together the lowermost of them or the appendant weight were fasten'd to the ground For in this case there appears no reason to believe that their power to resist separation would be less than it was before And yet it seems evident that the uppermost Marble would not be perpendicularly pull'd up but by such a force as were at least I say at least able to lift up a weight equal to that of the last mention'd Marble and of a Pillar of Air having the Stone for its Base and reaching to the top of the Atmosphere since at the instant of Revulsion before the Air can get in and spread it self between the Stones there is not for ought appears any such Body under the upper Marble as can help the hand to sustain the weight both of that Marble and the incumbent Cylinder of the Atmosphere which then gravitates upon it and consequently upon the hand becâ—use there is no Air nor other equivalent Body underneath it to sustain its part of the weight as the lower Air is wont to do in reference to the heavy Bodies that lean on it and to the weight of the incumbent Air. And therefore we need not much marvel if when only a less weight than that of the foremention'd Pillar of the Atmosphere hangs at the lower Marble it should be capable of being drawn up by the uppermost rather than suffer a divulsion from it As we see that when two Bodies being fasten'd together are endeavour'd to be drawn asunder by forces or weights not able to separate them they will usually both of them move that way towards which either of them is the most strongly drawn On which occasion I remember what I have sometimes observ'd in one of the wayes of trying the strength of Load-stones For if the Load-stone be able to take up more than its own weight you may as well lift up the Load-stone by a Knife as the Knife by the Load-stone And though one accustom'd to judge only by his Eyes would have imagin'd that when I held the great weights formerly mention'd suspended in the Air there was no strong endeavour to pull up the upper Marble from the lower because my hand being for a while held steddy seem'd to be at rest yet he will easily be invited to suspect that in such a thought there may be a great mistake who shall consider that neither did the weight sensibly appear to pull the lower Marble downwards though my hand assur'd me that the weight had not lost its Gravitation And if I shall adde that once when the weight after having been lifted up into the Air was casually so loosen'd from the upper Marble as suddenly to drop down my hand unawares to me was by the force of that Endeavour it just before employ'd to sustain the fallen weight carried up with such violence that I very sensibly bruis'd it by the stroak it gave against the face of a By-stander who chanc'd out of curiosity to hold his Head over the Marbles And here it will not be impertinent to bring in an Experiment that I once devis'd not only for other uses but to illustrate the subject we have been hitherto treating of The Tryal I lately found registred among my Adversaria in these Termes A Brass Valve of about an Inch Diameter was with Cement well fastned to the shorter Leg which was but of very few Inches in Length of a long Glass Syphon left open at the end of the other Leg. This Valve being let down to the Bottom of a tall Glass Body full of water so that 't was if I much mis-remember not between a Foot and half a yard beneath the surface of the water when there was let in as much water into the Pipe as reach'd in that as high as the surface of the External Water in the Tall Cucurbite Then about an Ounce weight was put into the opposite Scale of a Ballance to the neighbouring Scale whereof one end of a string was tyed whose other end was fastned to the said Valve whose parts would be thereby drawn asunder But when the water was empty'd out of the Pipe and the Valve was let down to the former depth there was requisite about 5 Ounces that is 4 Ounces more than formerly to disjoin the parts of the Valve and let the water get in between And when the Syphon being freed from water the Valve was listed higher and higher together with the Pipe there needed less and less weight to make a Disjunction two Ounces of Additional weight to the one Ounce requisite to counterpoize the Cover of the Valve it self on the water sufficing to lift up the Cover when the Valve was held about half way between its Lower station and the Top of the water a single Ounce sufficing afterwards and half an Ounce of Additional weight proving enough to disjoin the parts when the Valve was held but a little beneath the surface of the Liquor This relation of an Experiment which I afterwards show'd to many Virtuosi will perhaps seem somewhat dark to you without a Scheme but if you consider it attentively enough to apprehend it throughly I presume it will show you that whether or no there be upon any other score a repugnancy to the separation of smooth Bodies join'd by immediate contact yet certainly there may be a great Repugnancy upon the bare Account of the Gravity of the medium wherein the Divulsion is attempted For in our case the Fuga Vacui if there be any ought to resist the separation of the Parts of a Valve still kept under water as much near the Top of the water as at the Bottom And therefore the great difference found in that resistance at those different places may be attributed to the Pressure of the Ambient water that thrust them together And though it be true that Air is an Exceeding Light Body in comparison of water yet in divers Tryals I have found the Disproportion in Gravity of those two Fluids not to exceed that of a 1000. to 1. So that considering how many miles not to say scores of miles the Air may reach upwards there seems no absurdity at all to suppose that the bare Pressure of it against the Marbles formerly mention'd may keep them as coherent as we found them to be But since this I have been able to make an Experiment that does sufficiently confirm the former Doctrine For having suspended the two coherent Marbles in a Capacious Glass whence by a certain contrivance the Air could little by little be drawn out we found as we expected that whilst there remain'd any considerable quantity of Air in the Glass the lower Marble continued to stick to the other the Pressure of the remaining Air though but weak being yet sufficient for the sustentation of the lower Marble which it was not after the Air was further withdrawn And if when the Disjunction was made the upper Marble were by another contrivance let down upon the lower so as to
our selves to have distill'd from Benzoin has been and is still subject to much more frequent vicissitudes of Fluidity and Firmness for part of it all the year long continues in the form of a blackish Oyl and the rest according as the season of the year or of the day makes the weather cold or hot frequently changes its Texture sometimes appearing perfectly the same with the newly-mention'd Oyl and sometimes shooting into clear and variously-shap'd Crystals which fasten themselves to the bottom and sides of the Vessel till a warmer part of the day or of the Season resolves them again into a Liquor And these two last Observations may also serve to confirm what we formerly taught that the Fluidity of some bodies depended almost wholly upon the various agitation of their parts for in there instances the parts of the Anniseeds and those of the Bâ—nzoin upon the operation or absenâ—e of the languid heat of the ambient air sometimes agitating them and sometimâ—s suffering them to rest did constitute a fluid or a consistent Body Anâ— hâ—ving thus taken noâ—ice of this upon the by we will 〈◊〉 the other Examples mention'd under this second head that which it aâ—forded as to ouâ— presenâ— purpose by Salt-Pâ—tre which being â—issolv'd 〈◊〉 â—â—fficient quantity of common water will seem to be lost in it and to constitute with it one uniform fluid substance but if a competent quantity of that water be boil'd or permitted to exhale away and the remaining liquor be suffered to rest a while especially in a cool place the saline particles will be re-uniting themselves and by the exclusion of the aqueous parts constitute stable and determinately-figur'd Ice-icles or Crystals The consideration of this may suggest to us another way that seems quite contrary to the former whereby some bodies may become firm and solid and that is by the intermingling of a due proportion of water or some other Liquor For though the small parts of such fluid Bodies being themselves in motion are apt to give those of others such an agitation as we have formerly taught that Fluidity principally depends on it seems that the admission of any Liquor must rather conduce to the making of a body fluid than consistent yet if we consult Experience it will instruct us otherwise for when I have taken either an equal or a double weight of Oyl of Vitriol and distill'd it warily from running Mercury very much the greater part of the Liquor would come over and leave behind it a very white Powder considerably fixt And if we examine that familiar Production of Chymistry Mercurius dulcis which they now use to make by subliming of together two parts of crude Mercury with but one of Sublimate which consists chiefly of Mercury already we may find that in That which is counted the best the fluid Body of Quick-silver is so contex'd with the Salts it carries up in Sublimation that the dry and brittle Body they compose may contain far more perhaps twice more Quick-silver than Salt And other Experiments may perswade us that the mixture of a convenient Liquor may cement bodies into one hard Concretion which would scarce be compacted together otherwise Nor is it against reason that it should be so for there may be differing qualifications required to a body whilst it is constituting and when it is constituted and though the motion of the parts that make it up oppose the firmness of a formed body yet it may conduce to the making of a firm body for when a great many hard Corpuscles lye together loose and incoherent they do as we formerly noted emulate a fluid body whereas by the mixture of a Liquor those loose Corpuscles being for a while dissociated and put into motion they may after many Evolutions apply themselves to one another after that manner that is most requisite to make them touch one another closely and according to a greater surface Whereupon it often follows that the Liquor in which they did formerly swim is either squeez'd out upon their closing or else so dispers'd in small particles and dispos'd of among those of the harder Corpuscles that they are unable to agitate them or prejudice their mutual cohesion And here to dilucidate the subject under consideration by an instance that seems very pertinent to it we will make a further use of the Experiment formerly mention'd touching the burning of Alabaster For if the powder after it has done boyling and has been sufficiently burnt and kept some hours the most experienced Artificers observing that it is not so convenient to employ it presently after it is taken off the fire be well beaten and tempered up with fair water almost to the consistence of thin pap if the powder have been rightly prepar'd and skilfully temper'd you shall see that fluid substance in a few minutes of an hour bâ—gin to set as the Trades-men speak that is to exchange its Fluidity for Firmness so that if it were bâ—â—ore cast into a mould it will perfectly retain the figure of the internal surface thereof Now that in our mixture there is for a while such an agitatiâ—n of the hard parts produc'd upon the affâ—sion of â—he wateâ— and aâ—tâ—rwards an â—xcâ—usion of the sâ—perflâ—â—us water we may confirm partly by this That when any considerable quantity of burnt Alabaster is temper'd up with water the mixture after a little time grows sensibly hot and sometimes continues so for a pretty while and partly also by this That having purposely for tryals sake fill'd a new and good Glass-Vial containing about half a pint or pound with the mixture we speak of and when it was top full stop'd it up very close the liquid mixture within less than half an hour crack'd the Vial though standing in a window in several places and at those crevises discharg'd it self of about a spoonful of clear water the remaining mixture retaining perfectly the figure and dimensions of the Vial and growing as hard as Chalk or somewhat harder insomuch that we were fain to imploy several strokes with a strong Iron to divide the mass And let me here adde that some other substances may this way afford much solider Bodies than burnt Alabaster does and therefore it may be a thing of good use to enquire out and try what other Bodies easily to be procur'd may be thus brought to a new and lasting Solidity For the Learned Hydrographer Fournier speaking of those Damms or Digues as he calls them in his Language which are sometimes made in the Sea to secure Shipping as I have seen at the Port of Genoa and elsewhere after having told us that the Romans made the fairest Harbours in the World by the help of a certain Sand to be met with at Cuma and Puteoli in the Kingdome of Naples which Sand mingl'd with a third part of Quick-lime acquires in the water a flint-like hardness subjoyns this Observation of his own J'ay veu c. that is I have seen sayes he in
the Câ—ve so famous for petrifying Liquor to be there seen observing some drops of water to congeal into stone whilst he stood by took them away with him and sent them me in a Letter Nay we shall scarce deny that an external agent of almost insensible bulk may turn animal Bodies into stony ones by introducing a new texture into their parts if we will with some modern Writers believe Aventinus who in his Bavarian History has recorded that at a time and place by him specified above forty Country-men as also some Milk-maids with their Cows kill'd upon an Earthquake had their Bodies by a terrene Spirit turned into statues which he sayes were seen by the Chancellour of Austria and himself And some relations of this Nature we meet with in other Authors which if they be allowed of seem much to confirm our Doctrine for in these strange petrifications the hardning of the Bodies seems to be effected principally if not only as in the induration of the fluid substances of an Egg into a Chick by altering the disposition of their parts since the petrifying wind or steam cannot be suppos'd to have any such considerable perhaps not any sensible propoâ—tion as to bulk to the body chang'd by it as to be thought to effect this change principally as an Ingredient Adde we to all these things that Pamphilio Piacentino is by an other Author quoted for writing an unparrel'd Story which because written in Italian I shâ—ll English the substance of it which is this That a Woman in Venice after having eaten an Apple was tâ—ken with hideous tortures and in the space of twenty four hours dying was turned into exceeding hard stone and this was judged to be the effect of the poyson'd Apple she had eaten Which narrative if we may believe it as confidently as the famous Alleger of it Pamphilio appears to do would seem to argue that even to the wonderful induration of Bodies there is sometimes no other principle requisite than what may result from the lucky mixture of the parts of several Bodies And lest we should seem to build altogether upon the Observations of others which cannot by us be now brought to strict examination we will have recourse to a prâ—cticable Experiment of our own trying which though we have elsewhere mention'd we shall not scruple here to repeat because we there omitted to speak of that Circumstance of it which is the most pertinent to our present design Take then two Ounces of Quick-silver two Ounces and a half of the best Verdigreese about half an Ounce or an Ounce of common Salt a pint or pound of White-wine-Vinegar and as much fair water mingle the Verdigreese Quick-silver and the Salt very well and put the mixture with a little of the Vinegar and water into a new Frying-Pan I try'd it in a new Earthen Vessel but without good success in which fry it over the fire for diverse hours keeping it continually stir'd and putting in more Vinegar and water from time to time as that already put in consumes away then take out the mixture and in several clean waters wash it carefully from the adhering Salts then dry away all the Aqueous moisture with a clean linnen Cloâ—h and you shall have a bright Amalgama almost like Quick-silver Now that which is remarkable and to our present purpose in this Experiment is that though this dry'd mixture be a good while after it is perfectly cold not only soâ—t but so neer to fluid that I have cast it into moulds and madâ— imbost Images of it when it has been dexterously made but scarce otherwise I have found that by laying i◠〈◊〉 hours in the air which seem'd less cold than it self it has acquir'd such a hardness that being thrown against the floor it would rebound and was brittle like over-harden'd Steel And yet in this Example the induration of the Amalgam appears not to proceed from an innate and inward principle but from the new Texture resulting from the coalition of the mingled Ingredients that make up the Amalgam whose parts being variously moved partly by the fire and perhaps too by the Salts and partly by the native propensity to motion of the Mercurial Corpuscles were by little and little or by degrees so dispos'd that whereas before touching one another but loosly it was easie to thrust some of them towards the middle of the body without stirring much of the Mass as to sense by this change of Texture the particles are brought to touch one another more closely and in greater portions of their surfaces and to be so complicated intangled or otherwise connected among themselves that you cannot endeavour to thrust one of them out of its place but that its motion shall be resisted by many others to whom it is so fasten'd that you cannot move one part of the Mass without either moving the whole with it or manifestly breaking it off from the whole and thereby destroying the continuity and unity of the Body Now whereas in setting down this Experiment we spoke as if several Ingredients did concur to constitute the soft Mass which afterwards grew so hard we might very safely do so since the Quicksilver was not so barely chang'd in Texture as that formerly said to have been coagulated by the meer fume of Lead but conceal'd in its self a great number of metalline Corpuscles besides others as we made appear by separating from the Amalgam meerly by the force of fire a pretty quantity of true and perfect Copper That the Salts also both were Ingredients though in small proportion of the Mass and might have some operation upon the other particles we may render probable by this that having purposely expos'd some of this Mass for a pretty while to a moist Air we found as we look'd for that the formerly invisible particles of Salt that had so insinuated themselves into the Amalgam that all the water wherein it was wash'd did not separate them from it had so wrought upon the metalline particles that were most outward that they had in many parts of the surface of the Mass turned themselves with it into a kind of Verdigreese which seemed almost to hide the surface of the Concretion And that in the more inward parts of a much harder Body than our yielding Amalgam where Cuprious particles abound saline Corpuscles may have a great operation may appear by certain sorts of Minerals to be found in some parts of England and elsewhere under the form of stones of which they make Vitriol for these abounding with vitriolate that is both saline and metalline particles will after they are taken out of the ground and laid in the open air by the working of the inward Salt some sooner and some later swell and burst asunder which could hardly come to pass without a great change made in the internal disposition of the parts of such stony Concretions And I remember that having lâ—id a mineral of Kin to these stones a while in
but in divers other Bodies that the want of an exquisite Depuration may produce in Experiments variety of Events As for instance It has been complain'd of by sober men that their Preparations of Silver though never so carefully made have been apt to produce violent Vomits whereas we have not observ'd a well-prepar'd Medicine of duly refin'd Silver to work Emetically even in Women and Girls but by Seige or Urine But we cannot wonder at the violent operation of Medicines made of ordinary Silver for not only that which is coyned is wont as the Mint-masters themselves have confess'd to me to be allay'd with sometimes about a twelfth part sometimes a smaller or greater proportion of Copper for the greater conveniency of the Coyn but even that Silver which is commonly at great rates sold for refin'd Silver is not wont to be sufficiently freed from its Copper Which I not long since manifested in the presence of one of our richest and eminentest Refiners by dissolving some of his purest Silver in his own Aqua fortis for the greenness of the Solution quickly betray'd the adherency of Venus to the Silver And no wonder for I have seldom seen our chiefest Refiners blow off from their Silver upon the Test above half its weight of Lead whereas we think not our Silver sufficiently refin'd for some purposes till it have been freed from five or six times its weight of Saturn and then it has sometimes afforded a Solution almost as clear as water with only now and then a light touch of Sky-colour but nothing near so high as the Ceruleous Liquor that is supposed to be a true Tincture of Silver artificially separated from the rest of the Body Now that ill effects by the mixture of Copper may be produc'd in such Medicines as ought to be of pure Silver he that is acquainted with the violent Emetick qualities of Venus can scarcely doubt And as in men's bodies so in other subjects those Experiments may easily deceive the Artists expectation when he hopes to perform with Silver and Copper together those things which suppose and require Silver without Copper or any adventitious Metal And as Silver so Gold is very often employ'd for pure when it is not so for even the foliated Gold which is commonly sold here in England how fine soever 't is reputed is not altogether free from the pollutions of other Metals for our Gold-beaters though for their own profit sake they are wont to use the finest coyned Gold they can get as that which is capable of the greatest extension under the Hammer yet they scruple not to employ coyned Gold and that the Mint-masters as themselves inform me are wont to allay with Copper or Silver to make the Coyn more stiff and less subject to be wasted by attrition And as for those many Gold-smiths and Chymists who think their Gold most requisitely refined when they have blown from it on the Test a due proportion of Lead they may be therein sometimes mistaken for though Saturn may carry away with him all the Copper that did imbase the Gold yet he does not likewise free it from the Silver for which purpose Aqua fortis is therefore wont to be us'd nay the skilfullest Refiner that I ever yet knew hath several times affirmed to me that coupleing fine Gold with Lead the Gold has after retained and protected from the fire a proportion of Silver that lay lurking in the Lead and was afterwards separated from the Gold by Aqua fortis but in so small quantity that the Experiment the cost and pains considered was not lucriferous And of this sort of Instances Pyrophilus more might be presented if we did not think Prolixity might be unwelcome to you But as many Experiments succeed not according to expectation because the Menstruums employ'd about them were not pure enough so some miscarry because such Menstruums are but too exactly depurated for it is not so much the purity of Liquors in their kind as their fitness for the particular purpose to which they are design'd that is in Experiments to be principally regarded For instance we have sometimes for recreation sake and to affright and amaze Ladies made pieces of white paper and linnen appear all on a flame without either burning findging or as much as discolouring them This is performed by plunging the paper very throughly in weak Spirit of Wine and then approaching it to the flame of a candle by which the spiritous parts of the Liquor will be fired and burn a pretty while without harming the paper But if this Experiment be tryed with exquisitely rectifi'd Spirit of Wine it will not succeed Of this Phaenomenon this plausible reason has been assign'd that the flame of the Spirit of Wine is so pure and subtile that like an Ignis lambens it will not fasten upon the paper But Experience has inform'd us that this Conjecture is but a mistake for the flame of Spirit of Wine is so hot that I have in Lamp-furnaces employ'd Spirit of Wine instead of Oyl and with the same flame I have not only lighted paper but candles and even melted foliated gold The true reason therefore why that paper is not burned by the flame that plays about it seems to be that the aqueous part of the spirit of wine being imbibed by the paper keeps it so moist that the flame of the sulphureous parts of the same spirit cannot fasten on it And therefore when the deflagration is over you shall always find the paper moist and sometimes we have found it so moist that the flame of a candle would not readily light it And on the other side having purposely made tryals of plunging paper into sufficiently dephlegmated spirit of wine the paper not having aqueous moisture to defend it was very readily kindled and burned by the flaming spirit And one of our best ways to try the pureness of spirit of wine is grounded on this very supposition For dipping it in a Cotton-wiek like that of a candle and setting it on fire if the flame fasten on the wiek it is a sign of the goodness of the spirit but if it do not we conclude it to be weak and not sufficiently dephlegm'd It hath been likewise observ'd that Aqua fortis will work more readily on Lead if it be allay'd with water than if it be purely rectifi'd I other-where also mention an Aqua fortis I have us'd which was so strong that it would not well dissolve silver it self unless I first diluted it with fair water And within this very week wherein I write these things I have had an unwelcome proof that Liquors may by too exquisite a Depuration be made unfit for our purposes For having to gratifie some ingenious friends made a certain Menstruum wherewith we had formerly done some things upon Gold which were not altogether without cause thought strange enough we took care at this time to separate it from whatever was either of an aqueous or an earthy
it is to be found in so great a number of Compound Bodies Vegetable Animal and even Mineral that it seems to us to be not only one of the most Catholick of Salts but so considerable an Ingredient of many sublunary Concretes that we may justly suppose it may well deserve our serious enquiries since the knowledge of it may be very conducive to the discovery of the Nature of several other Bodies and to the improvement of divers parts of Natural Philosophy SECT II. But not having at present much leisure allow'd me by several avocations to make accurate Enquiries into the nature of Salt-Petre in general and which is more considerable being not yet furnish'd wiâ—h a competent number of Experiments requisite to such a purpose I must content my self for this time to tender you some assistance towards the discovery of how differing Substances may be obtain'd from Nitre and compound it again by presenting you some Reflections on an Experiment which my desire to hasten to another Subject obliges me to set down nakedly as I first try'd it by way of Narrative SECT III. We took then common Nitre as we bought it at the Druggists and having by the usual way of Solution Filtration and Coagulation reduc'd it into Crystals we put four ounces of this purifi'd Nitre into a strong new Crucible in which the Vessel being first well neal'd to prevent cracking and cover'd to prevent the falling in of any thing that might unseasonably kindle the Petre we melted it into a limpid Liquor and whilst it was in fusion cast into it a small live Coal which presently kindled it and made it boil and hiss and flash for a pretty while after which we cast in another glowing Coal which made it fulminate afâ—esh and after that we cast in a third and a fourth and so continu'd the operation till the Nitre would neither fulminate nor be kindled any more after which we continu'd to keep it in a strong fire for above a quarter of an hour that if any volatile part should yet remain it might be forced off SECT IV. Then taking out the Crucible and breaking it whilst it was hot we took out as carefully as we could the remaining fix'd Nitre before it had imbib'd much of the moisture of the air and dividing it into two equal parts we dissolved one of those portions in as much fair water as would just suffice for the solution of it and then drop'd on it Spirit of Salt-petre till the ebullition occasion'd by the mutual action of those contrary Liquors did perfectly cease and forthwith Filtrating this mixture we expos'd it in a new open Vial to the air in a window and returning to the other portion of fix'd Nitre which we had set apart and not dissolv'd we drop'd on that likewise of the same Spirit till the hissing and ebullition were altogether ceas'd and then we expos'd this mixture also in an open glass Jar to the air in the same window with the former SECT V. The event of these Trials was that the mixture wherein fair water was employ'd did in a few hours fasten to the lower part of the sides of the Glass wherein it was put some saline particles which seem'd by their form and partly too by their shooting about the lower parts of the Vessel to be Salt-petre amongst whose little Crystals nevertheless there appear'd to swim very little grains much smaller than Mustard-seeds of some other kind of Salt environ'd with a downy matter not unlike that which is oftentimes to be observ'd in Rose-water and several other distill'd Waters when they begin to decay The Crystals were the next day taken out being by that time grown somewhat greater and more numerous and disclos'd themselves upon tryal to be indeed Nitrous as well by their manner of burning as their shape Concerning the latter of which since learned Modern Writers have mis-represented it some making Nitre to be Cylindrical and others of a figure less approaching to the true one I think my self oblig'd in this place to observe to you by the way that having purposely consider'd some large Crystals of refin'd and unanalyz'd Nitre the figure being in such best discern'd they appear'd to have each of them six flat sides not always of equal breadth in respect of one another whereof any two that were opposite were commonly parallel But to return to our augmented Crystals of Nitre what the other matter that adher'd to them was there was so very little of it that we could not well discern though we then suspected it to proceed from the want of a just or exact proportion betwixt the Volatile and fix'd parts of the Nitre that were to be re-united SECT VI. The remaining Liquor being pour'd into an open glass Jar and left in the same window continued five or six days without manifesting any considerable alteration but at the end of that time there began to appear in it very fine crystalline styriae of Petre which grew more and more numerous during a fortnight longer at which time being wearied with attending the so slow consumption of the Liquor we pour'd it from the Crystals and set it in a digesting Furnace to evaporate more nimbly SECT VII The other mixture wherein no water was employ'd did presently for a great part of it subside in the form of Salt over which there swam a little liquor which also seem'd to keep the subsiding particles of Salt from congealing into one coherent mass or so much as greater lumps and a part of this drenched Salt being taken out and permitted to dry in the Air did not appear very regularly figur'd but yet seem'd here and there to recede very little from the shape of Salt-Petre and being cast on a quick coal it burned partly after a manner not peculiar that we have observ'd to any distinct kind of Salt and yet it partly seem'd to imitate the flashing way of deflagration proper to Nitre The remaining part of this Salt together with the Liquor swimming upon it we kept for about a month in the open air without discerning any observable change in the Liquor till towards the latter end of that time and then we found it partly coagulated into small saline masses whose figure we were not able to discern and therefore dissolving the whole mixture in a little fair water and filtrating it we found after evaporation in a digesting Furnace about one half of the Salt shot into fine small Iceicles of the shape of Crystals of Petre but somewhat differing from them in taste upon their first being put upon the Tongue but upon a live coal they burned not unlike Petre. And the remaining half of this dissolution being somewhat hastily pressed to exhale let fall its Salt in a figure which we could not reduce either to that of Salt-Petre or of any other determinate kind of Salt For the clear comprehending of this Experiment you may be pleas'd Pyrophilus to take notice SECT VIII 1. That a
to have been destitute of moisture when committed to Distillation SECT XXIII But this not being precisely a Phaenomenon of our Experiment we shall not here prosecute it though perhaps we else where may but rather observe to you Pyrophilus that whereas good Spirit of Nitre being left in an open vessel is wont to smoke and waste it self in an Exhalation sensible especially if it be excited by a little heat not only in the Nose but to the Eye this Fugitive Spirit when it is once re-united to its own fix'd Salt emits no such steam though kept a good while near a considerable fire which Instance may somewhat assist us to make out that the most fugitive parts of Concretes may in spight of their natural Mobility be detain'd in bodies by their Union and texture with the more sluggish parts of them among which those lighter and more active Ingredients may be so entangled as to be restrain'd from Avolation SECT XXIV Another thing worth considering in our Experiment is this that upon the dropping of the acid spirit into the Alkalizate liquor if you place the open-mouthed glasse wherein the Experiment is perform'd betwixt the light and your eye you may plainly discern that the Saline particles of these liquors tosse one another or are tossed by some brisk invisible substance to the height of divers fingers breadth up into the air whence most of them fall back into the Vessel like a thick shower of little drops of rain And it were worth enquiring whence this sparkling of the parts of these mixt liquors arises and whether the Saline Corpuscles may be conceiv'd rapidly to move differing ways and so thwarting each other in their courses and rudely justling at their Occursions some of them are forc'd to bound or fly upwards almost like Ivory balls meeting each other on a Billyard-Table And to assist you in this Enquiry give me leave to inform you that the particles thus thrown into the air appear to be most of them Saline by this Observation that soon after the fall of the fore-mention'd showers you shall find the sides of the glasse wherein the affusion of the Nitrous spirit has been made all embroidered with little grains of Salt left there by those wandring drops that fell besides the liquor SECT XXV And let me farther observe to you that there seems to be a very nimble agitation in the particles of the Spirit of Nitre by this That upon the pouring of Aqua fortis whose Active part is little else than Spirt of Nitre upon a Solution of Salt of Tartar in fair water in which divers small lumps of the Salt remain'd yet undissolv'd we have observ'd the acid spirit to sever the particles of the Salt with such impetuosity that the numberlesse little Bubbles produc'd upon their Conflict and hastily ascending in swarms from some of the little lumps made them emulate so many little but rapidly rising Springs And to make it yet appear more probable that there may be such crossing motions in the parts of these liquors we observ'd that after the two contrary Salts had by their mutual conflict tir'd each other or rather had been upon their occursions fastned to one another there would follow no farther ebullition or skipping up and down of little drops of the liquors upon the putting in of more Spirit of Nitre unlesse there were added likewise more of the Alkalizate liquor SECT XXVI And before we passe on from this Reflection it may not be uselesse to take notice of the difference that there may be betwixt those active parts of a body which are of differing Natures when they are as it were Sheath'd up or Wedg'd in amongst others in the texture of a Concrete and the same particles when extricated from these Impediments they are set at liberty to flock together and by the exercise of their nimble motions display their proper but formerly clogg'd activity or acquire a Disposition to be briskly agitated by some fine interfluent matter For though in the entire body of Salt-Petre the Ingredients it consists of or the differing substances into which the fire dissipates it do so mutually implicate and hinder each other that the Concrete whilst such acts but very languidly yet when the parts come to be dislocated and the halituous and Alkalizate particles are enabled or made to disband from the Concrete and associate themselves with those of their own nature we see with how great an activity both the acid Spirit and the fix'd Salt are endow'd SECT XXVII And we may yet farther observe that it is not barely an indefinite nimblenesse of motion and activity of the particles of Saline liquors that enables them to perform each of their particular effects for to the production of some of these there seems requisite besides perhaps a Modification of their Motion a determinate Figure of the corpuscles answerable to that of the pores of the body by them to be dissolv'd as Spirit of Nitre corrodes Silver but not Gold which neverthelesse its particles associated with those of Sal-Armoniack and thereby acquiring a new Figure and perhaps a differing Motion will readily dissolve and the liquor of fix'd Nitre will for the same reason dissolve such Sulphureous and unctuous bodies as the acid spirit will not corrode nay and I have carefully observ'd that there may be liquors that will not dissolve some bodies unlesse the motion or activity of their particles be allay'd or modify'd by the mixture of fair water or such unactive vehicles SECT XXVIII Another particular which in our Experiment we may take notice of is the unwarinesse of those vulgar Chymists who presume confidently and indiscriminately enough to ascribe to each of the heterogeneous Ingredients or in their language Principles of a Concrete analys'd by the fire the virtues and properties perhaps too in an exalted degree of the entire body But though this be an errour of very ill consequence in reference to divers Chymical preparations of Medicines yet having else-where discours'd purposely of it we shall here content our selves to allege against it the instances afforded us by the Experiment under consideration for in that we may observe that when Salt-Petre is distill'd the volatile liquor and fix'd Salt into which it is reduc'd by the fire are endowed with properties exceeding different both from each other and from those of the undissipated Concrete for the Spirit of Nitre is as we formerly have observ'd a kind of Acetum Minerale and possesses the Common qualities to be met with in acid spirits as such whereas the fix'd Nitre is of an Alkalizate nature and participates the qualities belonging generally to lixiviate Salts and Salt-petre it self is a peculiar sort of Salt discriminated by distinct properties both from those Salts that are eminently acid as Allum Vitriol Sal-gemmae c. and from those that are properly Alkalizate as Salt of Tartar and Pot-ashes and accordingly we may easily observe a vast disparity in the effects and operations of these
water SECT IX We shall anon when we come to treat of Firmness mention our having made a certain substance so dispos'd to Fluidity that it may be made to change the stable consistence for a liquid one by so small an Agitation as only the Surplusage of that which the ambient Air is wont to have about the middle even of a Winters day above what it hath in the first or latter part of it Nay we have made ev'n a Metalline Salt or Vitriol capable of this proclivity to liquefaction of which we have unquestionable witnesses And therefore it need not appear incredible that other heaps or aggregates of Corpuscles much lighter than these though heavier than those of the Air may have all their parts so minute and fitted for motion that the wonted agitation of the Air may not only about noon but at all other times of the day keep them in motion and thereby in the state of Fluidity SECT X. And here I must adde that 't was not altogether without cause that I lately took notice of the shapes as well as the sizes of Bodies in reference to their fitness to constitute fluid ones For though I be not sure but that in those Bodies as Sal-Armoniack Antimony c. which are by the fire sublim'd into flowers rather than distill'd into Liquors the magnitude of the component Corpuscles may not be a hinderance to the Fluidity of the Body they constitute yet this seems as probably referable to their figure unapt for the requisite motion as to their bulk And I have sometimes made to this purpose this Experiment That by slowly distilling Oyl-Olive per se in a glass Retort plac'd in Sand I found as I expected that about the third part of the Oyle which was driven over into the Receiver did there coagulate into a whitish Body almost like Butter So that although it seem'd manifest by the strong smell and very piercing taste of this white substance that the Oyle which afforded it had its particles as it were torn in pieces and though distillation be wont to obtain Liquors ev'n from consistent Bodies yet in our Experiment of a concrete that is naturally fluid the distill'd Liquor it self proves not to be so of which no cause seems more obvious than that the newly-acquired shape of the dissipated parts of the Oyly Corpuscles makes them unfit for motion either Absolutely speaking or at least in Respect of one another by making them less pliant than formerly or giving them a figure more easie to be entangl'd with the neighbouring Corpuscles or else by making their surfaces less smooth and slippery than before SECT XI But to return thither whence we have digress'd and mention some more familiar Examples of the Conduciveness of the smallness of a Bodies disjoyned parts to its Fluidity we may take notice that of Bodies that consist of incoherent parts and are made up as it were by Aggregation those de caeteris partibus in their being pour'd out most resemble Liquors that are the smallest as would appear upon the emptying of several Sacks the one of Apples the other of Walnuts the third of Filberts the fourth of Corn the fifth of Sand and the sixth of Flowre Confectioners also Cooks and others that make much use of whites of Eggs will easily reduce those clammy and viscous Bodies into a thin and fluid substance to which for its affinity with water many give the same name and yet this difference of Fluidity being effected only by long and skilfully beating the mass with a whisk or even with a spoon seems to be produc'd but by pulling asunder the parts which perhaps before were long and somewhat twin'd and breaking them into shorter or lesser and consequently more voluble ones And I remember I have seen a good quantity of that jelly that is sometimes found on the ground and by the Vulgar call'd a Star-shoot as if it remain'd upon the extinction of a falling Star which being brought to an eminent Physician of my acquaintance he lightly digested it in a well-stopt glass for a long time and by that alone resolv'd it into a permanent Liquor which he extols as a specifick to be outwardly apply'd against Wens SECT XII And here we will subjoin an Observation afforded us by the Art of Casting which has sometimes yielded us a not unpleasant Diversion 'T is observ'd then by Gold-smiths well veâ—s'd in that Art and has been recommended to me by an Artificer eminently skilful in it as one of the chief Remarques belonging to it that when any such curious work of Silver is to be cast as requires that the impression of hairs or very slender Lines be taken off by the Metal it is not enough that the Silver be barely melted but it must be kept a considerable while in a strong fusion For if it be too soon pour'd out the figure it will make will be but blunt whereas if it be kept a competent time in Fusion the matter becoming thereby more Liquid as well as hotter will be thin enough to run into the smallest cavities of the Mould and so receive a figuration ev'n from the delicatest of them Whence it may probably be deduc'd that some Bodies already fluid may by a further comminution of their parts be made yet more fluid The like increase of Fluidity may be observ'd in some other fluid Bodies especially unctuous ones as Turpentine Oyle c. when heat begins to break as well as agitate their parts I may elsewhere have occasion to mention how by the operation of the fire the Crystalline Salt of Urine may be reduc'd without Additaments to a strong and ponderous Liquor though in this as perhaps also in some of the former Instances 't is not unlikely that as we may hereafter more particularly declare there may concurre to the prâ—duc'd change of consistence some alteration in the figure of the Corpuscles whereof the firm Body consisted And if that be true which Helmont in several places affirms of his prodigious Liquor Alkahest it is possible to turn Plants Animals Stones Minerals Metals or whatever kind you please of consistent Body here below into a Liquor equiponderant to the resolv'd Concrete which if granted seems to argue That the most solid Body by being divided into parts small enough to be put into motion by the causes that keep those of water and other Liquors in agitation may become fluid Bodies And this Intimation I shall adde for the sake of Philosophers that barely by long Digestions and much more if they be help'd by seasonably-repeated Distillations in exactly stopt Vessels and a due degree of heat there may be made in the parts of many Bodies both Vegetable and Animal so great a change from the state of consistence to that of Fluidity as those that contenting themselves with ordinary courses of Chymistry have not had a peculiar curiosity for tryals of this nature will not be forward to expect SECT XIII The Second of the above-mention'd three
Conditions is That there be store of vacant spaces intercepted betwixt the component particles of the fluid Body or at least about those of theâ— that are superficial for without this there will not bâ— room for each of the Corpuscles to continue its agitation upon the surfaces of the neighbouring ones and there would be no Cession of any because there would be no place unpossest for the impell'd Corpuscle to be received in But when I speak of vacant spaces ordinarily if not always requisite to be intercepted betwixt the particles of fluid Bodies I intend not to determine whether or no such spaces should or may be vacuities properly so call'd it being commonly sufficient to this second Condition of a fluid Body that in the little spaces intercepted between those that either are or at least are consider'd as solid parts there be none but such as will easily yield to them and cannot considerably resist the freedom of their motions Which being premis'd to keep this Condition from being mistaken we may in confirmation of it take notice how Snow which at its first falling is of a loose and open texture does easily yield to the impressions of the hand But when by being strongly compress'd and form'd into Balls the little Icy bodies it consists of are brought into a closer order and many of them thrust into the little spaces formerly possest only by the yielding Air they become unable to give way to the motions of our hand as before but compose a hard and resisting Body We see also that when water is strongly forced into and kept compressed in a Bladder so that its exteriour particles have not about them as before the yielding Air to give way to them when they should according to their wont swell about the sides of the Bodies that endeavour to press it inwards it emulates a hard body and resists such motions as otherwise it would readily yield to unless a more easie Cession be occasion'd by the Retching of the moisten'd Bladder it self And I chuse to instance in a Bladder distended with water rather than in one full of Air because though this latter will also emulate a hard Body yet in this case the tention of the Bladder would perhaps be ascrib'd to a kind of Spring which diverse Experiments have taught us to belong to the Air whence it might be said that since the enclos'd Air will suffer it self to be thrust inward a good way though it will quickly when permitted flye out again the hardness of a well-blown Bladder proceeds not from want of the rooms requisite to the Cession of the aerial Corpuscles but to the motion of Restitution natural to them when like an innumerable company of little Bow or Springs being bent by the force that compresses the sides of the Bladder they do as soon as it is taken off stretch themselves out again some one way some another as far as is permitted them by the imprisoning bladder which they thus every way keep strongly distended But this having of vacant spaces or some yielding matter about the Corpuscles of a fluid Body seems requisite to its being so but as what in a School-term one may call a Removens prohibens I mean only as it obviates that impediment to their motion which exquisite fulness may be conceiv'd to give to the various glidings amongst themselves of the parts of a Body suppos'd to be perfectly of the same hardness or softness or if you please altogether equally dispos'd or indispos'd to yield to one another And although in such Bodies as Water Wine Oyle Quick-silver and the like that are generally agreed upon to be fluid Liquors it will I presume be granted that this second Condition we have been speaking of may take place yet I will not say that 't were altogether absurd to question whether there may not be a portion of matter consisting of parts so minute and so agitated and consequently so easie to be either crumbl'd into yet smaller parts or squeez'd into any figure as occasion requires that they may incessantly change places among themselves and thereby constitute a most fluid Body without any vacuities receptacles or yielding matter about them unless perhaps it be about the exteriour parts of those of them that from time to time happen to be the superficial Corpuscles of this thinnest Liquor But though we have said that this may be question'd without absurdity yet it will not so much concern us in this place to examine whether the affirmative may be rationally maintain'd as to proceed to consider what is farther requisite to that state of matter we are now treating of especially the Qualification yet unmention'd seeming to be the principal of all SECT XIV For the Third and Chief Condition of a fluid Body is that the particles it consists of be Agitated Variously and Apart whether by their own innate and inherent motion or by some thinner substance that tumbles them about in its passage through them For this seems to be the main difference betwixt solid Ice and fluid Water that in the one the parts whether by any newly acquir'd texture or for want of sufficient heat to keep them in motion being at rest against one another resist those endeavours of our fingers to displace them to which in the other the parts being already in motion easily give way For whereas in the Ice every part actually at rest must by the Law of Nature continue so till it be put out of it by an external force capable to surmount its resistance to a change of its present state in Water each Corpuscle being actually though but slowly mov'd we need not begin or produce a new motion in it but only byass or direct that which it has already which many familiar Instances manifest to be a much easier task From this Agitation of the small parts of Liquors it comes to pass that these little Bodies to continue their motion do almost incessantly change places and glide sometimes over sometimes under and sometimes by the sides of one another Hence also may be render'd a reason of the softness of fluid Bodies that is their yielding to the touch for the particles that compose them being small incoherent and variously mov'd it can be no difficult matter as we lately intimated to thrust them out of those places which being already in motion they were dispos'd to quit especially there being vacant rooms at hand ready to admit them as soon as they are displac'd And hence it likewise happens that these little Bodies must be very easily moveable any way upon the motion of the mass or Liquor which they compose and that being very small and moving so many ways they cannot but according to Aristotle's Definition of things fluid be very unfit to bound themselves but very easie to be bounded by any other firm Body for that hinders them from spreading any further and yet to continue â—heir various and diffusive motion as much as they can
especially their gravity at least here about the Earth equally depressing and thereby levelling as to sense their uppermost superficies they must necessarily move to and fro till their progress be stopt by the internal surface of the Vessel which by terminating their Progress or Motion toward the same part does consequently necessitate the Liquor those little Bodies compose to accommodate it self exactly for ought the Eye is able to discern to the contrary to its own figure SECT XV. This short and general Account of Fluidity may we hope be as well further explicated and illustrated as confirmed by the following Instances and Experiments and therefore we shall forthwith proceed to Them And it will be fit to mention in the first place those that are afforded us by the Body our Author treats of Salt-Petre they having occasioned our writing about this Subject Salt-Petre then may be made fluid two several wayes either by or without a Liquor By the intervention of a Liquor it puts on the form of a fluid Body when being dissolv'd in water or aqueous juices it is not by the Eye distinguishable from the solvent Body and appears as fluid as it which seems to proceed from hence that the agitated particles of the water piercing into the joints or commissures of the Corpuscles of the Salt do disjoyn them and thereby divide the Nitre into parts so small that it is easie for those of the water wherewith they are associated not only to support them but move them to and fro whence it comes to pass that these Particles being so small and swimming some one way some another in the yielding body of water make no such resistâ—nce against the motion either of a mans hand or other external Body that strives to displace them as they did in their saline form But that with much less Liquor a Nitrous body may be rendred fluid may appear to him that shall expose such fix'd Nitre as our Author teaches to make to the moist Air of a Cellar For there it will run per deliquium as Chymists speak into a Liquor which consists of no more aqueous Particles than are necessary to keep the saline ones which seem to be much smaller than those of unanalyz'd Nitre in the agitation requisite to Fluidity SECT XVI And hence we may proceed to consider what Fluidity Salt-Petre is capable of without the intercurrence of a Liquor and this may be two-fold For first if it be beaten into an impalpable powder this powder when it is pour'd out will emulate a Liquor by reason that the smallness and incoherence of the parts do both make them easie to be put into motion and make the pores they intercept so small that they seem not at a distance to interrupt the unity or continuity of the Mass or Body But this is but an imperfect Fluidity both because the little grains or Corpuscles of Salt though easily enough moveable are not alwaies in actual motion and because they continue yet so big that both they and the spaces intercepted betwixt them are near at hand perceivable by sense But if with a strong fire you melt this powder'd Nitre then each of the saline Corpuscles being sub-divided into I know not how many others and these insensible parts being variously agitated by the same heat both which may appear by their oftentimes piercing the Crucible after fusion wherein they lay very quietly before it the whole body will appear a perfect Liquor and be thought such by any Beholder that shall judge of it but by the Eye and such also is the Fluidity of melted metals in which when they are brought to fusion in vast quantities I have seen the surface wav'd like that of boyling water and sometimes parcels of Liquor thrown up a pretty way into the Air. And not only Fire and other actually and manifestly hot Bodies are able to make some hard ones fluid but it seems also that some bodies may be brought to Fluidity by others which to the touch appear cold if they be but fitted to change the texture of the hard body and put its inflected parts into a convenient motion as may be seen in the Chymical Experiment of turning the brittle body of Camphire into an Oyl for the time by letting it lye upon Aqua fortis which perhaps bends and complicates the formerly rigid particles and puts them into such a motion that they do as well glide along as somewhat twine about each other And I further try'd not having found it mention'd by the Chymists that Camphire may by a dexterous application of heat be brought in close glasses both to flow and to boyl almost like Oyl 'T is true that these Liquors taken from the fire quickly lose that name and grow solid again But the duration of a thing is not always necessary to denominate it such for the Leaf of a Tree for instance whilst it flourishes may be as truly green as an Emerald though the leaf will after a while wither and turn yellow which the stone will never do and in cold Climates where Lakes c. at other times navigable are sometimes frozen so hard that Carts and ev'n great Ordnance may safely be drawn over them Ice and water are the one a stable and the other a liquid Body notwithstanding that the same portion of matter which at one time is frozen into a hard and solid substance was a little before a fluid Body and now and then in a very short time will be thaw'd into a Liquor again SECT XVII I know not whether it be requisite to take notice that the Fluidity which Salt-Petre acquires upon fusion by fire seems very much of kin to that which is acquir'd by solution in water But if fusion be made rather by the Ingress and transcursions of the atoms of fire themselves than by the bare propagation of that motion with which the agitated particles that compose fire beat upon the out-side of the vessels that contain the matter to be melted in such case I say both those kinds or manners of Fluidity newly ascrib'd to Salt-Petre will appear to be caus'd by the pervasion of a foreign body Only in dissolution the fluid body is a Visible and Palpable Liquor and consequently more gross whereas in fusion the fluid substance that permeates it is more thin and subtil and divides it into much smaller parts and so adds very little to its bulk SECT XVIII But because some scruple may possibly arise about this matter from hence that the powder of Nitre how fine soever seems fluid but just whilst it is pouring out and ev'n then is but very imperfectly so and that as for fusion that is wont to reduce the melted body to a new and permanent state as the formerly-mention'd powder of Salt-Petre which before fusion was but a heap of incoherent particles is by it made a solid and considerably hard Body to prevent I say or remove such scruples we will set down one Experiment that
it touches for sometimes the little eminencies and pores of the surface of the dry body on or against which the Liquor flows are of such magnitudes and figure that the particles of the Liquor find admittance into those pores and are detain'd there by which means they usually soften it and sometimes the pores and asperities of the dry bodies surface are so incommensurate in bigness figure to the particles of the Liquor that they glide over the surface without sticking or adhering firmly to any part of it This may be exemplifi'd in Quick-silver which cannot be said to be a humid body in respect of our hands or cloaths or of almost all other bodies of the World upon whose surfaces it will roul without leaving any of its particles lodg'd in their pores or fastn'd to their little eminencies whence it is called by vulgar Chymists the water that wets not the Hands but in reference to divers Metals especially Gold and Tin Quick-silver may be said to be a humid Liquor for it insinuates it self into their pores and thereby mollifies their bodies as other Liquors do those that are moistned by them And even water that wets almost all other Animal and Vegetable and many mineral bodies besides that it is commonly enough observ'd to stand in almost globular drops upon Cabbage-leaves seems not a humid Liquor in relation to the feathers of Ducks Swans and other water-fowl whom Nature having design'd to flye sometime in the Air and live sometimes in the water she providently makes their feathers of such a texture that they do not like the feathers of divers other birds admit the water which imbib'd would make them unfit for the use of flying And 't is observable that upon the change of texture in a Liquor it may be brought to stick to the surface of a body to which before it would not adhere as may appear by this that though Quick-silver alone will not stick to glass yet if there be mixt with it a due proportion of Lead Tin and Tin-glass though neither of them will adhere to glass yet their liquid mixture as we have often tryed and elsewhere taught readily will even without the assistance of heat SECT XX. If it be objected that this various agitation of the insensible parts of water and resembling bodies wherein we make the Nature of Fluidity chiefly to consist is but an imaginary thing and but precariously asserted since by our own Confession they are so small that the particles themselves and more the diversity of their motions are imperceptible by sense which represents water for Example to us as one continu'd body whose parts are at perfect rest If this I say be urged against our Doctrine we shall not deny the Objection to be plausible but must not acknowledge it to be unaswerable For of the seeming continuity of Water and other Liquors this may be the Reason That the particles whereof the Liquor consists being too small to be visible and being not only voluble but in actual motion the pores or vacant spaces intercepted between them must also be too little to be discern'd by the Eye and consequently the body must appear an uninterrupted or continu'd one not to mention that were the parts of the Liquor less minute their shifting of places would hardly be perceiv'd by the Eye each displac'd Corpuscle being immediately succeeded by another like it 'T is true that a heap of grains of Nitre though upon its effusion out of the Vessel it somewhat emulates a fluid body does yet when it rests in the Vessel appear to be but an aggregate of many little incoherent bodies heap'd up together because the intervals or holes left between them are great enough to affect the sense But if the same Salt be reduc'd into an Alchoole as the Chymists speak or impalpable powder the particles and intercepted spaces bâ—ing then extreamly lessen'd the body they make up will much more resemble an intire mass though it be look'd upon from a nearer distance and so when this powder is by the fire further broken into parts incomparably smaller than those of the powder and which consequently intercept such extreamly little pores that not only Salt-Petre but some Metals and ev'n Gold it self from which it will not be suppos'd that any thing exhales to lessen it are by some affirm'd for I have not my self diligently enough observ'd it and do yet doubt it to take up rather less than more room melted than cold why should we not grant that these pores may be little enough not any where to discontinue the body as to sense SECT XXI And that the incoherent parts of fluid bodies are also diversly agitated some this way and some that way though the sense cannot discern it may be prov'd by their sensible operations For without such local motion how could the particles of water pierce into the recesses of Bodies and occasion those putrefactive alterations that are wont to be imputed to superfluous moisture And how comes it else to pass that aqueous Liquors so readily diffuse themselves into and so exquisitely mingle with one another as we see when red and white Wine are in a trice confounded into Claret and without this various agitation of the parts of water how could it be that lumps of Sugar or Salt cast into it should quickly be so perfectly dissolv'd in it that the lumps themselves totally disappear and the dissociated parts are carried about every way by those of the water even from the bottom to the very top as is evident particularly in Sea-salt which when the superfluous Liquor is sufficiently exhal'd begins visibly to coagulate not at the bottom but upon the surface of the water and not only Salt but even Gold it self though the heaviest of bodies may have its parts so scatter'd by the agitation of those waters as Experience has taught us and as you may easily try by putting a little of the Solution of Gold made in Aqua Regis into 15 or 20 times as much fair water which will all thereby be immediately enobled with a Golden Colour That the little bodies whereof flame consists are fiercely agitated appears oftentimes even to the Eye and will scarce be denied by him that considers the operations of it and the vivid beams it darts round about it against the neighbouring bodies And that the particles that compose our common air are also very diversly agitated we may be induc'd to believe by sundry particulars As first by those little moats that from a shady place we see swimming up and down in the Sun-beams and by the tremulous motion which that of swarms of little bodies in the air seems to impart to distant objects look'd on after Sun-rise through a good Telescope and which by the bare Eye in hot weather may be often discover'd by certain very dilute shades which seem to tremble upon the walls of high-roof'd Halls and Churches and other spacious Buildings Next and more easily by
manifested by an easie and ocular proof which I devis'd about 10 or 12 years ago when being yet scarce more than a Boy I first began to consider what Fluidity might be The Experiment as I writ it down with all the Circumstances and Observations relating to it I have not now by me but having divers times been desir'd to shew it to Learned men Physitians Mathematicians and others I cannot have forgotten those Phaenomena of it that are the most pertinent to our present Subject Supposing then that in pure Spirit of Wine beside the aqueous parts that glide softly along each other there are store of volatile and Spirituous Corpuscles whose agitation is stronger I let fall from a pretty height that it might be broken into small drops by its fall into any wide-mouth'd glass fill'd with this Liquor which must not be ovâ—r dephlegm'd lest the Oyl sink in it a little common Oyâ— or Spirit of Turpentine which I therefore made choice of because its tenacity greater than that of the Chymical Oyls of Spices makes it that it will neither mingle with Spirit of Wine nor spread it self as divers other distill'd Oyls will upon the surface of it but keep it self in the form of round drops whose shape facilitates their motion The Oyly drops then swimming at the top of the Spirit of Wine will be by the disorderly rovings of the agile parts of it which hit against them little Globes as the vivous Spirits ascend to exhale made to move restlâ—sly to and fro in an irregular manner the drops sometimes bearing up to one another as if all or most of them were presently to unite into one body and then suddenly falling off and continuing to shift places with one another after a manner pleasant and strange enough to them that never before saw the Experiment and this dance will continue for half an hour or an hour or a shorter or much longer time according to the quantity and strength of the Liquor till the spirituous parts being flown away the drops being no longer impell'd lye at rest upon the disspirited Liquor as they would upon common water And whereas the nimble motion of the drops might be suspected to proceed from some secret contrariety in Nature betwixt the Oyl of Turpentine and Spirit of Wine besides that I could easily shew that those two Liquors have no Antipathy I not only try'd the Experiment with another inflammable Liquor than Spirit of Wine but if I much misremember not sound as I expected that little pieces of chop'd straw such both being light and not easily imbibing moisture being gently let fall upon the Spirit of Wine were in a tumultuous manner carried to fro upon the surface of it though I am not sure but that the motion of the Oyly drops may be in part due to some partial solution made of them by the vivous Spirit which during that â—ction may tumble them to and fro not to add that I have by some tryals been tempted to suspect the air may have some interest in the motion of the drops However I have mention'd the recited Experiment not as if I thought that either it or fugitive Spirit of Wine were fit to teach us the nature of fluid Bodies in general but to shew by an ocular example that there may be a quick and intestine motion in some parts of a Liquor notwithstanding that the unassisted Eye can discern no such matter I shall not here relate how having caus'd to be Hermetically seal'd up some of these Liquors in a glass to try how long the extravagant dance of the drops would last when the more spirituous parts of the vinous Liquor could not exhale my vessel was soon broken without any discernable violence Nor shall I now take notice of any of the other Phaenomena of our Experiment partly because I have elsewhere mention'd most of them and partly because I think it more pertinent to our present Theme to observe that this unseen agitation of the minute parts will not only hold in light and spirituous Liquors For that the insensible parts even of the heaviest Liquors themselves are also in actual motion though many may think it unfit to be believed will follow from what has been already delivered concerning the nature of fluid bodies as such and may be confirm'd by this that whereas three of the heaviest Liquors we yet know of are Quick-silver Oyl of Tartar per Deliquium and Oyl of Vitriol that first-nam'd will even in the cold penetrate into the pores of foliated Gold and destroy the texture of that closest of Metals the Liquor also of Salt of Tartar will in the cold draw tinctures from several bodies and we have endeavour'd to evince the agitation of the parts of Oyl of Vitriol not only by shewing how in the cold it would corrode divers Metals but by casting little pieces of Camphire into it which without the assistance of the sire were made liquid by it and appeared like so many drops of Oyl And he that yet doubts whether the parts of these two Oyls as Chymists abusively call them how ponderous soever they be are fiercely agitated or no may probably be soon satisfied by shaking an ounce or two of each of them together and observing the heat hissing ebullition and sparkling that will suddenly ensue upon their being blended SECT XXV But here we must take notice that though it belong to the Nature of fluid Bodies that their parâ—s do easily shift places yet that is to be understood only as to thâ— parts of the same fluid Bodies as water or of such differing fluid Bodies as are dispos'd readily to admit each others particles and mingle together as we see in Water and Wine For otherwise fluid Bodies may be of such differing natures that when two or more of them are put together they will not mix but each retain its own distinct surface so that in regard of one another the contiguous Bodies do in some degree emulate each of them the Nature of a consistent Body for though it cannot be look'd upon as a hard body but a soft because of the easie Cession of its superficies yet it does like a compact or consistent body deny to mingle permanently with the contiguous Liquor or other fluid substance And I somewhat wonder that Lucretius and other Atomists should at least for ought I remember over-see this Observation since it is obvious enough in Oyl which will not mix with water but float upon its surface Not to mention that Quick-silver will not incorporate with any of the familiar Liquors known to the Ancients I had almost forgot that I promis'd at the beginning of this Discourse an Instance concerning Flame which I will therefore now recite And it is That having by an easie preparation of Copper by the intervention of a little Sal Armoniack which I have already taught in another Treatise so open'd the Body of that Metal as to make it inflammable I took some
not of the figures compos'd by them of the small parts of hanging drops of water and such other Liquors as are not thought to consist of Corpuscles hooked or branch'd may be ascrib'd to the contact of their small parts and the exclusion of air These I say and some other such things might be here consider'd but that we are forbidden to examine them particularly and especially what has been represented touching the solidity of glass which we suspect another cause may have a great Interest in by our haste which calls us to the remaining part of our Discourse Though then it be hence to omit other proofs elsewhere mention'd sufficiently manifest that the Air has a spring and that a strong one yet there appears no great necessity of having recourse to it for the giving an Account why the two smooth glasses above mention'd were able to adhere so closely to each other For a probable Reason of the same Phaenomenon may be rendeâ—'d by the pressure of the Air consider'd as a weight And fiâ—st we must recall to mind what we a little above said of the Recoyling or Rebounding of the Pressure of a Cylinder of Air from the Earth to the suspended piece of glass proceeding from this that the fluid Air which is not without some Gravity being hinder'd by the resisting surface of the terrestrial Globe to fall lower must diffuse it self and consequently press as well upwards as any other way Next we may consider that when the surfaces of two flat Bodies of any notable and for example of equal breadth do immediately touch each other and lye both of them level with the Horizon and one of them directly over the other in this case I say since the Air cannot move in an instant from the edges to the middle of the two surfaces that lye upon each other the lowermost cannot be drawn away downwards in a perpendicular line from the uppermost but that by reason of the stiffness and contact of the two Bodies it must necessarily happen that at the instant of their separation should it be effected the lowermost glass will be press'd upon by the whole Crooked Pillar of Air suppos'd to reach from the top of the Atmosphere and to have for Basis the superficies of the undermost glass For at that instant the Air having not time to get in between the two glasses there is nothing between them during that instant to resist the pressure of that Air which bears against the lower superficies of that undermost glass and consequently such a revulsion of the lower glass cannot be effected but by a weight or force capable to surmount the power of the weight of the abovemention'd Cylinder of the Atmosphere and this as I said because that by reason of the sudden separation the upper surface of the glass has not any air contiguous to it which were it there would according to the nature of Fluid and springy Bodies press as much against the upper surface of the glass as the Pillar of the Atmosphere against the lower and consequently sustain that Endeavour of the Air against the lower side of the glass which in our propos'd case must be surmounted by the weight or force employ'd to draw down the lower glass And hence we may understand to adde that upon the by That it is not necessary that the contiguous surfaces of the two flat glasses we have been treating of be parallel'd to the Horizon For if you should hold them perpendicular to it their divulsion would not cease to be difficult provided it were attempted to be made by suddenly pulling one of the broad surfaces from the other in a level line and not by making one of the surfaces slide upon the other for in the former case the separation of the contiguous Bodies will be hinder'd by the weight or pressure of the lateral Air if I may so speak that bears against the broad sides of the glasses contiguous to it But whereas in these cases we suppose the superficies of the two glasses to be so exactly flat and smooth that no Air at all can come between them Experience has inform'd us that it is extreamly difficult if at all possible to procure from our ordinary Tradesmen either Glasses or Marbles so much as approaching such an Exquisiteness For we could very hardly get either experienc'd Stone-cutters or Persons skill'd at grinding of glasses to make us a pair of round Marbles though of an inch or two only in Diameter that would for so much as two or three minutes hold up one another in the Air by contact though they would easily enough take up each other if the uppermost were drawn up nimbly before the Air could have leisure to insinuate it self betwixt them But this notwithstanding we endeavour'd by the following Expedient not only to manifest that the Power or Pressure of the Air is in these Experiments very great but also to make some Estimate though but an imperfect one how great that Power is Having then provided a pair of Marbles of an inch and half in Diameter and as flat and smooth as we could get and having consider'd that as 't was the getting in of the Air between them that for the reason above declar'd hinder'd them from sticking strongly together so the Access afforded to the Air was for the most part due to that scarcely evitable roughness or inequality of their surfaces that remain'd in spight of the Polish considering these things I say we suppos'd that the intrusion of the Air might be for some while prevented by wetting the surfaces to be joyn'd with pure Spirit of Wine and that yet this Liquor that seems the freest that we know of from tenacity would not otherwise than by keeping out the air prove a Cement to fasten the stones together But because the easie separation of such smooth Bodies as adhere but by contact does in great part as we formerly noted proceed from this That whereas it is very difficult to hold such Bodies exactly level for any considerable space of time and yet the least Inclination any way gives the lower Body opportunity to slide off because of this I say we resolv'd in the first place to see what could be done by fastening to the upper Marble certain Wires and a Button in such manner as that the lower Marble when it was joyn'd might freely fall directly down but noâ— slip much aside being hinder'd by the Wire And in pursuit of this we found that not only the dry Marbles could be made to take up and hold up one another but that once by drawing up the upper Marble nimbly we could take up but not keep up for any time together with the lower Marble a Scale and in it a pound weight of 16 Ounces Troy After this we moisten'd the surfaces of the Marbles with such pure Alkalizate Spirit of Wine as we elsewhere teach to make which was so thin and subtil that not only we burn'd some of it before we
of Amber does by detainiâ—â— some parts which though more gross then the rest may yet be no useless one impair the Remedy and that it does not upon some other score infringe the medicinal vertue of the Oyl the Experiment will not be unuseful For the Liquor that is thus prepared is not only very diaphanous and well colour'd but so pure and subtle that 't will swim not only upon Water but upon Spirit of Wine it self And 't will be no despicable thing it by extending or further applying this Experiment to other indispos'd Bodys many Empyreumatical Oyls distill'd by strong fires in Retorts can be brought to emulate essential Oyls as Chymists call them drawn in Limbicks as to clearness and lightness The additament I last thought fit to make use of for purifying Oyl of Amber was briefly this â„ž Two Pound or somewhat less of good Brandy One Pound of good Sea-Salt and half a Pound of the Oyl to be subtiliz'd mix and distil them together Upon the mention I made above of the white Coagulum of the Spirits of Wine and Urine I remember what I have sometimes observ'd in the essential Oyl of Anniseeds as Chymists speak distill'd with store of water in a Limbick and Refrigeratory namâ—ly that in the heat of Summer it would remain a perfâ—ct Liquor like other Chymical Oyls but during â—he cold of the Winter though they notwithstanding that season continued fluid as before the Oyl of Anniseeds would coagulate into a Body though not of an uniform Texture to the Eye like Butter but rather almost like Camphire yet like it white and consistent not without some kind or degree of Brittleness And on this occasion I will here insert an Experiment which should have been set down in that part of the former History of Fluidity where I mention that the small parts of a Body may be sufficiently agitated to constitute a Liquor by the Air or other Agents not seâ—sibly hot themselves The Experiment take â—hus Casting by chance my Eyes in the Winter time upon a glass of Oyl of Anniseeds which stood coagulated by the cold of the season I presently bethought my self of making a Liquor whose process belongs to another Treatise of which as soon as I had prepar'd it I made this Tryal I melted with a gentle heat the congeled Oyl of Anniseeds to make it flow and then cover'd parâ— of it in another glass wiâ—h a Mixâ—ure I had provided and hâ—ving let thâ—m both rest in the window I found that the meer Oyl being fully refrigerated again coagulated as before but that which was cover'd with the other Liquor continu'd fluid both day and night and in several changes of weather and does still remain at the bottom of the Menstruum a clear Oyl distinct from it though I have purposely shaken them together to confound them And because Pyrophilus I have not discover'd to you the Menstruum I made use of I will here present you with a Succedaneous Experiment made with a common Liquor I took then good clear Venetian Turpentine and having slowly evaporated about a fourth or fifth part of it till the remaining substance being suffer'd to cool would afford me a coherent Body or a fine Colophony I caus'd some of this transparent and very brittle Gum of which I have elsewhere taught you some uses to be reduc'd to fine powder of which I put into pure Spirit of Wine a greater proportion then I judg'd the Liquor was capable of dissolving to the end that when the Spirit had taken up as much of the Powder as it could there might remain at the bottom a pretty quantity of our Colophony On which though the Menstruum being already glutted could not act powerfully enough to dissolve it yet it might give the matter which it had already so far softened as to reduce it into a coherent mass agitation enough to emulate a fluid though somewhat viscous Body And accordingly I obtain'd a sluggish Liquor which continued fluid as long as I pleas'd to continue the Menstruum upon it The like Experiment I try'd with clarify'd Rosin and with fine Colophony though but bought at the Shops and although the Tryal sometimes succeeded not ill yet I found not the success constant and uniform whether because the Bodys to be dissolv'd were not defecated and pure enough or that I did not hit upon the best proportion between the Solvent and them But this circumstance I shall not omit that when the glutinous Liquor was separated from the Menstruum it would by degrees though but slowly harden in the Air. The Application of which property for the preservation of small and very tender Bodies I shall not here more expresly hint then by having barely nam'd it I had forgot to adde that whilst the substance continu'd fluid I could shake it as I lately told you â— could the Oyl of Anniseeds with the supernatant Menstruum without making between them any true or lasting Union Which last circumstance brings into my mind another Experiment that I likewise forgâ—t to adde to that part of the former History of Fluidity where I take notice that the particular Textures of fluid Bodies may be reckon'd among the chief causes of their being dispos'd or indispos'd to mingle with one another For partly to confirm this Conjecture and partly to manifest that 't is not universally true which Chymists are wont to think that Acid Salts and Oyls will not incorporate or mingle I took an arbitrary quantity and as I remember equal weight of common Oyl of Vitriol and common Oyl of Turpentine as I bought them at the Druggists these I put together very slowly for that circumstance should not be omitted and obtain'd according to my desire an opacous and very deep-colour'd mixture whose almost Balsam-like consistence was much thicker than either of the Liquâ—rs that compos'd it The like Experiment also succesfully try'd with some other Chymical Oyls but found none preferable for this purpose to Oyl of Turpentine And to make it probable that the disposition of these Liquors to mingle thus presently together depended much on their Texture we made the mixture be warâ—ly â—â—sâ—ill'd over for else the Experiment will searce sucâ—eed aâ—d thereby obtain'd as we elsewhere menâ—ion to another puâ—pose a certain gross substance which was that which seem'd to mediate the former union betwixt the two Liquors For this substance being separated and thereby the Texture of one of the Liquors or perhaps both being chang'd the Liquors which came over very clear into the Receiver swome upon one another nor have I since been able by shaking them together to confound them for any considerable time but they presently part again and do to this day remain distinct as well as transparent But afâ—er having forgot to set down these things in their proper place I must not forget also that to employ here more words about them were to digress To this then annex we that the Liquor we elsewhere mention
in a convenient quantity of Water does upon its recoagulation so dispose of the aqueous Particles among its own Saline ones that if the Experiment be well and carefully made almost the whole mixture will shoot together into fine Chrystals that seem to be of an uniform Substance and are consistent enough to be even brittle and to endure to be pulveriz'd siâ—ted c. though the Concretion may have such a Proportion of Water in it that as I remember when the Experiment succeeded well from three parts of Water and but one of Salt I had about four parts of Crystals I need not tell you that this Salt sâ—ems to have a somewhat more then ordiâ—ary Resâ—mblance of a â—rue Coagulum since it reduces so much water into a stable consiâ—tence yet it does in no contemptible proportion materially concur to the Body produc'd But I may hereafter which I must not do now entertain you about a Salt of a differing kind from this and which put me upon considering whether there may not be a Coagulum more properly so call'd of Common Water which may in a very small proportion operate upon a great quantity of that Liquor as Runnet does on Milk I have not yet examined whether it will be sufficient to refer meerly to the second and third ways lately mention'd of making Bodies become stable in the Phaenomena I am about to speak of or whether it may be reasonably suppos'd and added as a fifth way that the Bodies to be coagulated may in great part be brought to be so by so acting upon the Bodies to which they are put that the Agent Liquor if I may so speak does by its action comâ—unicate to the subject it works on or lose upon some other account some subâ—le parts whose absence fits the dispos'd remaining Fluid for such a Cohesion as may suffice to make a Body be though very soft yet consistent But however 't will not be amiss to take some notice of Effects which what e're the cause be belong to the History of Fluidity and Firmness I some years since prepar'd a Substance of a whitish colour which would not only destroy the Fluidity of some other Liquors but would give a consistency to a notable proportion of Oyl of Vitriol it self though the parâ—s of this Liquor be presum'd upon the score of its corrosiâ—eness and iâ—s aptness to grow very hot with many other Bodies and make them smoke to be very vehemently agitaâ—ed And I remember that I sometimes shew'd the curious a Glass Vial well stopt upon thâ— bottom of which lay a little of this newly mention'd whiâ—ish powder ovâ—r which theâ—e was a considerable propoâ—â—ion of Oyl of Vâ—â—riâ—l in a consistent Form without seeming to have any thing to do with the Powder as indeed it had been only pour'd upon it and suffer'd to stand in the cold for some time which if I mistake not was a day or two at the end of which the above mention'd change was wrought on the Liquor by the powder which did not appear to be dissolv'd thereby Which Phaenomenon seem'd indeed to argue that there happen'd in this Experiment that was not the only one of the kind I then made something like the coagulation formerly mention'd of Quicksilver by the Vapour of Lead some subtle parts of the Coagulator if I may so call it invisibly pervading the Liquor whose Fluidity was to be suspended though it seem not improbable to me that the effect produc'd might depend upon both causes this newly express'd and the other a little abovemention'd where I guess'd that a change of Texture and thereby of Consistence in the Menstruum might be the result of the Operation of the Menstruum and the Body it acts upon And because this powder is not so easie to be prepar'd I shall adde that you may though not so well as by the newly mention'd way see the Coagulation of a Menstruum upon a firm Body which it does not seem to dissolve by the ensuing Experiment Take Crystals of Salt-Petre very well dryed but not powdeâ—'d and gently pouring on it in a Glass Vial some good Oyl of Vitriol till it swim about half an Inch or perhaps more above the Salt leave the Vial clos'd with a cover of Paper in a cool quiet place where it may not be shaken and if the Tryal succeed with you as did it with me the Liquor will though slowly so settle it self about the Nitre that though you incline the Vial to any side or perhaps turn it upside down it will not run out and I have sometimes taken notice of little Saline Bodies and as it were Fibres that seem'd to keep the parts of the mixture united together I made also some other Tryals to coagulate unflegmatick A. F. upon Nitre and some other Bodies the Phaenomena of which Tryals did not oblige me to renounce the lately mention'd Conjectures about the causes of such changes of consistency in Liquors as I have been speaking of For I still think it highly probable that the best Coagulator I have met with acts but as a finer sort of Runnet which in an inconsiderable quantity really disperses material parts of it self through the Liquor to be wrought on though these when the Coagulator is a consistent Body be perchance so few or subtle as not to make any Visible diminution of the Body it parts with A more eminent Example to our present purpose may be afforded us Sometimes for I am sure the Experiment will not Always succeed by the notable way of coagulating Quick-silver and thereby turning it from a fluid into a firm body by the vapour of melted Lead in which when it is taken off the fire but before it be quite grown hard again a little cavity must be made with a pebble or a stick that the Quicksilver tied up in a rag may be nimbly put into that hole and be congeal'd by the permeating stream of the cooling lead Which Effect may be less hopefully expected by the way wont to be prescrib'd by Authors most of whom I doubt never made tryal of it then by another that I have practis'd and may on another occasion shew you And that some metalline steam does really invade the Quicksilver seems probable by the wasting of Lead by fusion and by the operations ascrib'd by Chymists to the fume of Lead upon Gold about which I may elsewhere tell you what is come to my Knowledge And I remember that not long since an ingenious Physician of my acquaintance keeping some Lead long in fusion to reduce it per se into a Calx and holding his head often over rhe melting pot to observe the alterations of the metal was suddenly purg'd diverse times both upwards and downwards which both he and I ascrib'd to the Saturnine exhalations And though I suspected the Congelation formerly-mention'd might proceed from the egress of some subtil substance that formerly agitated but after deserted the Mercuriaâ— Corpuscles yet that the Concretion of
common Oyl of Vitriol and cast into it diverse little pieces of Camphire which floating upon it were by degrees and after some hours wholly reduc'd into a reddish Oyl that was to be seen altogether upon the top of the other Liquor Then having foâ—merly try'd that Oyl of Vitriol would easily mix with common Oyl we try'd also by shaking the saline and Camphorate Liquors together to unite them and easily confounded them into one high-colour'd Liquor which seem'd very uniform and continu'd so at least as to sense for many hours Then we added to this mixâ—ure three or four times as much fair water and as we expectâ—d the Camphire immediately recover'd a white consistent Body and by degrees setled at the top of the Lâ—quoâ— where we mâ—y observe that the Camphire is noâ— made hard buâ— fluid by its mixture with the saline Corpuscles of Oyl of Vitriol and exchanges its Fluidity for Firmness upon the affusion of Saltless water And thus much it may suffice to have said touching the Chymists deriving the stability of Bodies from their abounding in Salt And as for the hardness and brittleness they ascribe to the same principle how much they may be increas'd or diminished in a body without the accâ—ssion or decrement of the saline principle or ingredient may appear by that Experiment mention'd by us to several purposes of tempering a slender piece of Steel for when it has been sufficiently heated by plunging it red hot into fair water which is more likely to dissolve than increase its Salt you may make it not very hard alone but very brittle whereas by only suffering it to cool leisurely in the air it will be both much less hard and more tough and if after having quench'd it in cold water you again heat it till it have attain'd a deep blew it will become comparatively soft and very flexible and that not from any wasting of the saline ingredient by the fire for if this softn'd steel be again heated red hot and suddenly refrigerated whether in water or otherwise as before it will re-acquire both hardness and brittleness Now that by these operations a real change is made in the disposition of the small parts of the steel we have elsewhere evinc'd ev'n by a sensible proof And that by procuring a closer order more immediate contact of the parts of a body a man may without encreasing the Salt encrease the hardness of it is as we formerly also noâ—ed obvious in Snow which whilst it lies in flakes as it falls upon the ground composes but a soft and yielding body But when the same snow is by being strongly press'd every way betwixt the hands formed into Balls the little whether Iceicles or frozen bubbles it consists of are so approach'd to one another and forced into an order which allows so little wast of room that the formerly-intercepted spaces being most of them fill'd up with little bodies the Iceicles can no longer yield as they did before to the pressure of a mans fingers but constitute a mass considerably hard which yet may be made harder being melted into water and afterwards frozen into Ice for this having been a fluid Body and in such Room is wont to be better husbanded than in others the bubbles intercepted in it cannot keep it from being of so close a texture as to be considerably hard I know that not only profest Chymists but other persons who are deservedly rank'd amongst the modern Philosophers do with much confidence entirely ascribe the induration and especially the Lapidescence of bodies to a certain secret internal principle by some of them call'd a form and by others a petrifying Spirit lurking for the most part in some liquid vehicle And for my part having had the opportunity to be in a place where I could in a dry mould and a very elevated piece of ground cause to be digg'd out several Crystalline bodies whose smooth sides and Angles were as exquisitely figur'd as if they had been wrought by a skilful Artist at cutting of pretious Stones and having also had the opportunity to consider divers other exactly or regularly shap'd Stones and other Minerals some digg'd out of the Earth by my friends and some yet growing upon stones newly torn from the Rock I am very forward to grant that as I elsewhere intimate it is a plastick Principle implanted by the most wise Creator in certain parcels of matter that does produce in such concretions as well the hard consistence as the determinate figure We deny not then that these effects depend most commonly upon an internal principle but the difficulty consists in conceiving how that internal principle produces its effects which these Writers not pretending to explicate intelligibly we thought it not amiss briefly to survey some of the principal ways by which it seems that Nature makes bodies firm and stable whereby we may be assisted to judge whether it be as necessary to have recourse to a plastick Principle or a Gorgonick spirit in all other quick and notable Indurations of Bodies in the cold as in the hardning of such Bodies whose curious and determinate either internal Textures or outward shapes common to several Concretions of one kind argue their having been fram'd by some one formative power or by diverse seminal Principles conven'd together But this we will do without affirming either that she cannot by some other yet unobserv'd way make consistent bodies or that of the ways by us discours'd of she is wont so to confine her self to any one thaâ— she does not frequently make use of two or more of them to produce the same effect And because Hardness is a high degree of Firmness I suppose it will not be impertinent to shew by some examples how small an external operation may without any appearing adventitious Salt make a soft body hard and even brittle when there appears not any other change to be made than that of the Texture or disposition of its component particles It is a Tradition amongst Naturalists that Coral grows soft at the bottom of the Sea but when it is brought up into the open Air though it retains its bulk and figure it hardens into a stony Concretion according to that of Ovid. Ovid. 15. Metamorph. Sic coralium quo primum contigit auras Tempore durescit mollis suit herba sub undis Whether or no this Tradition is strictly true we had noâ— opportunity when we staid at Marseilles whose neighbouring Sea is the chiefest in Europe where Coral is wont to be fish'd to give our selves an ocular satisfaction But whatever some say to disâ—redit the tradition nay how confidently soever Beguinus who seems to have the most strongly argu'd against iâ— hath rejected it it must not be denyed to be sometimes at least true and that 's enough to serve our present turn For the Learned Gassendus in the Life of Piereskius relating how that incomparable Gentleman had the curiosity to fish for Coral near
Toulon a noble Port not far from Marseilles has among other things this passage viz. The plants which were pluckt up and drawn out were neither red nor handsome till their Bark was pull'd off in some parts they were soft and would give way to the hand as towards the tops which being broken and squeez'd they sent forth milk like that of Figs. I remember likewise that the Learned Jesuite Fournier who being also a French Hydrographer and one that writes of Marseilles and Toulon as places very well known unto him may be safely credited on this occasion after he has particularly describ'd the way of fishing Corals near Toulon he adds These plants are neither red nor polish'd when they are drawn out of the water till their Rind have been taken off nay they are soft and being brokâ—n or else squeez'd betwixt the fingers they throw out a kind of milk resembling that of Figs and when one leaves off pressing them he may see the small holes or pores that harbour'd the milk that was squeez'd out Thus far He. The credibleness of a good part of these narratives has been confirmed to me by a practiser of Physick in the East-Indies who having made some stay at his return on the Island of Mehila near that of Madagascar where store of white Coral is reported to grow I enquired of him whether he had gathered any and whether he found it soft whilst it was growing and he anâ—wer'd me that he had of late years diverse times gather'd Coral upon the Sands of that Island and found it when he gather'd it exceeding white and to use his expression as soft as an Onion adding that though it would in a very short time grow hard in the air which he ascrib'd how justly I know not to the external heat of the Sun yet it is very well known to the Sea-men that deal in that ware that if it be not gather'd at a seasonable time of the the year it will not keep long but either crumble away or otherwise decay which disagrees not with the experienc'd Piso who in his natural History of Brasil speaking of some places of the Brasilian Coast where diverse stony plants some like little Trees some otherwise fram'd may be seen in clear weather growing in the bottom of the Sea tells us that è fundo erutae mox durissimae sà insolentur in littore siccae niveique coloris fiunt As remarkable a change is that I meet with in Scaliger who tells us as upon his own knowledge of some who at the Urinary passages voided a slimy matter which in the Air coagulated into a firm substance the story being memorable take it in his own words thus Ex bovillis oppidanus nostris adjutus medicamentis eminxit vitrum sane ex illa nobili Paxagorae pituita dum mingeretur albuminis mollitie emissum vitri duritie ac splendore Senatoris filius ejecit pultis modo multos maximos qui aeris contactu postea in gypseam tum speciem tum firmitatem concrevere hic quoque nunc rectè valet Having likewise had the acquaintance of an inquisitive Merchant of Dantzik and also of an ingenious Chymist that spent some time in that City and the neighbouring Country along whose coast our European Amber is wont to be dragg'd out of the Sea I enquir'd of them whether they had never observ'd in Amber a property like that which is reported of Coral and one of them as I remember the other also hath assured me upon his own particular Observation that lumps of Amber are sometimes taken soft out of the Sea and grow hard in the Air which is the more credible to me because I have at a Polonian noble-mans seen besides other intercepted things a whole Spider and that none of the least perfectly inclosed in a piece of hard and transparent yellow Amber And elsewhere I have seen ten or twelve if I mis-remember not the number piâ—ces of such Amber which contain'd one a Fly another a Spider a third a Straw and each of the rest some such other thing And it seems not impossible that the contract of the external air may put the parts of such small Bodies into a new motion whereby some voluble Corpuscles that hinder their reciprocal adhesion may be excluded and the particles themselves prest or otherwise dispos'd into a closer order and we find that some Oyl-colours after they are brought to their due temper may be preserv'd very long in the same degree of softness if they and the shells that contain them be kept all the while under water whereas in the air they would quickly change their Texture and become dry and hâ—rd But though in this last mention'd Example and some others the removal of the body out of the water into the air seem manifestly to contribute to its growing hard yet it seems not to us so easie to determine what share the air has in effecting such indurations for Gassendus relates of Piereskius that he being wont in the Summer time to wash himself in one of the lesser streams of the River of Rhosne he there made the following Observation Once upon a time he felt the ground which he had wont to find even and soft to be grown hard with little round balls or bunches like hard boiled Eggs when the shell is peel'd off at which wondring he took some of them up and carried them home that he might shew them to his Master and demand of him the Reason But the miracle was increas'd when a few days after returning to the River he found those little balls or lumps turned into perfect pebble stones which he observ'd likewise to befal those which he had carried and laid up at home But how far this story will prove that such coagulations must be effected by a substantial form or a petrifying Liquor we define not especially since not to repeat what we deliver'd already touching calcin'd Marble out of Fournier we have elsewhere deliver'd upon our own Observation that two or three spoonfuls of such pap of burnt Alabaster as we have lately been speaking of and instead of which Artificers use another stone call'd by them Plaster of Paris burnt and and temper'd up with fair water did in the bottom of a vessel-full of water into which we pour'd it in a short time coagulate into a hard lump notwithstanding the water that surrounded it which it seems by the Texture of the mass was kept out of its pores as it is out of those of the Oyls of Cinnamon and Cloves which though fluid bodies and sinking in water suffer not its particles to insinuate themselves into theirs and Artificers observe that the coagulating property of burnt Alabaster will be very much impair'd if not lost if the powdeâ— be kept too long especially in the open Air before it be made use of and when it has been once temper'd with water and suffer'd to grow hard they tell me they cannot by