would appear great vibrations of the water in the upper part of the Tube the rising and the falling amounting sometimes to a foot or near half a yard but these grew lesser and lesser as those of the Quicksilver in the Torricellian Experiment use to do 4. One may use an ordinary Pail to hold the stagnant water but we rather imploy'd a vessel of Earth made for another purpose somewhat slender and of a Cylindrical shape because in a narrow vessel t is more easie to guess by the rising and falling of the Liquor how the Pump is ply'd and to perceive even smaller Leaks 5. I must not forget to take notice that though the newly nam'd Gentlemen came to me when they had seen the Experiment tryed within less than an hour after the time I had look'd upon the Baroscope and observ'd the Quick-silver to stand somewhat beneath 29 inches and 3 eights yet when presently upon their return I consulted the same instrument again the Mercury appear'd to be sensibly risen being somewhat though but very litle above 9 and 20 inches and 3 eights and 5 or 6 hours after at bed-time I found it to be yet more considerably risen Which may keep Your Lordship from wondring at what I intimated a little above touching Monsieur Paschal's Experiment as well as touching the disappointment of the Pump-makers endeavours For t is not onely possible that as I have elsewhere noted Water may be raised in the same Pump though we suppose it still equally stanch higher at one time than at another but 't was contingent that in Monsieur Paschal's noble attempt to imitate the Torricellian Experiment with Water in stead of Quick-silver the proportion betwixt the heights of those two Liquors in their respective Tubes answer'd so well to their specifick Gravities For the varying weight of the Atmosphere being not then that appears known or consequently taken into consideration if Monsieur Paschal having tryed the Torricellian Experiment when the Air was for instance very heavy had tryed his own Experiment when the Atmosphere had been as light as I have often enough observ'd it to be he might have found his Cylinder of Water to have been half a Yard or two foot shorter than the formerly measur'd height of the Quick-silver would have required I have now no more to adde about this 15 th Experiment but that it may serve for a sufficient confirmation of what I note in another Treatise against those Hydraulical Pneumatical Writers who pretend to teach wayes of making Water pass by inflected Pipes and by the help of Suction from one side of a Mountain to the other be the Mountain never so high For if the Water be to ascend as 't were spontaneously above 35 or 36 foot a Sucking Pump will not ordinarily at least here in England be able to raise it And now I speak of Mountains it will not be altogether impertinent to add that if it had not been for unseasonable weather I had thought fit to make the foregoing 11 th Experiment of elevating Mercury by Suction to be tryed at the top of an Hill not far from the place I then was at For by what has been already delivered it appears that we might have estimated the height to which the Water may be there elevated by Suction without repeating the Experiment with a thirty five foot Tube which we could not hope for conveniency to do by the utmost height to which our Engine could have rais'd Mercury and it may be of some use to be able from Experiments to make some estimate for it can scarce be an accurate one how much it may be expected that Pumps shall caeteris paribus loose of their power of elevating Water by Suction by being imploy'd at the top of an Hill in stead of being so at the bottom or on a Plain Remembring always what I lately intimated that even in the same place Liquors will be brought to ascend by Suction to a greater or less height at one time than another according to the varying Gravity of the Atmosphere EXPERIMENT XVI About the bending of a Springy Body in the Exhausted Receiver THe cause of the Motion of Restitution in Bodies and consequently of that which makes some of them Springy which far the greater part of them are not has been ingeniously attempted by some Modern Corpuscularians and especially Cartesians but since divers Learned and Judicious men do still look upon the cause of Elasticity as a thing that needs to be yet farther enquired into and because I am not my self so well satisfied as to blame their Curiosity I held it not unfit to examine by the help of our Engine their Conjecture who imagine that the Air may have a great stroak in the making of bodies Springy and this I the rather did because I had elswhere shewn that there is no need to assert that in all Bodies that have it the Elastical power flows immediately from the Form but that in divers of them it depends upon the Mechanicanical structure of the Body To make some Tryal therefore whether the Air have any great Interest in the Motion of Restitution we took a piece of Whalebone of a convenient bigness and length and having fasten'd one end of it in a hole made in a thick and heavy Trencher to be placed on the Plate of the Engine we tyed to the other end a Weight whereby the Whalebone was moderately bent the weight reaching down so near to a Body plac'd in a level position under it that if the Spring were but a little weaken'd the weight must either lean upon or at least touch the Horizontal plain or if on the other side the Spring should grow sensibly stronger it might be easily perceiv'd by the distance of the weight which was so near the plain that a litle increase of it must be visible This done we convey'd these things into the Receiver and order'd those that pump'd to shake it as litle as they could that the weight might not knock against the Body that lay under it or so shake it as to hinder us from discerning whether or no it were depress'd by the bare withdrawing of the Air. And when the Air had been well pump'd out I watcht attentively whether any notable Change in the distance of the weight from the almost contiguous plain would be produc'd upon its being let in again for the weight was then at rest and the returning Air flowing in much more speedily than it could before be drawn out I thought this the likeliest time to discover whether the absence of the Air had sensibly altered the Spring of the Whalebone But though the Experiment were made more than once I could satisfie my self onely in this that the depression or elevation of the Weight that was due to the true and meer change of the Spring was not very considerable since I did not think my self sure that I perceiv'd any at all for though it be true that sometimes
is not requir'd the Engine should be very much exhausted 58. 59 Experiment 18. About an easie way to make the Pressure of the Air sensible to the Touch of those that doubt of it 59 VVith a Caution in using of it 61 Experiment 19. About the subsidence of Mercury in the Tube of the Torricellian Experiment to the level of the stagnant Mercury 61 Some confirmations of what had been said in the first Treatise of the Physico-Mechanical Experiments Exp. 17. 62. 63 Experiment 20. Shewing that in Tubes open at both ends when no fuga Vacui can be pretended the weight of Water will raise Quick-silver no higher in slender than in larger Pipes 63 Two Tryals one with Tubes of several bignesses open at both ends 64. 65. the other with them after the Torricellian way 65. 66 Experiment 21. Of the Heights at which pure Mercury and Mercury Amalgam'd with Tin will stand in Barometers 66 A Note concerning the inconvenience if the Amalgam be too thick the use that may be made of this Experiment to discover how much two mixt Bodies penetrate one another as also to further illustrate that the height of the Liquors in the Torricellian Experiment depends upon the Aequilibrium with the outward Air. 67 Experiment 22. Wherein is proposed away of making Barometers that may be transported even to distant Countries 68 The figure the Barometer is to be of the way of filling it putting it into a Frame and securing it from the harm the Mercury its self might do in the Transportation by its moving up and down in the upper empty part 69. 70. c. The great serviceableness of this Instrument with an intimation of others of a different kind 74. 75 A Postscript advertising that there has been since some difference found betwixt an ordinary Baroscope and these Travailing ones with a guess at the reason of it and that for all this the portable Baroscopes may be serviceable 76. 77 Experiment 23. Confirming that Mercury in a Barometer will be kept suspended higher at the top than at the bottom of a Hill On which occasion something is noted about the height of Mountains especially the Pic of Tenariff 77 Other Authors Opinions about it examined 80 A more moderate height allow'd than that asserted by Ricciolus 81. 82. with a consideration to be had in the measuring the altitude of Mountains distant from the Sea 84 Experiment 24. Shewing that the Pressure of the Atmosphere may be exercis'd enough to keep up the Mercury in the Torricellian Experiment though the Air presse upon it at a very small Orifice 85 Experiment 25. Shewing that an oblique pressure of the Atmosphere may suffice to keep up the Mercury at the wonted height in the Torricellian Experiment and that the spring of a litle included Air may do the same 87 VVhat use may be made of the former Experiment for a portable Baroscope 88. 89 Experiment 26. About the making of a Baroscope but of litle practical use that serves but at certain times 90 The Argument it affords against a fuga Vacui ib. Experiment 27. About the Ascension of Liquors in very slender Pipes in an Exhausted Receiver 91 Experiment 28. About the great and seemingly spontaneous Ascension of Water in a Pipe fill'd with a compact body whose Particles are thought incapable of imbibing it 93 By it an Explication that has been made of the cause of Filtration examined A probable cause of the Ascension of Sap into trees hence suggested An attempt to make a Syphon that should run of it self without Suction 95. 96 Experiment 29. Of the seemingly spontaneous ascension of Salts along the sides of Glasses with a conjecture at the Cause of it 97 Experiment 30. About an attempt to measure the Gravity of the Cylinders of the Atmosphere so as that it may be exprest by known and common weights 101 Wherein also the specifick Gravities of Mercury and VVater are compared 102 Experiment 31. About the Attractive virtue of the Loadstone in an Exhausted Receiver 105 Experiment 32. Shewing that when the Pressure of the External Air is taken off t is very easie to draw up the Sucker of a Syringe though the Hole at which the Air or VVater should succeed be stopt 106 The first Tryal 107. The 2 d Tryal containing a variation of the foregoing 109 Experiment 33. About the opening of a Syringe whose Pipe was stopt in the exhausted Receiver and by the help of it making the pressure of the Air lift up a considerable weight 111 Experiment 34. Shewing that the cause of the ascension of Liquors in Syringes is to be derived from the pressure of the Air. 113 Exemplified in three several Tryals 113. 115. 117 Experiment 35. Shewing that upon the pressure of the Air depends the sticking of Cupping-glasses to the fleshy parts they are apply'd to 118 Experiment 36. About the making without heat a Cupping-Glass to lift up a great weight 122 Experiment 37. Shewing that Bellows whose nose is very well stopt will open of themselves when the pressure of the external Air is taken off 124 Experiment 38. About an attempt to examine the Motions and Sensibility of the Cartesian Materia subtilis or the Aether with a pair of Bellows made of a Bladder in the exhausted Receiver 127 Experiment 39. About a farther attempt to prosecute the Inquiry propos'd in the fore-going Experiment 132 First with a Syringe and a Feather 132. 133. c. Then with a Syringe in water 136 If there be an Aether what kind of body it must be with a confirmation of the 34 th Experiment 138 Experiment 40. About the falling in the exhausted Receiver of a light body fitted to have its motion visibly varied by a small resistance of the Air. 139 A Design mentioned to try this way what the degrees of celerity would be of descending bodies in an exhausted Receiver 141 A Caution given concerning this present Experiment ib. Directions given which way to lengthen Receivers for the Trial of this and other Experiments 142 Experiment 41. About the propagation of Sounds in the exhausted Receiver 143 A Contrivance describ'd necessary for this and divers Experiments 144 The Trial perform'd by it 145. 146 Another Trial with an Alarum watch 146. 147 An assertion of Mersennus examined a proposal of his shewn to be unpracticable 148. 149 A mention of some other Trials designed concerning Sound 149. 150 Experiment 42. About the breaking of a Glass-drop in an Exhausted Receiver 150 VVherein an Hypothesis ascribing the cause of the breaking of them to the force of the external Air is examined ib. Experiment 43. About the production of Light in the exhausted Receiver 151 Experiment 44. About the production of a kind of Halo and Colours in the Exhausted Receiver 152 The reason of it proposed with a suggestion that the same cause might have been of that Apparition of Light mentionea in the formerly publisht Experiments 153. 154 Experiment 45. About the production of Heat by Attrition
of the good Spirit by composing that Passion which his Zeal against the Idolatry of the King of Israel had put the Prophet into it made him capable of being acted by the Spirit of Prophesy For chearfulness of Temper is one of the Dispositions requir'd by the Rabinnical Jews themselves for fitting Men for Prophecy That may possibly be the Reason why the Scriptures mention Instrumental Musick as receiv'd in the Schools of the Prophets especially when they were actually Prophesying as it should seem to dispose them for the freer Influences of the Divine Spirit The Singing Hymns to such Instruments is call'd Prophesying in the places now mention'd So far the nature of the Spiritual Worship of the Gospel is from superseding this assistance of Instrumental Musick as our Adversaries would have us believe that on the contrary I had done not satisfied about them Onely He sometimes as I also did observ'd the Salient water to describe part of a line perfectly enough Parabolical with which sort of Curves he has been particularly conversant This made me resolve for further satisfaction to attempt by another contrivance of whose success if I can procure the Implements I need Your Lordship may expect an account what the Figures will be not onely of Salient water but Mercury and other Liquors and that when the Receiver is much better exhausted then it was necessary it should be in the foregoing Experiment EXPERIMENT V. About a way of speedily breaking Flat Glasses by the weight of the Atmosphere FOr the more easie understanding of some of the subsequent Tryals it will be requisite in this place to mention among Experiments about the Spring of the Air the following Phaenomenon belonging to its Weight This is one of those that is the most usually shown to Strangers as a plain and easie proof both that the Weight of the incumbent Air is considerable and that the round figure of a Receiver doth much more conduce to make an exhausted Glass support that weight than if the upper part of the Receiver were flat To make this Experiment we provided a Hoop or Ring of Brass of a considerable thickness whose height was 2 ½ or 3 Inches and the Diameter of whose Cavity as well at the upper as lower Orifice should have been just 3. Inches but through the errour of the workman was 3. inches and 2 10. To this Hoop we successively fasten'd with Cement divers round pieces of Glass such as is used by Glasiers to whose Shops we sent for it to make Panes for Windows and thereby made the Brass-ring with its Glass-cover a kind of Receiver whose open Orifice we carefully cemented on to the Engine and then we found as we had conjectured that usually at the first Exuction though sometimes not till the second the Glass-plate would be broken inwards with such violence as to be shatter'd into a great multitude of small fragments and which was remarkable the irruption of the external Air driving the Glass inwards did constantly make a loud Clap almost like the Report of a Pistol Which Phaenomenon whether it may help us to discover the cause of that great noise that is made upon the discharging of Guns for the Recoyl seems to depend upon the Dilatation and Impulse of the Powder I must not stay to consider EXPERIMENT VI. Shewing that the breaking of Glass-plates in the foregoing Experiment need not to be ascrib'd to the Fuga Vacui THough I long since inform'd you that in the Experiments I then presented Your Lordship it was not my purpose to deliver my own Opinion whether there be a Vacuum or no and though I do not in this Tract intend to declare my self either way yet that I may on this occasion also show that the Pressure of the Air may suffice to account for divers Phaenomena which according to the vulgar Philosophers must be referr'd to Natures abhorrency of a Vacuum I will illustrate the foregoing Experiment by another the substance whereof is this That if instead of the above mentioned brass Hoop both whose Orifices are of equal breadth you imploy a hollow but taller piece of Brass or which is more easily made of Latton shap'd like a Conus iruncatus or a Sugar-loaf whose upper part is taken off parallel to the bottom and if you make the two Orifices of a breadth sufficiently unequal as if the larger being made as wide as that of our Brass-hoop the straiter were less than an Inch in Diameter You will find that if this piece of Metal be made use of as the other was in the foregoing Experiment the flat Glass cemented on to the Orifice will be easily broken as formerly when t is fastned to the wider Orifice but if the straiter Orifice be turn'd upward the Glass that covers it if it be of a due thickness though no thicker than the former will remain entire notwithstanding the withdrawing of the Air from beneath it Which seems sufficiently to argue that t is not precisely Natures abhorrency of a vacuum that is the cause why Glasses are usually broken in such Experiments since whether the wider or the narrower Orifice be uppermost and cover'd the Metalline part of the vessel being the same and onely varying its posture the capacity of the exhausted vessel will be equal and therefore Nature ought to break the Glass as well in one case as the other which yet the Experiment shows she does not Wherefore this Diversity seems much better explicable by saying that when the wider Orifice is uppermost the Glass that covers it must serve for the Basis of a large Atmospherical Pillar which by its great weight may easily force the resistance of the Glass whereas when the smaller Orifice is uppermost there leans upon its Cover but so slender a Pillar of the Atmosphere that the natural tenacity or mutual cohaesion of parts in the Glass is not to be surmounted by a weight that is no greater EXPERIMENT VII About a convenient way of breaking blown Bladders by the Spring of the Air included in them THe foregoing Experiments having sufficiently manifested the strength of the Airs Spring upon fluid Bodies I next thought fit to try whether the force of a little included Air would also upon consistent and even Solid bodies emulate the Operations of the weight of the Atmosphere In the prosecution of which Enquiry we thought fit to make two sorts of Tryals the one where the Air is included in the Bodies on which its Spring does work and the other where t is External to them Of the first sort are this 7 th and the two following Experiments and of the second sort are some other Tryals to be comprehended under the 10 th Experiment Having formerly mention'd to Your Lordship that we were several times able though sometimes not without much difficulty to make a blown Bladder break with the Spring of its own Air I should not think it worth while to say any thing here about the same Phaenomenon but that
joyned as it may easily be to the rest of the Frame by 2 or 3 litle Hinges and a Hasp by whose help the Case may be readily opened and shut at pleasure The 3 d thing we proposed to our selves is nothing near so easie as the 2 d nor have we yet had opportunity to try whether the way we made use of will hold if the Barometer be transported into very remote parts though by smaller Removes we found cause to hope that 't will succeed in Greater The Grand difficulty to be obviated was this That though 't were easie to hinder the spilling of the Mercury by stopping the Orifice of the shorter Leg of our Siphon yet that would not serve the turn for the upper part of the Tube being destitute of Air if the Mercury be by the motion of the Instrument put to vibrate it will be apt for want of meeting with any Air in the upper part of the Tube to check its motions to hit so violently against the Top of the Glass as to beat it out or to crack some of the neighbouring parts To obviate this great inconvenience our way is to incline the Tube till the Mercury be impell'd to the very top of it and yet there will remain a competent quantity in the shorter leg of the Glass if that be not at first made too short This done the remaining part of the shorter Leg is to be quite fill'd up either with Water or Mercury and the Orifice of it is to be very carefully and firmly stopt for which purpose we use our strong black Cement for by this means the Mercury in the longer Leg having no room to play cannot strike with violence as before against the top of the Glass But though by many times successively shaking the Baroscope we did not perceive that 't was very like to be prejudiced by the shakes it must necessarily indure in Transportation to remote places if due care be had of it by the way yet till further Tryal have been made I shall not pretend to be certain of the Event But thus much of conveniency we have already found in this Contrivance that we sent it some miles off to the top of a Hill and had it brought home safe again the phaenomena at the top and bottom of the Hill being answerable to what we might have expected if we had imployed another Baroscope When the Instrument is to be sent away the height of the Mercurial Cylinder to be measured from the surface of the stagnant Mercury in the shorter Leg being taken for that place day and hour and compar'd if it may be with that of another good Baroscope which is to continue in that place as much of the Gutter as is unfill'd by the Glass may be well stuffed with Cotten or some such thing to keep the Glass the more firm in its posture and that the Tube be not shaken or press'd against the Wood some of the same matter may be put between the rest of the Frame and the Cover which ought to be well bound together And when the Instrument is arriv'd at the remote place where t is to be imployed for if it be to be sent but a litle way it may be carried safely without using any adventitious Liquor the Water that is added may be taken off again by soaking it up with pieces of Sponge Linnen c. but if in stead of Water you put in Mercury as it ought to have been put in by Weight so it is to be taken out till you have just the Weight that was put in and t is not difficult to take out the Mercury by degrees by the help of a small Glass-pipe since You may either suck up litle by little as much as remains of the additional Mercury when by erecting the Barometer and warily unstopping the Orifice of the lower Leg as much Mercury as will of its self flow out is efflux'd or else you may take out the superfluous Mercury by thrusting the lower end of the litle Pipe into that Liquor and when it has taken in enough stopping the upper end close with your finger to keep it from falling back again when you remove the Pipe NB. If it should happen in a long voyage that by the numerous Shakings of the Instrument there should from the additional Water or Mercury in the shorter Leg get up into the longer any litle Aerial Bubble which seems the onely but I hope not likely danger in this Contrivance he that is to use the Instrument at the end of the Voyage may if he be skilful free the Mercury from it by the same way that we lately prescrib'd to free it from Air when the Instrument was first fill'd I presume I need not tell Your Lordship that the chief use of this Travailing Baroscope is That he that uses it in a remote part keeping a Diary of the heights of the Mercury by comparing these heights with those at which the Mercury stood at the same times in the Barometer that was not remov'd the Agreement or Difference of the weight of the Atmosphere in distant places may be observed To which this may be added the Conveniency which the structure of these Instruments gives them to be securely let down into deep Wels or Mines and to be drawn up to the top of Towers and Steeples and other elevated places not here to consider whether by a convenient addition these as well as some other Barometers may not be made to discover even very minute Alterations of the Atmospheres Pressure Whether this Travailing Baroscope being furnish'd at its upper end with a very good Ball and Socket and at the lower end with a great weight which way of keeping things steady in a Ship has been happily used by the Royal Society on another occasion whether I say our Instrument may by this Contrivance or some other that might be suggested to the same purpose be made any thing serviceable at Sea notwithstanding the differing motions of the Ship I have had no opportunity to try but whether it may or may not be useful in spite of the rolling of the Ship it may at least be made use of in flat Calms which divers times happen in long Voyages especially to the East-Indies and to Africk and then the Instrument which at other times may lie by without being at all cumbersom may be made use of as long as the Calm lasts to acquaint the Observer with the weight of the Atmosphere in the Climate where he is and that upon the Sea which may give some welcome Information to the Curiosity of Speculative Naturalists and perhaps prove either more directly or in its consequences of some use to Navigators themselves as by enabling them by its suddain changes to foretell the end of the Calme Besides that having one of these Instruments ready at hand where ever they set foot on shore though it be but upon a small Island or a Rock they can presently and easily
Instrument as a Baroscope You need but heat a Pin or slender Wire red hot and so burn a hole through the Stoppel And this Expedient which I could not conveniently advertise Your Lordship of sooner may be of Use when a Travailing Baroscope is to be often remov'd because having once stopt the whole Orifice well t is far more easie to stop and open a Pin-hole accurately than to close and unstop the whole Orifice of the Tube Note I endeavoured to confirm more than one of the foregoing Particulars by this one Experiment Having caus'd a Portable Barometer to be made with the shorter Leg of a somewhat more than ordinary length I afterwards caus'd the upper part of this Leg to be drawn out very slender as in this 25 th Experiment and lastly I caus'd the same shorter Leg to be either about or somewhat above the middle bended downwards so that the small Orifice of the slender Apex pointed towards the Ground This done I was to have measur'd the height of the suspended Mercury but not having a fit Ruler at hand I then deferr'd and afterwards forgot to do it but I remember that neither I nor some others vers'd in such Experiments to whom I shew'd it took any notice that the Mercury was less high than in ordinary Barometers whence 't was concluded that the Atmosphere could exercise his Pressure not onely at a very small Orifice which in our Experiment did litle if at all exceed a Pin-hole but when the Air must at this little Orifice press upwards to be able to press upon the Surface of the stagnant Mercury EXPERIMENT XXVI About the making of a Baroscope but of litle practical use that serves but at certain times TO shew some Ingenious men by a Medium that has not hitherto that I know of been made use of That the not subsiding of Quick-silver in an inverted Tube that is a little shorter than 30 inches or thereabouts does not proceed from such a fuga Vacui as the Schools ascribe to Nature but from the Gravity of the external Air I devised the following Experiment Having made choice of a time when it appear'd by a good Baroscope which I had frequently consulted for that purpose that the Atmosphere was considerably heavy I caus'd Galspipe Hermetically seal'd at one end and in length about 2 foot and a half to be fill'd with Quick-silver save a very litle wherein some drops of Water were put that we might the better discern the Bubbles if any should be left after the inversion of the Tube into an open Glass with stagnant Mercury in it Having by this means though not without difficulty freed the Tube from bubbles we so order'd the matter that the Quick-silver and the litle water that was about it fill'd the Tube exactly without leaving any interval that we could discern at the top and yet the Mercurial Cylinder was but very little higher than that of our Baroscope was at that time This done the newly fill'd Pipe was left erected in a quiet place where the Liquors retain'd their former height for divers dayes But though an ordinary School-Philosopher would confidently have attributed this sustation of so heavy a Body to Nature's fear of admitting a Vacuum yet it seems that either she is not alwayes equally subject to that fear or some other cause of the Phaenomenon must be assign'd for when a pretty while after I had observ'd by the Baroscope that the Atmosphere was grown much lighter than before repairing to my short Tube I found that according to my expectation the Quick-silver was not inconsiderably subsided and had left a Cavity at the top which afterwards grew lesser according as the Atmosphere grew heavier NB. 1. The Tube imployed about this Experiment may be brought to the requisite shortness either by wearing off a little of the Glass at the Orifice of it or by increasing the height of the stagnant Mercury into which it hath been inverted 2. When the Quick silver in our short Tube was much subsided there appeared in the Water that swam upon it a litle Bubble about the bigness of a small Pins head but considering how careful we had been to free the Tube from bubbles before we set it to rest it may very well be that this so small a Bubble was not produc'd till after the subsiding of the Quick-silver whereupon the Aerial Particles in the Water became less compress'd than before not to mention that the Bubble such as it was appear'd very much greater than it would have done if the Pressure of the Atmosphere had not been kept from it by the weight of the subjacent pillar of Mercury EXPERIMENT XXVII About the Ascension of Liquors in very slender Pipes in an Exhausted Receiver VVHat I related to Your Lordship in the 35 th of the publish'd Experiments pag. 138. about the seemingly spontaneous Ascension of Water in slender Pipes has occasion'd the making of many Tryals by the Curious whereby that Experiment has been not a little diversify'd but because among those I have yet heard of none have been made in our Engine it may not be amiss to adde the following Tryal which may be of use in the Examen of one or two of the chief Conjectures that have hitherto been propos'd about the cause of that odde phaenomenon We ting'd some spirit of Wine with Cocheneel which being put into the Receiver and the Air withdrawn did exceedingly bubble for a pretty while Then little hollow Pipes of differing Sizes being put into it the red Liquor ascended higher in the slenderer than the others but upon the withdrawing of the Air there scarce appear'd any sensible difference in the heights of the Liquor nor yet upon the letting it in again Afterwards two such Pipes of differing Sizes being fasten'd together at a distance with Cement were let down into the same spirit of Wine when the Receiver was well exhausted notwithstanding which the Liquor ascended in them for ought we could plainly see after the ordinary manner onely when the Air was let in again there seem'd to be some little and but very litle rising at least in one of the Pipes In this Tryal this Phaenomenon was noted That though there appear'd no Bubbles at all in the vessel'd spirit of Wine notwithstanding that we continued to pump yet there did for a pretty while arise bubbles in that part of the Liquor that was got into the slender Pipes which I guess'd to proceed from the sustentation in part of the spirit of Wine made by the inside of the Pipe whereto it adher'd EXPERIMENT XXVIII About the great and seemingly spontaneous Ascension of Water in a Pipe fill'd with a compact body whose Particles are thought incapable of imbibing it VPon occasion of the seemingly spontaneous Ascension of Water in slender Pipes of Glass I consider'd that 't would be easie by another way to make it rise to a far Greater height than hitherto had been done for since we had found by Observation
that caeteris paribus the slenderer the little Pipes were that we imployed the higher the Liquor would rise in them and since the Hydrostaticks had taught us that often times even in very crooked Pipes Water would be made to ascend by the same wayes of raising it to the same perpendicular height or thereabouts as in straight ones I thought that I might well substitute a Powder consisting of solid Corpuscles heap'd upon one another and included in a Glass-Cane in stead of the litle Pipes I had hitherto used For I consider'd the litle intervals that would necessarily be left between these differingly shap'd and confusedly plac'd Corpuscles would allow passage to the Water as did the Cavities of the little Pipes and yet would in many places be straiter than the slenderest Pipes I had us'd And though beaten Glass or fine Sand c. might have been imployed about this Experiment yet I judg'd it far more convenient to make use of some Metalline Calx because the Operation of the Fire making a more exquisite Comminution of Solid bodies than our Pestles are wont to do is fit to supply us with exceeding minute Granes that intercept proportionable Cavities between them Upon this Consideration therefore besides others to be hereafter hinted I took a strait pipe of Glass open at both ends and of a moderate wideness for it need not be very slender and having tyed a Linnen-rag to one end of it that the Water might have free passage in and the Powder not be able to fall out we carefully and as exactly as we could fill'd the Cavity with Minium which is Lead calcin'd without addition to Redness and then having erected the Tube so that the bottom of it rested upon that of a somewhat shallow and open mouth'd Glass containing Water enough to swim an Inch or two above the bottom of the Tube into whose cavity it did as I expected insinuate it self by degrees as appear'd by a litle change of colour in that part of the Minium which it reacht till the open Glass being from time to time supplied with fresh liquor it attain'd to the height of about 30 inches And then our Society expressing a Curiosity to see it and have it plac'd among better things I was hinder'd from making any further Observations with that particular Glass Wherefore taking afterwards another Tube and some Minimum carefully prepared I prosecuted the Experiment so as to make the Water rise in the Pipe about 40 inches above the surface of the stagnant Water and I guess'd it had risen higher but by reason that at the upper part of the Minimum the difference of colour was so small as not to be easily distinguishable with certainty I forbore to allow a greater height to the Ascension of the Water nor could I where I then was much promote the Experiment for want of such Accommodations as I desir'd but about the Experiment as I try'd it I shall take notice of the following particulars I tryed some other Powders besides red Lead as beaten Glass pieces of fine Spunge Putty c. but did not find any of them do so well which success was yet perhaps but accidental and therefore the Tryal may be repeated especially with Putty because that being a Metalline Calx as well as Minium consists of very small Grains and by reason of its Great whiteness receives a Greater change of colour by wetting than Minium does in which especially if it be very fine the discoloration that Water makes toward the upper part of the Tube is sometimes not so easie to be clearly discern'd 2. I did indeed endeavour to remedy this inconvenience by using in stead of meer Water tincted Liquors as Ink tincture of Safron c. but they seem'd not to rise near so high as Water alone as if the dissolv'd ingredients did by degrees choak the pores of the Minium 3. To have the Grains of our Powder more minute and the smaller intervals between them I chose not onely to use the finest sort of Minium I could procure but also to sift it through a very fine Searce and to put it but by litle and litle into the Tube that by ramming it from time to time it might be made to lie the closer which Expedients succeeded not ill 4. It seem'd by a Tryal or two for I am not sure the observation will alwayes hold that if the Tube were very slender as about the bigness of a Swans quill the Experiment succeeded not well 5. It may be worth while to observe in what times the Water ascends to such and such heights for at the beginning t will ascend much faster then afterwards and sometimes t will continue rising 24 or 30 hours and sometimes perhaps much longer 6. One of the scopes I propos'd to my self in this Experiment was to discover a mistake in the Explication that some Learned modern Writers have given us of the cause of Filtration for whereas they teach that the parts of Filtre that touch the Water being swell'd by the ingress of it to their pores are thereby made to lift up the Water till it touch the superiour parts of the Filtre that are almost contiguous to them by which means these being also wetted and swell'd raise the Water to the other neighbouring parts of the Filtre till it have reacht to the top of it whence it s own Gravity will make it descend But in our case we have a Filtre made of solid Metalline Corpuscles where t will be very hard to shew that any such intumescence is produc'd as the recited Explication requires 7. Water ascends so few inches even in very slender Pipes as to seem much to favour their Judgment who dissallow the conjecture lately entertain'd by some ingenious men particularly M r H. about the raising of the Sap in Trees after the like manner that Water is raised in slender Pipes but without fully delivering yet my thoughts of that Speculation I may take notice that in the last Tryal above recited I made Water to ascend near if not above 3 foot ½ and if by so sleight an Expedient Water may be made to rise as high as is necessary for the Nutrition of some thousands of Plants for such a number there is that exceed not 3 foot 1 2 in height one may without absurdity ask why t is not possible that Nature or rather the most wise Author of it may have made such Contrivances in Plants as to make Liquors ascend in them to the Tops of the tallest Trees especially since besides divers things that we may already suspect as Heat and something equivalent to well plac'd Valves many others that perhaps are not yet dreamt of may probably concur to the Effect 8. As I formerly made by bending the slender Pipes we have been talking of short Syphons through which the Water runs without being at first assisted by Suction so I thought fit to try whether I could not in larger Pipes by the help of
Minium make much longer Syphons But though when the Orifices were turn'd upwards fine Minium were ramm'd into both the Legs and the Orifices were both of them clos'd yet when they came to be again turn'd downwards the weight of the Minium would somewhere or other and for the most part at or near the flexure make some such chink or discontinuation as to hinder the farther progress of the Water Which impediment though I judg'd it superable enough especially by making at the Flexure a little Pipe or Socket by which both Legs might be closely fill'd yet for want of Accommodations and leisure it was left unsurmounted Upon which account also I did not satisfie my self about the success of some former Tryals as of the Ascension of Water into pieces of Wood of differing sorts the operation of the Vicissitudes of the Suns beams and the absence of them upon liquors ascending in Tubes fill'd with Minium c. 9. Whether the Pressure of the outward Air be the cause of the Ascension of Liquors in our Tubes furnisht with Minium is a Probleme in order to whose Solution I could acquaint Your Lordship with a Contrivance wherewith to make some Tryals in our Engine But since it can scarce be well describ'd without many words unless You express a particular Curiosity to know it I shall not trouble You with it and the rather because the best way I know of examining this difficulty belongs to the 2 d part of this Continuation where mention is made of an attempt about it which did not I confess displease me EXPERIMENT XXIX Of the seemingly spontaneous Ascension of Salts along the sides of Glasses with a conjecture at the Cause of it TO the same Cause or the like with that of the Ascension of Water in slender Pipes may be probably referr'd an odde Phaenomenon which though I remember not to have been mentioned by any Chymical or other Writer I have not unfrequently observed as well by chance as in Tryals purposely made to satisfie my self and others about the truth of it The Phaenomenon in short was this That having in wide-mouth'd Glasses which should not be very deep expos'd to the Air a strong Solution of common Sea-salt or of Vitriol which reacht not by some inches to the top of the Glass and having suffered much of the aqueous part to exhale away very slowly the coagulated Salt would at length appear to have lin'd the inside of the Glass and to have ascended much higher not onely than the place where the surface of the remaining Water then rested at but than the place to which the Liquor reacht when 't was first poured in And if the Experiment were continued long enough I sometimes observed this Ascension of the Salt to amount to some inches and that the salt did not onely line the inside of the Glass but getting over the brim of it cover'd the outside of it with a Saline Crust which made them that saw how litle liquor remain'd in the Glass admire how it could possibly get thither And though I have mentioned but the Solution of Vitriol and Sea-salt because they are much easier than others to be procur'd and yet the Experiment succeeds better in Them than in some other far less parable Salts yet they are not the onely ones by whose Solutions the recited Phaenomenon may be Exhibited As for the Cause of this odd Effect though I shall not propose any thing about it with Confidence till I have further inquired into it and especially till I have tryed whether the Phaenomenon may be produced in an Exhausted Receiver yet by what I have hitherto observed I am inclin'd to conjecture that it may be referr'd to such a cause as that of the Ascension of Liquors in Pipes after some such manner as this First I observed that in Water and Aqueous liquors that part of the Surface which is next the sides of the Glass is whatever the reason of it be sensibly more elevated than the rest of the Superficies and if very litle clippings of Straw or other such minute and light bodies floating upon the Water chance to approach near enough to the sides of the Glass they will be apt which one would not expect to run up as t were this ascent of Water and rest against the sides of the Glass Next we may take notice with the Salt-boylers and Chymists that Sea-salt is usually wont to coagulate at the top of the Water in small and oblong Corpuscles so that as to these t is easie to conceive to them that have considered the first Observation how numbers of them may fasten themselves round about to the inside of the Glass And besides Sea-salt I have found by tryal divers others if their Solutions be slowly enough evaporated that will whilst yet there remains a good proportion of Liquor afford Saline Concretions at the top of the Water And the fastning of Saline particles to the sides of the Glass may perhaps be promoted by the Coldness that may be communicated to the Corpuscles contiguous to the Glass by reason of the coldness which the Glass may be suspected to have upon the score of its Density in comparison of Water But to proceed I consider that by the Evaporation of the aqueous parts of the Solution the surface of the remaining liquor must necessarily subside and those Saline particles that were contiguous to the inside of the Glass and the more elevated part of the Water having no longer enough of Liquor to keep them dissolv'd will be apt to remain sticking to the sides of the Glass and upon the least farther Evaporation of the Water will be a litle higher than the greater part of the Superficies of that Liquor by which means it will come to pass that by reason of the litle inequalities that will be on the internal surface of the adhering Corpuscles of the Salt and perhaps also on the internal Superficies of the Glass there will be intercepted between the Salt and the Glass litle Cavities into which the Water contiguous to the bottom will ascend or be impell'd upon such an account as that whereon t is rais'd in slender Pipes And when the Liquor is thus got to the top of the Salt and comes to be exposed to the Air the Saline part may by the evaporation of the Aqueous be brought to coagulate there and consequently to increase the height of the Saline filme if I may so call it which by the like means may be at length brought to reach to the very top of the Glass whence it may easily be brought over to the outside of the vessel where the natural weight of the Solution will facilitate its progress downwards and the skin of Salt together with the contiguous surface of the Glass may at length constitute a kind of Syphon To this Explication it agrees well that I have usually observed the Saline filme hitherto mentioned to be with great ease separable from the Glass in large Fleaks
such Barrels but with a foure-square Bit as they call it which leaves the Cavity too Angular or too imperfectly round whereas if an Hexahedrical Bit be imploy'd it will as he affirm'd make the Cavity almost as Cylindrical as can be reasonably desired I say nothing here of making use for our purpose of a Trunk as they call a hollow Cylinder of Wood because I elsewhere shew that Wood at least such as the Trunks to shoot Pellets with are wont to be made of is not of a Texture close enough for such an use 3. Because in Cylinders of Mercury 30 inches is a height which the Atmosphere is seldome heavy enough to be able to counterpoise and because 29 inches is somewhat nearer the middle between the greatest and the least heights at which I have observed the Mercury at differing times to stand in good Barometers Your Lordship may if You please abate a 30 th part of the weight assign'd above to a Mercurial Cylinder of 30 inches though I take 29 and ¼ or thereabouts to be somewhat a more usual height of the Mercury than precisely Nine and twenty 4. The Weight of a Mercurial Cylinder in an Aequilibrium with the Atmosphere and of one inch in Diameter being thus setled we may by the help of the doctrine of Proportions and a few Propositions especially the 14 th of the 12 th book of Euclides Elements easily enough calculate the weight of a Cylinder of Mercury of another Diameter and consequently the force of the Pressure of an Atmospherical Pillar of the same Diameter For since according to the forenam'd 14 th Proposition of the 12 th Cylinders of equal Bases are to one another as their Heights and since by the 2 d Proposition of the same 12. Element Circles such as are the Bases of Cylinders are to one another as the Squares of their Diameters and since lastly we suppose that Mercury being a Homogeneous body at least as to sense the Mercurial Cylinders will have the same proportion to each other in Weight that they have in Bulk since I say these things are so if for instance we desire to know what will be the weight of a Cylinder of 30 inches high whose Diameter is two inches the Rule will be this As the square of the Diameter of the Standard Cylinder as I call that whose weight is already known is to the square of the Diameter of the Cylinder propos'd so will the bulk of the former Cylinder be to that of the later and the weight of that to the weight of this According to which Rule the square of 1 inch which is the Diameter of the standard Cylinder being but 1 whereby Your Lordship may perceive how much the measure I pitcht on facilitates Computations and the square of 2 which is the Diameter of the propos'd Cylinder being 4 the bulk or solid Contents of this later Cylinder and consequently its Weight will be 4 times as great as those of the standard Cylinder and so since the lesser has been already suppos'd to weigh 11 8l Haberdupoise the Mercurial Cylinder of two inches in Diameter will weigh 47 2l of the same weight EXPERIMENT XXXI About the Attractive virtue of the Loadstone in an Exhausted Receiver SOme Learned modern Philosophers that have attempted to explicate the cause and manner of Magnetical Attraction or Coition give such an account of it as supposes that the Air between the two Magnetical Bodies being driven away by their Effluviums from between them presses them on the parts opposite to those where the Contact is to be made and upon some such score for I must not now stay to deliver their Theories Circumstantially the Air is suppos'd to contribute very much to the Attraction and Sustentation of the Iron by the Loadstone wherefore partly to examine this Opinion and partly for some other Purposes not necessary now to be mentioned we thought fit to make the following Exptriment We took a small but vigorous Loadstone cap'd and fitted with a loose plate of Steel so shap'd that when it was sustained by the Loadstone we could hang at a litle Crook that came out of the midst of it and pointed downwards a Scale wherein to put what Weights we should think fit Into this Scale we put sometimes more and sometimes less weight and then by shaking of the Loadstone as much as we guess'd it would be shaken by the motion of the Engine we found the greatest weight that we presum'd it would be able to support in spite of the Agitation 't would be exposed to which prov'd to be besides the Iron-plate and the Scale VI Ounces Troy weight to which if we added half an ounce more the whole weight appear'd too easie to be shaken off This done we hung the Loadstone with all the weight it sustain'd at a Button of Glass which we had procur'd to be fastned on to the top of the inside of a Receiver when 't was first blown and though in about 12 Exuctions we usually emptied such Receivers as as much as was requisite for most Experiments yet this time to exhaust it the more accurately we continued pumping till we had exceeded twice that number of Exuctions at the end of which time shaking the Engine somewhat rudely without thereby shaking off the Weight that hung at the Loastone the Iron seem'd to be very near as firmly sustain'd by it as before the Air began to be pump'd out I said very near rather than altogether because that the withdrawing of the Air though it be not suppos'd to weaken at all the Power of the Loadstone precisely considered yet it must lessen its power to sustain the Steel because this in so thin a medium must weigh heavier than in the Air by the weight of as much Air as is equal in bulk to the appended Body Some other Magnetical Tryals and also some Electrical ones I remember I attempted to make by the help of our Engine but not having the Notes I took of them now at hand I shall suspend the mentioning them till I can give Your Lordship a more punctual Account of them EXPERIMENT XXXII Shewing that when the Pressure of the External Air is taken off t is very easie to draw up the Sucker of a Syringe though the Hole at which the Air or Water should succeed be stopp'd HAving taken notice that some learned Opposers of the Modern Doctrine about the weight of the Atmosphere think themselves more than ordinarily befriended by the difficulty we find in drawing up the Embolus or Sucker of a Syringe when the hole at which the Air or Water should succeed is stopt and by the violence with which as soon as t is let go tis as they imagine drawn back And supposing the reason of this confidence of theirs to be that Men have not yet been able in these Phaenomena as in some others to prove the interest of the Atmosphere's Gravity by direct or confessedly analogous Experiments I presum'd it
being to be absent for a while my self that the Pipe should be fill'd with spirit of Wine tincted with Cocheneel that the liquor and its motions might be the better discern'd and that the Pipe being fill'd that Air might be excluded which vvould else be harboured in the Pipe which Caution was omitted in the foregoing Experiment And this the Person to whom I committed it affirm'd to have been carefully done though when he inverted the Pipe thus fill'd into the rest of the red Liquor that was put into a Viol he could not possibly do it so well but that a bubble of Air got into the Pipe and took up some though but a litle room there By that time I was call'd upon to see the Event of the Tryal and could come to look upon it the Receiver was almost quite exhausted vvherefore after I had made the pumping be continued a litle longer and perceived that the tincted spirit was fallen down out of the Pipe and that which lay in the Viol seem'd almost to boyl at the top by reason of the emersion of numerous Bubbles I caus'd the Sucker to be by the help of the Turning-key drawn up by our aestimate about two inches and a half notwithstanding which vve could not perceive the spirit of Wine to rise in the Pipe though the Pumping were before left off For vvhich reason I order'd the Air to be let in very leisurely upon which vve could plainly see that the red spirit was quickly driven up to the top of the Pipe and that it was so likewise into the Cavity of the Barrel appeared when the Receiver was removed by the small Quantity of Liquor that remained in the viol and the plenty of it which came out of the Syringe NB. That if I had not vvanted dexterous Artificers to work according to a Contrivance I had design'd I had attempted to imitate by the help of the bare Spring of the Air such Experiments as in the lately recited Tryals vvere made to succeed by the help of the Pressure exercis'd by the Air upon the account of its Weight EXPERIMENT XXXV Shewing that upon the Pressure of the Air depends the sticking of Cupping Glasses to the fleshy parts they are apply'd to T Is sufficiently known that if the Air within a Cupping Glass be rarified by the flame of Tow Flax or the like burn'd for a litle while in it and the Glass be presently clapt upon some fleshy part of a Mans body there will quickly ensue a painful and visible swelling of the part cover'd by the Cupping Glass T is also known that this Experiment is wont to be urg'd by the Schools as a clear proof of that abhorrence of a Vacuum they ascribe to Nature for say they the reason of this phaenomenon is plainly that the internal Air of the Cupping Glass praeternaturally rarified by heat when the Instrument is applied That heat after a while ceasing the succeeding Cold must again necessarily condense the Air and so this contracted Air being no longer able to fill the whole space it replenished before there would ensue a vacuum if the flesh covered by the Cupping Glass or adjoyning to it did not swell into the Cavity of it to fill the place deserted by the Air. Those Moderns that assert the Weight of the Atmosphere do thence ingeniously endeavour to deduce the phaenomenon And indeed if to their Hypothesis about the Airs Weight the consideration of its Spring be added 't will be easie enough to explicate the phaenomenon by saying That when the Cupping Glass is first set on though much of the Air it formerly contain'd were a litle before expell'd by the heat yet the same heat increasing the pressure of the remaining Air is the cause that the absence of the Air driven out of the Glass does not immediately occasion so sensible a pain but when that adventitious agitation of the included Air ceases that Air having now because of the paucity of its Corpuscles but a weak Spring can no longer press upon the part covered by the Cupping Glass neer so strongly as the outward Air does by its Weight press upon all the neighbouring parts of the flesh by which means according to what we have more than once explicated already some of the yielding flesh or other body covered by the skin must be forceably thrust into the cavity of the Cupping Glass where there is less Pressure then at the outside of it And the fibres and membranous parts being thus violently stretcht there must needs follow a sensible Pain as well as Tumour Which Tumour yet does not fill up the Cupping Glass not onely because of the resistance of the skin to be so far distended but also if the included Air have not been much rarified because of the Spring of the imprisoned Air which grows so much the stronger by how much the swelling flesh reduces the Air into less room as I have sometimes tried by applying a Cupping Glass to Quick-silver or even to Water which will rise in it but to a certain height But though by this or some such Explication the Argument urged by the Schools in favour of the fuga vacui may be sufficiently enervated yet it suited better with the design of this Treatise to propose some new Experiment to illustrate our Hypothesis and though it seem'd to be far more difficult to do it in reference to Cupping Glasses than to other subjects yet I pitcht upon two different wayes of Experimenting whose success not disappointing me I shall now give Your Lordship an account of them We took a Glass of about one Inch and a half in Diameter but a good deal longer than an ordinarily shap'd Cupping Glass of that breadth would have been that there might be the more room for the flame to burn in it and rarifie the Air. We also provided a Receiver shap'd almost like a Pear this Receiver was open at both ends at the sharper whereof there was but a small orifice but at the obtuse end there rose up a short neck whose Orifice was wide enough to admit with ease the newly mentioned Cupping Glass without touching the sides of it and we were not willing it should be much larger lest it should not be so exactly cover'd by the Palm of the hand that should be laid upon it and lest also the hand should be broken or hurt by the too great weight of the Atmosphere when the included Air should be withdrawn from under it These things being thus prepared and the smaller Orifice of the Receiver being fastned with Cement to the Engine I caused the Cupping Glass to be fastned with the mouth upwards to the Palm of the hand of a Youth whom your Lordship may remember to have seen with me whose hand seem'd fram'd by Nature for this Experiment being broad strong and very plump And having pull'd the Glass to try whether it stuck well on I caus'd him to put it into the Receiver and lay his hand so upon the Orifice
this Turning-key and the other to the uppermost Marble and which string past through the Crank or Hook belonging to the Brass-Cover we did I say by the help of this string and by turning round the Key draw up the superiour Marble and by reason of their coherence the lowermost also together with the weight that hung at it by which means being sure that the two Marbles stuck close together we began to pump out the Air that kept them coherent and after a while the Air being pretty well withdrawn the Marbles fell asunder But we having so order'd the matter that the lowermost could fall but a litle way beneath the other we were able by inclining and shaking the Engine to place them one upon another again and then letting in the Air somewhat hastily that by its Spring it might press them hard together we found the Expedient to succeed so well that we were not onely able by turning the abovementioned Cylindrical Key to make the uppermost Marble take up the other and the annexed weight but we were fain to make a much more laborious and diligent Exhaustion of the Air to procure the disjunction of the Marbles this second time than was necessary to do it at the first And for further prevention of the Objections or Scruples that I foresaw some Prepossessions might suggest I thought fit to make this further Tryal that when the Marbles were thus asunder and the Receiver exhausted we did before we let in the Air make the Marbles fall upon one another as before but the litle and highly expanded Air that remained in the Receiver having not a Spring near strong enough to press them together by turning the Key we very easily rais'd the uppermost Marble alone without finding it to stick to the other as before Whereupon we once more joyn'd the Marbles together and then letting in the external Air we found them afterwards to stick so close that I could not without inconvenience strain any further than I fruitlesly did to pull them fairly asunder and therefore gave them to one that was stronger than I to try whether he could do it which He also in vain attempted to perform And now my Lord though I had thoughts of adding divers other Experiments to those I have hitherto entertained You with yet upon a review finding These to amount already to fifty I think it not amiss to make a Pause at so convenient a Number And the rather because an odd Quartainary Distemper that I slighted so long as to give it time to take Root is now grown so troublesome that I fear it may have too much influence upon my Style which Apprehension obliges me as well to avoid abusing or distressing Your Lordship's Patience as to allow my self some seasonable Refreshment to reserve the mention of the design'd Additions till they can with less trouble to us both be presented You by My Dear Lord Your Lordship's most humble Servant and Affectionate Uncle ROBERT BOYLE Oxford March the 24. 1667. NOTES c. About the ATMOSPHERES of Consistent Bodies here below SHEWING That even HARD and SOLID BODIES and some such as one would scarce suspect are capable of emitting EFFLUVIA and so of having ATMOSPHERES An Advertisement HE that shall take the pains to peruse the following Paper will easily believe me when I tell him that t was not design'd to come abroad with the Experiments in whose company it now appears But the Stationer earnestly representing that divers Experiments being reserved by me for another occasion the remaining ones alone would not give the Book a Thickness any thing proportionable to its Breadth I consented at his sollicitation to annexe to them the following Observations because of some affinity between the small Atmospheres of lesser Bodies and the great Atmosphere that surrounds the Terrestrial Globe in which the other that do at least help to compose it are lost and confounded as Brooks and Rivers are in the Ocean And to save the Reader the pains of making Guesses to what kind of Writing the ensuing Discourse may belong I shall here intimate that t is dismembred from certain Papers about Occult Qualities in general which make part of the Notes I long since designed and also partly published about the Origine of Qualities of which Notes those that concern'd Effluviums being the most copious I referr'd them to four general Heads whereof the first onely is treated of in the following Discourse the others being withheld as having not affinity enough with the Atmosphere to accompany This whereon they have no such absolute Dependance but that they may well enough spare it And I make the less Scruple to let it appear without them because the Inducements already mentioned are not a litle strengthned by this superadded Consideration That the following Notes may give light to several of the Observations I have made of some lesse heeded Phanomena of the Alterations of the Air in case they be allowed to enter into the Appendix to this Continuation Of the Atmospheres of Consistent Bodies THe School Philosophers and the Vulgar in considering the more abstruse Operations and Phaenomena of Nature are wont to run into Extremes which though opposite to one another do almost equally contribute to keep men ignorant of the true causes of those Effects they admire For the Vulgar being accustomed to converse with sensible objects and to conceive grosly of things cannot easily imagine any other Agents in Nature then those that they can see if not also touch and handle and as soon as they meet with an Effect that they cannot ascribe to some palpable or at least sensible Efficient they are and stick not to confess themselves utterly at a loss And though the vulgar of Philosophers will not acknowledg themselves to be pos'd by the same phaenomena with the vulgar of Men yet in effect they are so But the School-philosophers on the contrary do not onely refuse to acquiesce in sensible Agents but to solve the more Mysterious Phaenomena of Nature nay and most of the Familiar ones too they scruple not to run too far to the other side and have their recourse to Agents that are not onely invisible but inconceivable at least to men that cannot admit any save Rational and consistent Nations they ascribe all abstruse Effects to certain substantial Forms which however they call Material because of their dependence on Matter they give such Descriptions to as belong but to Spiritual Beings as if all the abstruser Effects of Nature if they be not perform'd by visible Bodies must be so by immaterial substances whereas betwixt visible bodies and Spiritual Beings there is a middle sort of Agents invisible Corpuscles by which a Great part of the difficulter phaenomena of Nature are produc'd and by which may intelligibly be explicated those Phaenomena which 't were absurd to refer to the former and precarious to attribute to the latter Now for methods sake I will refer the Notes that occur to me
about Effluviums to four Heads whereof the first is mentioned in the Title of this Paper and each of the other three shall be successively treated of in as many distinct ones That Fluid Bodies as Liquors and such as are manifestly either moist or soft should easily send forth Emanations will I presume be granted without much difficulty especially considering the sensible Evaporation that is obvious to be observ'd in Water Wine Urine c. and the loose contexture of parts that is suppos'd to be requisite to constitute soft Bodies as Flowers Balsomes and the like but that even Hard and ponderous Bodies notwithstanding the Solidity and strict cohesion of their component parts should likewise emit Steams will to many appear improbable enough to need to be solemnly prov'd Whether you admit the Atomical Hypothesis or prefer the Cartesian I think it may be probably deduc'd from either that very many of the Bodies we are treating of may be suppos'd exhaleable as to their very minute parts For according to the Doctrine of Lucippus Democritus and Epicurus each indivisible particle of Matter hath essentially either a constant actual motion or an unlooseable endeavour after it so that though it may be so complicated in some Concretions with other minute parts as to have its Avolation hindred for a while yet it can scarce otherwise be but by this incessant Indeavour of all the Atomes to get loose some of them should from time to time be able to extricate themselves and fly away And though the Cartesians do not allow Matter to have any innate motion yet according to them both Vegetables Animals and Minerals consist of litle parts so contexed that their Pores give passage to a Celestial Matter so that this Matter continually streaming through them may well be presum'd to shake the Corpuscles that compose them by which continued concussion now some Particles and then others will be thrown and carried off into the Air or other contiguous Body fitted to receive them But though by these and perhaps other considerations I might indeavour to shew à priori as they speak that t is probable Consistent Bodies themselves are exhaleable yet I think it may be as satisfactory and more useful to prove it à posteriori by particular Experiments and other Examples That then a dry and consistent form does not necessarily infer in the Bodies that are endowed with it an indisposition to send forth Steams which are as it were litle Colonies of Particles is evident not onely in the leaves of Damask Roses whether fresh or dried as also in Wormwood Mint Rue c but in Ambergreece Musk Storax Cinamon Nutmegs and other odoriferous and spicy bodies But more eminent Examples to our present purpose may be afforded us by Camphire and volatile Salts such as are Chymically obtain'd from Harts-horn Blood c. for these are so fugitive that sometimes I have had a considerable Lump of volatile Salt either of fermented Urine or of Harts-horn fly away by litle and litle out of a Glass that had been carefully stopt with a Cork without leaving so much as a Grain of Salt behind it And as for Camphire though by its being uneasie to be powder'd it seems to have something of Toughness or Tenacity in it yet I remember that having for tryals sake counterpois'd it in nice Scales even a small lump of it would in a few hours suffer a visible loss of its weight by the avolation of strongly sented Corpuscles and this though the Experiment were made both in a North Window and in Winter But I expect you should require Instances of the Effluviums of Bodies of a close or solid Texture wherefore I proceed to take notice that Amber Hard wax and many other Electrical bodies do when they are rubb'd emit Effluviums For though I will not now meddle with the several Opinions about the cause and manner of Electrical Attraction yet besides that almost all the Modern Naturalists that aim at explicating things intelligibly ascribe the Attraction we are speaking of to Corporeal effluxes and besides that I shall ere long have occasion to shew you that there is no need to admit with Cartesius That because some Electrical bodies are very close and fixt what they emit upon rubbing is not part of their own Substance but somewhat that was harbour'd in their Pores besides these things I say I have found that many Electrical bodies may by the very Nostrils be discovered when they are well rubb'd to part with store of Corpuscles as I have particularly but not without attention been able to observe in Amber Rosin Brimstone c. I know not whether it will be worth while to take notice of the great Evaporation I have observ'd even in Winter of Fruits as Apples and of Bodies that seem to be better cover'd as Eggs which notwithstanding the closeness of their Shels did daily grow manifestly lighter and lighter as I observ'd in them and divers other bodies that I kept long in Scales and noted their Decrements of weight but perhaps you will be pleas'd to hear that having a mind to shew how considerable an Evaporation is made from Wood I caus'd a thin Cup capable of holding about a Pint or more to be Turn'd of a Wood that was chosen by the Turner as solid and dry enough though it were not of the closest sort of Woods such as are Lignum vitae and Box. And as I caus'd the shape of a Cup to be given it that it might have a greater Superficies expos'd to the Air and consequently might be the fitter to emit store of Steams into it so the Success did not onely answer my Expectation but exceed it for though the Tryal were made some time in Winter there was so quick and plentiful an Evaporation made from the Cup that I found it no easie matter to counterpoise it for whilst Grains were putting into the opposite Scale to bring the tender Ballance to an Aequilibrium the copious avolation of invisible Steams from the Wood which had so much of Superficies contiguous to the Air would make the Scale that held it sensibly too light And I remember that for further satisfaction being afterwards in a City where there were both good Materials and workmen I order'd to be made a Boule about the same bigness with the former of well season'd wood which being suspended in the Chamber I lay in which circumstance I therefore mention because the Weather and a litle Physick I had taken obliged me to keep a fire there it quickly began manifestly to loose of its weight and though the whole Cup wanted near two Drams of 2 Ounces yet in 12 hours viz. from 10 a clock in the morning to the same hour at night it lost about 40 Grains for t was above 39 but of such Experiments and the Cautions belonging to them I may elsewhere speak farther It were not difficult for me to multiply Instances of the continual Emanation of Streams from Vegetable
urge that t is affirm'd not onely by the generality of our Chymists but by learned modern Physitians that when either Glass of Antimony or Crocus metallorum impregnate Wine with Vomative and Purgative Particles they do it without any decrement of their weight because the Scales in Apothecaries Shops and the litle accurateness wont to be imployed in weighing things by those that are not vers'd in Statical affairs make me though not deny the Tradition which may perchance be true yet unwilling to build upon observations which to be relyed on are to be very nicely made and therefore I shall rather take notice that though the Loadstone be concluded to have constantly about it a great multitude of Magnetical Effluvia which may be call'd its Atmosphere yet it has not been observed to loose any thing of its Weight by the recess of so many Corpuscles But because if the Cartesian Hypothesis about Magnetisms be admitted the Argument drawn from this instance will not be so strong as it seems and as it otherwise would be I shall add a more unexceptionable Example for I know you will grant me that Odours are not diffus'd to a distance without Corporeal Emanations from the Odorous body and yet though good Amber-Greece be even without being excited by external heat constantly surrounded by a large Atmosphere you will in one of the following Discourses find cause to admire how inconsiderable the wast of it is If it be said that in Tract of time a Decrement of weight may appear in Bodies that in a few hours or dayes discovers not any the Objection if granted overthrows not our Doctrine it being sufficient to establish what we have been saying if we have evinc'd that the Effluvia of some Bodies may be subtle enough not to make the Body by their avolation appear lighter in Statical Trials that are not extraordinarily and as it were obstinately protracted And this very Objection puts me in mind to adde that for ought we know the Decrement of Bodies in Statical Experiments long continued may be somewhat Greater than even nice Scales discover to us for how are we sure that the weights themselves which are commonly made of Brass a Metal very unfixt may not in Tract of time suffer a litle Diminution of their Weight as well as the Bodies counterpois'd by them and no man has I think yet tryed whether Glass and even Gold may not in tract of time loose of their Weight which in case they should do it would not be easily discover'd unless we had Bodies that were perfectly fixt by comparison to which we might be better assisted than by comparing them with Brass weights or the like which being themselves less fixt will lose more than Gold and Glass My third and last consideration is that there may be divers other wayes besides those furnish'd us by Staticks of discovering the Effluvia of solid Bodies and consequently of shewing that t is not safe to conclude that because their Operation is not constant or manifest such Bodies do never emit any Effluvia at all and so are uncapable to work by their intervention on any other Body though never so well dispos'd to receive their Action And this I the rather desire that you would take notice of because my chief though not onely design in these Notes is you know to illustrate the Doctrine of occult Qualities and it may conduce to explicate several of them to know that some particular Bodies emit Effluvia though perhaps they do it not constantly and uniformly and though perchance too they do not appear to emit any at all if they be examin'd after the same manner with other exhaleable Bodies but onely may be made to emit them by some peculiar way of handling them or appear to have emitted them by some determinate operation on some other single Body or at most small number of Bodies Perchance you did not think till you read what I lately told you about Glass that from a Body that had endured so violent a fire there could by so sleight a way as rubbing a litle while one piece against another be obtain'd such steams as may not onely affect but offend the Nostrils Nor should we easily believe if Experience did not assure us of it that a Diamond that is justly reputed the hardest known Body in the World should by a litle rubbing be made to part with Electrical Effluvia Nay that I may give some kind of confirmation to that part of the last Paragraph that seems most to need it I shall adde that I once had a Diamond not much bigger than a large Pen which had never been polish'd or cut whose Electrical virtue was sometimes so easily excited that if I did but pass my fingers over it to wipe it the virtue would disclose it self and if as soon as I had taken it out of my Pocket I applied a hair to it though I touch'd not the Stone with my fingers that I might be sure not to rub it that Hair would be attracted at some distance and many times one after an other especially by one of the sides of the Stone whose surface was made up of several almost triangular Planes and though this excitation of the Diamond seemed to proceed onely from the warmth that it had acquir'd in my Pocket yet I did not find that That warmth though it seem'd not to be alter'd had alwaies the same effect on it though the wiping it with my finger fail'd not that I remember to excite it Something like this uncertainty I always observ'd in another Diamond of mine that was much nobler than the first and very well polished and in a small Ruby that I have yet by me which would sometimes be considerably Electrical without being rubb'd when I but wore the Ring it belong'd to on my litle finger and sometimes again it seem'd to have lost that virtue of operating without being excited by friction and that sometimes within a few minutes without my knowing whence so quick a change should proceed But I must insist no longer on such particulars of which I elsewhere say something and therefore I prceed to take notice that we should scarce have dream'd that when a Partridg or a hunted Deer has casually set a foot upon the ground that part where the Footstep hath been though invisibly impress'd should continue for many hours a Source of Corporeal Effluxes if there were not setting Dogs and Spaniels and Bloud-hounds whose noses can take notice at that distance of time of such Emanations though not onely other sorts of Animals but other sorts of Dogs are unable to do so I saw a stone in the hands of an Academick an Acquaintance of mine which I should by the Eye have judg'd to be an Agate not a Blood stone and consequently I should not have thought that it could have communicated Medicinal Effluvia appropriated to excessive Bleeding if the Wearer of it had not been subject to that Disease and had