New experiments physico-mechanical, touching the air

The Citations English'd

PAg. 12. Quanquam vis, &c. Although the force of that motion in the evacuated Receiver be diminished, being opprest by the con∣sistence of the Air moved within, yet it is not extinguished: and there∣fore that oppression being taken off will have strength enough to excite an appearance of light, though somewhat weaker than ordinary.

p. 13, 14. Sine, &c. Without which Hypothesis let never so much labour, art, cost be bestowed for the finding out of the invisible causes of natural things, all will be in vain.

p. 15. Cum ejus, &c. Seeing almost all its parts are flexil, like little soft feathers to fine threds.

Ibid. Sed quisquis, &c. But it matters not who was the Author of that Supposition. For the very Hypothesis it self, wherein is supposed a motion of subtil matter, which is swift without any cause assigned, and hath moreover divers innumerable circulations of Corpuscles generated from the single motion of that matter, is not the conceipt of a man of wit or sense.

p. 16. Nempe hoc, &c. This is the thing that the great Des-Cartes somewhere admired, that he, whether his Positions are true or false, doth never in argumentation make any right inference from his Suppositions.

p. 17. Quod sane, &c. Which is indeed a most evident argument of the weight of the Air.

Ibid. Quod quidem lanx, &c. That the Scale in which the Bladder is, is more deprest than the other, they may be certain, their eyes bear∣ing them witness: but that this comes from the natural gravity of the Air he cannot be assured; especially if they are ignorant what is the efficient cause of Gravity.

p. 18. Quod vesica, &c. That the Bladder, whether it be blown up with a pair of Bellows, or with the breath of ones mouth, is heavier than when it is not blown up, I will not deny, because of the greater quantity of Atoms from the Bellows, or of fuliginous Corpuseles that are blown in from the breath. But notwithstanding they gather nothing of sufficient certainty from this Experiment of a blown Bladder. They ought to have put into the Scales two Vessels of equal weight, whereof one should be shut and the other open: For by this means Air not blown in, but onely inclosed, had been weighed. When therefore you shall see Air so weighed, we will afterwards consider what may be said con∣cerning the Phaenomenon you bring.

p. 19. Quod Atmosphaerae, &c. That many Particles both of Earth and Water mingled with the AEthereal body are in the Atmosphere, I am easily persuaded: but that in the middle of the AEther they should move upwards, downwards, every way, and that one leaning on the back of another they should not gravitate, is a thing utterly unconceivable.

p. 20. Aer quo, &c. The Air, with which in the beginning the Sphe∣rical Glass was full, being moved by those Earthy Corpuscles in a simple circular motion, and being comprest by the force of the Injection, that of it which is pure (penetrating the injected Water) gets out into the open Air, and gives place to the Water. It follows therefore that those ear∣thy Corpuscles have less place left, in which they can exercise their natu∣ral motion: therefore beating one upon another they force the water to go out; it thus going out, the external Air (because the Universe is supposed to be full) penetrates it, and successively takes up the place of the Air that goes out, until the Corpuscles, the same quantity of Air being restored, regain a liberty natural to their motion.

p. 21. Quoniam, per, &c. Because by the drawing back of the Sucker the pure Air was thrust in, but the earthy parts were not thrust in; there was a greater proportion of earthy Particles, which without the Cylin∣der were near the Sucker, unto the pure Air, in which they exercised their motion as well after this revulsion as before. Wherefore these Par∣ticles so moved having less place to exercise their natural motion in, some of them fell foul and beat upon the rest. So that of necessity the Particles that were near the surface of the Sucker must drive it upwards.

Ibid. Vidisti, &c. You see now that the Spring of the Air, which they fuppose, is either an impossible thing: or they must (for its defence) have recourse to the Hypothesis of Mr. Hobbs.

p. 23. Quia cuticula omnis, &c. Because every skin is made up of small threds or filaments, which by reason of their figures cannot accurately touch in all points. The Bladder therefore, being a skin must be per∣vious not onely to Air but to Water also, as to sweat: Therefore of the Air beat in by force there is the same compression within the Bladder that there is without. The endeavour of which, the way of its motions being every way cross, tends every way to the concave superficies of the Bladder. Wherefore it is of necessity that it must swell every way, and the vehemency of the endeavour increasing, be torn at last.

p. 26. Intellexti, &c. Have you understood my Hypotheses? 1. That there are with the Air intersperst many earthy Particles, endued with a simple circular motion, congenite to its nature. 2. That there is a greater quantity of these Particles in the Air that is near the Earth, than in that which is more remote from it.

p. 27. Ne{que} est, &c. nor is there any one that hitherto has brought any reason why it may not be so.

p. 29. Nihil, &c. Nothing is moved but by a contiguous Body that is in motion.

Ibid. Dum Suctor, &c. While the Sucker is drawn back, by how much a greater place is left (within,) by so much a lesser place is left to the external Air, which being thrust backwards by the motion of the Sucker towards the outmost parts, doth move in like manner the Air that is next it self, and that Air the next, and so forwards; so that it is of necessity at last that the Air must be compell'd into the space deserted by the Sucker, and to enter between the convex and surface of the Sucker, and the concave of the Cylinder. For it being supposed that the parts of the Air are infinitely subtil, it is impossible but they should insinuate themselves that way by which the Sucker is drawn down. For first, the contact of those surfaces cannot be perfect in all points, because the surfaces themselves cannot be made infinitely smooth. Then, that force which is applied to draw back the Sucker, doth distend in some measure the cavity of the Cylinder. Lastly, if in the confines of (that is, betwixt) the two surfaces any one single hard Atom should enter, pure Air will enter at the same way, although with a weak endeavour. I might also have accounted that Air which for the same cause insinuates it self through the Valve of the Cylinder. You see therefore the conse∣quence from the retraction of the Sucker, to the being of an Empty place is taken away. It will follow also that the Air which is driven up into the place deserted by the Sucker, because it is driven up thither by a great force, is moved with a very swift and circular motion betwixt the top and the bottom in the Cylinder, because there is nothing there that can weaken its motion: and you know that there is nothing that can give motion to its own self, or diminish it.

p. 39. Haerent hic, &c. Here our men are at a stand: How will you expedite this difficulty?

A. I have don't already: For the Air being beaten back by the re∣traction of the Sucker, and finding no place in the world (which we suppose to be full) where it might dispose it self, besides that which by driving out other bodies from their places it may make for it self, is by perpetual pulsion at length forced in the Cylinder with so great swiftness, between the concave surface of the Cylinder and the convex surface of the Sucker, as may answer that store of power which you found necessary to the drawing back of the Sucker. Now the Air, with what swiftness it enters, retains the same within, and then distends every way the sides

of the Brass Cylinder, which is (of it self) Elastical. Therefore the Air in the Cylinder being vehemently moved, endeavours or thrusts against all parts of the concave surface of the Cylinder; but in vain, untill the Sucker, is drawn back: But as soon as the Sucker having slipt the hand, ceases to make its impulse upon the Air, that Air which was before driven in, by reason of its endeavour against every point of the internal superficies of the Cylinder and of the Elastical force of the Air, will insinuate it self between the same surfaces with the same swiftness as that by which it was impell'd, that is, with that velocity which answers the strength of the impulsion. If therefore so great a power of Weight be hung upon the Sucker as may answer the power of the hands by which it was impulss'd; the swiftness with which the same Air goes out of the Cylinder, finding no place in the world (which is full) where to dispose it self, will again impell the Sucker to the top of the Cylinder, for the same reason that the Sucker a little before made an impulse upon the Air.

p. 44. In vas, &c. B. We poured water into an open Vessel, we pla∣ced in the water a long, streight, slender Tube; and we observed that the water did ascend from the Vessel underneath into the erected Tube.

A. No wonder: For the small Particles that are interspers'd in the Air near the Water, did by their motion beat upon the surface of the Water, so that the Water must of necessity ascend into the Pipe, and that sensibly into a Pipe that was so exceeding slender.

p. 45. Siquis, &c. If any one after the frequently-repeated impulse and retraction of the Sucker, endeavour to draw out the Stopple of the upper Orifice of the Receiver, he shall find it gravitates very much, as if a weight of many pounds hung upon it. Whence comes this?

A. From a strong circular endeavour of the Air within the Receiver, made by the violent ingress of the Air between the convex surface of the Sucker and the concave of the Cylinder, procured by the repeated impulse and revulsion of the Sucker, which you improperly call the Exsuction of the Air. For by reason of the fullness of Nature the Stopple cannot be drawn out, but the Air that is in the Receiver (contiguous to the Stopple) must be drawn out too: which Air, if it were settled and at rest, the Stopple would easily be drawn out; but whiles that doesmost swiftly circulate, it comes out very hardly, that is, it seems to be very heavy.

B. Very likely: For as soon as fresh Air is by degrees let into the Re∣ceiver, it likewise by degrees loses this seeming gravity.

p. 47. Vidimus, &c. We saw also water, being let down into the Re∣ceiver, after some returns of the motion of the Sucker, to bubble so as if it had boiled over a fire.

A. This likewise happens, as we spake, by reason of the swiftness of the circulating Air: unless perhaps you find the water hot too whiles it bubbles. For if we were sure it was hot, we must find out some other cause of the Phaenomenon.

B. We are certain it is not sensibly hot.

A. In what therefore can the greater or lesser motion of the Atmo∣sphere promote such a motion as this?

B. I suppose they do not attribute this motion to the Atmosphere.

p. 49. A. It is manifest from this Experiment, that the Receiver is not made empty by this exsuction of Air, as you call it: For the water could not be moved but by some contiguous mover, that was it self in motion. Therefore this Phaenomenon seems to contain no weak demon∣stration of my Hypothesis.

p. 50. Besides, tell me, could you see the water bubbling in that manner?

B. What else?

A. Do not your Associates grant that Vision is made by a continued action from the object unto the eye? Do they not also think action to be motion, and all motion to be of some body? How therefore could the motion be derived from the object, the water, unto your eyes through a Vacuum, that is somewhat that is not a body?

B. Our friends do not affirm the Recipient to be so empty that no Air at all is left.

A. No matter whether the Receiver be wholly, or for the greater part empty; for which ever you suppose, the derivation of the motion from the object to the eye will be intercepted.

B. It may be so; I can't tell what to answer.

p. 51. Credin' tu, &c. Do you think these Animals were therefore so quickly killed because they wanted Air? How then do they who make a trade of Diving live under water, of whom there be some who being accustomed from their childhood have wanted Air a whole hour? No. Thatmost vehement motion by which Bladders shut therein are distended and broken, kills these Animals shut up in the Receiver.

Ibid. Ego contra, &c. I on the contrary think that neither the Air can be suck'd out, nor that the Animal would so soon dye if it were suck'd out. The action indeed to which this death is a consequent may seem either a certain suction (and so, that the Animal is kill'd by the exsuction of the included Air, its Respiration being taken away) or a compulsion of the Air from all parts towards the Centre of the spherical Glass in which the Animal is inclosed, and so may be seen to dye stifled by the

tenacity of the compress'd Air, as it were, with Water; the Air more tenacious than usual, being drawn into the inwards of the Lungs, and there between the Pulmonary Artery and Vein stopping the course of the blood.

p. 53. Placet, &c. Your Hypothesis pleases me better than that of the Spring of the Air: For from its truth depends the truth of a Vacuum or a Plenum; but from the truth of that nothing follows on either part of the Question. The make of the Air (sayes he) is like that of comprest wooll. Well; wooll is made of hairs or threds. Right; but of what figure? if of a Parallelopipedon, there can be no compression of parts: if not of a Parallelopipedon, there will be betwixt the hairs certain spaces left, which if they be empty they suppose some place empty, to prove that a Vacuum is possible; if full, they say that is full which they sup∣pose to be empty.

p. 56. Fuere, &c. There were some of them that said there remained in those coals (though they seem'd extinguish'd) some fiery Particles, which being blow'd up by the Air upon its admission did re-kindle the rest of the mass.

Ibid. Nae, &c. In good faith they seem not so much as to have consi∣dered what they should speak, as to have taken it up at all adventures. Do you believe that in a kindled coal, there is any part which is not a coal but fire; or in a red-hot Iron there is any part that is not Iron but Fire? A great City may be set on fire by one spark: Now if the body of fire be different from the thing fired, there can be no more parts of fire in the whole Town on fire than that one spark. We see bodies of divers kinds may be set on fire by the light of the Sun, as well by the Refraction as the Reflexion that is made in Burning-glasses. And yet I do not believe that there is any man thinks that Particles of fire darted from the Sun can pass through the substance of a crystal Globe. And in the Air between the Sun and the Globe there is no fire.

p. 58. When is it that we may truly say of a man that he is dead, or (which is the same) hath expired his Soul? For it has been known that some men who have been taken for dead, being brought out the next day revived.

A. It is hard to determine the point of time in which the soul is sepa∣rated from the body. Proceed therefore to other Experiments.

p. 59. Si acus, &c. If a Needle excited by a Loadstone hang freely within the Receiver, it will nevertheless follow the motion of the Iron which is drawn about without the Receiver. So objects put within will be seen by those that are without, and sounds made within will be heard

without: all these as well after as before the exsuction of the Air, except that the sounds are somewhat more weakly heard after than before.

B. These are most manifest signs that the Receiver is alwayes full, and that the Air cannot thence be suck'd out. That the sounds thence are more weak to ones hearing is a sign of the consistence of the Air; for the consistence of the Air is diametrically opposite from its motion.

p. 61. Quia nihil &c. Because there was nothing there that the weight of the Atmosphere should do; no more strong or evident Argument could be made against a Vacuum than this Experiment. For if of two coherent Marbles either of them should be thrust forward that way that their surfaces lye contiguous, they would easily be sever'd; the neigh∣bouring Air successively flowing into the deserted place. But so to pull them asunder, that at one time they should lose their whole contact, is impossible, the world being full. For then either motion must be made from one term to another in an instant, or two bodies at the same time must be in the same place: to say either of which is absurd.

p. 62. Confitentur, &c. They themselves and all others confess, that all Ponderation is an endeavour every way by right lines unto the Centre of the Earth; and so that it is made not by the figure of a Cylinder or Column, but by a Pyramide, whose top is the Centre of the Earth, and whose Basis is part of the surface of the Atmosphere.

Ibid. Conatus, &c. Therefore the endeavour of all the points that ponderate will be propagated to the surface of the upper Marble, before it can be propagated further (suppose) to the Earth.

p. 64. Has, &c. These Scales he puts one upon another and draws out the Air, and then are they kept so comprest and united by the gravity of the external Air, that six strong men cannot pull them asunder. But if at length by the use of utmost endeavour they are pluckt in sunder, they make a noise equal to the report of a Musquet; but as soon as ever by the Stop-cock open'd there is the least entrance given to the Air, they are severed of their own accord.

p. 65. Sed vis, &c. But can the Spring, which they say is in the Air, confer nothing to the holding up the Marble? — Nothing at all: For there is no endeavour of the Air to the Centre of the Earth, more than to any other point in the Universe. For seeing that heavy things tend from the circumference of the Atmosphere unto the Centre of the Earth, and thence again to the circumference of the Atmosphere by the same reflected lines, the endeavour upwards will be equal to the endea∣vour downwards, and so destroying one another they will endeavour neither way.

p. 66. Non potest ergo pars BC, &c. Therefore the part BC (that is a part of the Atmosphere placed any where within the whole) cannot (by reason of its greatness) descend, although it be heavy, and there∣fore it cannot press or gravitate.

Ibid. Si possibile, &c. If I should deny it possible, that by the art of man two furfaces of two bodies could be made so accurately fit that they should touch in all points, so that there could no creable Corpuscle pass between them; I do not see how they could defend their own Hypothesis, or disprove our Negative assertion.

Ibid. Vtraque, &c. Both these Fancies, as well that of the Weight as of the Spring or Antitupy of the Air, are Dreams. But if it be granted that there is a kind of Recoyling in those small hairs or slender Corpus∣cles of which the Air consists; one may enquire whence it is that those crooked bodies, settled and at quiet in that posture, came to be moved into a streightness. They ought, if they will be esteemed Natural Phy∣losophers, to assign some possible cause of this.

p. 67. Cur non, &c. Why cannot the water, which when it was in∣jected did compress the particles of Air, be again cast out by the same particles explicating themselves?

A. Because when explicated they require no greater place than when comprest: As in a vessel full of water, wherein are many Eeles, the same proportion of place receives them, whether they are folded round or at length. Therefore they cannot drive up the water by their Spring, which is nothing else but the motion of bodies explicating themselves.

B. The comparison of Air to Eeles in water I suppose will be well received by our Academians.

p. 68. Vides, &c. You see how foolish a thing it is to bring for the explication of such effects Metaphorical words, as the shunning of a Vacuum, the ahhorrence of Nature, &c. which heretofore the Schools used to defend their reputation.

Ibid. In the Gardeners Watering-pots therefore is the water suspended, because that which issues out at so small a hole is so little, that it cannot diffuse it self to such a length, that by its descent it may give passage to the Air through the circumferences of the holes. Nor can the Air driven off by the water going out find any other place besides that which the water leaves.

p. 69. Qui per, &c. He that sucks water into his mouth by a Pipe, first sucks up the Air between, whereby he removes the distended external Air, which being removed (the world being full) it can have no place but by removing the next, and so by continual pulsion the

water is at length driven into the Pipe, and doth fucceed the Air which is suckt out.

p. 72. Id vero, &c. But that is impossible: For in a Siphon, unless both legs are filled with water, the water will not ascend out of the Bason. The cause of its ascent into that cloth is the motion of the earthy Atoms which are near the water, I say the simple circular motion com∣municated to the Air in which they move, which Atoms striking the water beat it up into the woolly matter, which beating of them against the cloth makes it more and more moist, till it becomes all over wet. And when it is so, &c.

p. 73. A. Fateris, &c. You confess then that your Collegiates have as yet in nothing advanced the knowledge of natural causes, but that one of them hath found out an Engine, in which there may be such a motion of the Air excited, that the parts of the Sphere may together every way tend unto the Centre, and that the Hypotheses of Mr. Hobbs, before pro∣bable enough, may be thence made more probable.

B. Right; I am not ashamed to confess it; for it is somewhat to arrive so far, if we can make no further progress.

A. Why so far? To what end such preparation and charge for Engines difficult to be made, to make no further discovery than Mr. Hobbs had made before you? Why did you not rather begin where he ended? Why did you not use the Principles he had laid; and when Aristotle had rightly said, That without the knowledge of Motion there is no knowledge of Nature, how durst you take such a task upon your selves?

Ibid. Est, &c.

Thus to have made an entrance though we missOf further progress, some performance is.

p. 75. But most of us distinguish the nature of fluid from that which is not fluid, by the greatness of the parts of which any body consists and is made up with. Wherefore we do not onely look upon Air, Water, and all Liquors, but upon Ashes also and Dust, as fluid bodies. And we deny not that fluid things may be made of things not fluid; for we do not digest the Notion of infinite Divisibility.

A. Infinite Division cannot be conceived, but (infinite) Divisibility may easily. I on the contrary do not understand the distinction of Fluids and not Fluids, which you take from the greatness of the parts: could I digest this, I must say, the ruines of shattered rubbish stones that lye in Pauls were fluid. But if those ruines cannot be called fluid because the stones are too big, define me the bigness that the parts of a ruin'd wall must have that they may be called fluid. But you that cannot under∣stand infinite Divisibility, tell me what you think to be the cause why I

should think it more hard for Almighty God to create a fluid body less than any Atom proposed, that its parts might actually flow, than to create the Ocean. Therefore you make me despair of any fruit of your meeting, by saying, that they think Air, Water, and other fluids consist of Non-fluids; as if a wall that began to fall and be ruinous were called by them a fluid body. If they may speak so, every thing is fluid, for even Marble it self may be broken into parts less than any Atom imagin'd by Epicurus.

p. 79. Ruina, &c. The ruines that lye in Pauls Church might be called fluid.

Ibid. Si sic, &c. If they may so speak, there is nothing but is fluid, for even Marble may be beaten into parts less than any Epicurean Atom.

p. 80. Divisio, &c. Division that is infinite cannot be conceived, Divisibility may easily.

p. 81, 82. Quia corpuscula, &c. But the Corpuscles (such as are the Atoms supposed by Lucretius and also by Mr. Hobbs) being hard before might be easily compacted by any of the mention'd causes, so that it is not to be doubted but that the whole to be made of those Corpuscles will be hard.

Ibid. Si dura, &c. If hard bodies are made out of parts originally hard, why are not fluid bodies made of parts originally fluid? Could great fluids, as the AEther, be created; and could not small ones? He that first made a body hard or fluid, could if he would have made it greater or less than any other proposed body. Now if a fluid body be made of parts not fluid, (as you speak) and hard bodies onely from hard parts; doth it not follow that nothing neither fluid nor hard is made of original fluids?

p. 84. B. Quaenam, &c. What are the principles of Fluidity and Firmness.

A. Of Fluidity nothing but Rest, of Firmness Motion, such as is fit to produce that effect. By Rest I understand the rest of two parts one with another, when they each touch, but neither press one another. For entire bodies of fluids may be in motion their fluidity abiding, and hard bodies be at rest although their parts be in motion.

p. 85. At{que} binc, &c. And hence it is manifest that there is a great compression in the Air so moved and shut up, namely, so great as that force by which it was driven in was able to make; and also that from so great compression some degree of consistence must be made, though less than that of the consistence of water. Now if in all the same Particles of Air, besides the motion by which one presses another, there was also

the simple circular motion and that vehement enough, it would be al∣most impossible any one of them should be moved from its little circle; but that the other Particles resisting, the whole would be pressed together, that is, become hard: For that is hard of which no part gives place but upon the motion of the whole. You see therefore that hardness may be made in a most fluid body by this simple circular motion of Particles, which was before imparted to them by two contrary motions.

p. 86. At{que} talis, &c. And such indeed may be the cause of the Durum primum, or first hard body. But of the second, that is, of the cohesion of two of these first hard bodies, the cause may be the very same simple circular motion, conjoyned with their superficial contact, or perhaps their being one with another intricated.

Ibid. Si supponamus, &c. If we suppose with them that the cause of hardness is the greatness or thickness of the parts, what reason can we give why congealed water should be harder or firmer than the same water is before such congelation?

p. 87. Ut sit, &c. That it be conceivable, that is, not absurd; and that from its being granted the necessity of the Phaenomenon may be inferr'd.

p. 88. Qui, &c. They which putting bodies to bodies shew the new and admirable works of Nature do wonderfully inflame the minds of men with the love of Philosophy, and do not a little instigate them unto the search of Causes, and on that account are worthy of commendation.

True; for they enrich Natural History, without which Natural Science is in vain sought for.