the admirable Design and finding out all the Measures and Proportions of so Beautiful an Order when he aims to penetrate too deep into the Truth frames to himself an indefinite number of falsities which proceeds from no other cause but his Ambition to take those Wings Nature never design'd perchance fearing to be some time or other discovered by him unwillingly in the preparation of her greater Works yet upon these he begins to raise himself and tho charged with the weight of a Material Body stretches forth these Pinions to soar higher than the Scale of Sense leads and fixes himself upon that Light whose Rays too powerful for his Eyes dazle and blind him Thus we see from Mans Rashness the first Seeds of false Notions came from which yet it happens not that the bright Splendor of Gods Excellent Creatures is at all shaded or by their Commerce with them in the least vitiated since all these Imperfections are to be Attributed to Mans Ignorance vitiated whence they had their Beginnings when improperly applying the Causes to the Effects he takes not from either the verity of their Beings but onely delineates in his own mind a false Conception of their Relation to each other and agreement not that the soveraign Beneficence of God when he Creates our Souls denies them to pry as we may say for a Moment into the Immense Treasure of his Eternal Wisdom adorning them as with the most precious Jewels with some first Sparks of Truth sufficiently evident from their retaining Notions not to be acquired here whence we must conclude They received them from some other Place But it happens through our Misfortune that these rare Gems as they are but loofly set in the Mind yet too tender when she first falls into her Earthly Habitation and wraps her self in this Clay so for a time they fall out of their Collets are sullyed and worth nothing till by assiduous and careful Study they are again reset in their proper places This is what the Mind attempts in the search of Nature wherefore we must Confess we have no better means then Geometry which at first Essay hits the Truth and frees at once from all doubts and wearying Researches And indeed she leads into the way of Philosophical Speculations but at last leaves us not that Geometry has not a large Field to expatiate in and Travels not over all Natures Works as they all submit to those Mathematick Laws by which the Eternal Decree freely Rules and Commands them but because we hitherto are unable to follow her in so long and wide a Path onely a few steps Now where we may not trust our selves to go farther we can relye on nothing with greater Assurance than the faith of Experience which like one that having several loose and scattered Gems endeavours to fix each in its proper Collet by Adapting the Effects to the Causes and again the Causes to the Effects if not at first Essay as Geometry yet at last succeeds so happily that by frequent Trying and Rejecting she hits the Mark We ought then to proceed with much Circumspection lest too great a relyance and trust in Experience turn us out of the way and impose upon us since it sometimes falls out that before the clear Truth appears to us when the first more open Vailes of Deceit are taken off we discover some cheating Appearances that indeed have some likeness and Resemblance of Truth and these are the imperfect Lineaments that are seen through the last coverings that more nearly vail the lovely face of Truth through the fine Web whereof she sometimes seems so plain and lively that some might conclude She was Nakedly Discovered Here then we ought to carry our selves as Master-workmen to discern between Truth and Error and the utmost perspicacy of Judgment is but requisite to see well what really is from what is not And to be the better able to perform this Task doubtless 't is necessary to have at some time or other seen Truth unvailed an Advantage they onely have who have had some taste of the studies of Geometry Nor is it of less use to search among Experiments already made than to attempt New ones if haply any may be found that have at all disguised the simple Face of Truth wherefore 't is aimed at in our Academy besides what has been Invented by us to try also either for Curiosity or as we light upon them by chance those things which have been already done or wrote off by others observing too well That under this Name of Experiments frequent Errors have crept in and been entertained This was the first Motive to the perspicacious and indefatigable Mind of the most Serene Prince Leopold of Tuscany who in the Recess of those daily Negotiations and solicitous Cares that attend his High Quality diverted into the rough Path of the Noblest Sciences But his Highness's discerning Judgment easily foreseeing that the Reputation of great Authors proves too often hurtful to the Studious who through too much Confidence and Veneration of their Names fear to call in question what is delivered upon their Authority wherefore he judges it an Vndertaking worthy of his great Mind to confront with the most Acurate and sensible Experiments the force of their Assertions and with the due rejection of Errors and Embraceing of Realities to make so desirable and inestimable a Present to those that earnestly wish for the discovery of Truth These prudent Instructions of our most Serene Patron received with due Reverence and Respect by our Academy has not moved us to be indiscreet Censurers of the Learned Pains of others nor made us bold Obtruders of our own Sentiments for Truths and discoveries of Abuses but it is our Principal Intent to incite others also to repeat with the greatest severity and niceness the same Experiments as we have now adventured to do with those of any other Person Tho in Publishing these first Essays we have what we could abstained therefrom that we might by this due respect gain upon the Adversary to believe the sincerity of our Impartial and Respectful Thoughts And to the full compleating of so generous and useful an Vndertaking we desire onely a free Correspondence with those several Societies that are disperced throughout the more Illustrious and Noted Parts of Europe That with the same design of attaining such high Ends so profitable a Commerce being in all parts round about promoted we may all go on with equal freedom enquiring as much as possible and participating of the Truth and for our parts we will concur to this Work with the greatest simplicity and ingenuity whereof 't is no small Argument That when we have related the Experiments of others we have still mentioned the Authors Name when known to us and that we have often freely confessed that supposition concerning some Experiments which when put in practice we were never so successful as to bring to Perfection But above all to prove clearly the unfeigned sincerity
Then the Pearl sink down again and at the same time other parts thereof gathering into new Bubbles raise themselves And so all the while the Ebullition or Fermentation lasts there is a continual Motion of them up and down through the Vinegar A RELATION OF VARIOVS ACCIDENTS Observable in some ANIMALS Included in Vacuo FRom the very time Torricelli found out his First Experiment of Mercury he had thoughts of including several Animals in the void space to make Remarks upon their Motion Flight Breathing and all other observable Accidents But not being then provided with fit Instruments for this purpose he was contented to perform what he was able to do for small and tender Animals oppressed by the Mercury under which of necessity they must lye to be at the top of the Vessel when inverted and immersed in the Stagnant Mercury would be most commonly dead or expiring so that it would be hard to determine whether they had received more damage from the Suffocation of the Mercury or from the want of Air. And either for this cause he forbore or was deterred from attempting the Experiment in an open Vessel misdoubting the sufficiency of the Ligature to sustain the air bearing thereon with its whole Weight and besides he was diverted soon after this Invention by other Employments which wholly took him up that he had no time to apply himself to this and give it a greater perfection which it is probable he would have done if a too hasty Death had not prevented him But we being satisfied that the force of the Air was not so great that the Cement and a Bladder well tyed down was unable to withstand it have always successfully made use of a Vessel open at both ends as already hath been shewn and as we have also done in these Wherefore we will now proceed to give an account of the Accidents observed in divers Animals included in this Vessel as follows An Horse-leech being kept in vacuo above an hour remained alive and well freely moving her self as if she had been in the Air. The same did a Snail in both these tho deprived of the Air we could observe nothing to argue it had any Effect upon them Two Grass hoppers were for a quarter of an hour very lively continually moving up and down but not leaping upon the admission of the air they leaped away A Butterfly whether hurt by the hand in putting it into the Vessel or whether it suffered from the want of air 't is certain that as soon as the vacuum was made she was quite deprived of Motion except a scarce discernable and languid Tremour in her Wings which upon the Ingress of the air shoke very much but we could not discover well whether the Animal it self or the Motion of the air caused it but upon taking out of the Vessel we found it dead There are a sort of Flyes larger than ordinary commonly called Moscone in Italian that make a great Buzzing through the air with their Wings one of these which being shut up in the Vessel continued to buz very vigorously as soon as ever the vacuum was made fell down as if it had been dead and the noise of its wings ceased we presently gave it air whereupon it moved a little but the Remedy was too late for it was scarce taken out before it died A Lizard in vacuo quickly grew sick and soon after closing her Eyes seemed to be dead but we agreed afterward that we observed some Respiration perceiving a little swelling in the Thorax between the Fore-legs we continued the Confinement for the space of six Minutes in which time it had lost all breathing and appeared Dead we then admitted the air which so recovered it that presently the Vessel being opened she leaped out and ran away catching it again we included it the second time and she appeared sick as before but the air revived her again we Imprisoned her the Third time and in Ten Minutes after some strainings as if poysoned she vomited and fell down quite dead in the Glass Another little Lizard in less time suffered the same strainings or Convulsions and then had a little Rest and as if she had taken breath and gotten strength thereby she endeavoured several times to creep up the sides of the Vessel when the same Convulsions returned with strange Distortions of the Mouth and swelling of the Eyes as if they would have started out of her Head she turned upon her Back and after a little gaping for breath dyed It was after observed that she had discharged something by the Mouth and Anus whence the Belly became flaccid and empty Another beginning to suffer the same torments had immediate Relief from the Air. A small Bird as soon as the vacuum was made began to gape and pant for breath and shaking its Head hung down its Wings and Tail after half a Minute when it seemed almost dead we gave it air and so at first it seemed to revive but in few moments shutting the Eyes it dyed A Gold-finch and after that another though presently succoured with the air yet found it too late So sudden is the irreparable hurt these tender Animals receive from the privation thereof The almost Instantaneous Death of these Birds may at first view seem to contradict an Experiment of Mr. Boyles wherein he mentions a Larks living in the Evacuated Receiver though one of its Wings was hurt about Ten Minutes And a Sparrow taken with Bird-lime endured for Seven Minutes at the end of which seeming dead she was recovered with the fresh air and being again included and the Vessel Evacuated in the space of Five Minutes dyed But whoever Reflects upon the different ways of making the Vacuum in the one and the other Instrument will confess that the two Experiments how different soever they seem do indeed wonderfully agree for whereas in that the air is thinned by repeated Attractions and slow and little more then insensible acquists at each draught in our Instrument 't is reduced to the greatest degree of Rarity by the Instantaneous fall of the Mercury to which when the air is brought 't is no longer serviceable to their Respiration And if when we had included the Animals we inclined the upper Mouth of our Vessel below the perpendicular Height of 28 6 10 Inches reckon'd from the Level of the Stagnant Mercury in the Basin and opening the lower Mouth we gradually raised it by little and little to an upright we have observed the very same Effects related by Mr. Boyle the air then of necessity passing through all the intermediate degrees of Rarefaction from a greater to a greater as it does in Evacuating his Receiver is not so soon rendered useless to the Respiration of these Animals A soft Crab at first putting in moved then grew feeble and began to faint away when he had stood a little while motionless or rather
of making the Experiment under Water which perhaps might detect something to us so we took the bladder out of the Fish alive and well tying it in a Net fastened a convenient weight and sunk it in water and then made the vacuum when we might see many small bubbles of air issue from the slender part thereof where 't is probable the Natural Meatus is which transmits it when the Vessel was opened the air shrunk it like the other Lastly willing to see what way the air takes from the bladder to get out of the Fishes Body whether by the Gills or Mouth we covered a Roach with the same Net that by affixing a Weight it might be kept under water the vacuum being made we saw a great deal of air come out of his Mouth in large bubbles as before from the submersed bladder Here should have been the End of these Experiments but while these Sheets were in the Press one of our Academy having thought of a way to facilitate very much the management of our Vessel to make the vacuum we will not omit to set it down here and the rather because we found it indeed very convenient The Invention consists in joyning to the Cane BE Tab. 10. Fig. 1. the Retum BFG designed in the Figure by the Prick'd Line for putting as usual the Mercury in at the Mouth AC when it comes up to G in the Return we tye it down close and fill it up to AC where being closed after the usual manner it is sufficient to open the Mouth G and without any immersion all the Mercury above 28 6 10 Inches taken from G towards E runs out and Note that the Ball FG serves to keep in the Mercury in the fluctuating Motions it makes in the Two Branches of the Cane before it rests caused by the impetus of its fall This is all at present touching the Natural Pressure of the Air and its Various Effects EXPERIMENTS OF Artificial Freezing AMong the rest of the stupendious Works of Nature that admirable Power has been always much regarded whereby she binds the slippery Waves changing their fleeting Inconstancy into Solidity and hardness This Effect tho daily before our Eyes in comparison of others more secret and rare yet has continually afforded Ample Subjects of Curious Speculation to the Mind of Man for whereas Fire when disingaged in swiftly winged sparks by insinuating it self through the close Pores of Flinty and Metalline Bodies opens melts and reduces them to a perfect Fluid so Cold on the contrary a much stranger thing stops and consolidates the most Fluid Liquors changing them into downy Snow and glassie Ice which upon the least Ray or warm breath break Prison and steal away in their first fluidity again And which is yet more amazing so violent a force of Cold in Freezing is observed penetrating not onely Glass but even the secret Pores of Metals As in the Subterranean Caverns and deep Mines the Raging Flames impetuously divide and in fury open all those dark Passages so Cold in the Act of Freezing cracks shut Vessels of thick and strong Glass stretches distends and at last tears those of pure Gold and bursts asunder those of Cast Brass and of such thickness as to break them by dead weight would require perchance nay assuredly some Thousand weight upon this strange Phenomenon of Freezing observable in water more than any other Fluid Some have thought that where the Cold operates in its proper Laboratory with fit materials it reduces the pure Water to such a temperament that it turns it into even the hardest Rock-Cristal and Gems of various Colours according to the different Tinctures received from the neighbouring Mineral steams nay even into the Invincible hardness of the Diamond And Plato was of this Opinion That Diamonds were Generated of the remains of those Waters whence in the secret Caverns of the Earth he thought Gold was produced and therefore a Diamond is called the off-spring of Gold by that Divine Philosopher in Timaeo But to return to the Causes of Freezing The ingenious in all times have had various Sentiments thereof whether it does indeed come from any real and proper body of cold which in the Schools they call Positive that as Light and Heat are Originally in the Sun is either in the Air or Water or Ice it self or any other part of the Vniverse as its proper place and Residence where it has its Repository and Treasury in which sence the Words of the Divine Oracle in Sacred Writ may be taken Hast thou entered into the Treasures of the Snow or hast thou seen the Treasures of the Hail Or whether Cold is nothing else but a Total Privation or driving away of Heat Touching this and other curious Observations of the Artifice used by Nature in Freezing whether she Atchieves her End by Contracting or Rarefying the Fluid whether the Change proceeds slowly or instantaneously c. we were induced to try several Experiments of Artificial Freezing made by the outward application of Ice and Salt fully perswaded that the operation does not at all vary from the procedure of Nature when by the pure and simple cold of the Air she Congeals Water What hitherto we have had the good luck to observe upon so vast and boundless a Subject capable of so great and endless Observations will be offered to you in the following Experiments Experiments To know if Water dilates it self in Freezing IT was the thoughts of Galileo That Ice was rather Water Rarefied than condensed because says he Condensation consists in Diminution of Bulk but increase of weight and Rarefaction in the increase of Lightness and Bulk too but water in freezing gains in Bulk and Ice is lighter than Water since it swims thereon c. This being supposed which Experience will sufficiently prove we were curious to see what water would do when confined in a Vessel where it had not the least room to dilate yet on all sides being encompassed with Ice to freeze it since we still observed agreeable to Galileo that water as well frozen into great Mountains of Ice as in the smallest pieces and of what Figure soever continually swims upon the Surface of other Water a certain proof that in the act of freezing the increasing of the Bulk considered it grows lighter whether it be by the interposition of small and insensible vacuities or interspersion of Minute Particles of air or the like matter after the manner of little blebs in Cristal and Glass for such they appear to the Eye through the body of the Ice when held up against the Light in some places thicker in others fewer and if the Ice be broke into small pieces under Water they rise up through the Water in great Numbers The First Experiment TAking a Vessel of thin Silver Plate with Two Covers to screw on such as we use to cool our Sherbet and other Drinks in Summer we fill'd it with fair water cooled
wonderfully intend the freezing and if besides the strong-Water you add salt it will prove most powerful nay sugar produces such an Effect but not much in comparison of common Salt Nitre and Sal-armoniac which we found much more successful in the operation of freezing than all the Rest The Sixth Experiment Touching what Metal preserves Ice best PUtting Ice in Vessels of several different Metals to observe which kept it the longest unthaw'd yet of this we could obtain nothing certain tho we may say at large from a very great number of Experiments which we made that it was preserved best of all in Lead very well in Tin but a short time in Copper and Iron less in Gold and yet a lesser time in Silver nevertheless at sometimes this order was changed it melting sooner in Tin and Lead than in Silver and Gold wherefore as we hinted this Experiment is not to be much confided in but proposed here rather to excite others to attempt it by some more secure way than to shew any certainty we obtained in our Observations The Seventh Experiment Of Freezing a Piece of Ice to a Table GAssendus Writes and it is very true That if a Plate of Ice be laid upon a flat Table and well sprinkled above with Salt it will freeze fast down to the Table we were desirous to make the same Experiment with Nitre but it succeeded not so as to shew us the least beginning of Adhaesion we have often observed in those stuck down with common Salt that we much more easily separated them from the Table by lifting them up Perpendicularly or at one end first as a Board nailed down is raised up with a Lever than they could be forced along parallel to the Plain moreover the Water on the under-side of the Ice was Salt and that side also thereof was Opake and covered with a white hoariness made of innumerable small particles of Salt and brought to the Light it appeared rough as if it had been prettily razed with the point of a Diamond like the Glass of those Vessels which from the Artificial similitude they have to Ice we call Ice-glasses The Eighth Experiment Of freezing the Dew upon the outsides of Vessels THat Dew which covers the outsides of Glasses containing any cold Liquor or Ice is sometimes observed to congeal there and the same happens when the Ice or Snow in the Vessel begins to alter with the strong Water or Salt there is also an Exhalation or cloudy moist Vapour rises up as it seems from the bottom of the Vessels whence proceeds a very cold air which besides that it sensibly affects the hand is likewise more discernable by the agitation which it causes in the flame of a Candle brought near it This Experiment we repeated by putting Ice sprinkled with strong water and Salt in several Vessels of different Figures and Metals to observe if either the one or the other afford any variety in the smoaking and as to the materials we could not perceive any diversity whether the Cups were of Glass Earth Wood Metal or precious Stones But as to the Figure it seemed to us that whereas in Beer-glasses and all other tall narrow Vessels the smoak began above on the contrary in wide bouls it smoaked from the bottom freely upwards for a short space In a Golden Boul we observed an effect which ought to be Vniversal in all Vessels tho it is less observable in some by reason of their shape it was this when the smoak ceased that crust of Ice began to let fall after the manner of dew a fine Ice like poudered Glass and continued till the ice in the Boul being dissolved that thin outward covering likewise melted The Exhalation said to proceed from the ice seems very different from that of any combustible Matter and much resembles the Morning mists that rise from the Earth The Ninth Experiment Of Reflected Cold. WE were willing to try if a Concave Glass set before a mass of 500 l. of Ice made any sensible repercussion of Cold upon a very nice Thermometer of 400 deg placed in its Focus The truth is it immediatly began to subside but by reason of the nearness of the Ice 't was doubtful whether the direct or reflected rays of Cold were more Efficacious upon this account we thought of covering the glass and whatever may be the cause the Spirit of Wine did indeed presently begin to rise for all this we dare not be positive but there might be some other cause thereof besides the want of the reflection from the Glass since we were deficient in making all the Trials necessary to clear the Experiment EXPERIMENTS Touching an Effect of HEAT and COLD Lately observed as to the Alteration of the inward Capacity of Glass and Metalline Vessels WE said in the Experiments of Artificial Freezing that the first Motion observed to be made by the Liquors exposed in Vessels to freeze was a small rising up there called Rise upon Immersion because it happens upon the Vessels first touching the freezing mixture and you must know the contrary to this is observable when it is immersed in hot Water for the Levels of the contained Fluids sensibly subside and then as it were take time to Rise again which they do with a quick Spring up to the degree they stood at when first immersed in the hot Water and thence successively rise as the heat received continues to rarifie lighten and raise them On the other side tho they are raised upon the first immersion into cold Water or ice yet they not onely subside again to the former height but continue to do so for many Degrees till at last sometimes after a little Rest sometimes without any they all remount Oyl and Spirit of Wine excepted until the whole freezing is finish'd This Effect was by some attributed to a cause much favoured by several following Experiments their apprehension was That the appearance of this sudden motion in water and other fluids was not really from any intrinsic alteration of rarity or density at that moment wrought in their natural temperament by the power of any Tab. 15. p. 105. contrary quality of the outwardly applyed ambient which some by a noted Word call Antiperistasis but rather to speak first of the subsiding upon the immersion of Vessels in hot Water their thoughts are that it comes from the fixing of several volatile Corpuscles of the fire evaporated from the hot Water into the external pores of the Glass which as so many wedges forcing and separating the parts thereof must necessarily distend and enlarge the internal Capacity thereof till they find a way through the hidden Passages of the Glass to the Liquor therein contained That on the other side Cold binding up and contracting those pores of the Glass makes the Vessel become too scanty for the bulk of Water in it before that bulk of Water yet unaffected by the Cold contracts likewise In fine that the
Vessel being first sensible of Cold or Heat by shrinking or enlarging it self also first is the true cause of that Phenomenon of the Rise or Fall as it becomes more strait or large to the contained Liquors yet not vitiated by the quality of the ambient This Opinion was rendred more probable to us by the following Experiment An Experiment Proving That in the Instant that the External Heat or Cold dilates or contracts the vessel yet then the natural temperament of the Liquors therein contained is unaltered WE included in a Globe of Glass filled with Water several small bubbles of Coloured Glass empty and sealed Hermetically these were all near the Specifick gravity of the Water by means of the air they had in them whence the Floaters upon the top of the water upon the least breath of warmth sunk down and those at the bottom upon any accession of Cold mounted upwards hanging this Instrument in the air and suffering the bubbles to rest we began to approach to it underneath a pan of Water heated and after that of Cold Water mix'd with Ice well broken And though upon the application of these different Ambients we observed the same Effects in the Level of raising it self upon the touch of the Cold and subsiding upon that of the hot Water yet we could not find when the water seemed condensed and contracted that any of them at the bottom rose up nor when the Water seemed rarefied and enlarged any of the Floaters sunk to the bottom but these were observed to fall and those to rise when the Water after its abatement upon the first impression of heat began to rise again and when after its rising upon the impression of Cold it began to subside again an argument to insinuate that the water and so any other Fluids in this first Motion do not really move themselves but onely obey the alteration of the Vessels they are contained in Yet it may be objected That these first alterations did really proceed from the inward changes of the Liquors which tho discernable by the Eye by means of the small Neck of the vessel yet were not great enough to be discerned in changing the aequilibrium of the Bubbles of which it may be thought that in that very instant they began really to move though in their first parting from Rest the Eye could not perceive it To this is answered That the true Rarifaction and the true Condensation of the Water that is able to make it rise or fall so very little a space as it does rise or fall at the entrance into the Icey mixtture or hot Water is sufficient to alter the Aequilibrium also between it and the bubbles apparently to the Eye And indeed when the Water really rises or falls from a true Rarifaction or Condensation the bubbles likewise begin correspondently to move before ever it comes to the same Degree at which the same bubbles remaining immoveable it stood at the instant of its first immersion Nevertheless the discovery of this Effect ought not to cause in us the least scruple of the truth of our Thermometers since the whole contraction or dilatation in Vessels containing an Ounce and half at most amounts but to a grane whence proportionably how small will that be in Vessels of a few granes content such as our Thermometer of 50 deg which are the most convenient and exact and upon that account most made use of to discover the Alterations of the Air Now to manifest by divers ways even to sense the Truth of this Phenomenon we made the following Experiments which first founded in the Theory are confirmed by the Effects The First Experiment Shewing the Alteration of the Size of a brass-Ring put in the Fire and in Ice its Figure still remaining unaltered THere was ordered to be cast a Ring of Brass and by turning it was fitted exactly to a Cilinder of the same Metal this was put in the fire for a short space and then being put upon the Cilinder while hot it was sensibly loose being dilated by the heat into a Ring of the same shape it was of before but its concavity was 9 100 parts larger when it had remained some time upon the Cilinder and had communicated its heat thereto between the increasing of that and the shrinking of the Ring by little and little as it cooled they not onely came to fit as at first but were so firmly united that before they were quite cold a considerable force was but requisite to separate them The contrary in all respects happened when we intensly froze the Ring The Second Experiment Whereby it appears that Bodies are dilated by the imbibing of moisture as well as by the insinuation of heat WE made a Conical Ring of Box whose concave Superficies was curiously turned and polish'd there was also made a stock or Conical Mandril of Steel turned and well smoothed and nicely divided with many circles Parallel to the Base fitting the Ring upon this we marked which of those Circles the bottom thereof just touched taking it off we let it lye in Water three whole days that it might have time to penetrate through the whole stubstance of the Wood then we put it on again and observed that the Concavity was stretch'd the bottom of the Ring falling much lower upon the stock than it did at first This Ring was made two several ways in one the Ligneous Fibres were Perpendicular in the other Parallel to the Plane of the Basis the first after soaking in the water kept its spherical Figure exactly the other came near to an Oval and put upon the stock sunk down much short of the former Observe to make these Rings of firm clear Wood that is without Knots and of an uniform hardness especially when the Fibres are cut transversly that so all being swell'd by the steeping their enlargment may be the more sensible Note also as was said at first that the Rings must lie so long in the Water as their whole substance may be penetrated for the Effect will be different if those that are but a little soaked on the outside be put upon the Stock because they will not slide down so far as when they were dry Therefore let them be well impregnated and satiated with moisture that their dilatation may be the more visible The Third Experiment Which discovers more evidently the readiness of Glass to contract and dilate it self upon Heat and Cold. THere was made a hollow Ring of Glass as in the Figure about Two Foot in Diameter with Two Funnels that when the Liquor was poured in at one the Air might have vent at the other then was made a Cross of Glass just to touch with its Extremities the Concave of our hollow Ring and filling the Vessel with hot Water by the Funnel as it proceeded in dilating it self so visibly either the one or the other of the Glass Rods lost their hold for they did not bear equally
stiff against the Instrument and at last both were loosened so that the Cross being at liberty fell down upon the Table whereon we set the Instrument within the Circumference of the Ring After this pouring the hot Water out we fill'd it with a mixture of Salt and Ice dissolved and it not only held the Cross again but with greater firmness than at first The Fourth Experiment To find the same Effect in Metals HAving bent a small Plate of Tin like a Stirrup and hung it up so as the two Extremities might touch a Plane put under them upon which we drew two Lines where the aforenamed Extremities must necessarily strike if they had been prolonged we then put a live Cole over the bending of the Plate and attentively observing one of the Points we discerned that by little and little it parted from the line drawing within it and this was when the convex of the Plate onely being heated dilated it self and the Concave was contracted but when it had penetrated which it soon did the whole thickness of the Tin being then equally dilated the point not onely again reacht the Line but passed beyond it more or less in Proportion to the Heat communicated by the Fire to the bending of the Stirrup The Fifth Experiment To observe by the Sound the like Dilatation in a Stirrup of Glass WE fitted a Minikin to a broad Stirrup of Glass as in the Figure and tuned it an Octave to the string of a Guitarre and applying the heat to it after the same manner as we did to the Stirrup of Tin when it had not yet affected the Concave Superficies thereof but onely the Convex Tab. 16. p. 110. the Tone was flatter because as in the foregoing Experiment the aperture was lessened and consequently the string slackened but when the heat had penetrated quite through the String was straitned so as the Sound was sharper than the first tuneing The Sixth Experiment Discovering the same Effect more clearly to the Eye WE fastned to the same String with a bit of Thread a small Leaden Plummet and put under it a little Plate of Glass so as not quite to touch the Weight and applyed fire to the usual place the Effect as to the stirrup was the very same as at other times for being at first drawn together the Cord became slacker and the Weight Rested upon the plate of Glass but at last extending the Aperture it strained the Cord and raised up the Plummet the contrary Effect was wrought by Ice made use of instead of the Coal but sensibly less in proportion as its activity is less than the fires The Seventh Experiment Shewing the same effects in Wire strings A Leaden Plummet being fastened to a nealed Brass-Wire and hung over a Glass Plate at a little distance therefrom drew nearer to touch it as the Wire became heated by applying a lighted Candle to it and still retired from it upon every little Rubbing with Ice In like manner two wires of mixt brass tuned unisons so that one being struck the other sounded were made discordant either by approaching to one of them a live Coale or a piece of Ice that by lengthening the wire made the Tone flatter and this by shortning it sharpened the Sound thereof The Eighth Experiment Whereby from the appearance of a contrary Effect 't is confirmed That the first Motion of Liquors comes from the Capacity of the Vessels being altered in the instant of Immersion IT may happen upon the first Immersion of Vessels into the Ambient Hot or Cold Body that the Level of the contained Liquors shews a different Effect from that before-named that is That it may immediatly rise in a hot Ambient and subside in a Cold one this will be always if the Vessel be made in the shape represented by the Figure in this upon the first touch of warm Water the Liquors will presently Rise because in the lateral Angles being very strong and thick of Metal in comparison of the hollowed faces the heat acting first upon the outward Superficies lessens those Angles as we said before it does to the Stirrup of Glass and so necessarily comes to stretch the thinner hollowed parts which Dilating inwards happen at first to lessen the Capacity of the Vessel and to raise the Liquor in the Neck which falls again from that space new filled when the heat has penetrated the whole substance of the Glass and the Vessel begins to enlarge it self uniformly returning to its first size and larger and at last the Liquor Rises again when impregnated with the fiery corpuscels it begins to Rarifie And it is manifest that the contrary to this is observed from Cold the same causes acting contrarily And Note That the Capacity of the Vessel was lessened by the pressure of the Hand onely made upon two opposite hollow sides nor could the Rising of the Liquor be attributed to the heat of the Hand Rarifying it for it was raised after the same manner by pressing the Vessel with two pieces of Ice The use of the next Instrument may easily be comprehended from its Figure being onely a Plate of Steel perforated with Circles of divers Measures to observe the different increasings caused by different Degrees of Heat given to the same or several Conical Rings of Metal The Ninth Experiment To shew That a Vessel may be distended not onely by Heat or by soaking up of moisture but also by Weight THere were made Two Vessels of Glass the one Conical the other Pyramidal and letting them into a thick Table we marked round the outside of the Vessels how far they sunk down then taking them out we fill'd them with Mercury and put them again into the holes in the Table but they would not go down so low as the Mark made at first because they were distended by the force of the Mercuries weight EXPERIMENTS About the Compression of Water THat Experiments do not always reach the truth aimed at is not from any defect of the Idea conceived of them in the mind but rather happens from the necessity we have of material Bodies and corruptible Instruments to put our Conceptions in Practice which though of themselves unable to blemish the Theory and Speculative part yet through the Defaults in their substances are not always capable of seconding our thoughts but we must not hence conclude the Experimental Method fallacious in the Quest of Natural Events for though by it we may sometimes come short of the very depth of that Truth which we first sought after yet it is hard if it does not give some glimmerings and marks to discover the falsity of any contrary supposition This has been our Fate in our Research Whether water can suffer any Compression as air does in which attempt for as much as the weakness of our Vessels came short of affording us a perfect knowledge of the Truth we making use of Glass ones as most fit because
being crammed with little Balls of Solid Crystal were dissected by us in a few hours and opening their Ventricles in the Sun they seemed to us covered all over with a glittering Coat which examining with a Microscope we found it to be onely strewed over with exquisitely fine and impalpable powder of Crystal In others likewise crammed with hollow Bubbles of Crystal-Glass with a small hole in them we were amazed to find of the said Bubbles some already broken and powdered others onely crack'd and filled with a Whitish Substance like curdled Milk got in at the small hole and we also observed that those were better powdered than the others which had in the Maws with them a greater Quantity of small Stones And 't is less strange that they break and grind to pieces Corke and any hard Woods as Cypress and Beech and rub to Powder Olive-stones the hardest Pine-Apple Kernels and Pistaches put down their Mouths with the Husk on Pistol bullets in Twenty four Hours we have found much Battered and several little hollow square Boxes of Tin were observed to be some scratched and battered others tore open from one side to the other FINIS A TABLE OF The Principal Matters Contained in this Work A. ACademie del Cimento intends not to dispute of the Experiments Page 16 and 33. Air diminishes the force of all Bodies that cut it p. 146. perhaps in continual motion p 14. Presses together those Bladders that seemed full in Vacuo p. 18. Dilates and Expands it self in Vacuo ib. What remains in the void space above the Mercury presses not thereon p. 23. When it is Dilated beyond the state of its Natural Compressure p. 23. The measure thereof ib. Proportion between Air Natural and Air Expanded as 1 to 174. p 24 When most rarifyed unfit for Respiration of Animals p. 61. Of Altering the Colours of several Fluids p. 133. Amber in Vacuo loses its Electric Quality p. 43. Which sort richest in that Quality p 128. Attracts any thing but flâ—me p. 129. Rubb'd upon smooth Bodies Attracts not p. 130 Acts no more upon the attracted Body than it suffers thereby p. 130. Acts upon all Liquids ib. By what Liquors hindred from attracting p. 131. Antiperistasis Experiments against it p. 151. Attraction by what hindred in Amber by the same also in other Bodies of Electic Virtue p. 129. A peculiar Effect observed in the Attraction of Rose and Table Diamonds p. 13â— B. Balls of Glass burst with great Violence p. 150 A Barbel taken alive out of a Vacuum and kept in a Pond with some observables thereon p. 66 Birds soon killed in Vacuo and why p. 63 Bladders of Fish in Vacuo p. 66 Blâ—bs in Ice what p. 71 Brass to what thickness burst by Frost p. 77 Bullets not wrapt about fly farther with the same charge of powder than those that are p. 144 C. Canes of Glass how made to be stop'd with a Finger easily p. 26 Cement to joyn together the mouths of Vessels p. 17 Change of Air produces an alteration in Experiments p. 1 Changing of Colours in several Liquors p. 133 Circles in Water move swifter as the force that makes them is greater p. 139 Clocks uncapable to shew the Minute divisions of time p. 10. Why made use of in the Experiments of Freezing p. 82 Cold whether reflected by Glasses as Heat and Light are p. 103 Cold and Heat Clouds and Mists encrease and lessen the weight of the Air p. 15. supposed by some the parent of Rock Cristal and Gems p. 70. Whether any thing Positive or onely a Privation of heat p. 70. Once imprest upon a Fluid shoots it into Ice after 't is taken out of the freezing mixture p. 80. * whether caused by an Intrusion of frigorifique Atoms p. 152 D. Dew upon the outsides of Glasses frozen p. 102 Diamonds how generated according to Plato p. 70 Table Diamonds less Electric than Roses p. 131 Digestion of some Animals how performed Several Experiments thereon p. 160 Drops of Liquors thought to be Spherical from the Airs Pressure p. 40 Disproved p. 41 E. A Cold Ebullition caused by a mixture of Sal Armoniac and Oyl of Vitriol p. 153 A strange Effect of Heat in subliming Liquors included in Vessels p. 150 Electricity what substances impregnated therewith p. 128 Experiments requiring an Exact measure of Time p. 11 the best way of Examining Nature p. 1â—4 Extrusion or pulsion of Bodies a thing known to the Ancients more especially evident from a Passage in Plato's Timeus p. 118 F. Fire and its Effluvia what Effect they have in Vacuo p. 46 Fishes kept a while in Vacuo dye disgorging some Air. p. 65 Flame diverts and abates the Virtue of Amber p. 129 Fluids aptest to move and why p. 13 Why different Fluids are raised to different heights by the incumbent Air p. 14. Fluids added to the Airs Pressure raise the Mercury above the usuâ— height p. 30 Force of Rarifaction in freezing Water how great p. 77 How thought reducible to dead Weight ib. Freezing how caused in Fluids p. 95 Artificial with its procedure and accidents p. 77 * Made in a very short time almost instantaneous p. 80 * What order it observes in divers Fluids p. 83 Tables of Freezings p. ib. The Explâ—catian of the Terms used in the Tables of Freezings p. 81 Those of the same Fluids Repeated still uniform p. 84 Natural Freezing with the procedure thereof p. 95 Diversity of the Figure of the Vessels causes some little diversity in the Freezings p. 96 Whether caused by the intrusion of Frigorifick Atoms p. 70 Froth in Vacuo expands it self p. 59 A sort of Funnel to fill Vessels with narrow Necks p. 3 G. Gems Transparent all Electric more or less p. 128 Glass Vessels enlarged by hot Water and lessened by cold p. 104 Stretch'd by the weight of the contained Mercury p. 113 Impenetrable by Odours and Moisture p. 155 Glass Balls burst with great violence p. 150 Glass and Cristal Electrical p. 128 Gold Vessels distended by the force of freezing p. 76 Gun-Powder fired with a Burning glass p. 144 H. Height of Liquors set in hot Water or Ice altered by the dilating or contracting of the Vessel p. 105 Horizontal discharge of Cannon dispatch the Ball in about the same time that it falls from the Mouth of the Piece perpendicular to the ground p. 143 Humidity of Winds how distinguish'd p. 9 I. Ice according to Galileo is Water Rarifyed not Condensed p. 71 Has not its full hardness at first p. 95 Produced by Art tenderer than the Natural ib. Made in Vacuo wherein different from that made in Air p. 98 How to find that difference ib. Sends forth a moist Exhalation p. 102 Sprinkled with Salt destroys the Vertue of Amber p. 129 The cause thereof proposed by some p. 130 Instruments shewing the heat and cold of the Air p. 2 Shewing the moisture of the Air p. 8 To measure time p. 10 Shewing the different