should directly exclude them all But since in my Explications of Qualities I pretend only that they may be explicated by Mechanical Principles without enquiring whether they are explicable by any other that which I need to prove is not that Mechanical Principles are the necessary and onely things whereby Qualities may be explained but that probably they will be found sufficient for their explication And since these are confessedly more manifest and more intelligible than substantial Formâ— and other Scholastic Entities if I may so call them 't is obvious what the consequence will be of our not being oblig'd to have recourse to things whose existence is very disputable and their nature veâ—y obscure There are several ways that may be employed some on one occasion and some on another either more directly to reduce Qualities as well as divers other things in nature to Mechanical Principles or by shewing the insufficiency of the Peripatetic and Chymical Theories of Qualities to recommend the Corpuscularian Doctrine of them For further Illustration of this Point I shall adde on this occasion that there are three distinct sorts of Experiments besides other proofs that may be reasonably employ'd though they be not equally effiâ—acious when we treat of the Origine of Qualities For some Instances may be brought to shew that the propos'd Quality may be Mechanically introduc'd into a portion of matter where it was not before Other Instances there may be to shew that by the same means the Quality may be notably varied as to degrees or other not essential Attributes And by some Instances also it may appear that the Quality is Mechanically expell'd from or abolish'd in a portion of matter that was endow'd with it before Sometimes also by the same Operation the former quality is destroyed and a new one is produc'd And each of these kinds of Instances may be usefully employ'd in our Notes about Particular Qualities For as to the first of them there will be scarce any difficulty And as to the second since the permanent Degrees as well as other Attributes of Qualities are said to flow from and do indeed depend upon the same Principles that the Quality it self does if especially in bodies inanimate a change barely Mechanical does notably and permanently alter the degree or other considerable attribute it will afford though not a clear proof yet a probable presumption that the Principles whereon the Quality it self depends are Mechanical And lastly if by a bare Mechanical change of the internal Disposition and structure of a body a permanent Quality confess'd to flow from its substantial Form or inward Principle be abolish'd and perhaps also immediately succeeded by a new Quality Mechanically producible if I say this come to pass in a body Inanimate especially if it be also as to sense similar such a Phaenomenon will not a little favour that Hypothesis which teaches that these Qualities depend upon certain contextures and other Mechanical Affections of the small parts of the bodies that are indowed with them and consequently may be abolish'd when that necessary Modification is destroyed This is thus briefly premis'd to shew the pertinency of alledging differing kinds of Experiments and Phaenomena in favour of the Corpuscular Hypothesis about Qualities What has been thus laid down may I hope facilitate and shorten most of the remaining work of this Preamble which is to shâ—w though but very briefly that there may be several ways not impertinently employable to recommend the Corpuscularian Doctrine of Qualities For first it may sometimes be shewn that a Substantial Form cannot be pretended to be the necessary Principle of this or that Quality as wâ—ll for instance hereafter be made manifest in the Asperity and Smoothness of bodies and in the Magnetical Vertue residing in a piece of Iron that has been impregnated by a Load-stone 'T is true that the force of such Instances is indirect and that they do not expresly prove the Hypothesis in whose favour they are alledged but yet they may do it good service by disproving the Grounds and Conclusions of the Adversaries and so by removing Prejudices making way for the better entertainment of the truth Secondly we may sometimes obtain the same or the like Quality by Artificial and sometimes even temporary Compositions which being but factitious bodies are by Leerned Adversaries confess'd not to have Substantial Forms and can indeed reasonably be presum'd to have but resulting Temperaments As will be hereafter exemplifi'd in the production of Green by compounding Blew and Yellow and in the Electrical Faculty of Glass and in the temporary whiteness produc'd by beating clear Oyl and fair Water into an Ointment and by beating water into a froth and more permanently in making Coral white by flawing it with heat and in divers other Particulars that will more properly be elsewhere mention'd Thirdly then in some cases the Quality propos'd may be either introduced or vary'd or destroy'd in an inanimate body when no change appears to be made in the body except what is Mechanical and what might be produc'd in it supposing such a parcel of matter were artificially fram'd and constituted as the body is though without any Substantial Form or other such like internal Principle So when a piece of Glass or of clarify'd Rosin is by being beaten to powder deprived of its Transparency and made white there appears no change to be made in the pulveriz'd body but a comminution of it into a multitude of Corpuscles that by their number and the various scituations of their surfaces are fitted copiously to reflect the sincere Light several ways or give some peculiar Modification to its Rayes and hinder that free passage of the beams of Light that is requisite to Transparency Fourthly as in the cases belonging to the foregoing number there appears not to intervene in the Patient or Subject of the change any thing but a Mechanical alteration of the Mechanical Structure or Constitution so in some other cases it appears not that the Agent whether natural or factitious operates on the Patient otherwise than Mechanically employing onely such a way of acting as may proceed from the Mechanisme of the matter which it self consists of and that of the body it acts upon As when Goldsmiths burnish a Plate or Vessel of Silver that having been lately boil'd lookt white before though they deprive it of the greatest part of its colour and give it a new power of reflecting the beams of Light and visible Objects in the manner proper to specular bodies yet all this is done by the intervention of a burnishing Tool which often is but a piece of Steel or Iron conveniently shap'd and all that this Burnisher does is but to depress â—â—â—â—â—tle prominencies of the Silver and reduce them and the little cavites of it to one physically level or plain Superficies And so when a Hammer striking often on a Nail makes the head of it grow hot the Hammer is but a purely Mechanical Agent and
will I hope satisfie you that how unanimously so ever men have deduced all magnetick operations from the form of the Loadstone yet some internal change of pores or some other Mechanical alterations or inward disposition either of the excited Iron or of the Load-stone it self may suffice to make a body capable or uncapable of exercising some determinate magnetical operations which may invite you to cast a more unprejudiced eye upon those few particulars I shall now subjoin to make it probable that even Magnetical Qualities may be Mechanically produced or altered EXPER. V. I Have often observed in the shops of Artificers as Smiths Turners of metals c. that when hardened and well tempered tools are well heated by Attrition if whilest they are thus warmed you apply them to filings or chips as they call them or thin fragments of Steel or Iron they will take them up as if the instruments were touched with a Loadstone but as they will not do so unless they be thus excited by rubbing till they be warmed by which means a greater commotion is made in the inner parts of he Steel so neither would they retain so vigorous a Magnetism as to support the little fragments of Steel that stuck to them after they were grown cold again Which may be confirmed by what if I much misremember not I shewed some Acquaintances of yours which was that by barely rubbing a conveniently shaped piece of Steel against the floor till it had gained a sufficient heat it would whilest it continued so discover a manifest though but faint attractive power which vanished together with the adventitious Heat EXPER. VII WE elsewhere observe which perhaps you also may have done that the Iron bars of windows by having stood very long in an erected posture may at length grow Magnetical so that if you apply the North point of a poised and excited Needle to the bottom of the Bar it will drive it away attract the Southern and if you raise the magnetick needle to the upper part of the Bar and apply it as before this will draw the Northern extream which the other end of the bar expelled probably because as 't is elsewhere declared the bar is in tract of time by the continual action of the Magnetical effluvia of the Tarraqueous Globe turned into a kind of Magnet whose lower end becomes the North-pole of it and the other the Southern Therefore according to the Magnetical Laws the former must expel the Northern extream of the Needle and the later draw it EXPER. VIII I Have found indeed and I question not but other observers may have done so too that if a bar of Iron that has not stood long in an erected posture be but held perpendicular the forementioned experiment will succeed probably upon such an account as that I have lately intimated But then this virtue displayed by the extreams of the bar of Iron will not be at all permanent but so transient that if the bar be but inverted and held again upright that end which just before was the uppermost and drew the north-end of the needle will now being lowermost drive it away which as was lately observed wâ—ll not happen to a bar which has been some years or other competent time kept in the same Position So that since length of time is requisite to make the verticity of a bar of Iron so durable constant that the same extream will have the same virtues in reference to the Magnetical needle whether you make it the upper end or the lower end of the bar it seems not improbable to me that by length of time the whole Magnetick virtue of this Iron may be increased and consequently some degree of attraction acquired And by this Consideration I shall endeavour to explicate that strange thing that is reported by some Moderns to have happened in Italy where a bar of Iron is affirmed to have been converted into a Load-stone whereof a piece was kept among other rarities in the curious Aldrovandus his Musaeum Metallicum For considering the greatness of its Specific Gravity the malleableness and other properties wherein Iron differs from Loadstone I cannot easily believe that by such a way as is mentioned a metal should be turned into a stone And therefore having consulted the book it self whence this Relation was borrowed I found the story imperfectly enough delivered The chiefest and clearest thing in it being that at the top of the Church of Arimini a great iron-bar that was placed there to support a Cross of an hundred pound weight was at length turned into a Load-stone But whether the reality of this transmutation was examined and how it appeared that the fragment of the Loadstone presented to Aldrovandus was taken from that bar of Iron I am not fully satisfied by that Narrative Therefore when I remember the great resemblance I have sometimes seen in colour besides other manifest Qualities betwixt some Loadstones and some course or almost rusty Iron I am tempted to Conjecture that those that observed this Iron-bar when broken to have acquired a strong Magnetical virtue which they dreamed not that tract of time might communicate to it might easily be perswaded by this virtue and the resemblance of colour that the Iron was turned into Loadstone especially they being prepossess'd with that Aristotelian Maxim whence our Author would explain this strange Phaenomenon that inter Symbolum habentia facilis est transmutatio But leaving this as a bare conjecture we may take notice that what virtue an oblong piece of Iron may need a long tract of time to acquire by the help onely of its position may be imparted to it in a very short time by the intervention of such a nimble agent as the fire As may be often though not always observed in Tongs and such like Iron Utensils that having been ignited have been set to cool leaning against some wall or other prop that kept them in an erected posture which makes it probable that the great commotion of the parts made by the vehement heat of the fire disposed the Iron whilst it was yet soft and had its pores more lax and parts more pliable disposed it I say to receive much quicker impressions from the Magnetical effluvia of the Earth than it would have done if it had still been cold And 't is very observable to our present purpose what differing effects are produced by the operation of the fire upon two Magnetick bodies according to their respective constitutions For by keeping a Loadstone red-hot though you cool it afterwards in a perpendicular posture you may deprive it of its former power of manifestly attracting But a bar of Iron being ignited and set to cool perpendicularly does thereby acquire a manifest verticity Of which differing events I must not now stay to inquire whether or no the true reason be That the peculiar Texture or internal constitution that makes a Loadstone somewhat more than an ordinary Ore of
and History of Precipitations if well delivered will be a thing of more extent and moment than seems hitherto to have been imagined since not only several of the changes in the blood and other liquors and juices of the humane body may thereby be the better understood and they prevented or their ill consequences remedied but in the practical part of Mineralogy divers usefull things may probably be performed by the assistance of such a Doctrine and History To keep which conjecture from seeming extravagant I shall only here intimate that 't is not alone in bodies that are naturally or permanently liquid but in those solid and ponderous bodies that are for a short time made so by the violence of the fire that many of the things suggested by this Doctrine may have place For whilst divers of those Bodies are in fusion they may be treated as liquors and metalls and perhaps other heterogeneous bodies may be obtained from them by fit though dry Precipitants as in some other writings I partly did and may elsewhere yet further declare FINIS Experiments and Notes ABOUT THE MECHANICAL PRODUCTION OF Magnetism By the Honourable ROBERT BOYLE Esq Fellow of the R. Society LONDON Printed by E. Flesher for R. Davis Bookseller in Oxford 1676. ADVERTISEMENT Concerning the following NOTES About OCCULT QUALITIES THE following Papers about Magnetism and Electricity would appear with less disadvantage if the Author's willingness and Promise that this Tome should be furnished with notes about some Occult Qualities as well as about divers sorts of those that are presumed to be Manifest did not prevail with him to let the ensuing Notes appear without those about the Pores of Bodies and Figures of Corpuscles that should have preceded them and some others that should have accompanied them But the Author chose rather to venture these Papers abroad in the Condition such as 't is they now appear in than make those already printed about manifest Qualities stay longer for Accessions which some troublesome Accidents will not suffer him to hasten to the press and without which he now fears this Tome may swell to a more than competent Bulk Experiments and Notes ABOUT THE Mechanical Production OF MAGNETICAL QUALITIES THough the vertues of the Loadstone be none of the least famous of Occult Qualities and are perhaps the most justly admired yet I shall venture to offer something to make it probable that some even of these may be introduced into bodies by the production of Mechanical changes in them To make way for what I am to deliver to this purpose it will be expedient to remove that general and settled prejudice that has kept men from so much as thinking of any Mechanical account of Magnetisms which is a belief that these Qualities do immediately flow from the Substantial Form of the Loadstone whose abstruse nature is disproportionate to our understandings But for my part I confess I see no necessity of admitting this supposition for I see that a piece of Steel fitly shaped and well excited will like a Loadstone have its determinate Poles and with them point at the North and South it will draw other pieces of Iron and Steel to it and which is more communicate to them the same kind though not degree of attractive and directive vertue it had it self and will possess these faculties not as light and transient impressions but as such setled and durable Powers that it may retain them for many years if the Loadstone to which it has been duly applied were vigorous enough Of which sort I remember I have seen one and made some tryals with it that yielded an income to the owner who received money from Navigators and others for suffering them to touch their needles swords knives c. at his excellent Magnet Now in a piece of steel or iron thus excited 't is plain that the Magnetic operations may be regularly performed for whole years by a body to which the form of a Loadstone does not belong since as it had its own form before so it retains the same still continuing as malleable fusible c. as an ordinary piece of the same metal unexcited so that if there be introduced a fit disposition into the internal parts of the metal by the action of the Load-stone the metal continuing of the same Species it was before will need nothing save the continuance of that acquired disposition to be capâ—ble of performing Magnetical Operations and if this disposition or internal constitution of the excited iron be destroyed though the form of the metal be not at all injured yet the former power of Attraction shall be abolished as appears when an excited iron is made red hot in the fire and suffered to cool again And here give me leave to take notice of what I have elsewhere related to another purpose namely that a Loadstone may as I have more than once tryed be easily deprived by ignition of its Power of sensibly attracting Martial bodies and yet be scarce if at all visibly changed but continue a true Loadstone in other capacities which according to the vulgar Philosophy ought to depend upon its Substantial Form and the Loadstone thus spoiled may notwithstanding this Form have its Poles altered at pleasure like a piece of Iron as I have elsewhere particularly declared And I will confirm what I have been saying with an experiment that you do not perhaps expect namely that though it be generally taken for granted without being contradicted that I know of by any man that in a sound Loadstone that has never been injured by the fire not only the attractive Power but the particular Vertue that it has to point constantly when left to it self with one of its determinate extreams to one determinate pole flowes immediately from the substantial or at least essential Form yet this Form remaining undestroyed by Fire the Poles may be changed and that with ease and speed For among my notes about Magnetical Experiments whence I borrow some passages of this paper I find the following Account EXPER. IV. TO shew that the virtue that a Loadstone hath by this determinate Pole or Extream to attract for example the South-end of a poised needle and with the opposite extream or Pole the North-end of the same needle I made among other tryals the following Experiment Taking a very small fragment of a Loadstone I found agreeably to my conjecture that by applying sometimes one Pole sometimes the other to that pole of a small but a very vigorous Loadstone that was fit for my purpose I could at pleasure in a few minutes change the Poles of the little fragment as I tryed by its operations upon a needle freely poised though by applying a fragment a pretty deal bigger for in it self it appeared very small I was not able in far more hours than I employed minutes before to make any sensible change of the Poles This short Memorial being added to the preceding part of this discourse
Iron which metal as far as I have tried is the usual ingredient of Loadstones being spoiled by the violence of the fire this rude Agent leaves it in the condition of common Iron or perhaps of ignited Iron-ore whereas the fire does soften the Iron it self which is a metal not an Ore agitating its parts and making them the more flexible and by relaxing its pores disposes it to be easily and plentifully pervaded by the Magnetical steams of the Earth from which it may not improbably be thought to receive the verticity it acquires and this the rather because as I have often tryed and elsewhere mentioned if an oblong Loadstone once spoil'd by the fire be thorowly ignited and cooled either perpendicularly or lying horizontally North and South it will as well as a piece of Iron handled after the same manner be made to acquire new poles or change the old ones as the skilful experimenter pleases But whatever be the true cause of the disparity of the fires operation upon a sound Loadstone and a bar of Iron the effect seems to strengthen our conjecture That Magnetical operations may much depend upon Mechanical Principles And I hope you will find further probability added to it by some Phaenomena recited in another paper to which I once committed some promiscuous Experiments and Observations Magnetical EXPER. XII IF I may be allowed to borrow an Experiment from a little Tract that yet lyes by me and has been seen but by two or three friends it may be added to the instances already given about the production of Magnetism For in that Experiment I have shewn how having brought a good piece of a certain kind of English Oker which yet perhaps was no fitter than other to a convenient shape though till it was altered by the fire it discovered no Magnetical Quality yet after it had been kept red-hot in the fire and was suffered to cool in a convenient posture it was enabled to exercise Magnetical operations upon a poâ—s'd Needle EXPER. XIII AS for the Abolition of the Magnetical vertue in a body endow'd with it it may be made without destroying the Substantial or the Essential Form of the body and without sensibly adding diminishing or altering any thing in reference to the Salt Sulphur and Mercury which Chymists presume Iron and Steel as well as other mixt bodies to be composed of For it has been sometimes observed that the bare continuance of a Loadstone it self in a contrary position to that which when freely placed it seems to effect has either corrupted or sensibly lessened the vertue of it What I formerly observed to this purpose I elsewhere relate and since that having a Loadstone whose vigor was look'd upon by skilful persons as very extraordinary and which whilst it was in an Artificers hand was therefore held at a high rate I was careful being by some occasions call'd out of London to lock it up with some other rarities in a Cabinet whereof I took the key along with me and still kept it in my own Pocket But my stay abroad proving much longer than I expected when being returned to London I had occasion to make use of this Loadstone for an Experiment I found it indeed where I left it but so exceedingly decayed as to its attractive power which I had formerly examin'd by weight by having lain almost a year in an inconvenient posture that if it had not been for the circumstances newly related I should have concluded that some body had purposely got it out in my absence and spoiled it by help of the fire the vertue being so much impaired that I cared little to employ it any more about considerable Experiments And this corruption of the Magnetical vertue which may in tract of time be made in a Loadstone it self may in a trice be made by the help of that Stone in an excited Needle For 't is observ'd by Magnetical Writers and my own Trials purposely made have assured me of it that a well pois'd Needle being by the touch of a good Loadstone excited and brought to turn one of its ends to the North and the other to the South it may by a contrary touch of the same Loadstone be deprived of the faculty it had of directing its determinate extreams to determinate Poles Nay by another touch or the same and even without immediate Contact if the Magnet be vigorous enough the Needle may presently have its direction so changed that the end which formerly pointed to the North pole shall now regard the South and the other end shall instead of the Southern respect the Northen pole EXPER. XV. AND to make it the more probable that the change of the Magnetism communicated to Iron may be produc'd at least in good part by Mechanical operations procuring some change of texture in the Iron I shall subjoyn a notable Experiment of the ingenious Doctor Power which when I heard of I tryed as well as I could and though perhaps for want of conveniency I could not make it fully answer what it promised yet the success of the trial was considerable enough to make it pertinent in this place and to induce me to think it might yet better succeed with him whose Experiment as far as it concerns my present purpose imports that if a Puncheon as Smiths call it or a Rod of Iron be by being ignited and suffered to cool North and South and hammered at the ends very manifestly endow'd with Magnetical vertue this vertue will in a trice be destroyed by two or three smart blows of a strong hammer upon the middle of the oblong piece of Iron But Magnetism is so fertile a Subject that if I had now the leisure and conveniency to range among Magnetical Writers I should scarce doubt of finding among their many Experiments and Observations divers that might be added to those above delivered as being easily applicable to my present Argument And I hope you will find farther probability added to what has been said to shew that Magnetical operations may much depend upon Mechanical Principles by some Phaenomena recited in another Paper to which I once committed some promiscuous Experiments and Observations Magnetical FINIS Experiments and Notes ABOUT THE MECHANICAL ORIGINE OR PRODUCTION OF Electricity By the Honourable ROBERT BOYLE Esq Fellow of the R. Society LONDON Printed by E. Flesher for R. Davis Bookseller in Oxford 1675. Experiments and Notes ABOUT THE MECHANICAL ORIGINE OR PRODUCTION OF Electricity THat 't is not necessary to believe Electrical Attraction which you know is generally listed among Occult Qualities to be the effect of a naked and solitary Quality flowing immediately from a Substantial Form but that it may rather be the effect of a Material Effluvium issuing from and returning to the Electrical Body and perhaps in some cases assisted in its Operation by the external air seems agreable to divers things that may be observ'd in such Bodies and their manner of acting