shew vs that the lesse the atomes should penetrate into a moouing body by reason of the extreme density of it the more efficaciously they would worke and the greater celerity they would cause in its motion And hence we may giue the fullest solution to the obiection aboue which was to this effect that seeing diuision is made onely by the superficies or exteriour part of the dense body and that the vertue whereby a dense body doth worke is onely its resistance to diuision which maketh it apt to diuide it would follow that a hollow boule of brasse or iron should be as heauy as a solide one For we may answere that seeing the atomes must stricke through the body and that a cessible body doth not receiue their stroakes so firmely as a stiffe one nor can conuey them so farre if vnto a stiffe superficies there succeede a yielding inside the stroakes must of necessity loose much of their force and consequently can not mooue a body full of ayre with so much celerity or with so much efficacy as they may a solide one But then you may peraduenture say that if these stroakes of the descending atomes vpon a dense body were the cause of its motion downewardes we must allow the atomes to mooue faster then the dense body that so they may still ouertake it and driue it along and enter into it whereas if they should mooue slower then it none of them could come in their turne to giue it a stroake but it would be past them and out of their reach before they could strike it But it is euident say you out of these pretended causes of this motion that such atomes can not mooue so swiftly downewardes as a great dense body since their litlenesse and their rarity are both of them hindering to their motion and therefore this can not be the cause of that effect which we call grauity To this I reply that to haue the atomes giue these blowes to a descending dense body doth not require that their naturall and ordinary motion should be swifter then the descent of such a dense body but the very descent of it occasioneth their striking it for as it falleth and maketh it selfe a way through them they diuide themselues before it and swell on the sides and a litle aboue it and presently close againe behind it and ouer it as soone as it is past Now that closing to hinder vacuity of space is a suddaine one and thereby attaineth great velocity which would carry the atomes in that degree of velocity further then the descending body if they did not encounter with it in their way to retarde them which encounter and retarding implyeth such stroakes vpon the dense body as we suppose to cause this motion And the like we see in water into which letting a stone fall presently the water that was diuided by the stone and swelleth on the sides higher then it was before closeth vpon the backe of the descending stone and followeth it so violently that for a while after it leaueth a purling hole in the place where the stone went downe till by the repose of the stone the water returneth likewise to its quiet and so its superficies becometh euen In the third place an enquiry occurreth emergent out of this doctrine of the cause of bodies moouing vpwardes and downewardes Which is whether there would be any naturall motion deepe in the earth beyond the actiuity of the sunnes beames For out of these principles it followeth that there would not and consequently there must be a vast orbe in which there would be no motion of grauity or of leuity for suppose that the sunne beames might pierce a thousand miles deepe into the body of the earth yet there would still remaine a masse whose diameter would be neere 5000 miles in which there would be no grauitation nor the contrary motion For my part I shall make no difficulty to grant the inference as farre as concerneth motion caused by our sunne for what inconuenience would follow out of it But I will not offer att determining whether there may not be enclosed within that great sphere of earth some other fire such as the Chymistes talke of an Archeus a Demogorgon seated in the center like the hart in animals which may raise vp vapours and boyle an ayre out of them and diuide grosse bodies into atomes and accordingly giue them motions answerable to ours but in different lines from ours according as that fire or sunne is situated since the farre-searching Author of the Dialogues de Mundo hath left that speculation vndecided after he had touched vpon it in the 12 knott of his first Dialogue Fourthly it may be obiected that if such descending atomes as we haue described were the cause of a bodies grauity and descending towardes the center the same body would att diuers times descend more and lesse swiftly for example after midnight when the atomes begin to descend more slowly then likewise the same body would descend more slowly in a like proportion and not weigh so much as it did in the heate of the day The same may be said of summer and winter for in winter time the atomes seeme to be more grosse and consequently to strike more strongly vpon the bodies they meete with in their way as they descend yet on the other side they seeme in the summer to be more numerous as also to descend from a greater height both which circumstances will be cause of a stronger stroake and more vigourous impulse vpon the body they hitt And the like may be obiected of diuers partes of the world for in the torride zone it will alwayes happen as in summer in places of the temperate zone and in the polar climes as in deepest winter so that no where there would be any standard or certainty in the weight of bodies if it depended vpon so mutable a cause And it maketh to the same effect that a body which lyeth vnder a thicke rocke or any other very dense body that can not be penetrated by any great store of atomes should not be so heauy as it would be in the open and free ayre where the atomes in their complete numbers haue their full stroakes For answere to these and such like instances we are to note first that it is not so much the number or the violence of the percussion of the striking atomes as the density of the thing strucken which giueth the measure to the descending of a weighty body and the chiefe thing which the stroake of the atomes giueth vnto a dense body is a determination of the way which a dense body is to cutt vnto it selfe therefore multiplication or lessening of the atomes will not make any sensible difference betwixt the weight of one dense body where many atomes do strike and an other body of the same density where but few do strike so that the stroake downewardes of the descending atomes be greater then the stroake vpwardes
gett into the eye whose fabrike is fitt to gather and vnite those species as you may see by the anatomy of it and from the eye their iourney is but a short one to the braine in which we can not suspect that they should loose their force considering how others that come from organes further off do conserue theirs and likewise considering the nature of the optike spirits which are conceiued to be the most refined of all that are in mans body Now that light is mingled with such litle atomes issuing out of the bodies from which it is reflected appeareth euidently enough out of what wee haue Sayed of the nature and operations of fire and light and it seemeth to be confirmed by what I haue often obserued in some chambers where people seldome come which hauing their windowes to the south so as the sunne lyeth vpon them a great part of the day in his greatest strength and their curtaines being continually drawne ouer them the glasse becometh dyed very deepe of the same colour the curtaine is of which can proceed from no other cause but that the beames which shoote through the glasse being reflected backe from the courtaine do take something along with them from the superficies of it which being of a more solide corpulence then they is left behind as it were in the strainer when they come to presse themselues through passages and pores too litle for it to accompany them in and so those atomes of colour do sticke vpon the glasse which they can not penetrate An other confirmation of it is that in certaine positions the sunne reflecting from strong colours will cast that very colour vpon some other place as I haue often experienced in liuely scarlet and cloth of other smart colours and this not in that gloating wise as it maketh colours of pure light but like a true reall dye and so as the colour will appeare the same to a man wheresoeuer he standeth Hauing thus shewed in all our senses the conueniency and agreeablenesse of our opinion with nature which hath been deduced out of the nature of the obiects the nature of our spirits the nature and situation of our nerues and lastly from the property of our braine our next consideration shall be of the difficulty that occurreth in Mr. des Cartes his opinion First we know not how to reconcile the repugnaÌ„cies appearing in his position of the motion of the Ether especially in light for that Ethereall substance being extreme rare must perforce by eyther extreme liquid or extreme brittle if the first it can not choose but bowe and be pressed into fouldes and bodies of vnequall motions swimming euery where in it and so it is impossible that it should bring vnto the eye any constant apparition of the first mouer But lett vs suppose there were no such generall interruptions euery where encountring and disturbing the conueyance of the first simple motion yet how can we conceiue that a push giuen so farre off in so liquid an element can continue its force so farre We see that the greatest thunders and concussions which at any time happen among vs can not driue and impart their impulse the ten thousandeth part of the vast distance which the sunne is remoued from our eye and can we imagine that a little touch of that luminous body shâ—uld make an impression vpon vs by mouing an other so extremely liquid and subtile as the Ether is supposed which like an immense Ocean tossed with all varieties of motion lyeth betweene it and vs. But admitt there were no difficulty nor repugnance in the medium to conuey vnto vs a stroke made vpon it by the sunnes motion lett vs at the least examine what kind of motions we must allow in the sunne to cause this effect Certainely it must needes be a motion towardes vs or else it can not stricke and driue the medium forward to make it striâ—ke vpon vs. And if it be so eyther the sunne must perpetually be coming neerer and neerer to vs or else it must euer and anone be receding backwardes as well as mouing forwardes Both which are too chymericall for so great a witt to conceite Now if the Ether be brittle it must needes reflect vpon euery rubbe in meeteth with in its way and must be broken and shiuered by euery body that moueth acrosse it and therefore must alwayes make an vncertaine and most disorderly percussion vpon the eye Then againe after it is arriued to the sense it is no wayes likely it should be conueyed from thence to the braine or that nature intended such a kind of instrument as a nerue to continue a precise determinate motion for if you consider how a lute string or any other such medium conueyeth a motion made in it you will find that to do it well and clearely it must be stretched throughout to its full extent wâ—â—h â— kind of stiffenesse whereas our nerues are not straight but lye crooked in our body and are very lither till vpon occasion spirits coming into them do swell them out Besides they are bound to flesh and to other partes of the body which being cessible must needes dull the stroake and not permitt it to be carried farre And lastly the nerues are subiect to be at euery turne contracted and dilated vpon their owne account without any relation to the stroakes beating vpon them from an externe agent which is by no meanes a conuenient disposition for a body thâ—t is to be the porter of any simple motion which should alwayes lye watching in great quietnesse to obserue scrupulously and exactly the arrant he is to carry so that for my part I can not conceiue nature intended any such effect by mediation of the sinnewes But Monsieur des Cartes endeauoureth to confirme his opinion by what vseth to fall out in palsies when a man looseth the strength of mouing his handes or other members and neuerthelesse retaineth his feeling which hâ— imputeth to the remaining intire of the stringes of the nerues whiles the spirits are someway defectiue To this we may answere by producing examples of the contrary in some men who haue had the motion of their limbes intire and no wayes preiudiced but haue had no feeling at all quite ouer their whole case of skinne and flesh as particularly a seruant in the colledge of Physitians in London whom the learned Haruey one of his Masters hath told me was exceeding strong to labour and very able to carry any necessary burthen and to remoue thinges dexterously according to the occasion and yet he was so voyde of feeling that he vsed to grind his handes against the walles and against course lumber when he was employed to rummage any in so much that they would runne with bloud through grating of the skinne without his feeling of what occasioned it In our way the reason of both these conditions of people the paralitike and the insensible is easy to be rendered for they proceed out
which the contained substance should goe out as the moystening of the stringes and mouth of a purse almost shutteth it vntill in some for example the stomacke after a meale the humour being attenuated by little and little getteth out subtilely and so leauing lesse weight in the stomacke the bag which weighth downe lower then the neather orifice at which the digested meate issueth riseth a little and this rising of it is also furthered by the wrinkling vp and shortning of the vpper part of the stomacke which still returneth into its naturall corrugation as the masse of liquid meate leaueth soaking it which it doth by degrees still as more and more goeth out and so what remaineth filleth lesse place and reacheth not so high of the stomacke and thus at leÌ„gth the residue and thicker substance of the meate after the thinnest is gott out in steame and the middling part is boyled ouer in liquor cometh to presse and grauitate wholy vpoÌ„ the orifice of the stomacke which being then helped by the figure and lying of the rest of the stomacke and its stringes and mouth relaxing by hauing the iuice which swelled them squeezed out of them it openeth it selfe and giueth way vnto that which lay so heauy vpon it to tumble out In others for example in a woman with childe the enclosed substaÌ„ce retained first by such a course of nature as we haue sett downe breaketh it selfe a passage by force and openeth the orifice at which it is to goe out by violence when all circumstances are ripe according to natures institution But yet there is the expulsion which is made by physicke that requireth a little declaration It is of fiue kindes vomiting purging by stoole by vrine sweating and saliuation Euery one of which seemeth to consist of two partes namely the disposition of the thing to be purged and the motion of the nerues or fibers for the expulsion as for example when the Physitian giueth a purge it worketh two thinges the one is to make some certaine humour more liquid and purgeable theÌ„ the rest the other is to make the stomacke or belly sucke or vent this humour For the first the property of the purge must be to precipitate that humour out of the rest of the bloud or if it be thicke to dissolue it that it may runne easily For the second it ordinarily heateth the stomacke and by that meanes it causeth the stomacke to sucke out of the veines and so to draw from all partes of the body Besides this it ordinarily filleth the belly with winde which occasioneth those gripings men feele when they take physicke and is cause of the guttes discharging those humours which otherwise they would retaine The like of this happeneth in saliuation for the humours are by the same meanes brought to the stomacke and thence sublimed vp to be spitten out as we see in those who taking Mercury into their body eyther in substance or in smoake or by applicatioÌ„ do vent cold humours from any part the Mercury rising from all the body vp to the mouth of the patient as to the helme of a sublimatory and the like some say of Tobacco As for vomiting it is in a manner wholy the operation of the fibers prouoked by the feeling of some inconuenient body which maketh the stomacke wrincle it selfe and worke and striue to cast out what offendeth it Sweating seemeth to be caused by the heating of some introus body by the stomake which being of subtile partes is by heate dispersed from the middle to the circumference and carrieth with it light humours which turne into water as they come out into the ayre And thus you see in generall and as much as concerneth vs to declare what the naturall faculties are and this according to Galen his owne mind who affirmeth that these faculties do follow the complexion or the temper of the partes of a mans body Hauing explicated how voluntary motion proceedeth from the braine our next consideration ought to be to examine what it is that such an obiect as we brought by meanes of the senses into the braine from without doth contribute to make the braine apply it selfe to worke such voluntary motion To which purpose we will goe a steppe or two backe to meete the obiect at its entrance into the sense and from thence accompany it in all its iourney and motions onwardes The obiect which striketh at the senses dore and getting in mingleth it selfe with the spirits it findeth there is eyther coÌ„forme and agreeable to the nature and temper of those spirits or it is not that is to say in short it is eyther pleasing or displeasing to the liuing creature or it may be of a third kind which being neyther of these we may terme indifferent In which sort soeuer the obiect affect the sense the spirits carry it immediately to the braine vnlesse some distemper or strong thought or other accident hinder them Now if the obiect be of the third kind that is be indiffent as soone as it hath strucken the braine it reboundeth to the circle of the memory and there being speedily ioyned to others of its owne nature it findeth them annexed to some pleasing or displeasing thing or it doth not if not in beastes it serueth to little vse and in men it remayneth there vntill it be called for But if eyther in its owne nature it be pleasing or displeasing or afterwardes in the memory it became ioyned to some pleasing or annoying fellowshipp presently the hart is sensible of it for the hart being ioyned to the braine by straight and large nerues full of strong spirits which ascend from the hart it is impossible but that it must haue some communication with those motions which passe in the braine vpon which the hart or rather the spirits about it is eyther dilated or compressed And these motions may be eyther totally of one kind or moderated and allayed by the mixture of its contrary if of the former sort one of them we call ioy the other griefe which do continue about the hart and peraduenture do oppresse it if they be in the vtmost extremity without sending any due proportion of spirits to the braine vntill they settle a little and grow more moderate Now when these motions are moderate they immediately send vp some aboundance of spirits to the braine which if they be in a conuenient proportion they are by the braine thrust into such nerues as are fitt to receiue them and swelling them they giue motion to the muscles and tendons that are fastened to them and they do moue the whole body or what part of it is vnder command of those nerues that are thus filled and swelled with spirits by the braine If the obiect was conformable to the liuing creature then the braine sendeth spirits into such nerues as caâ—â—y the body to it but if otherwise it causeth a motioÌ„ of auersion or flight from it To the cause of this latter we giue
of intension and Remission and others do not ibid. § 7. That in euery part of our habitable world all the foure Elements are found pure in small atomes but not in any great bulke pag. 142. CHAP. XVII Of Rarefaction and Condensation the two first motions of particular bodies pag. 144. § 1. The Authors intent in this and the following chapters ibid. § 2. That bodies may be rarifyed both by outward heat aud how this is performed pag. 145. § 3. Of the great effects fo Rarefaction pag. 147. § 4. The first manner of condensation by heate pag. 148. § 5. The second manner of condensation by cold pag. 149. § 6. That yce is not water rarifyed but condensed pag. 151. § 7. How wind snow and haile are made and wind by raine allayed pag. 152. § 8. How partes of the same or diuers bodies are ioyned more strongly together by condensation pag. 153. § 9. Vacuites can not be the reason why water impregnated to the full with one kind of salt will notwithstanding receiue more of an other pag. 154. § 10. The true reason of the former effect pag. 155. § 11. The reason why bodies of the same nature do ioyne more easily together then others pag. 156. CHAP. XVIII Of an other motion belonging to particular bodies called Attraction and of certaine operations termed Magicall pag. 157. § 1. What Attraction is and from whence it proceedeth ibid. § 2. The true sense of the Maxime that Nature abhorreth from vacuity pag. 158. § 3. The true reason of attraction pag. 159. § 4. Water may be brought by the force of attraction to what height soeuer pag. 160. § 5. The doctrine touching the attraction of water in syphons ibid § 6. That the syphon doth not proue water to weigh in its owne orbe pag. 161. § 7. Concerning attraction caused by fire pag. 162. § 8. Concerning attraction made by vertue of hoat bodies amulets etc. pag. 163. § 9. The naturall reason giuen for diuers operations esteemed by some to be magicall ibid. CHAP. XIX Of three other motions belonging to particular bodies Filtration Restitution and Electricall attraction pag. 166. § 1. What is Filtration and how it is effected ibid. § 2. What causeth the water in filtration to ascend pag. 167. § 3. Why the filter will not droppe vnlesse the labell hang lower then the water ibid. § 4. Of the motion of Restitution and why some bodies stand bent others not pag. 168. § 5. Why some bodies returne onely in part to their natural figure others entirely pag. 170. § 6. Concerning the nature of those bodies which do shrinke and stretch pag. 171. § 7. How great and wonderfull effects proceed from small plaine and simple principles ibid. § 8. Concerning Electricall attraction and the causes of it pag. 172. § 9. Cabeus his opinion refuted concerning the cause of Electricall motions pag. 174. CHAP. XX. Of the Loadestones generation and its particular motions pag. 175. § 1. The extreme heat of the sunne vnder the zodiake draweth a streame of ayre from each Pole into the torride zone ibid. § 2. The atomes of these two streames coming together are apt to incorporate with one an other pag. 176. § 3. By the meeting and mingling together of these streames att the Equator diuers riuolets of atomes of each Pole are continuated from one Pole to te other pag. 177. § 4. Of these atomes incorporated with some fitt matter in the bowels of the earth is made a stone pag. 179. § 5. This stone worketh by emanations ioyned with agreeing streames that meete them in the ayre and in fine it is a loadestone ibid. § 6. A methode for making experiences vpon any subiect pag. 181. § 7. The loadestones generation by atomes flowing from both Poles is confirmed by experiments obserued in the stone it selfe ibid. § 8. Experiments to proue that the loadestone worketh by emanations meeting with agreeing streames pag. 182. CHAP. XXI Positions drawne out of the former doctrine and confirmed by experimentall proofes pag. 185. .1 The operations of the loadestone are wrought by bodies and not by qualities ibid. § 2. Obiections against the former position answered pag. 186. § 3. The loadestone is imbued with his vertue from an other body ibid. § 4. The vertue of the loadestone is a double and not one simple vertue 188. § 5. The vertue of the laodestone worketh more strongly in the Poles of it then in any other part ibid. § 6. The laodestone sendeth forth its emanations spherically Which are of two kindes and each kind is strongest in that hemisphere through whose polary partes they issue out ibid. § 7. Putting two loadestones within the sphere of one an other euery part of one laodestone doth not agree with euery part of the other loadestone pag 189. § 8. Concerning the declination and other respects of a needle towardes the loadestone it toucheth ibid. § 9. The vertue of the laodestone goeth from end to end in lines almost paralelle to the axis pag. 191. § 10. The vertue of loadestone is not perfectly sphericall though the stone be such pag. 192. § 11. The intention of nature in all the operations of the loadestone is to make an vnion betwixt the attractiue and attracted bodies ibid. § 12. The maine globe of the earth is not a loadestone ibid. § 13. The laodestone is generated in all partes or climats of the earth pag. 193. § 14. The conformity betwixt the two motions of magnetike thinges and of heauy thinges ibid. CHAP. XXII A solution of certaine Problemes concerning the loadestone and a short summe of the whole doctrine touching it pag. 194. § 1. Which is the North and which the South Pole of a loadestone ibid. § 2. Whether any bodies besides magnetike ones be attractiue ibid. § 3. Whether an iron placed perpendicularly towardes the earth doth gett a magneticall vertue of pointing towardes the north or towardes the south in that end that lyeth downewardes pag. 195. § 4. Why loadestones affect iron better then one an other ibid. § 5. Gilberts reason refuted touching a capped loadestone that taketh vp more iron then one not capped and an iron impregnated that in some case draweth more strongly then the stone it selfe ibid. § 6. Galileus his opinion touching the former effects refuted pag. 196. § 7. The Authors solution to the former questions pag. 197. § 8. The reason why in the former case a lesser loadestone doth draw the interiacent iron from the greater pag. 198. § 9. Why the variation of a touched needle from the north is greater the neerer you go to the Pole pag. 199. § 10. Whether in the same part of the world a touched needle may att one time vary more from the north and att an other time lesse pag. 200. § 11. The whole doctrine of the loadestone summed vp in short pag. 201. CHAP. XXIII A description of the two sortes of liuing creatures Plantes and Animals and how they are framed in common
consider the way or space which a weight lying vpon the thing is to goe forwardes to do the same effect in the same time as the percussion doeth And what excesse the line of the blow hath ouer the line of that way or space such an excesse we must adde of equall weight or force to the weight we had already taken And the weight composed of both will be a fitt Agent to make the like impression This Probleme was proposed vnto me by that worthy religious man Father Mersenius who is not content with aduancing learning by his owne industry and labours but besides is alwayse out of his generous affection to verity inciting others to contribute to the publike stocke of it He proposed to me likewise this following question to witt why there is required a weight of water in double Geometricall proportion to make a pipe runne twice as fast as it did or to haue twice as much water runne out in the same time Vnto which I answere out of the same ground as before That because in running twice as fast there goeth out double water in euery part of time and againe euery part of water goeth a double space in the same part of time that is to say because double the celerity is drawne into double the water and double the water into double the celerity therefore the present effect is to the former effect as the effect or quadrate of a double line drawne into it selfe is to the effect or quadrate of halfe the said line drawne into it selfe And consequently the cause of the latter effect which is the weight then must be to the cause of the former effect that is to the former weight in the same proportion namely as the quadrate of a double line is to the quadrate of halfe that line And so you see the reason of what he by experience findeth to be true Though I doubt not but when he shall sett out the treatise which he hath made of this subiect the reader will haue better satisfaction In the meane while an experience which Galileo deliuereth will confirme this doctrine He sayth that to make the same pendant goe twice as fast as it did or to make euery vndulation of it in halfe the time it did you must make the line att which it hangeth double in Geometricall proportion to the line att which it hanged before Whence it followeth that the circle by which it goeth is likewise in double Geometricall proportion And this being certaine that celerity to celerity hath the proportion of force which weight hath to weight it is euident that as in one case there must be weight in Geometricall proportion so in the other case where onely celerity maketh the variance the celerity must be in double Geometricall proportion according as Galileo findeth it by experience But to returne to our maine intent there is to be further noted that if the subiect strucken be of a proportionate cessibility it seemeth to dull and deaden the stroake whereas if the thing strucken be hard the stroake seemeth to loose no force but to worke a greater effect Though indeed the truth be that in both cases the effects are equall but diuerse according to the natures of the thinges that are strucken for no force that once is in nature can be lost but must haue its adequate effect one way or other Lett vs then first suppose the body strucken to be a hard body of no exceeding biggnesse in which case if the stroake light perpendiculary vpon it it will carry such a body before it But if the body be too great and haue its partes so conioyned as that they are weaker thē the stroake in this case the stroake driueth one part before it and so breaketh it from the rest But lastly if the partes of the strucken body be so easily cessible as without difficulty the stroake can diuide them then it entereth into such a body vntill it hath spent its force So that now making vp our account we see that an equall effect proceedeth from an equall force in all the three cases though in themselues they be farre different But we are apt to account that effect greater which is more considerable vnto vs by the profitt or damage it bringeth vs. And therefore we vsually say that the blow which shaketh a wall or beateth it downe and killeth men with the stones it scattereth abroad hath a greater effect then that which penetrateth farre into a mudde wall and doth litle harme for that innocuousnesse of the effect maketh that although in it selfe it be as great as the other yet it is litle obserued or considered This discourse draweth on an other which is to declare how motion ceaseth And to summe that vp in short we say that when motion cometh vnto rest it decreaseth and passeth through all the degrees of celerity and tardity that are betweene rest and the height of that motion which so declineth And that in the proportion of the odde numbers as we declared aboue that it did encrease The reason is cleare because that which maketh a motion cease is the resistance it findeth which resistance is an action of a moouer that mooueth some thing against the body which is mooued or some thing equiualent to such an action wherefore it must follow the lawes that are common to all motions of which kind those two are that we haue expressed in this conclusion Now that resistance is a countermotion or equiualent to one is plaine by this that any body which is pressed must needes presse againe vpon the body that presseth it wherefore the cause that hindereth such a body from yielding is a force mouing that body against the body which presseth it The particulars of all which we shall more att large declare where we speake of the action and reaction of particular bodies THE TENTH CHAPTER Of Grauity and Leuity and of Locall Motion commonly termed Naturall IT is now time to consider that distinction of motions which is so famous in Aristotle to witt that some motions are naturall others violent and to determine what may be signifyed by these termes For seeing we haue said that no body hath a naturall intrinsecall inclination vnto any place to which it is able to moue it selfe we must needes conclude that the motion of euery body followeth the percussion of extrinsecall Agents It seemeth therefore impossible that any body should haue any motion naturall to it selfe And if there be none naturall there can be none violent And so this distinction will vainsh to nothing But on the other side liuing creatures do manifesty shew naturall motions hauing naturall instruments to performe certaine motions wherefore such motions must of necessity be naturall to them But these are not the motions which we are to speake of for Aristotles diuision is common to all bodies or att the least to all those we conuerse withall and particulary to those which are called heauy and
our whole scope both in this and in all other occasions where like qualities are vrged is to prooue superfluous and ill grounded in nature and to be but meere termes to confound and leaue in the darke whosoeuer is forced to fly vnto them THE THERTEENTH CHAPTER Of three sortes of violent motion Reflexion Vndulation and Refraction THe motion we haue last spoken of because it is ordinarily either in part or wholy contrary to grauity which is accounted the naturall motion of most bodies vseth to be called violent or forced And thus you haue deliuered vnto you the natures and causes both of naturall and of forced motion yet it remaineth that we aduertise you of some particular kindes of this forced motion which seeme to be different from it but indeed are not As first the motion of reflexion which if we do but consider how forced motion is made we shall find that it is nothing else but a forced motion whose line wherevpon it is made is as it were snapped in two by the encounter of a hard body For euen as we see in a spoute of water that is strongly shott against a wall the water following driueth the precedent partes first to the wall and afterwardes coming themselues to the wall forceth them againe an other way from the wall right so the latter partes of the torrent of ayre which is caused by the force that occasioneth the forced motion driueth the former partes first vpon the resistent body and afterwardes againe from it But this is more eminent in light then in any other body because light doth lesse rissent grauity and so obserueth the pure course of the stroake better then any other body from which others do for the most part decline some way by reason of their weight Now the particular law of reflexion is that the line incident and the line of reflexion must make equall angles with that line of the resistent superficies which is in the same superficies with themselues The demonstration whereof that great witt Renatus Des Cartes hath excellently sett downe in his booke of Dioptrikes by the example of a ball strucken by a rackett against the earth or any resisting body the substance where of is as followeth The motion which we call vndulation needeth no further explication for it is manifest that since a pendant when it is remooued from its perpendicular will restore it selfe therevnto by the naturall force of grauity and that in so doing it gaineth a velocity and therefore can not cease on a suddaine it must needes be carried out of the force of that motion directly the coÌ„trary way vntill the force of grauity ouercoming the velocity it must be brought backe againe to the perpeÌ„dicular which being done likewise with velocity it must send it againe towardes the place from which it fell att the first And in this course of motion it must coÌ„tinue for a while euery vndulation being weaker then other vntill att last it quite ceaseth by the course of nature settling the ayre in its due situatioÌ„ according to the naturall causes that worke vpon it And in this very manner also is performed that vndulation which we see in water when it is stirred from the naturall situation of its sphericall superficies Galileo hath noted that the time in which the vndulations are made which follow one an other of their owne accord is the same in euery one of them and that as much time precisely is take vp in a pendants going a very short arch towardes the end of its vibration as was in its going of the greatest arch att the beginning of its motion The reason whereof seemeth strange to him and he thinketh it to be an accident naturall to the body out of its grauity and that this effect conuinceth it is not the ayre which mooueth such bodies Whereas in truth it is clearely the ayre which causeth this effect Because the ayre striuing att each end where it is furthest from the force of the motion to quiett it selfe getteth att euery bout somewhat vpon the space and so contracteth that into a shorter arch That motion also which we call Refraction and is manifest to sense onely in light though peraduenture hereafter more diligent searchers of nature may likewise find it in such other bodies as are called qualities as in cold or heate c. is but a kind of Reflexion for there being certaine bodies in which the passages are so well ordered with their resistances that all the partes of them seeme to permitt light to passe through them and yet all partes of them seeme to reflect it when light passeth through such bodies it findeth att the very entrance of them such resistances where it passeth as serue it for a reflectent body and yet such a reflectent body as hindereth not the passage through but onely hindereth the passage from being in a straight line with the line incident Wherefore the light must needes take a plye as beaten from those partes towardes a line drawne from the illuminant and falling perpendicularly vpon the resisting superficies and therefore is termed by mathematicians to be refracted or broken towardes the Perpendicular Now at the very going out againe of the light the second superficies if it be parallel to the former must needes vpon a contrary cause strike it the contrary way which is termed from the Perpendicular But before we wade any deeper into this difficulty we can not omitt a word of the manner of explicating refraction which Monsieur Des Cartes vseth so witty a one as I am sorry it wanteth successe He therefore following the demonstration aboue giuen of reflexion supposeth the superficies which a ball lighteth vpon to be a thinne linnen cloth or some other such matter as will breake cleanely by the force of the ball striking smartly vpon it And because that superficies resisteth onely one way therefore he inferreth that the velocity of the ball is lessened onely one way and not the other so that the velocity of its motion that way in which it findeth no resistance must be after the balles passage through the linnen in a greater proportion to the velocity which it hath the other way where it findeth resistance then it was before And therefore the ball will in lesse time arriue to its periode on the one side then on the other and consequently it will leane towardes that side vnto which the course wherein it findeth no opposition doth carry it Which to shâ—w how it is contrary vnto his owne principle lett vs conceiue the cloth CE to be of some thickenesse and so draw the line OP to determine that thicknesse And lett vs make from B vpon AL an other Parallelogramme like the Parallelogramme AL whose diameter shall be BQ And it must necessarilly follow that the motion from B to Q if there were no resistance were in the same proportion as from A to B. But the proportion of the motion from
and water into a decompound of two saltes and water vntill all his partes be anew impregnated with the second grosser salt as before the pure water was with the first subtiler salt And so it will proceed on if proportionate bodies be ioyned vntill the dissoluing composition do grow into a thicke body Vnto which discourse we may adde that when the water is so fully impregnated with the first salt as it will receiue no more remayning in the temper it is in yet if it be heated it will then afresh dissolue more of the same kind Which sheweth that the reason of its giuing ouer to dissolue is for want of hauing the water diuided into partes little enough to sticke vnto more salt which as in this case the fire doth so peraduenture in the other the acrimoniousnesse of the salt doth it And this is sufficient to giue curious wittes occasion by making further experiments to search out the truth of this matter Onely we may note what happeneth in most of the experiencies we haue mentioned to witt that thinges of the same nature do ioyne better and more easily then others that are more estranged from one an other Which is very agreeable to reason seeing that if nature do intend to haue thinges consist long together she must fitt them for such consistence Which seemeth to proceed out of their agreement in foure qualities first in weight for bobies of diuers degrees in weight if they be att liberty do seeke diuers places and consequently substances of like weight must of necessity find one an other out and croud together as we haue shewed it is the natute of heate to make them do now it is apparent that thinges of one nature must in equall partes haue the same or a neere proportion of weight seeing that in their composition they must haue the same proportion of Elements The second reason of the consistence of bodies together that are of the same nature is the agreement of their liquid partes in the same degree of rarity and density for as it is the nature of quantity in common to make all partes be one quantity so it is the nature of the degrees of quantity when two partes do meete that are of the same degree to make them one in that degree of quantity which is to make them stick together in that degree of sticking which the degree of density that is common to them both maketh of its owne nature Whereas partes of different densities can not haue this reason of sticking though peraduenture they may vpon some other ground haue some more efficacious one And in this manner the like humide partes of two bodies becoming one the holes or receptacles in which those humide partes are contained must also needes be vnited The third reason is the agreeable proportion which their seuerall figures haue in respect of one an other for if any humidity be extracted out of a mixed body especially by the vertue of fire it must haue left pores of such figures as the humidity that is drawne out of them is apt to be cutt into for euery humide body not being absolutely humide but hauing certaine dry partes mixed with it is more apt for one kind of figure and greatnesse then for an other and by consequence whensoeuer that humidity shall meete againe with the body it was seuered from it will easily runne through and into it all and will fill exactly the cauities and pores it possessed before The last quality in which bodies that are to consist long together do agree is the biggnesse of the humide and dry partes of the same body for if the humide partes be too bigge for the dry ones it is cleare that the dry ones must needes hang loosely together by them because their glew is in too greate a quantity But if the humide partes bee too little for the dry ones then of necessity some portion of euery little dry part must be vnfurnished of glew by meanes whereof to sticke vnto his fellow and so the sticking partes not being conueniently proportioned to one an other their adhesion can not be so solide as if each of them were exactly fitted to his fellow THE EIGHTEENTH CHAPTER Of an other motion belonging to particular bodies called Attraction and of certaine operations termed Magicall HAuing thus ended the two motions of rarefaction and of condensation the next that offer themselues are the locall motions which some bodies haue vnto others These are sometimes performed by a plaine force in the body towardes which the motion is and other whiles by a hidden cause which is not so easily discerned The first is chiefely that which is ordinarily said to be done by the force of nature to hinder Vacuum and is much practised by nature as in drawing our breath in sucking and in many other naturall operations which are imitated by art in making of pumpes syphons and such other instruments and in that admirable experiment of taking vp a heauy marble stone meerely by an other lying flatt and smoothly vpon it without any other connexion of the two stones together as also by that sport of boyes when they spread a thinne moystned leather vpon a smooth broad stone and presse it all ouer close to it and then by pulling of a string fastened att the middle of the leather they draw vp likewise the heauy stone In all which the first cause of the motion proceedeth from that body towardes which the motion is made And therefore is properly called Attraction For the better vnderstanding and declaring of which lett vs suppose two marble stones very broad and exceeding smoothly polished to be laid one flatt vpon the other and lett there be a ring fastened att the backe part of the vppermost stone and exactly in the middle of it Then by that ring pull it vp perpendicularly and steadily and the vndermost will follow sticking fast to the ouermost and though they were not very perfectly polished yet the nethermost would follow for a while if the ring be suddainely plucked vp but then it will soone fall downe againe Now this plainely sheweth that the cause of their sticking so strongly together when both the stones are very well polished is for that nothing can well enter between them to part them and so it is reduced to the shortnesse of the ayre that is betwixt them which not being capable of so great an expansion nor admitting to be diuided thickewayes so much as is necessary to fill the first growing distance between the two stones till new ayre findeth a course thither that so the swelling of the one may hinder vacuity till the other come in to the rescue the two stones must needes sticke together to certaine limits which limits will depend of the proportion that is between the weight and the continuity of the nethermost stone And when we haue examined this we shall vnderstand in what sense it is meaned that Nature abhorreth from Vacuity and what
not dayly the effects If then we can but arriue to decypher the first characters of the hidden Alphabet we are now taking in hand and can but spellingly reade the first syllabes of it we neede not doubt but that the wise Author of nature in the masterpiece of the creature which was to expresse the excellency of the workeman would with excellent cunning and art dispose all circumstances so aptly as to speake readily a complete language rising from those Elements and that should haue as large an extent in practise and expression beyond those first principles which we like children onely lispe out as the vast discourses of wisest and most learned men are beyond the spellinges of infantes and yet those discourses spring from the same roote as the others spellinges doe and are but a raysing of them to a greater height as the admired musike of the best player of a lute or harpe that euer was is deriued from the harsh twanges of course bowestringes which are composed together and refined till att length they arriue to that wonderfull perfection And so without scruple we may in the businesse we are next falling vpon conclude that the admirable and almost miraculous effects we see are but the eleuating to a wonderfull height those very actions and motions which we shall produce as causes and principles of them Letr vs then suppose that there is a solide hard body of an vnctuous nature whose partes are so subtile and fiery that with a little agitation they are much rarifyed and do breath out in steames though they be too subtile for our eyes to discerne like vnto the steame that issueth from sweating men or horses or like the steame that flyeth from a candle when it is putt out but that these steames as soone as they come into the cold ayre are by that cold soddainely condensed againe and by being condensed do shorten themselues and by little and little do retire till they settle themselues vpon the body from whence they sprung in such manner as you may obserue the little tender hornes of snailes vse to shrinke backe if any thing touch them till they settle in little lumpes vpon their heades If I say these stringes of bituminous vapour should in their way outwardes meete with any light and spungie body they would pierce into it and settle in it and if it were of a competent biggenesse for them to wield they would carry it with them which way soeuer they goe so that if they shrinke backe againe to the fountaine from whence they came they must needes carry backe with them the light spungy body they haue fixed their dartes in Consider then that how much heate rarifyeth so much cold cōdenseth and therefore such partes as by agitatiō were spūne out into a subtile thridde of an inch long for exāple as they coole do grow bigger and bigger and consequently shorter and shorter till att length they gather thēselues backe into their maine body and there they settle againe in cold bitumen as they were att the first and the light body that they sticke vnto is drawne backe with them and consequently sticketh to the superficies of the bitumen As if something were tyed att one end of a lutestring extended to its vtmost capacity and the other end were fastened to some pinne as the string shrinketh vp so that which is tyed att it must needes moue neerer and neerer the pinne which artifice of nature iugglers do imitate when by meanes of an vnseene haire they draw light bodies to them Now if all this operation be done without your seeing the little thriddes which cause it the matter appeareth wonderfull and strange But when you consider this progresse that we haue sett downe you will iudge it possible And this seemeth to be the case of those bodies which we call Electricall as yellow amber iett and the like All which are of a bituminous vnctuous nature as appeareth by their easy combustibility and smell when they are burned And if some do not so apparently shew this vnctuous nature it is because eyther they are too hard or else they haue a high degree of aqueous humidiry ioyned with their vnctuosity and in them the operation will be duller in that proportion for as we see that vnctuous substances are more odoriferous then others and do send their steames further off and more efficaciously so we can not doubt but that such bodies as consist in a moist nature do accordingly send forth their emanations in a feebler proportion Yet that proportion will not be so feeble but that they may haue an Electricall effect as well as the more efficacious Electricall bodies which may be perceptible if exact experience be made by an instrument like the mariners needle as our learned countryman Doctor Gilbert teacheth But that in those eminent agents the spirits whereby they attract are vnctuous is plaine because the fire consumeth them and so if the agents be ouerheated they can not worke but moderate heate euen of fire encreaseth their operation Againe they are clogged by mysty ayre or by wetting and likewise are pierced through and cutt asunder by spiritt of wine or aquae ardentes but oyle doth not hurt them Likewise they yield more spirits in the sunne then in the shade and they continue longer when the ayre is cleared by North or by Easterne windes They require to be polished eyther because the rubbing which polisheth them doth take off from their surfaces the former emanations which returning backe do sticke vpon them and so do hinder the passage of those that are within or else because their outsides may be foule or lastly because the pores may be dilated by that smoothing Now that hardnesse and solidity is required doth argue that these spirits must be quicke ones that they may returne smartly and not be lost through their languishing in the ayre Likewise that all bodies which are not eyther exceeding rare or else sett on fire may be drawne by these vnctuous thriddes concludeth that the quality by which they do it is a common one that hath no particular contrarieties such a one as we see is in grease or in pitch to sticke to any thing from which in like manner nothing is exempted but fire and ayre And lastly that they worke most efficaciously when they are heated by rubbing rather then by fire sheweth that their spirits are excitated by motion and are thereby made to flye abroad in such manner as we see in pomanders and in other perfumes which must be heated if you will haue them communicate their sent and alike effect as in them agitation doth in iett yellow amber and such other Electricall bodies for if vpon rubbing them you putt them presently to your nose you will discerne a strong bituminous smell in them all which circumstances do shew that this Electricall vertue consisteth in a certaine degree of rarity or density of the bodies vnctuous emanations Now if these refined and viscous
all the ayre in this our hemisphere is as it were strewed ouer and sowed with aboundance of northerne atomes and that some brookes of them are in station others in a motion of retrogradation backe to their owne north pole the southerne atomes which coming vpon them att the equator do not onely presse in among them wheresoeuer they can find admittance but do also go on fowardes to the north pole in seuerall files by themselues being driuen that way by the same accidentall causes which make the others retire backe seising in their way vpon the northerne ones in such manner as we described in filtration and thereby creeping along by them wheresoeuer they find them standing still and going along with them wheresoeuer they find them going backe must of necessity find passage in great quantities towardes and euen to the north pole though some partes of them will euer and anone be checked in this their iourney by the maine current preuayling ouer some accidentall one and so be carried backe againe to the aequator whose line they had crossed And this effect can not choose but be more or lesse according to the seasons of the yeare for when the sunne is in the Tropike of Capricorne the southerne atomes will flow in much more aboundance and with farre greater speede into the torride zone then the northerne atomes can by reason of the sunnes approximation to the south and his distance from the north pole since he worketh faintest where he is furthest off and therefore from the north no more emanations or atomes will be drawne but such as are most subtilised and duly prepared for that course And since onely these selected bandes do now march towardes the aequator their files must needes be thinner then when the sunnes being in the aequator or Tropike of Cancer wakeneth and mustereth vp all their forces And consequently the quiett partes of ayre betweene their files in which like atomes are also scattered are the greater whereby the aduenient southerne atomes haue the larger filter to clymbe vp by And the like happeneth in the other hemisphere when the sunne is in the Tropike of Cancer as who will bestow the paines to compare them will presently see Now then lett vs consider what these two streames thus incorporated must of necessity do in the surface or vpper partes of the earth First it is euident they must needes penetrate a pretty depth into the earth for so freesing persuadeth vs and much more the subtile penetration of diuers more spirituall bodies of which we haue sufficiently discoursed aboue Now lett vs conceiue that these steames do find a body of a conuenient density to incorporate themselues in in the way of density as we see that fire doth in iron and in other dense bodies and this not for an houre or two as happeneth in fire but for yeares as I haue beene told that in the extreme cold hilles in the Peake in Darbyshire happeneth to the dry atomes of cold which are permanently incorporated in water by long continuall freesing and so make a kind of chrystall In this case certainely it must come to passe that this body will become in a māner wholy of the nature of these steames which because they are drawne from the Poles that abound in cold and drynesse for others that haue not these qualities do not contribute to the intended effect the body is aptest to become a stone for so we see that cold and drought turneth the superficiall partes of the earth into stones and rockes and accordingly wheresoeuer cold and dry windes raigne powerfully all such countries are mainely rocky Now then lett vs suppose this stone to be taken out of the earth and hanged in the ayre or sett conueniently vpon some little pinne or otherwise putt in liberty so as a small impulse may easily turne it any way it will in this case certainely follow that the end of the stone which in the earth lay towardes the north pole will now in the ayre conuert it selfe in the same manner towardes the same point and the other end which lay towardes the south turne by consequence to the south I speake of these countries which lye betweene the aequator and the North in which it can not choose but that the streame going from the north to the aequator must be stronger then the opposite one Now to explicate how this is done suppose the stone hanged east and west freely in the ayre the streame which is drawne from the north pole of the earth rangeth along by it in its course to the aequator and finding in the stone the south steame which is growne innate to it very strong it must needes incorporate it selfe with it and most by those partes of the steame in the stone which are strongest which are they that come directly from the North of the stone by which I meane that part of the stone that lay northward in the earth and that still looketh to the north pole of the earth now it is in the ayre And therefore the great flood of atomes coming from the north pole of the earth will incorporate it selfe most strongly by the north end of the stone with the little flood of southerne atomes it findeth in the stone for that end serueth for the coming out of the southerne atomes and sendeth them abroad as the south end doth the northerne steame since the steames do come in att one end and do go out att the opposite end From hence we may gather that this stone will ioyne and cleaue to its attractiue whensoeuer it happeneth to be within the sphere of its actiuity Besides if by some accident it should happen that the atomes or steames which are drawne by the sunne from the Polewardes to the aequator should come stronger from some part of the earth which is on the side hand of the Pole then from the very Pole it selfe in this case the stone will turne from the Pole towardes that side Lastly whatsoeuer this stone will do towardes the Pole of the earth the very same a lesser stone of the same kind will do towardes a greater And if there be any kind of other substance that hath participation of the nature of this stone such a substance will behaue it selfe towardes this stone in the same manner as such a stone behaueth it selfe towardes the earth all the Phenomens whereof may be the more plainely obserued if the stone be cutt into the forme of the earth And thus we haue found a perfect delineation of the loadestone from its causes for there is no man so ignorant of the nature of a loadestone but he knoweth that the properties of it are to tend towardes the North to vary sometimes to ioyne with an other loadestone to draw iron vnto it and such like whose causes you see deliuered But to come to experimentall proofes and obseruations vpon the loadestone by which it will appeare that these causes are well esteemed and
it a permanent vertue by which it worketh like a weake loadestone The second is that as it maketh the iron worke towardes the lesser loadestone by its permanent vertue so also it accompanyeth the steame that goeth from the iron towardes the little loadestone with its owne steame which goeth the same way so that both these steames do in company clymbe vp the steame of the little loadestone which meeteth them and that steame clymbeth vp the enlarged one of both theirs together The third effect which the greater loadestone worketh is that it maketh the steame of the little loadestone become stronger by augmenting its innate vertue in some degree Now then the going of the iron to eyther of the loadestones must follow the greater and quicker coniunction of the two meeting steames and not the greatnesse of one alone So that if the coniunction of the two steames between the iron and the little loadestone be greater and quicker then the coniunction of the two steames which meete between the greater loadestone and the iron the iron must sticke to the lesser loadestone And this must happen more often then otherwise for the steame which goeth from the iron to the greater loadestone will for the most part be lesse then the steame which goeth from the lesser loadestone to the iron And though the other steame be neuer so great yet it can not draw more then according to the proportion of its Antagonists coming from the iron Wherefore seeing the two steames betwixt the iron and the little loadestone are more proportionable to one an other and the steame coming out of the little loadestone is notably greater then the steame going from the iron to the greater loadestone the coniunction must be made for the most part to the little loadestone And if this discourse doth not hold in the former part of the Probleme betwixt a second iron and a loadestone it is supplyed by the former reason which we gaue for that particular purpose The third case dependeth also of this solution for the bigger an iron is so many more partes it hath to sucke vp the influence of the loadestone and consequently doth it thereby the more greedily and therefore the loadestone must be carried to it more violently and when they are ioyned sticke more strongly The sixt question is why the variations of the needle from the true north in the northerne hemisphere are greater the neerer you go to the Pole and lesser the neerer you approach to the Aequator The reason whereof is plaine in our doctrine for considering that the magnetike vertue of the earth streameth from the north towardes the aequator it followeth of necessity that if there be two streames of magnetike fluours issuing from the north one of them precisely from the pole and the other from a part of the earth neere the pole and that the streame coming from the point by side the pole be but a little the stronger of the two there will appeare very little differencies in their seuerall operations after they haue had a long space to mingle their emanations together which thereby do ioyne and grow as it were into one streame Whereas the neerer you come to the pole the more you will find them seuered and each of them working by its owne vertue And very neere the point which causeth the variation each streame worketh singly by it selfe and therefore here the point of variation must be master and will carry the needle strongly vnto his course from the due north if his streame be neuer so little more efficacious then the other Againe a line drawne from a point of the earth wyde of the pole to a point of the meridian neere the aequator maketh a lesse angle then a line drawne from the same point of the earth to a point of the same meridian neerer the pole wherefore the variation being esteemed by the quantities of the said angles it must needes be greater neere the pole then neere the aequator though the cause be the same But because it may happen that in the partes neere the aequator the variation may proceed from some piece of land not much more northerly then where the needle is but that beareth rather easterly or westerly from it and yet Gilberts assertion goeth vniuersally when he sayth the variations in southerne regions are lesse then in northerne ones we must examine what may be the reason thereof And presently the generation of the loadestone sheweth it plainely for seeing the nature of the loadestone proceedeth out of this that the sunne worketh more vpon the torride zone then vpon the poles and that his too strong operation is contrary to the loadestone as being of the nature of fire it followeth euidently that the landes of the torride zone can not be so magneticall generally speaking as the polar landes are and by consequence that a lesser land neere the pole will haue a greater effect then a larger continent neere the aequator and likewise a land further off towardes the pole will worke more strongly then a neerer land which lyeth towardes the aequator The seuenth question is whether in the same part of the world a touched needle may att one time vary more from the true north point and att an other time lesse In which Gilbert was resolute for the negatiue part but our latter Mathematiciens are of an other mind Three experiences were made neere London in three diuers yeares The two first 42 yeares distant from one an other and the third 12 yeares distant from the second And by them it is found that in the space of 54 yeares he loadestone hath att London diminished his variation from the north the quantity of 7 degrees and more But so that in the latter yeares the diminution hath sensibly gone faster then in the former These obseruations peraduenture are but little credited by strangers but we who know the worth of the men that made them can not mistrust any notable errour in them for they were very able mathematicians and they made their obseruations with very greate exactnesse and there were seuerall iuditious wittnesses att the making of them as may be seene in Mr. Gillebrand his print concerning this subiect And diuers other particular persons do confirme the same whose creditt though each single might peraduenture be slighted yet all in body make a great accession We must therefore cast about to find what may be the cause of an effect so paradoxe to the rest of the doctrine of the loadestone for seeing that no one place can stand otherwise to the north of the earth att one time then att an other how is it possible that the needle should receiue any new variation since all variation proceedeth out of the inequality of the earth But when we consider that this effect proceedeth not out of the maine body of the earth but only out of the barke of it and that its barke may haue diuers tempers not as yet
strength and security of the fabrike no more I hope will the slight escapes which so difficult a taske as this is subiect vnto endamage or weaken the maine body of what I haue here deliuered I haue not yet seene any piece vpon this subiect made vp with this methode beginning from the simplest and plainest notions and composing them orderly till all the principall variety which their nature is capable of be gone through and therefore it can not be expected but that the first modell of this kind and moulded by one distracted with continuall thoughts of a much different straine and whose exercise as well as profession hath allowed him but litle commerce with bookes and study must needes be very rough hewed and require a great deale of polishing Which whosoeuer shall do and be as exact and orderly in treating of Phylosophy and Theology as Mathematicians are in deliuering their sciencies I do assure my selfe that Demonstrations might be made and would proceed in them as currently and the conclusions be as certaine and as full as in the Mathematikes themselues But that is not all these demonstrations would haue the oddes exceedingly of the other and be to vs inestimably more aduantagious for out of them do spiring much higher and nobler effects for mans vse and life then out of any Mathematicall ones especially when they extend themselues to the gouuernement of Man as he is Man which is an art as farre beyond all the rules of Physike or other gouuernement of our body or temporall goodes as the end is beyond the meanes we employ to gaine it for all the others do but serue instrumentally to this end That we may liue well whereas these do immediately teach it These are the fruites in generall that I hope may in some measure grow out of this discourse in the handes of equall and iuditious Readers but the particular ayme of it is to shew what actions can proeeed from a body and what can not In the conduct whereof one of our chiefe endeauours hath beene to shew that those actions which seeme to draw strongly into the order of bodies the vnknowne nature of certaine entities named Qualities eyther do or may proceed from the same causes which produce those knowne effects that all sides agree do not stand in neede of any such mysticall Philosophy And this being the maine hinge vpon which hangeth and moueth the full and cleare resoluing of our maine and great question Of the Immortality of the Soule I assure my selfe the paines I haue taken in this particular will not be deemed superfluous or tedious and withall I hope I haue employed them with so good successe as hence foreward we shall not be any more troubled with obiections drawne from their hidden and incomprehensible nature and that we stand vpon euen ground with those of the contrary opinion for since we haue shewed how all actions may be performed among bodies without hauing any recourse to such Entities and Qualities as they pretend and paint out to vs it is now their part if they will haue them admitted to proue that in nature there are such Hauing thâ—n brought the Philosophy of bodies vnto these termes that which remaineth for vs to performe is to shew thâ—t those actions of our soule for which we call her a spiritt are of such a nature as they can not be reduced into those principles by which all corporeall actions are effected For the proofe of our originall intent no more then this can be exacted at our handes so that if our positiue proofes shall carry vs yet beyond this it can not be denyed but that we giue ouermeasure and do illustrate with a greater light what is already sufficiently discerned In our proceeding we haue the precedency of nature for laying for our ground the naturall conceptions which mankind maketh of quantity we find that a body is a meere passiue thing consisting of diuers partes which by motion may be diuersly ordered and consequently that it is capable of no other change or operation then such as motion may produce by various ordering the diuers partes of it and then seeing that Rare and Dense is the primary and adequate diuision of Bodies it followeth euidently that what can not be effected by the various disposition of rare and dense partes can not proceed or be effected by a pure body and consequently it will be sufficient for vs to shew that the motions of our soules are such and they who will not agree to this conclusion must take vpon them to shew that our first premisse is defectiue by prouing that other vnknowne wayes are necessary for bodies to be wrought vpon or to worke by and that the motion and various ordering of rare and dense partes in them is not cause sufficient for the effects we see among them Which whosoeuer shall attempt to do must remember that he hath this disaduantage before he beginneth that whatsoeuer hath beene hitherto discouered in the science of bodies by the helpe eyther of Mathematikes or Physickes it hath all beene resolued and hath fallen into this way which we declare Here I should sett a periode to all further discourse concerning this first Treatise of bodies did I not apprehend that the preiudice of Aristotles authority may dispose many to a harsh conceite of the draught we haue made But if they knew how litle reason they haue to vrge that against vs they would not crye vs downe for contradicting that oracle of nature not only because he himselfe both by word and by example exhorteth vs when verity leadeth vs an other way to forsake the trackes which our forefathers haue beaten for vs so we do it with due respect and gratitude for the much they haue left vs nor yet because Christian Religion as it will not heare of any man purely a man free from sinne so it inclineth to persuade vs that no man can be exempt from errour and therefore it sauoureth not well to defend peremptorily any mans sayings especially if they be many as being vncontrollable how be it I intend not to preiudice any person that to defend a worthy authors honour shal endeauour to vindicate him from absurdities and grosse errors nor lastly because it hath euer beene the common practise of all graue Peripatetikes and Thomistes to leaue their Masters some in one article some in an other but indeede because the very truth is that the way we take is directly the same solide way which Aristotle walked in before vs and they who are scandalised at vs for leauing him are exceedingly mistaken in the matter and out of the sound of his wordes not rightly vnderstood do frame a wrong sense of the doctrine he hath left vs which generally we follow Lett any vnpartiall Aristotelian answere whether the conceptions we haue deliuered of QuaÌ„tity of Rarity and DeÌ„sity of the foure first Qualities of the combinations of the Elements of the repugnance of vacuities be not exactly and rigorously
then this or precedent to it and that it agreeth so completely with our soule as she seemeth to be nothing else but a capacity fitted to Being it can not be denyed but that our soule must needes haue a very neere affinity and reseÌ„blance of nature with it but it is euident that Being hath not of it selfe any partes in it nor of it selfe is capable of diuision and therefore it is as euident that the soule which is framed as it were by that patterne and Idea and is fitted for Beinâ— as for its end must also of it selfe be voyde of partes and be in capable of diuisioÌ„ For how can partes be fitted to an indiuisible thing And how can two such different natures euer meete porportionably If it be obiected that the very notion of Being from whence we estimate the nature of the soule is accommodable to partes as for example we see that substance is endewed with quantity We answere that euen this doth corroborate our proofe for seing that the substances which our senses are acquainted withall haue partes and can not be without partes and yet neuerthelesse in our soule the notion of such substance is found without partes it is cleare that such substance hath this meerely from our soule and because it hath this indisibility from our soule it followeth that our soule hath a power and nature to bestow indiuisibility vpon what cometh into her And since it can not be denyed but that if any substance were once existent without partes it could neuer after haue partes it is euident that the nature of the soule is incapable of partes because it is existent without partes And that it is in such sort existent is cleare for this effect of the soules giuing indiuisibility vnto what she receiueth into her proceedeth from her as she is existent Now since this notion of Being is of all others the first and originall notion that is in the soule it must needes aboue all others sauour most of the proper and genuine nature of the soule in which and by which it is what it is and hath its indiuisibility If then it be pressed how can substance in reality or in thinges be accommodated vnto Quantity seing that of it selfe it is indiuisible We answere that such substance as is the subiect of Quantity and that hath Quantity is not indiuisible for such substance can not be subsistent without Quantity and when we frame a notion of it as being indiuisible it is an effect of the force of our soule that is able to draw a notion out of a thing that hath partes without drawing the notion of the partes which sheweth maâ—ifestly that in her there is a power aboue hauing of partes which being in her argueth her existence to be such Our last consideration vpon the nature of apprehension was how all that is added to the notion of Being is nothing else but respects of one thing to an other and how by these respects all the thinges of the world come to be in our soule The euideÌ„ce we may draw from hence of our soules immateriality will be not a whitt lesse then eyther of the two former for lett vs cast our lookes ouer all that cometh into our senses and see if from one end to an other we can meete with such a thing as we call a respect it hath neyther figure nor colour nor smell nor motion nor tast nor touch it hath no similitude to be drawne out of by meanes of our senses to be like to be halfe to be cause or effect what is it The thinges indeed that are so haue their resemblances and pictures but which way should a painter go about to draw a likenesse Or to paint a halfe or a cause or an effect If we haue any vnderstanding we can not choose but vnderstand that these notions are extremely different from whatsoeuer cometh in vnto vs by the mediation of our senses and then if we reflect how the whole negotiation of our vnderstanding is in and by respects must it not follow necessarily that our soule is of an extreme different nature from our senses and from our Imagination Nay if we looke well into this argument we shall see that whereas Aristotle pretendeth that Nihil est in intellectu quod non prius fuit in sensu this Maxime is so farre from being true in rigour of the wordes that the quite contrary followeth vndenyably out of it to witt that Nihil est in intellectu quod fuit prius in sensu Which I do not say to contradict Aristotle for his wordes are true in the meaning he spoke them but to shew how thinges are so much changed by coming into the vnderstanding and into the soule that although on the one side they be the very same thinges yet on the other side there remaineth no likenesse at all between them in themselues as they are in the vnderstading which is a most euident proofe when the weight of it is duely considered that the nature of our soule is mainely different from the nature of all corporeall thinges that come into our sense By this which we now come from declaring the admiration how corporeall thinges can be in the soule and how they are spiritualized by their being so will in part be taken away for reflecting that all the notioÌ„s of the soule are nothing but the generall notion of a substance or of a thing ioyned with some particular respect â—f then we consider that the respects may be so ordered that one respect may be included in an other we shall see that there may be some one respect which may include all those respects that explicate the nature of some one thing and in this case the generall notion of a thing coupled with this respect will containe all whatsoeuer is in the thing as for example the notion of a knife that it is a thing to cutt withall includeth as we haue formerly declared all that belongeth vnto a knife And thus you see how that mysticall phrase of corporeall thinges being spiritualized in the soule signifyeth no more but that the similitudes which are of them in the soule are Respects Thus hauing collected out of the nature of Apprehension in common as much as we conceiue needefull in this place to proue our assertion our next worke must be to try if we can do the like by reflecting vpon particular apprehensions We considered them of two sortes calling one kind vniuersall ones and the other collectiue ones in the vniuersall ones we tooke notice of two conditions the abstraction and the vniuersality of them now truly if we had no other euidence but what will rise from the first of these that alone would conuince and carry the conclusion for though among corporeall thinges the same may be now in one place now in an other or sometimes haue one figure sometimes an other and still be the same thinges as for example waxe or water yet it is impossible
surfaces 9 A body of greater partes and greater pores maketh a greater refraction then one of lesser partes and lesser pores 10 A coÌ„firmation of the former doctrine out of the nature of bodies that refract light 1 The coÌ„nexion of this chapter with the rest and the Authors intent in it 2 That there is a least cise of bodies and that this least cise is found in fire 3 The first coniunction of partes is in bodies of least cise and it is made by the force of Quantity 4 The second sort of coniunction is coÌ„pactednesse in simple Elements and it proceedeth from density 5 The third coniunction is of partes of different Elements and it proceedeth from quantity and density together 6 The reason why liquide bodies do easily ioyne together and dry ones difficultly 7 That no two hard bodies can touch one an other immediately 8 How mixed bodies arâ— framed in generall 9 The cause of the seuerall degrees of solidity in mixed bodies 10 The rule wherevnto are reduced all the seuerall combinations of Elements in compounding of mixed bodies 11 Earth and water are the basis of all permanent mixed bodies 12 What kind of bodies those are where water is the basis and earth the predominant Element ouer the other two 13 Of those bodies where water being the basis ayre is the predominant Element 14 What kind of bodies result where water is the basis and fire the predominant Element 15 Of those bodies where water is in excesse it alone being both the basis and the predominant Element 16 Of those bodies where Earth alone is the basis and also the predominant in excesse ouer the other threâ— Elements 17 Of those bodies where Earth is the basis and water the predominâ—t Element ouer the other two 18 Of those bodies where earth being the basis ayre is the predominant 19 Of those bodies where Earth being the basis fire is the predominant 20 All the second qualities of mixed bodies arise from seuerall combinations of the first qualities and are att last resolued into seuerall degrees of rarity and density 21 That in the planets and starres there is a like varietâ— of mixed bodies caused by light as here vpon Earth 22 In what maÌ„ner the Elements do worke vpon one an other in the compositioÌ„ of mixed bodies and in particular fire which is the most actiue 23 A particular declaration touching the generation of mettalls 1 Why some bodies are brittle and others tough or apt to withstand outward violence the first instrument to dissolue mixed bodies 2 How outward violence doth worke vpon the most compacted bodies 3 The seuerall effects of fire the second and chiefest instrumeÌ„t to dissolue all coÌ„pounded bodies 4 The reason why some bodies are not dissolued by fire 5 The reason why fire molteth gold but can not consume it 6 Why leade is easily consumed and calcined by fire 7 Why and how some bodies are diuided by fire into spirits waters oyles saltes and earth And what those partes are 8 How water the third iâ—strumeÌ„t to dissolue bodies dissolueth calx into salt and so into Terra damnata 9 How water mingled with salt becometh a most powerfull Agent to dissolue other bodies 10 How putrefactioÌ„ is caused 1 What is the sphere of actiuity in corporeall Agents 2 The reason why no body can worke in distance 3 An obiection answered against the manner of explicating the former axiomâ— 4 Of reaction and first in pure locall motion that each AgeÌ„t must suffer in acting and actâ— in suffering 5 The former doctrine applyed to other locall motions designed by particular names And that Suisseths argument is of no force against this way of doctrine 6 Why some notions do admitt of intension and Remission and others do not 7 That in euery part of our habitable world all the foure ElemeÌ„ts are found pure in small atomes but not in any great bulke 1 The Authors intent in this and the following chapters Mr. Thomas White 2 That bodies may be rarifyed both by outward and inward heat and how this is performed 3 Of the great effects of Rarefaction 4 The first manner of condensation by heate 5 The second manner of condensation by cold 6 That yce is not water rarifyed but condensed 7 How wind snow and haile are made and wind by raine allayed 8 How partes of the same or diuers bodies are ioyned more strongly together by condensation 9 Vacuites can not be the reason why water impregnated to the full with one kind of salt will notwithstaÌ„ding receiue more of an other 10 The true reason of the former effect 11 The reason why bodies of the same nature do ioyne more easily together then others 1 What AttractioÌ„ is and from whence it proceedeth 2 The true sense of the Maxime that Nature abhorreth from vacuity 3 The true reasâ— of attraction 4 Water may be brought by the force of attraction to what height soeuer 5 The doctrine touching the attraction of water in syphons 6 That the syphon doth not proue water to weigh in its owne orbe 7 Concerning attraction caused by fire 8 Concerning attractioÌ„ made by vertue of hoat bodies amulets etc. 9 The naturall reason giuen for diuers operations esteemed by some to be magicall 1 What is Filtration and how it is effected 2 What causeth the water in filtration to ascend 3 Why the filter will not droppe vnlesse the labell hang lower then the water 4 Of the motion of Restitution and why some bodies stand bent others not 5 Why some bodies returne onely in part to their natural figure others entirely 6 Concerning the nature of those bodies which do shrinke and stretch 7 How great and wonderfull effects proceed from small plaine and simple principles 8 Concerning Electricall attraction and the causes of it 9 Cabeus his opinion refuted concerning the cause of Electricall motâ—ons 1 The extreme heat of the sunne vnder the zodiacke draweth a streame of ayre from each Pole into the torride zone Chap. 18. §. 7. 2 The atomes of these two streames coming together are apt to incorporate with one an other 3 By the meeting and mingling together of these streames att the Equator diuers riuolets of atomes of each Pole are continuatâ—d from one Pole to the other 4 Of these atomes incorporated with some fitt matter in the bowels of the earth is made a stone 5 This stone worketh by emanations ioyned with agreeing streames that meete them in the ayre and in fine it is a loadestone 6 A methode for making experiences vpon any subiect 7 The Loadestones generatioÌ„ by atomes flowing from both Poles is confirmed by experiments obserued in the stone it selfe 8 Experiments to proue that the loadestone worketh by emanations meeting with agreeing streames 1 The operations of the loadestone are wrought by bodies and not by qualities 2 Obiections against the former positioÌ„ answered 3 The loadestone is imbued