egge; so that if you incline the Tube to what Angle soever (as in the eighth Observable aforesaid) the re-ascending Quicksilver will never totally and exactly fill the Tube, but a little Cap of Air will still stand in the top thereof.
15. That, use all the Artifice and Industry you can,
you cannot so cautiously fill the Tube, but that the Cy∣linder of Quicksilver will seem cragged and itched, and never purely smooth and polished, (though your Glass be never so smooth and dry, and your Quicksilver never so well purged) which interstices are filled up with Parti∣cles of Air that lurk 'twixt the Contiguities of the Glass and Quicksilver: and which after the descent of the Quicksilver do bubble up, and shoot themselves little by little into that seeming vacuity (as you may ocularly behold them) and doubtless are the occasion and hin∣drance why upon inclination of the Tube (as in 8. Ob∣serv.) the Quicksilver cannot totally replenish and fill the Tube again.
16. We filled a Tube of 27. inches with Quicksilver, and after inversion of it into a Vessel of Quicksilver, as in the Torricellian-Experiment we perceived, just upon retracti∣on of the finger, the little Particles of Air which re∣mained lurking between the sides of the Tube and the Quicksilver, on the suddain to become more visible, by a violent and rapid dilatation, flying out like so many little Springs wound up, and then all at once set at Li∣berty.
17. If you immerge the Tube into Vessels of Quick∣silver of several Capacities and larger Surfaces, the des∣cent of it will not alter.
18. Observe that the height of the Mercurial Cylin∣der, which here with us is found to be 29. inches at the least (if you order the Tube handsomely in filling of it) may seem greatly different from the French Observati∣ons, and those of Forrain Experimenters, as Parricellius himself, Doctor Pascal, Roberual, Doctor Pettit, and Pecquet, who all assign its Altitude to be but about 27. inches. To this I shall onely at present answer, that this
difference of the Mercurial Cylinder, may 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 toge∣ther. 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 Quick∣silver 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 Experi∣ment.
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 wil•• 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 Va∣cuity, 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 Experi∣ment.
4. There is some Air also interspersed in that seem∣ing Vacuity, which cannot be expelled upon any in∣clination of the Tube whatsoever, as by Obser. is ma∣nifest.
5. The most full Evidence against this pretended Vacuity is from the returgenscency of the empty Blad∣der suspended in this Vacuity; for, how should it be so full blown from nothing? as is by Exp. most incompara∣bly evinced.
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 Experi∣ment borrowed from the Mechanical Wit of Doctor Pascal, which shall passe for the second in the Bed∣roll of our Experiments.
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-ponde∣rous 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 Hogs∣head 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.
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 wa∣ter 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 imagi∣nary
Space in the Torricellian-Experiment aforesaid, cannot rationally be supposed to be repleated with any Mercurial Effluviums.
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 Quick∣silver, 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 re∣stagnant 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 regi∣on of water (which you first poured into the same Ves∣sel:)
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 Cylin∣der, it would be certainly far more Luminous (as con∣taining 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 Obser∣vat.
That the evacuated Cylinder in the Tube, is not filled with Atmosphaerical Air only.
BY Atmosphaerical Air, I understand such as we con∣stantly 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.
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 Con∣cave Surface of the Tube and the Cylinder of Quick∣silver) 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 com∣mon Air which supplies that seeming Vacuity.
HAving drawn the former negative Conclusions, and demonstrated, That it is not Light onely, not Mercurial Spirits, not Atmosphaerical Ayr, which is diffu∣sed 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) in∣geniously conceives, that the whole mass of Ayr hath a Spontaneous Eleter, or natural aptitude in it self to di∣late and expand it self upon the removal of all circum∣ambient obstacles (which he calls the Elastical motion of that Element) so that the particle of Ayr may be un∣derstood to be as many little Springs, which if at liberty, and not bound and squeesed up, will powerfully, strong∣ly, 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 an∣other, the superiour particles of the Ayr pressing the in∣feriour, 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 ex∣pand and dilate themselves: and when the circum∣resistency of other contiguous Bodies to them is remo∣ved, 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 ex∣pansion:)
which Elastick motion in the Ayr then ceases, when it comes to an aequilibration with those circum∣jacent 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 de∣monstrate.
Onely we differ from Pecquet in the strict notion he hath of Rarefaction and Condensation, which he sup∣poseth 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 es∣sential 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 Sub∣tler 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 na∣ture 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 Meta∣physical 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 ef∣fluviating from them) do swim at free and full Li∣berty.
2. Let us consider that this aether is of that Subtil and Penetrative Nature, that like the Magnetical Efflu∣viums, it shoots it self through all Bodies whatsoever, whose 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 Bo∣dies circuminclosed by it) but it also ponderates, and is heavy, in its own Atmosphaere.
But because I am resolved you shall take nothing up∣on 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.
TAke a Wind-gun (which new Artifice is now com∣mon) 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 great Mystery, which here, with all its consequences, I shall deliver.
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 immediate∣ly to the top of the said Hill, and repeating the Experi∣ment 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 Cir∣cumstances, 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 gra∣vity. Secondly, Why it falls no lower then 29. because a Cylinder of that weight does just aequipoise the Ela∣stick 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 Superincum∣bent 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 Super∣ponderant Ayr makes a lesser quantity of Quicksilver arise in the Tube: and so come the Mercurial Cylin∣ders 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 At∣mosphaere, 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 Moun∣tain-Experiment aforesaid) may every whit as ratio∣nally be supposed to proceed from a change in the Ela∣stick 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 o∣ther 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, 'tis not so easily credible.
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 gravi∣tate 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 a∣bove 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 ac∣complished 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 whe∣ther in Ayr or Water the Experiment be tryed, this ef∣fect 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 wa∣ter would raise up a Mercurial Cylinder of 29. inches; So the same Cylinder of 29. inches is raised by a Co∣lumn of the height of the whole Atmosphaere it self.
But we may by a far more facile and cheaper Experi∣ment 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 Supergravita∣tion 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 longer; and so faints, as the bulk of the Superponderant continually decreases.
The Reasons of all those extravagant Phae∣nomena, 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 ex∣ternal Ayr.
2. Because then the Cylinder of Quicksilver Super∣ponderates and overpowers both the Ayr's Elastick vir∣tue and gravity.
3. Because at that stint of 29. inches, the internal Cy∣linder 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 Ela∣stick resistence of the Ayr, and so will come (though with more vehemence and swiftness) to its wonted Alti∣tude of 29. inches.
6. Because by Addition or Diminution of the ves∣sel'd Quicksilver there is a change in the Tube and Ves∣sel, 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 Cylin∣der; for in that Angle of Inclination, the Perpendicu∣lar is still 29. inches.
9. Because the Quicksilver, by its long descent, ha∣ving acquired a greater motion than was requisite to bring it down to its determinate Altitude, cannot sud∣denly 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 Mer∣curial 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 Bo∣dy 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 Cylin∣der 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 suffici∣ently 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.
WE took such a like AB (as in the 1. Eperi∣ment) 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 Vessel••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 Quicksil∣ver, Water, and Ayr.
In which Experiment there are three or four remark∣able Appearances, which ought not to pass our Obser∣vation:
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 pre∣sently
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 collap∣sion 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 in∣to 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 circum∣stances annexed to it, makes the Water's gravitation more eminently appear: For, since 14. inches of Wa∣ter 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 Super∣incumbent 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.
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 Quick∣silver 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 de∣scended two inches below the ordinary stint.
We also tunnell'd into the Tube a Cylinder of Quick∣silver, but of five inches in Altitude (letting the Ayr sup∣ply the other Segment of 40. inches;) and reversing it, as before, it fell down within two inches of the Quick∣silver in the Vessel.
Observe, that in these mixed Experiments of Ayr and Quicksilver, or Water and Mercury, or all three toge∣ther, that when you have revers'd the Tube, you must hold it close stop'd so long perpendicular, till the seve∣ral Bodies have acquired their several respective and proper places.
To this Experiment likewise we must annex one con∣siderable 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 pos∣sibly 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 Wa∣ter, by its weight onely (as is manifest in the precedent Experiment) and no innate Elatery, did depel the Suc∣cumbent 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 Ex∣periments.
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 re∣versing it into Vessel'd Quicksilver, as in the former Ex∣periments, 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 up∣on the restagnant Quicksilver in the Vessel, to about one inch deep, and draw the Tube out of the Quick∣silver 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 Mer∣cury.
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 re∣quired pitch and Standard of 29. inches, then proba∣bly 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 o∣ther Instruments (as is besides delivered in Exper.)
WE therefore fill'd our Glass-Tubes of 45 inches, half with Water, and the rest with Ayr, and af∣terwards 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 Quick∣silver) 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 de∣scent of Water to 3••. foot, very creditable to those that want Instruments to try it.
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 drop∣ped 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 tunnel∣ling in the Quicksilver, and reversing the Tube, as in the first Experiment, we found that after the Quicksil∣ver was come down to its wonted pitch, the Fish-Blad∣der 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 intu∣mescences 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 re∣moval 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 for∣mer extension and consistency again.
But hold; Before I pass from this Experiment, I must take Pecquet in hand, who, upon confidence of this Ex∣periment, insults highly over those that admit not of his Rarefaction, but will introduce a new aetherial sub∣stance 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 proba∣bility, 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 continu∣ally 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, Quick∣silver 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 Ae∣ther, as much lighter and subtiller than Ayr, as Ayr is then Water, How 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 in∣to 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 parti∣cles 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 Quick∣silver 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 efflu∣viums: 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 Ex∣periments, I will give you that ingenious, but very diffi∣cult Experiment of Auzotius, as quoted by Pecquet, which shall bring up the rere in this Muster-role of our Experi∣ments, and which will confirm all we have formerly de∣livered.
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, re∣verse it, and into the mouth of the Head let down a hol∣low 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 perpetual∣ly observes its Sandard-altitude from what height soe∣ver. 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 At∣mosphaerical Ayr that (in the first Experiment) raises and keeps up that Cylinder of Quicksilver in the Tube of 29. inches in Altitude, or thereabouts.
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, Esqr. and those Inge∣nious Gentlemen Mr. JOHN, and Mr. CHARLES TOVVNLEY, and Mr. GEORGE KEMP.
THe last year, 1660. came out that excellent Tra∣ctate of Experiments of Esqr. Boyle's, with his Pneu∣matical 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 cu∣riously and critically handled, the Experiments so judi∣ciously and accurately tried, and so candidly and intelli∣gibly 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 Experi∣ments. Nay, it had not that effect onely on me, but like∣wise it excited and stirr'd up the noble Soul of my ever honoured Friend, Mr. Townley, together with me, to at∣tempt these following Experiments.
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 con∣sonant to the Series and Chain of our former Experi∣ments: wherein it is proved, that one inch of Quicksil∣ver 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.
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 a known weight, as counterpoised the Quicksilver, and then mea∣suring the water in the Mercurial Vial aforesaid, we found it to contain near 14. times as much Water as it did of Mercury.
WE fill'd a Tube with Quicksilver, as in the Tor∣ricellian-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 af∣ter, 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 va∣riation 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.
AGain, we tried the Torricellian-Experiment afore∣said, 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 afore∣said 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 admis∣sion of a little more Ayr, though the Quicksilver then did not rise high enough to pass over into the other shank as before.
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 Ori∣fices, 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.
WE fill'd a Tube (though with much difficulty) such an one as is here described, with Quick∣silver, 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 won∣ted Standard again.
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 bet∣ter to distinguish their streams.
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 Quick∣silver, you forced it little by little out; and so either Water or Ayr passed up instead thereof.
APril 27. (1661.) we tryed the Torricellian-Experi∣ment in the Porch at the new Church in Pendle, (which standeth upon a considerable height) the wea∣ther 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 dili∣gence, 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 accurate∣ness, and in the same Tube, at the Beakon upon the ve∣ry 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 be∣ing 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.
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 in∣versed, 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 with∣drawn, 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.
WE took another Tube, containing in length from the Superficies of the external Quicksil∣ver into which we immers'd it (for so we measure all our Lengths) about 26. inches, containing equal divi∣sions of space, 31. and about an half, represented here by AB, which we fill'd so with Quicksilver, that be∣ing revers'd and stop'd at B, there remain'd 9. divisi∣ons fill'd with Ayr from A to E: then the Quicksil∣ver being left at liberty to fall down into a dish under∣neath, 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 per∣pendicular 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 bot∣tom 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.
| 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 |
| 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 considera∣ble 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 perpen∣dicular
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
Where note, That the measure of the Mercurial Stan∣dard, 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 Con∣version, Transposition, and Division of them. So that by these Analogies you may prognosticate the effects, which follow in all Mercurial Experiments, and pre∣demonstrate them, by calculation, before the senses give an Experimental thereof.
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 rear∣ed the Tube to a Turret at Townley-Hall, and fill'd it with water; then closing the top of the Glass-Pipe, and im∣mersing 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 conje∣ctured 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 remem∣ber 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 Lead∣cistern, and then by another Pump to raise it out of that other, eight yards, into a cistern above.
NOw to salve all these Mercurial Phaenomena, as also those mixed Experiments of Quicksilver and Wa∣ter, 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 whim∣sies of two Grandees, that is, Valerianus and Hobbs, which so grosly Philosophize: the former affirming the de∣serted 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 Hy∣potheses.
The first is of Roberual and Pecquet, of the Ayr's Ela∣sticity and Gravitation, which we have formerly em∣brac'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 ne∣ver 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 Expe∣rimental 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-Expe∣riments 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 Tor∣ricellian-Experiment) is fill'd with a small film of Quick∣silver, which being taken off the upper part of it, is both extenuated and extended through that seeming Va∣cuity.
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, Torricelli∣us, 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 there∣fore 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 there∣fore the uppermost surface of the Quicksilver being sli∣ced 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 per∣formed by a tenuous Funicle of Ayr, and, in the Pasca∣lian-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 Pneuma∣tical 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 Stan∣dard (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 preponde∣rant 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 Quick∣silver (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 ar∣gues; 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 fin∣ger to the Orifice of the Tube; from whence, saith he, 'tis plain, that the Quicksilver is there suspended by that tenuous, but tenaceous, rope in the Tube.
His fourth Argument is from the difficulty of Sucti∣on 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 Quicksil∣ver? Since here is nothing else required but the remo∣val 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, 'Tis not the external Ayr that causes that effect, neither by its Elasticity, Gravitation, nor both.
Now for the Positive Arguments to avouch his Prin∣ciples by, he has none at all; onely what he fetches à po∣steriori, 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 easily in pieces.
A Confutation of this Funicular Hypo∣thesis of Linus; by Henry Power, Mae. Dr.
Object. 1. IF you fill a Tube of 45. inches in length (as we have shewed you in Experiment 11.) ex∣cept 15. inches (which let the Ayr supply) and invert it, you shall perceive a greater protrusion of your fin∣ger by the erupturient Quicksilver, than can possibly be imputed to the Supergravitation of the Quicksilver in∣cluded in the Tube: for, if the whole Tube be fill'd with Quicksilver, and inverted, it shall not make such a forci∣ble 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 Dilata∣tion. Now, I confess, this is but an Argument quoad sen∣sum, and therefore not so much to be insisted upon, be∣cause 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 Lea∣ther, the first inch of their forced extension is perform∣ed by a lesser power then the second inch would be, and that then the third, &c. Now in the third of Boyle's Ex∣periments, 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 con∣trary to the nature of forced Extension, as is before de∣livered.
Object. 3. Again, If (according to Linus) the Blad∣der'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 Blad∣der 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 em∣bladder'd Ayr, which gradually increases, as the debili∣tated Ayr in the Receiver gives room for its expan∣sion.
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 Mer∣curial 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 Stan∣dard 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 fil∣ling one, and still were forced to thrust the Quicksilver down into it with a small wire) then reverse it very gent∣ly 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, be∣ing still close stopped with your finger, will remain full.
Now (according to Linus) the funicle AC exer∣cises the same power of pulling the Mercurial Surface A as C: and according to the Principles of Mecha∣nick'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, up∣on 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 wa∣ter stood in the shank at C, (viz.) 13. inches above the surface of the water in the vessel B, thence carry∣ing 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 ma∣nifest 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 Elastici∣ty of the Ayr (which Linus would abolish) as the Tor∣ricellian-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-Glas∣ses 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 respe∣ctively to what it was at the bottom, with this Observa∣ble, 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 quanti∣ty of the included Ayr.
Experiments in Capillary Tubes and Sy∣phons.
TAke a small Capillary Glass-pipe, or Tube, open at both ends; and dipping the one extreme perpen∣dicular
into the water, you shall see the water spontane∣ously 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, be∣fore 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 Stan∣dard-Altitude above the surface of the water in the ves∣sel: 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 Li∣quors 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 Vi∣triol by ⅓ so high as it; which may alter more or less, ac∣cording to the goodness of the said Oyls.
Seventhly, Now if you take out a Pipe (wherein in ei∣ther
of the said Oyls has first risen up to its wonted Stan∣dard) and immerge the end thereof into a lighter Li∣quor (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.
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.
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 dark∣ish hole, like a Spring. Observe:
IF you lift the vessel of Milk (with the pendent Leg drown'd in it) higher towards the flexure of the Sy∣phon, so that the Superficies of the Milk be nearer the flexure of the Syphon than the Superficies of the Wa∣ter, 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 in∣to 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.
NOw, contrariwise, if you lift the vessel of Water nearer the flexure of the Syphon than the Super∣ficies of the Milk is, then will the Water rise over the Sy∣phon 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, ei∣ther 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 Rari∣ty amongst the Mechanicks (viz) A Perpetual Motion: For the demonstrating of which, he devis'd this follow∣ing Experiment.
LEt the Glass DEF be fill'd with two several Li∣quors, so as they may remain in two distinct Regions, one above another, as AB, without the least mixture; (which may be performed in Milk and Water, placing a broad piece of Cork, or Bread, that will swim so upon the Milk, which must be the lower, as A, being heavier than Water, that it may receive the force of the Water's fal when you pour it upon the Milk:) this done, and the Cork or Bread being taken out, hang the Syphon ACB, first fill'd with Milk, upon the stick DCE, so artifici∣ally, that the longer end A may remain in the Region of Milk, and the shorter end B in the Region of Water; with this caution, That the flexure of the Syphon C be removed no higher from the Milk, than it would natu∣rally ascend to, if the Syphon was streight: Now (saith Mr. Charles) Since in the former Experiment the Water would rise over the top of the Syphon, and drive back the Milk; and afterwards rise to the top thereof, and there swim aloft: why here in the Syphon ACB, the like should not follow, (viz.) the Water at B drive the
Milk, (which is suppos'd first to fill the Syphon) back to C, then to A, where issuing out of the Pipe (as it did in the former Experiment) it would ascend to its proper Region of Water again, and so continue in a Circular Motion perpetually.
Now however this same Problem of M. Charles might seem probable in the Theory, yet it will prove more than most difficult (if not impossible) in the Practice. For,
1. We fill'd the Glass DEF, half full of Milk, and half full of Water, as AB; then hanging the Syphon (first fill'd with Milk) so artificially on the stick DE, so that the longer Shank might reach the Milk A, and the shorter might open into the Superincumbent Region of Water B, we observ'd this effect, That the Milk did for a small time run out of the Orifice B, and seem'd to fall into the inferiour Region of Milk; but at last the Milk (or at least the serous or more watrish parts thereof) so intermixed with the Water (which we could discern by the whiteness and opacity of the Water) that the flux was quite stifled.
2. Contrary to Mr. Charles his Prognosticks, the Wa∣ter did not rise up the short Shank, and drive back the Milk, but quietly permitted the Milk to drill through it; though I know it was not material which way the flux was performed, provided it would have been perpetual.
The Experiment failing in these two Liquors, we at∣tempted the same again in other two Liquors (which we were sure would not mix;) and to that purpose we fill'd the aforesaid Glass with Oyl of Tartar per deliquium, and Spirit of Wine, which we tinged yellow with Saffron, the better to distinguish the Liquors; and then adapting the Syphon, as before, we wish'd for a happy event in the Experiment. But Experience (which ought to be the
Mistress of wise men as well as fools) shew'd us the quite contrary; for the Syphon would not run at all, but con∣tinued full, which we afterwards conjectured to proceed from the Heterogeneity of the two Liquors▪ so that the Oyl of Tartar would not break out into the Spirit of Wine, no more than Milk or Water will do into the open Ayr, where the pendent Shank is shorter than the Stan∣dard-height of those two Liquors. So that, it seems, to effect this Experiment indeed, two such Liquors must be found out, as are in some wise Homogeneous, and of a Congruity, and the one considerably lighter than the o∣ther, which is tantùm non impossibile. For besides the for∣mer Liquors, we have tried Oyl and Water, and no Mo∣tion at all was perceived, for the same reason of incon∣gruity formerly delivered.
But these, and a hundred more Experiments of this nature are every day excogitated and tried by our No∣ble Society of Gresham-Colledge, which in a little time will be improved into far nobler Consequences and Theories, than can possibly be done by the single Ende∣vours of any Person whatsoever.