think it therefore very fit and highly useful that some speculative Wits well vers'd in Mathematical Principles and Mechanical Contrivances should employ themselves in deducing the chiefest Modes or Qualities of Matter such as are Heat Cold c. and the States or conditions of it if we think fit to distinguish these from its Qualities as fluid firm brittle flexible and the like from the above-mention'd most primitive and simple Affections thereof And I think the Common-wealth of Learning exceedingly beholden to those Heroick Wits that do so much as plausibly perform something in this kind But I think too we are not to despise all those Accounts of particular Effects which are not immediately deduc'd from those primitive Affections of either Atoms or the insensible Particles of Matter but from the familiar though not so universal Qualities of things as cold heat weight hardness and the like And perhaps it would be none of the least advantages which would accrue to Naturalists from a satisfactory explication of such Qualities by the most primitive and simple ones that it would much shorten the explication of particular Phaenomena For though there be many things in Nature that may be readily enough made out by the Size Motion Figure of the small Parts of Matter yet there are many more that cannot be well explain'd without a great deal of Discourse and divers successive Deductions of one thing from another if the purpos'd effect must be deduc'd from such primary and Universal Causes whereas if we be allow'd to take the Notions of Cold Heat and the like Qualities for granted the explications and proofs may be much more compendiously made He gives some Reason why Stones and Iron and all other heavy Bodies will swim in Quick-silver except Gold which will sink in it that teaches that all those other Bodies are in specie as they speak or bulk for bulk lighter than Quick-silver whereas Gold is heavier He I say may be allow'd to have render'd a Reason of the thing propos'd that thus refers the Phaenomenon to that known Affection of almost all Bodies here below which we call Gravity though he do not deduce the Phaenomenon from Atoms nor give us the cause of Gravity as indeed scarce any Philosopher has yet given us a satisfactory Account of it So if it be demanded why if the sides of a blown Bladder be somewhat squeez'd betwixt ones hands they will upon the removal of that which compress'd them fly out again and restore the Bladder to its former figure and dimensions it is not saying nothing to the purpose to say that this happens from the spring of those Aerial Particles wherewith the Bladder is fill'd though he that says this be not perhaps able to declare whence proceeds the Motion of Restitution either in a Particle of compress'd Air or any other bent spring And as for the Reasons of things assign'd by Physitians they must be most of them despis'd unless we will allow of such explications as deduce not things from Atoms or their Affections but only either from secondary Qualities or from the more particular Properties of Mixt Bodies If a Physitian be ask'd why Rhubarb does commonly cure Loosenesses he will probably tell you as a Reason that Rhubarb is available in such Diseases because it hath both a Laxative vertue whereby it evacuates Choler and such other bad humours as are wont in such cases to be the peccant Matter and an astringent Quality whereby it afterwards arrests the Flux But if you further ask him the Reason why Rhubarb purges and why it purges Choler more than any other humour 't is ten to one he will not be able to give you a satisfactory answer And indeed not only the manner whereby Purgative Medicines Work but those other Properties whereby some Bodies are Diuretick others Sudorifick others Sarcotick c. are not I fear so easie to be intelligibly made out as men imagine and yet a skilful Physitian would justly think himself wrong'd if the Reasons he renders of things in his own Profession were deny'd the Name of Reasons because made without recourse to Atomical Principles And indeed there are oftentimes so many subordinate Causes between particular Effects and the most General Causes of things that there is left a large field wherein to exercise Mens Industry and Reason if they will but solidly enough deduce the Properties of things from more general and familiar Qualities and also intermediate Causes if I may so call them from one another And I am the more backward to despise such kind of Reasons because I elsewhere declare that there are Some for I do not say Many things as particularly the Origine of Local Motion of which ev'n by the Atomical Doctrine no Physical Cause can well be render'd since either such things must be ascrib'd to God who is indeed the true but the supernatural Cause of them or else it must be said as it was by the old Epicureans that they did ever belong to Matter which considering that the Notion of Matter may be compleat without them is not to give a Physical efficient cause of the things in Question but in effect to confess that they have no such Causes But of this elsewhere more In the mean time that you may not be drawn away to undervalue such Writers as I have been pleading for nor think you ought to refrain from writing what occurs to you though true and useful unless you deduce it or at least can do so from the Epicurean Notions I shall here briefly represent to you what perhaps you will not hereafter think a despicable suggestion that there are two very distinct Ends that Men may propound to themselves in studying Natural Philosophy For some Men care only to Know Nature others desire to Command Her or to express it otherwise some there are who desire but to Please themselves by the Discovery of the Causes of the known Phaenomena and others would be able to produce new ones and bring Nature to be serviceable to their particular Ends whether of Health or Riches or sensual Delight Now as I shall not deny but that the Atomical the Cartesian or some such Principles are likely to afford the most of satisfaction to those speculative Wits that aim but at the knowledge of Causes so I think that the other sort of men may very delightfully successfully prosecute their ends by collecting and making Variety of Experiments and Observations since thereby learning the Qualities and Properties of those particular Bodies they desire to make use of and observing the power that divers Chymical Operations and other ways of handling Matter have of altering such Bodies and varying their effects upon one another they may by the help of Attention and Industry be able to do many Things some of them very Strange and more of them very Useful in humane life When a Gunner or a Souldier employs Gun-powder it is not necessary that he should consider or so much as
of the way of Philosophizing my friends esteem'd I thought I might without a more particular and explicit Enquiry into it say something to illustrate some Notions of it by making choice of such as being of the more simple and obvious did not require skill in the more mysterious points of the Hypothesis they belong'd to And as for the last of the three Discouragements above mention'd I consider'd that the Atomical Cartesian Hypotheses though they differ'd in some material points from one another yet in opposition to the Peripatetick and other vulgar Doctrines they might be look'd upon as one Philosophy For they agree with one another and differ from the Schools in this grand fundamental point that not only they take care to explicate things intelligibly but that whereas those other Philosophers give only a general and superficial account of the Phaenomena of Nature from certain substantial Forms which the most ingenious among themselves confess to be Incomprehensible and certain real Qualities which knowing men of other Perswasions think to be likewise Vnintelligible both the Cartesians and the Atomists explicate the same Phaenomena by little Bodies variously figur'd and mov'd I know that these two Sects of Modern Naturalists disagree about the Notion of Body in general and consequently about the Possibility of a true Vacuum as also about the Origine of Motion the indefinite Divisibleness of Matter and some other points of less Importance than these But in regard that some of them seem to be rather Metaphysical than Physiological Notions and that some others seem rather to be requisite to the Explication of the first Origine of the Vniverse than of the Phaenomena of it in the state wherein we now find it in regard of these I say and some other Considerations and especially for this Reason That both parties agree in deducing all the Phaenomena of Nature from Matter and local Motion I esteem'd that notwithstanding these things wherein the Atomists and the Cartesians differ'd they might be thought to agree in the main and their Hypotheses might by a Person of a reconciling Disposition be look'd on as upon the matter one Philosophy Which because it explicates things by Corpuscles or minute Bodieâ— may not very unfitly be call'd Corpuscular though I sometimes style it the Phoenician Philosophy because some ancient Writers inform us that not only before Epicurus and Democritus but ev'n before Leucippus taught in Greece a Phoenician Naturalist was wont to give an account of the Phaenomena of Nature by the Motion and other Affections of the minute Particles of Matter Which because they are obvious and very powerful in Mechanical Engines I sometimes also term it the Mechanical Hypothesis or Philosophy By such considerations then and by this occasion I was invited to try whether without pretending to determine the above-mention'd controverted points I could by the help of the Corpuscular Philosophy in the sense newly given of that Appellation associated with Chymical Experiments explicate some particular Subjects more intelligibly than they are wont to be accounted for either by the Schools or the Chymists And howâ—ver since the vulgar Philosophy is yet so vulgar that it is still in great request with the Generality of Scholars and since the Mechanical Philosophers have brought so few Experiments to verifie their Assertions and the Chymists are thought to have brought so many on the behalf of theirs that of those that have quitted the unsatisfactory Philosophy of the Schools the greater Number dazl'd as it were by the Experiments of Spagyrists have imbrac'd their Doctrines instead of those they deserted For these Reasons I say I hop'd I might at least do no unseasonable piece of service to the Corpuscular Philosophers by illustrating some of their Notions with sensible Experiments and manifesting that the things by me treated of may be at least plausibly explicated without having recourse to inexplicable forms real Qualities the four Peripatetick Elements or so much as the three Chymical Principles Being once resolv'd to write some such Specimina as I formerly judg'd requisite I soon bethought my self of the Experiment hereafter deliver'd concerning Salt-Petre divers of whose Phaenomena I did also as time would permit cast into one of the Essays I was then engag'd to write to a Friend And having dispatch'd that little Treatise it found so favourable a Reception among those Learned Men into whose hands it came that I was much encourag'd to illustrate some more of the Doctrines of the Corpuscular Philsosophy by some of the Experiments wherewith my Furnaces had suppliâ—d me which also as occasion serv'd I did partly by writing some Physico-Chymical Treatises and partly by making such large Notes on the Essay concerning Salt-Petre as might plentifully contribute to the History of Qualities of which I had sometimes thoughts And this continu'd till in the year before the last the publick Confusions in this then unhappy Kingdom reducing me to quit my former Design together with the place where my Furnaces my Books and my other Accommodations were I fell afterwards upon the making of Pneumatical tryals whereof I lately ventur'd to give the Publick an account in a Book of New Experiments Physo-mechanical about the Air. I should not trouble the Reader with so prolix a Preface to such small Treatises as those whereto this is prefix'd but for these two Reasons The one that I hope the fore-going Narrative will make me be the more favourably judg'd by the Philosophers I desire to serve if sometimes I write less skilfully of their Opinions than perhaps I should have done had I allow'd my self to search into them And the other that I am earnestly sollicited to publish some other Tracts tending to the same purpose that these do to which also should I ever be induc'd by the Reception these may meet with to trouble the World with them the same Preface as it is now penn'd may serve for an Introduction I had almost forgot to take notice That whereas at the end of the Essay concerning Salt-Petre I mention'd a then newly-publish'd Treatise of the laborious Glauber's which I had not then perus'd I found it to contain some Observations concerning the History of Salt-Petre which if they be true are considerable enough I must again recoÌ„mend the examination of them to the Readers Curiosity having been hinder'd by divers Avocations from saving him that labour my self And whereas also some years after I was inform'd of another little Book he had put out since the former wherein he teaches us a way of purifying Salt-Petre to make a Conjunction of the spirituous and fixter parts of it and then to suffer the Mixture to evaporate and so crystallize into Nitre This would I confess have made me apprehensive of passing for a Plagiary with those that did not know me but that it was easie for me to clear my self by the Testimony of very Learned Men who had some years before perus'd my Treatise and especially of one person
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
me a Difficulty which though un-mention'd at our meeting may afford an Objection perhaps more difficult than any of not to say all the foregoing namely That 't is scarce imaginable how such solid and hard Bodies should have their internal parts wrought upon by such slight Agents as the air and perhaps some yet minuter matter that is dispersed in it and how it is possible that where there is an actual Motion it should be so slow that a Corpuscle of Iron for instance seated in the internal Part of a Magnetick Needle should spend so long time as our conjecture requires in travelling so little a space as from thence to the next Superficies of the Needle But to this double Objection though some instances which you will meet with in the following part of this Paper may be properly applyed to solve it yet not to make your curiosity wait I will here speak a word or two to each of the members of the Objection SECT IV. And to the first I say That these Intestine Motions of the Corpuscles of hard Bodies need not be solely nor perhaps principally ascribed to those obvious external Agents to which we are wont to refer them since these may but excite or assist the more principal or internal Causes of the Motions we speak of as you may gather from what was but lately mention'd of the connate and unlooseable mobility of the Atoms according to Epicurus and the permeation of the most Solid Bodies by the Cartesian Materia Subtilis and we may see by the sudden effects of the Load-stone in endowing Steel wiâ—h Magnetick Qualities and depriving it of them again both which suppose the intervention of a change of Texture and this a production of Local Motion in the Metal that very minute and insensible Corpuscles of matter are not uncapable of effecting durable changes in the solidest Bodies And as for the other member of the Objection I confess it is not easie for us who are wont perhaps too much to follow our Eyes for Guides in judging of things corporeal and to deny existence to most things to most things whereto Nature has deny'd a visible bulk 't is not easie I say for us to imagine so great a slowness as 't is very possible for Nature to make use of in her Operations though our not being able to discern the motion of a shadow of a Dial-plate or that of the Index upon a Clock or Watch ought to make us sensible of the incompetency of our eyes to discern some motions of natural Bodies which reason tells us ought to be incomparably slower than these But not now to dispute about the existence and Attributes of infinite slowness or at least a slowness in the next possible degree to infinite I consider that it has not that I know of been demonstrated nor attempted to be so that the motion of the Corpuscle for example of the Needle above mention'd must be made in a direct line from the place where 't was first supposed to be to the Superficies of the Needle for it seems more rational and to agree better with the Phaenomena to suppose that the way of this Corpuscle in the Body 't would quit is extreamly crooked and intricate almost like that of a Squib in the air or on the ground for it being on the one hand urg'd on by the Causes whatever they be that make it strive to fly away and on the other hand hindred by the Corpuscles whereto 't is connected and by the occursions of other Corpuscles whose motions may be opposite to or disagreeing with those of our design'd Corpuscle it may probably before it can extricate it self be reduc'd to encounter and wrestle as it were with many other Corpuscles and be by them sometimes thrust or impell'd to the right hand and to the left and sometimes also repell'd inwards even after it is come to the superficial part of the Needle whence it may not presently have the liberty to fly away but may be drawn back by some other Corpuscle wherewith it is yet connected and which happening to be it self thrust inward may draw after it and so entangle again our almost disbanded Corpuscle besides that the gravity of the component Particles of a Body is oftentimes such that 't is easier for the Agent that puts them in motion to continue them in that slow motion among themselves than drive them up into so light a medium as the air as experience shews in those Bodies that are called Fixt as Gold and Glass though in actual fusion But I forget that I promis'd you to decline Speculations and therefore I shall only name to you a couple of Instances which will serve to confirm both what I was lately saying and what I am now in proving SECT V. The first of these I shall take from what is usually granted as matter of Fact namely that if a Spring though made of so hard a Body as Steel be forcibly bent and kept but a moderate while in that posture as soon as the force that kept it bent is removed it will again return to its former Figure but if it be kept too long in that forc't position it will by degrees lose that which they call the motion of Restitution and retain its new crooked Figure though the force that bent â—t be removed which shews both the power of some of the more familiar Agents in Nature and which is that the shewing whereof I here chiefly aim at that where there is a continued endeavour of the parts of a Body to put themselves into another state yet the motion or rather the progress may be much more slow than men seem as yet to have taken notice of since 't was a great while before â—he Texture of the Corpuscles of the Steel were so alter'd as to make them lose their former springiness But I will second this with a more illustrious Experiment which will at once confirm what I have just now said and shew that the Air or the invisible Corpuscles harbour'd in it may have no inconsiderable power to act upon and effect changes in the solidest Bodies To this purpose I shall only observe to you that though if a Bar of Iron having one of its ends held perpendicularly and at a fit distance to the Lilly or North-Point of the Mariners Compass I mean that which points towards the North it will as I elsewhere mention drive it away towards the East or West and if this same lower end of the Bar of Iron be put into a contrary posture it will presently lose its temporary magnetism as I elsewhere declare Yet if this Bar be very long kept upright in a Window or other convenient place then as some late Magnetical Writers will tell you it will have acquired a constant and durable magnetick power Which is a Phaenomenon that makes exceedingly for our present puâ—pose since it hence appears both that the Air together with the magnetical Effluvia of the
well known by his Writings who was pleas'd to like it so well as to desire he might translate it and had accordingly long before turn'd it into very elegant Latin I might perhaps venture to adde that though I could not justifie my self by so convincing a proof of my Innocence yet he that shall take the pains to consider that I could not borrow of Glauber the various Phaenomena I have particularly set down and much less the Reflections on them shall compare in what differing manners and to what differing purposes we two propose the making of Salt-Petre out of its own Spirit and fixt Salt He but prescribing as a bare Chymical Purification of Nitre what I teach as a Philosophical Redintegration of it He I say who shall compare these things together will perchance think that I was as likely to find this last nam'd Experiment as another Which things I say not as if I scrupl'd to make use of the industrious Glauber's or any other mans Experiments especially when I borrow not with them any of the Doctrines I build on them but because since I neither did nor could take any notice of Glauber's Book in mine I judg'd it requisite to say something to prevent my being thought to have unthankfully taken one of the chief Passages of my Discourse from a Book to which I was utterly a stranger The Reasons of my thus consenting to publish the following History of Fluidity and Firmness without the rest of those Annotations which I writ upon the same Essay touching Salt-Petre are partly that these are my recentest Composures of this Nature having been writen but the last year save one and were set down when I allow'd my self to be less unacquainted with Writers addicted to the modern Philosophy partly also because the considerableness of the Subject invited me to make these Annotations much more copious and somewhat less unaccurate than my Notes upon almost any other part of the Essay partly and indeed principally because mention being sometimes made of this History in my freshly publish'd Physico-Mechanical Experiments both the Printer and some Learned Gentlemen who were pleas'd to think that Book not unworthy the Translating have sollicited me to let this Treatise be annexed to the several Versions they are about of that Pneumatical piece and to the English Edition of the three fore-going Discourses which the Printer fears would without the company of these or some others make but too thin a Book And I thought fit to premise to this History the Essay concerning Salt-Petre not only because it might appear very improper to publish Annotations without the Text it self whereunto they relate but indeed because I find that there are still many Learned Men of the same disposition with those I have mention'd in the beginning of this Preface whence I am invited to divulge this Essay by the same Considerations that at first induc'd me to write it Especially since I remember not that among the new Philosophers I have met with any one Experiment that does so fairly and sensibly accommodate so many of their Opinions And indeed I freely confess that I shall think my self to have done no useless service to the Common-wealth of Learning if I prove so fortunate as by these or any other Writings of mine to the like purpose to beget a good understanding betwixt the Chymists and the Mechanical Philosophers who have hitherto been too little acquainted with one anothers Learning There being to this very day a great and almost general Mis-understanding betwixt the Corpuscular Philosophers and the Chymists most of Those on the one hand looking upon the Spagyrists as a company of meer and irrational Operators whose Experiments may indeed be serviceable to Apothecaries and perhaps to Physicians but are useless to a Philosopher that aims at curing no disease but that of Ignorance and most of the Spagyrists on the other hand looking upon the Corpuscularians if I may so call them as a sort of empty and extravagant Speculators who pretend to explicate the great Book of Nature without having so much as look'd upon the chiefest and the difficultest part of it namely the Phaenomena that Their Art has added to the former Edition of this vast and obscure Volume But that some of the principal of the Hermetick Opinions may be more handsomely accommodated by the notions of the Phoenician Hypotheses than by the common Philosophy of Elements of substantial forms which yet their Writers so frequently allude to and otherwise employ may appear from hence that whereas the Schools generally declare the transmutation of one Species into another and particularly that of baser metals into Gold to be against Nature and Physically impossible the Corpuscular Doctrine rejecting the substantial forms of the Schools and making Bodies to differ but in the Magnitude Figure Motion or Rest and Situation of their component particles which may be almost infinitely varied seems much more favourable to the Chymical Doctrine of the possibility of working wonderful changes and even transmutations in mixt Bodies And on the other side there are scarce any Experiments that may better accommodate the Phoenician principles than those that may be borrowed from the Laboratories of Chymists For first Chymistry enabling us to depurate Bodies and in some measure to analyse them and take asunder their Heterogeneous parts in many Chymical Experiments we may better than in others know what manner of Bodies we employ Art having made them more simple or uncompounded than Nature alone is wont to present them us And next many Chymical operations being performed in close and yet in transparent vessels we may better know what concurs to the effects produced because adventitious Bodies or at least all grosser ones are kept from intruding upon those whose Operations we have a mind to consider And lastly the Bodies employ'd by the Chymists being for the most part active ones the progress of Nature in an Experiment and the series of successive alterations through which the matter passes from first to last is wont to be made more nimbly and consequently becomes the more easie to be taken notice of and comprehended So that all this considered I hope it may conduce to the Advancement of Natural Philosophy if as I said I be so happy as by any endeavours of mine to possess both Chymists and Corpuscularians of the advantages that may redound to each Party by the Confederacy I am mediating between them and excite them both to enquire more into one anothers Philosophy by manifesting that as many Chymical Experiments may be happily explicated by Corpuscularian Notions so many of the Corpuscularian Notions may be commodiously either illustrated or confirmed by Chymical Experiments A PHYSICO-CHYMICAL ESSAY CONTAINING An Experiment with some Considerarations touching the differing Parts and Redintegration of SALT-PETRE SECTION I. SALT-PETRE Pyrophilus though in that form wherein it is sold in Shops it be no very obvious Concrete yet either in its rudiments or under several disguises
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
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
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
violent knock of some other Corpuscles be broken in the midst of the whole Concretion and consequently in the middlemost body For suppose them as Adamantine as you please yet since Corpuscles as hard as they are can be made very violently to knock against them why may not these grate or break the middlemost Corpuscles or any of the others as we see that Diamonds themselves may be reduc'd to powder by other Diamonds though not as Artificers vers'd in the Trade inform me by Attrition with any other stone To prove that the Cohesion of the middlemost of the three lately-mention'd small Deyes with the other two the one above it the other below is not so strong as that of the parts of that middlemost Corpuscle notwithstanding that the contact between each two adjoyning Bodies is suppos'd to be full for so it must be in such Bodies though not alwayes in others visibly greater in which some subtiler substance may be suppos'd to come in part between them to prove this I say there must be assign'd some better cause of the Cohesion of the matter in one part of the propos'd Body than in the other And it cannot with probability be pretended that a Corpuscle presum'd uncapable to be divided should consist of hooked parts and if that should be pretended yet ev'n these hooks also â—eing true Bodies the Question would recur concerning Them and be still renewable in infinitum If it should be said that these minute Bodies are indissoluble because it is â—heir nature to be so that would not be to render a Reason of the thing propos'd but in effect to decline rendring any And though I know that in every Hypothesis about the principles of things something is allow'd to be assum'd as not being to be explain'd or prov'd by any thing more primary than it self yet I know not whether this excuse be proper in our Case wherein it seems that the entireness and permanency of any parcel of matter how minute soever may be probably enough deduc'd from the immediate Contact the Rest and the extreme littleness of its designable parts And if for a last refuge it should be said that the designable parts of these Corpuscles are therefore unseparable because there is no vacuity at all intercepted between them besides that this is contrary to the supposition formerly made for such extremely minute Deyes as we imagin'd to be one upon another having their surfaces according to our Postulatum flat smooth and exquisitely congruous could no more than the parts of either of the three Corpuscles have any vacuity intercepted between them besides this I say this is both to suppose a Vacuum in all divisible Bodies and that too as the cause of their being such and to decline the former Hypothesis touching the use of this Spirit and take Sanctuary among the Atomists to whose opinion about the account upon which those Bodies they call Atoms are not dissipated although some of the Considerations we have alledg'd against the newly examin'd opinion may in part be appli'd yet diverse of their other opinions do so fairly comport with the generality of our Experiments in these Notes touching Fluidity and Firmness that I am willing to decline clashing with them by not pursuing now any further a Disquisition which as I said a while ago is not necessary to my present design especially since the dim and bounded Intellect of man seldom prosperously adventures to be Dogmatical about things that approach to Infinite whether in vastness or littleness Nor indeed would I have that look'd upon as a resolute Declaration of what I think of so abstruse a Subject which I have rather propos'd to avoid saying nothing where I suppos'd it expected I should say something The other thing then which in our Description of a firm Body we mention'd as capable to make it so is the texture of the parts whether homogeneous or not that constitute it and though the Juxta-position and Rest of these parts may possibly alone suffice to make the Body stable yet this Texture seems to be the most usual cause of stability and sometimes also it may superadde a degree of that quality to that which bodies may have upon the former account only For though whilst the parts of the Body are actually at rest it cannot be fluid yet those parts if they cohere to one another but by rest only may Caeteris paribus be much more easily dissociated and put into motion by any external Body actually mov'd than they could be if they were by little hooks and eyes or other kind of fastenings intangl'd in one another it being often necessary in this case violently to break off these fastenings before the little bodies fasten'd together by them can be disjoyn'd and put into such a separate motion as is requisite to the constituting of a fluid Body We formerly made use of that familiar substance the white of an Egge to illustrate the nature of Fluidity Let us now try whether it will also assist us in our enquiry after the causes of stability When an Egge is made hard by boyling since whether we suppose this Induration to be effected by bare motion or impulse or else by the insinuation of fiery Corpuscles since I say there is nothing that appears to get in at the shell unless perhaps some calorifick Atoms and perchance too some little particles of the fluid water it is boyled in 't is not easie to discover from whence else this change of consistency proceeds than from a change made in the texture of the parts whereby they are connected and dispos'd after a new manner fit to make them reciprocally hinder the freedom of each others motions But if instead of hardning the whites of Eggs by the heat of the fire you beat them very well into froth you may perceive that froth to emulate the nature of a stable Body for not only you may raise it up to a pretty height and make it retain a sharp top almost like a Pyramide but I remember I have for curiosity sake made with a little care a long and proportionably thick Body of these bubbles hang down from my finger without falling like an ice-icle from one of the Reeds of a thatch'd House and yet in this there appears not any alteration to be made in the fluid Body save a meer Mechanical change of the disposition of its parts which may be confirmed by water beaten into froth for there the heaped bubbles will quickly subside and fall back into water of the very same consistence it was of before Now there may be several things whereby a body may be put into such a texture as is convenient to make it firm or stable And of these before we consider of them particularly it will be fit to take notice in general that for the most part 't is not from any of them Single but from two or more of them Concurring that the Stability of Concretions proceeds The first and
Schools that is by the thought or operation of the mind yet it would remain a great question whether oâ— no Nâ—ture does actually so far mince and sub-divide Bodiâ—s as may appear by what has been freshly noted And â—owever it is not only requisite to the constitution of a fluid body that the parts of it be small enough but that they be also actually mov'd For we observ'd not long since that the dust of Alabastar put into motion did though its Corpuscles were not insensible emulate a fluid Body and immediately ceas'd to be fluid when they ceas'd to be agitated whereas the particles of water as minute and apt as they are to constitute a fluid substance do yet make that hard and brittle body we call Ice when those little particles upon what account soever are reduced to be at rest By what has been hitherto discours'd we may also be assisted to judge of the Doctrine of the Chymists who teach that in all Bodies Coagulation Stability Hardness and Brittleness depend upon Salt for though what above has been said of Crudling of milk by saline Liquors and the hardness and brittleness obvious in Salts themselves may keep us from denying that the saline principle is very powerful in the coagulation of some bodies and does produce much firmness or even brittleness in many or most of the concretes wherein it is predominant yet this hardning power of Salt seems not to proceed from any peculiar and inexplicable property it has to coagulate other bodies or make them compact but from the shape and motion of its Corpuscles which it seems are more fitted by Nature than those of many other Concretes to insinuate themselves into the pores of other bodies and fasten their particles to themselves and to one another either by wedging their Corpuscles together or by their stiff and slender parts or their sharp angles or edges piercing diverse of them together as when many Pieces of Paper are kept from scattering by a Wire that runs through them or as when a Knife takes up at once diverse pieces of Bread and Meat by being stuck into them all But whensoever there is in the constituent parts of the body a sufficient fitness and disposition to adhere firmly to one another Nature may of those parts compose a stable body whether they abound in Salt or no it not being so much upon Chymical Principles or ev'n upon the Predominancy or Plenty of any one Ingredient as upon the shape and motion of the component parts of bodies that their Fluidity and Firmness depend I will not here urge that Salts are generally reducible by an easie mixtuâ—e with water into the form of Liquors nor that Sea-salt Salt of Tartar and diverse other sorts of Salts will of themselves ev'n in the Air if not very dry assume the form of fluid Bodies nor yet will I press the shortly to be mention'd Example of Coral which is confidently affirmed to be soft whilst it remains in the Salt water and to grow hard when taken out of it I will not here I say press these and the like Arguments but content my self to have hinted them because they are such as I cannot well in few words make out and vindicate Wherefore I shall rather demand what Salt can be made appear to pass out of the body of melted Lead into that of Quicksilver to perform in it the coagulation abovemention'd What accession of Salt is there to be observ'd when running Mercury is precipitated per se into a powder and how will it be prov'd that when in a well-stop'd glass the whole body of water is in frosty nights turned into firm Ice by the cold of the ambient air that coagulation is perform'd by Salt it having not yet been made appear by Chymists that either Salts or even the distill'd Spirits of them can penetrate without a kind of Prodigy the narrow pores of unheated glass It is usually observ'd in Eggs that though at their first coming out of the Hens belly the shells are soft yet soon after they grow hard and brittle and yet it appears not how the saline Ingredient is encreas'd to effect this speedy induration and to subjoyn that by the by albeit I am not averse from thinking that the coldness of the outward Air and its imbibing some of the loosest of the moist parts of the soft Egge-shell may concur to this effect yet there are many Observations of Egge-shells that have been found hard in the womb of the Hen. And I well remember I have taken notice that diverse Eggs not yet laid but found at one time in the body of the same Hen were each of them furnish'd with a compleat and brittle Shell But I think I can draw a much stronger Argument against the Chymical opinion from the consideration of an Egg for I demand what plenty of Salt can be made appear to pierce the hard shell and more close-wrought membrane that both lines it and involves the Egg especially since 't is certain that in Egypt and diverse other places Eggs may be hatch'd by a temperate external heat without the Hen. And yet we may here observe that the same internal substance of the Egg which at first was fluid the yolk and white that compos'd it being so is upon the exclusion of the Chick turn'd almost all of it into consistent Bodies some of them tough as the membranes and gristles of the Bird and some of them harder and almost brittle as his bones and beak and all this as we said without accession of new Salt It would be hard for Chymists to prove that Diamonds and Rubies which are counted the hardest Bodies we know and at particular tryals of whose hardness I have sometimes wonder'd do abound in Salt at least it will not be unreasonable for us to think so till Chymists have taught us intelligible and practicable wayes of separating at least some true Salt from either of those Jewels And it may be also doubted whether the blood of Animals when it is freest from Serum do not though a Liquor as much abound with Salt as their skins or their flesh And since 't is with Chymists that I am now Reasoning I presume I may be allow'd to press them with Arguments drawn from some of the Eminentest Writers of their Sect. For the generality of Chymists and evâ—n those that are by the rest and themselves too call'd Philosophers not only granting but asserting and maintaining the Transmutation of great quantities of Quick-silver and the other ignobler metals into Silver or Gold by means of the white or red Elixir I shall demand of them whence it happens that one grain of the powder of Projection can turn a whole pound of Mercury into true Gold or Silver and consequently change a very fluid Body into a very firm one though the proportion of Salt employ'd to coagulate the whole Mass of Quick-silver would not amount to the six thousandth or seven thousandth part of the Liquor
only they will have a Vitriolate Efflorescence if I may so speak on their superficies as I have observ'd in divers other Marchasites but they will in Tract of time burst the Stone in Pieces of which sort I had sometime since and I hope I have yet a bulky Marchasite that I procur'd from a Virtuoso that lives just by a Vitriol-work whither these among other Vitriol-Stones are brought and where this Stone being chosen for its largeness was taken up and carefully kept by that ingenious person till it burst of it self and till I sent for it And to satisfie my self a little further that the internal parts of Marchasites may be as well dispos'd to be vitriolated as the external I remember I broke a hard Marchasite that I had from another place and laying it some short time in a Chamber-Window I found the new superficies made by the Tracture about the middle of the Stone to have acquired an Efflorescence of a vitriolate Nature The other instance which is very odd and much talked of is this An ingenious Gentleman of my acquaintance casually meeting me one day told me that he had a Turquois-stone which if he were not mistaken had a wonderful property for there being in it several spots of Colours differing from the rest of the Gem these spots seem'd though very slowly to move from one part of the stone to the other And this he thought himself to have taken notice of for very many Months perhaps a couple of years This Relation seem'd so strange that the Relator was not at all surpriz'd when to ascertain my self of the truth of it I desired to have the Ring this stone was set in for a while in my own keeping to which he readily assenting besides that I took very heedful notice of the scituation of the spots I employ'd a very ingenious youth that then lived with me and was skill'd in drawing to make the Picture of the stone with the spots as they were then placed and afterwards to have a watchful eye upon it and from time to time as once perhaps in two or three weeks to draw a new Picture of them by comparing several of which Pictures it was unanimously concluded that the spots did shift places in the Turquois as if the matter they consisted of made its way through the substance of the stone As we lately noted that the Gum of Lignum Vitae seem'd to do through the substance of the Wood And as far as we observ'd the motion of these spots was exceeding slow and irregular though perhaps it might have been reduc'd to a somewhat less uncertainty were it not that by an unwelcome accident we were deprived of the opportunity of continuâ—ng our Observations long enough And this brings into my mind that the Turquois being a stone of which â— had met strange stories in good Authors I once askâ—d several questions about it of a noted Jeweller and enquiring among other particulars whether he had not observ'd some changes that seem'd spontaneous in the substance or colour of the stone he reply'd that in some few Turquois's he had observ'd two differing Blews in differing parts of the same stone and that one of those Colours would by slow and unperceived degrees invade and at length overspread that part of the stone which the other Colour possessed before I shall here add that the same Gentleman that lent me the spotted Turquois shew'd me afterward an Agate Haft of a Knife where was a certain Cloud which he told me an ingenious Person had for some years observ'd to remove to and fro in the stone and had a while since to convince the Relator lent him the Agate of whose Phaenomena he promis'd me an account when he shall have had the stone in his custody for a competent time till the expiration of which it may suffice to have said of this Agate what I have now related SECT IX But because that Diamonds and Glass are generally looked upon especially by Chymists as Bodies of the closest and firmest Texture that Nature and Art afford if we could shew an intestine motion even in the parts of these fitter Instances for our purpose could not in reason be desired I shall venture to say something of each of them though what I have to say about Diamonds is propos'd rather to ground a suspition of what may be than a demonstration that it must be In the first place then to remove that prejudice that may be entertain'd from the incomparable hardness of Diamonds â—which I confess experience has made me admire as if Bodies so hard and solid could not have their parts put into motion but by some extraordinary not to say prodigious force I shall only repeat here what I have elsewhere shewn that Diamonds are Bodies that easily enough become actually Electrical and that some Diamonds of which sort I have a small one by me will by rubbing upon a cloath be brought to shine in the dark the Quist of both which transient Qualities requiring a change of Texture even in the internal parts and the Friction that produces that change doing it immediately by putting the parts of the stone into local-motion it may be thence argued that a very moderate force may suffice to beget an internal motion in the inward Particles of Diamonds themselves And I am not sure but that more hidden Agents may make impressions upon these hardest Bodies For in a Ring that I am wont to wear on my little Finger which has no Diamond save one more than that shining one I lately mention'd I have I know not how often seem'd to my self to observe a manifestly greater clearness and sparklingness at some times than at others though I could not refer it to the clearness or dulness of the weather the moisture or driness of thâ— air the superficial clearness or foulness of the stone or any other manifest cause I could think of And in this I was the more enclin'd to think I might not be mistaken because besides that the notice I took of it was frequent I have by me a rough Diamond just as it came from the Rock in whose Electrical faculty I have taken notice of changes as to the degree of strength wherewith it attracted and that within the compass of a very little time though I could not find any cause whereto I could refer so surprizing a Phaenomenon And I must not here omit that chancing one day to shew the newly mention'd Diamond Ring to a very ingenious Lady that used to wear in Rings and Bracelets store of those Gems and telling her what changes I had taken notice of in the Diamonds she who had observ'd more about Gems than any Lady I had yet met with appeared but little surprized at what I told her and affirm'd to me that she had divers times observed the like alterations in some Diamonds of hers which sometimes would look more sparklingly than they were wont and sometimes far more dull than