EXPERIMENTS AND NOTES ABOUT THE MECHANICAL ORIGINE OR PRODUCTION OF ELECTRICITY (BOYLE-E3-P1,1E.3) That $'t $is {TEXT:'tis} not necessary to believe Electrical Attraction which you know is generally lifted {COM:sic} 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 . (BOYLE-E3-P1,2E.5) There are differing Hypotheses and all of them Mechanical , propos'd by the Moderns to solve the Phaenomena of Electrical Attraction . (BOYLE-E3-P1,2E.6) Of these Opinions the First is that of the learned Jesuite Cabaeus , who , though a Peripatetick and Commentator on Aristotle , thinks the drawing of light Bodies by Jet , Amber , &c. may be accounted for , by supposing , that the steams that issue , or , if I may so speak , sally , out of Amber , when heated by rubbing , discuss and expell the neighbouring air ; which after it has been driven off a little way , makes as it were a small whirl-wind , because of the resistance it finds from the remoter air , which has not been wrought on by the Electrical Steams ; and that these , shrinking back swiftly enough to the Amber , do in their returns bring along with them such light bodies as they meet with in their way . On occasion of which Hypothesis I shall offer it to be consider'd , Whether by the gravity of the Atmospherical Air , surmounting the Specifick Gravity of the little and rarifi'd Atmosphere , made about the Amber by its emissions , and comprising the light Body fasten'd on by them , the Attraction may not in divers cases be either caused or promoted . (BOYLE-E3-P1,3E.7) Another Hypothesis is that proposed by that Ingenious Gentleman Sir Kenelm Digby , and embraced by the very Learned Dr. Browne , who seems to make our Gilbert himself to have been of it and divers other sagacious men . (BOYLE-E3-P1,3E.8) And according to this Hypothesis , the Amber , or other Electrick , being chaf'd or heated , is made to emit certain Rayes or Files of unctuous Steams , which , when they come to be a little cool'd by the external air , are somewhat condens'd , and having lost of their former agitation , shrink back to the body whence they sallied out , and carry with them those light bodies , that their further ends happen to adhere to , at the time of their Retraction : As when a drop of Oyl or Syrup hangs from the end of a small stick , if that be dextrously and cautiously struck , the viscous substance will , by that impulse , be stretch'd out , and presently retreating , will bring along with it the dust or other light bodies that chanced to stick to the remoter parts of it . (BOYLE-E3-P1,4E.9) And this way of explaining Electrical Attractions is employ'd also by the Learned Gassendus , who addes to it , that these Electrical Rays if they may be so call'd being emitted several ways , and consequently crossing one another , get into the pores of the Straw , or other light body to be attracted , and by means of their Decussation take the faster hold of it , and have the greater force to carry it along with them , when they shrink back to the Amber whence they were emitted . (BOYLE-E3-P1,5E.10) A third Hypothesis there is , which was devised by the Acute Cartesius , who dislikes the Explications of others , chiefly because he thinks them not applicable to Glass , which he supposes unfit to send forth Effluvia , and which is yet an Electrical body ; and therefore attempts to account for Electrical Attractions by the intervention of certain particles , shap'd almost like small pieces of Ribbond , which he supposes to be form'd of this subtile matter harbour'd in the pores or crevises of Glass . (BOYLE-E3-P1,5E.11) But this Hypothesis , though ingenious in it self , yet depending upon the knowledge of divers of his peculiar Principles , I $can $not {TEXT:cannot} intelligibly propose it in few words , (BOYLE-E3-P1,5E.12) and therefore shall refer you to himself for an account of it : which I the less scruple to do , because though it be not unworthy of the wonted Acuteness of the Authour , yet he seems himself to doubt , whether it will reach all Electrical Bodies ; (BOYLE-E3-P1,6E.13) and it seems to me , that the reason why he rejects the way of explicating Attraction by the Emission of the finer parts of the attrahent to which Hypothesis , if it be rightly proposed I confess myself very inclinable is grounded upon a mistake , which , though a Philosopher may , for want of Experience in that Particular , without disparagement fall into , is nevertheless a mistake . (BOYLE-E3-P1,6E.14) For whereas our excellent Author says , that Electrical Effluvia , such as are supposed to be emitted by Amber , Wax , &c. $can $not {TEXT:cannot} be imagin'd to proceed from Glass , I grant the Supposition to be plausible , (BOYLE-E3-P1,6E.15) but $can $not {TEXT:cannot} allow it to be true . (BOYLE-E3-P1,6E.16) For as solid a body as Glass is , yet if you but dextrously rub for two or three minutes a couple of pieces of Glass against one another , you will find that Glass is not-4 onely-3 capable of emitting Effluvia , but such ones as to be odorous , and sometimes to be rankly stinking . (BOYLE-E3-P1,6E.17) But it is not necessary , that in this Paper , where I pretend not-3 to write Discourses but Notes , I should consider all that has been , or I think may be , said for and against each of the above-mentioned Hypotheses ; since they all agree in what is sufficient for my present purpose , namely , that Electrical Attractions are not the Effects of a meer Quality , but of a Substantial Emanation from the attracting Body : (BOYLE-E3-P1,7E.19) And $'t $is {TEXT:'tis} plain , that they all endeavour to solve the Phaenomena in a Mechanical way , without recurring to Substantial Forms , and inexplicable Qualities , or so much as taking notice of the Hypostatical Principles of the Chymists . Wherefore it may suffice in this place , that I mention some Phaenomena that in general make it probable , that Amber , &c. draws such light Bodies as pieces of Straw , Hair , and the like , by vertue of some Mechanical Affections either of the attracting or of the attracted Bodies , or of both the one and the other . (BOYLE-E3-P1,7E.20) {COM:insert_helsinki_sample_here} EXPERIMENTS AND NOTES ABOUT THE MECHANICAL PRODUCTION OF MAGNETICAL QUALITIES . (BOYLE-E3-P1,1M.24) 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 . (BOYLE-E3-P1,1M.26) 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 . (BOYLE-E3-P1,2M.27) EXPER. I . (BOYLE-E3-P1,2M.29) But for my part , I confess , I see no necessity of admitting this supposition ; (BOYLE-E3-P1,2M.31) 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 ; (BOYLE-E3-P1,2M.32) 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 , (BOYLE-E3-P1,2M.33) 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 . (BOYLE-E3-P1,3M.34) Now , in a piece of steel or iron thus excited , $'t $is {TEXT:'tis} 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 Loadstone , the metal , continuing of the same Species it was before , will need nothing save the continuance of that acquired disposition to be capable of performing Magnetical Operations ; (BOYLE-E3-P1,3M.35) EXPER. II . (BOYLE-E3-P1,3M.37) 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 . (BOYLE-E3-P1,4M.39) EXPER. III . (BOYLE-E3-P1,4M.41) 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 , (BOYLE-E3-P1,4M.43) 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 . (BOYLE-E3-P1,5M.44) 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 . (BOYLE-E3-P1,5M.45) For among my notes about Magnetical Experiments whence I borrow some passages of this paper , I find the following Account . (BOYLE-E3-P1,5M.46) EXPER. IV . (BOYLE-E3-P1,5M.48) 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 . (BOYLE-E3-P1,6M.51) 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 . (BOYLE-E3-P1,6M.52) This short Memorial being added to the preceding part of this discourse , 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 Loadstone 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 , (BOYLE-E3-P1,7M.54) I shall now subjoin to make it probable , that even Magnetical Qualities may be Mechanically produced or altered . (BOYLE-E3-P1,7M.55) EXPER. V . (BOYLE-E3-P1,7M.57) 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 : (BOYLE-E3-P1,8M.59) 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 the 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 . EXPER. VI . 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 . (BOYLE-E3-P1,8M.60) EXPER. VII . (BOYLE-E3-P1,8M.62) 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 ; (BOYLE-E3-P1,9M.65) and if you raise the magnetic 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 {TEXT:'tis} 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 . (BOYLE-E3-P1,9M.66) Therefore according to the Magnetical Laws , the former must expel the Northern extream of the Needle , and the later {COM:sic} draw it . (BOYLE-E3-P1,10M.67) EXPER. VIII . (BOYLE-E3-P1,10M.69) 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 : (BOYLE-E3-P1,10M.71) But then this virtue , displayed by the extreams of the bar of Iron , will not-1 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 , will 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 . (BOYLE-E3-P1,11M.72) 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 Loadstone , whereof a piece was kept among other rarities in the curious Aldrovandus his Museum Metallicum . (BOYLE-E3-P1,11M.73) For considering the greatness of its Specific Gravity , the malleableness and other properties , wherein Iron differs from Loadstone , I $can $not {TEXT:cannot} easily believe , that , by such a way as is mentioned , a metal should be turned into a stone . (BOYLE-E3-P1,12M.74) 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 Loadstone . (BOYLE-E3-P1,12M.75) 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 . (BOYLE-E3-P1,12M.76) 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 . (BOYLE-E3-P1,13M.77) EXPER. IX . (BOYLE-E3-P1,13M.79) 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 . (BOYLE-E3-P1,14M.81) EXPER. X . (BOYLE-E3-P1,14M.83) And $'t $is {TEXT:'tis} 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 . (BOYLE-E3-P1,14M.85) 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 : (BOYLE-E3-P1,14M.86) 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 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 ; EXPER. XI . 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 . (BOYLE-E3-P1,15M.87) 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 . (BOYLE-E3-P1,16M.89) 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 . (BOYLE-E3-P1,16M.90) EXPER. XII . (BOYLE-E3-P1,16M.92) If I may be allowed to borrow an Experiment from a little Tract that yet lyes by me , and has been seen but-2 by two or three friends , it may be added to the instances already given about the production of Magnetism . (BOYLE-E3-P1,16M.94) 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 pois'd Needle . (BOYLE-E3-P1,17M.95) EXPER. XIII . (BOYLE-E3-P1,17M.97) 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 . (BOYLE-E3-P1,17M.99) 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 . (BOYLE-E3-P1,17M.100) What I formerly observed to this purpose , I elsewhere relate , (BOYLE-E3-P1,17M.101) 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 . (BOYLE-E3-P1,18M.102) 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 . (BOYLE-E3-P1,18M.103) EXPER. XIV . (BOYLE-E3-P1,18M.105) 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 . (BOYLE-E3-P1,18M.107) For $'t $is {TEXT:'tis} 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 . (BOYLE-E3-P1,19M.108) 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 Northern pole . (BOYLE-E3-P1,19M.109) EXPER. XV . (BOYLE-E3-P1,19M.111) 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 ; (BOYLE-E3-P1,19M.113) 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 . (BOYLE-E3-P1,20M.114) 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 . (BOYLE-E3-P1,20M.115) 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 . (BOYLE-E3-P1,20M.116) Finis . (BOYLE-E3-P1,20M.117)