proportions of the comparison of their densities with the density of water for as we haue said the efficacy and force of desceÌ„ding is to be measured by that So then the stroakes of the atomes being more efficacious vpon water then vpon corke because the density of water is greater then the density of corke considering the aboundance of ayre that is harboured in the large pores of it it followeth that the atomes will make the water goe downe more forcibly then they will corke But the density of iron exceeding the density of water the same stroakes will make the iron descend faster then the water and consequently the iron must sinke in the water and the corke will swimme vpon it And this same is the cause why if a piece of corke be held by force att the bottome of the water it will rise vp to the toppe of the water as soone as the violence is taken away that kept it downe for the atomes stroakes hauing more force vpon the water then vpon the corke they make the water sinke and slide vnder it first a litle thinne plate of water and then an other a litle thicker and so by degrees more and more till it hath lifted the corke quite vp to the toppe Fiâ—thly it may be obiected that these atomes do not descend alwayse perpendicularly be sometimes sloapingly and in that case if their stroakes be the cause of dense bodies mouing they should moue sloaping and not downeward Now that these atomes descend sometimes sloapingly is euident as when for example they meete with a streame of water or with a strong wind or euen with any other litle motion of the ayre such as carryeth feathers vp and downe hither and thither which must needes waft the atomes in some measure along with them their way seeing then that such a gentle motion of the ayre is able to putt a feather out of its way notwithstanding the percussions of the atomes vpon it why shall it not likewise putt a piece of iron out of its way downewardes since the iron hath nothing from the atomes but a determination to its way But much more why should not a strong wind or a current of water do it since the atomes themselues that giue the iron its determination must needes be hurryed along with them To this we answere that we must consider how any wind or water which runneth in that sort is it selfe originally full of such atomes which continually and euery where presse into it and cutt through it in pursuing their constant perpetuall course of descending in such sort as we haue shewed in their running through any hard rocke or other densest body And these atomes do make the wind or the water primarily tend downewardes though other accidentall causes impell them secondarily to a sloaping motion And still their primary naturall motion will be in truth strongest though their not hauing scope to obey that but their hauing enough to obey the violent motion maketh this become the more obseruable Which appeareth euidently out of this that if there be a hole in the bottome of the pipe that conueyeth water sloapingly be the pipe neuer so long and consequently the sloaping motion neuer so forcible yet the water will runne out att that hole to obey its more powerfull impulse to the centerwardes rather then continue the violent motion in which it had arriued to a great degree of celerity Which being so it is easy to conceiue that the atomes in the wind or water which mooue perpendicularly downewardes will still continue the irons motion downewardes notwithstanding the mediums sloaping motion since the preuailing force determineth both the iron and the medium downewardes and the iron hath a superproportion of density to cutt its way according as the preualent motion determineth it But if the descending atomes be in part carryed along downe the streame by the current of wind or water yet still the current bringeth with it new atomes into the place of those that are carryed away and these atomes in euery point of place wheresoeuer they are do of themselues tend perpendicularly downewardes howbeit they are forced from the complete effect of their tendance by the violence of the current so that in this case they are mooued by a declining motion compounded of their owne naturall motion and of the forced motion with which the streame carryeth them Now then if a dense body do fall into such a current where these different motions giue their seuerall impulses it will be carryed in such sort as we say of the atomes but in an other proportion not in a perpendicular but in a mixt declining line compounded of the seuerall impulses which the atomes and the current do giue it in which also it is to be remembred how the current giueth an impulse downewardes as well as sloaping and peraduenture the strongest downewardes and the declination will be more or lesse according as the violent impulse preuayleth more or lesse against the naturall motion But this is not all that is to be considered in estimating the declination of a dense bodies motion when it is sinking in a current of wind or water you must remember that the dense body it selfe hath a particular vertue of its owne namely its density by which it receiueth and prosecuteth more fully its determination downewardes and therefore the force of that body in cutting its way through the medium is also to be considered in this case as well as aboue in calculating its declining from the perpendicular and out of all these causes will result a middle declination coÌ„pounded of the motioÌ„ of the water or wind both wayse and of its owne motion by the perpendicular line And since of these three causes of a dense bodies motion it s owne vertue in prosecuting by its density the determination it requireth is the most efficacious by much after it hath once receiued a determination from without its declination will be but litle if it be very dense and heauy But if it recede much from density so as to haue some neere proportion to the density of the medium the declination will be great And in a word according as the body is heauyer or lighter the declination will be more or lesse in the same current though not exactly according to the proportion of the diminishing of its density as long as there is a superproportion of its density to the medium since that such a superproportion as we haue declared heretofore maketh the mediums operation vpon the dense body scarce considerable And hence you see why a stone or piece of iron is not carried out of its way as well as feather because the stones motion downewardes is greater and stronger then the motion of a feather downewardes And by consequence the force that can deturne a feather from its course downewardes is not able to deturne a stone And if it be replyed that it may be so ordered that the stone shall haue no motion before
were lighter and consequently more rare then water because it swimmeth vpon it which is an effect of the ayres being contained in the belly of it as it is in yce not a signe of the mettalls being more rare then water Whereas on the contrary side the proofe is positiue and cleare for vs for it can not be denyed but that the mingling of the water with other bodies more dense then it must of necessity make the compound and also the water it selfe become more dense then it was alone And accordingly we see that yce halfe thawed for then much of the ayre is driuen out and the water beginneth to fill the pores wherein the ayre resided before sinketh to the bottome as an iron dish with holes in it whereby the water might gett into it would do And besides we see that water is more diaphanous then yce and yce more consistent then water Therefore I hope we shall be excused if in this particular we be of a contrary opinion to this great personage But to returne vnto the thridde of our discourse The same that passeth here before vs passeth also in the skye with snow haile raine and wind Which that we may the better vnderstand lett vs consider how windes are made for they haue a maine influence into all the rest When the sunne or by some particular occurrent rayseth great multitudes of atomes from some one place and they eyther by the attraction of the sunne by some other occasion do take their course a certaine way this motion of those atomes we call a wind which according to the continuance of the matter from whence these atomes rise endureth a longer or a shorter time and goeth a farther or a shorter way like a riuer or rather like those eruptions of waters which in the Notherne partes of England they call Gypsies the which do breake out att vncertaine times and vpon vncertaine causes and flow likewise with an vncertaine duration So these windes being composed of bodies in a determinate proportion heauyer then the ayre do runne their course from their hight to the ground where they are supported as water is by the floore of its channell whiles they performe their carrire that is vntill they be wasted eyther by the drawing of the sunne or by their sticking and incorporating into grosser bodies Some of these windes according to the complexion of the body out of which they are extracted are dry as those which come from barren mountaines couered with snow others are moist as those that come out of marishy or watry places others haue other qualities as of heate or cold of wholesomenesse or vnwholesomenesse and the like partly from the source and partly frō the bodies they are mingled with in their way Such then being the nature and origine of windes if a cold one do meete in the ayre with that moist body whereof otherwise raine would haue been made it changeth that moist body into snow or into haile if a dry wind meete with a wett body it maketh it more dry and so hindereth the raine that was likely to be but if the wett body ouercome the dry wind it bringeth the wind downe along with it as we see when a shoure of raine allayeth a great wind And that all this is so experience will in some particulars instruct vs as well as reason from whence the rest may be euidently inferred For we see that those who in imitation of nature would conuert water into yce do take snow or yce and mingle it with some actiue dry body that may force the cold partes of the snow from it and then they sett the water in some fitt vessell in the way that those little bodies are to take which by that meanes entering into it do straight incorporate themselues therewith and of a soddaine do conuert it into yce Which processe you may easily trye by mingling salt armoniake with the snow but much more powerfully by setting the snow ouer the fire whiles the glasse of water to be congealed standeth in it after the manner of an egg in salt And thus fire it selfe though it be the enemy and destroyer of all cold is made the instrument of freesing And the same reason holdeth in the cooling of wine with snow or yce when after it hath beene a competent time in the snow they whose charge it is do vse to giue the vessell that containeth the wine three or foure turnes in the snow so to mingle through the whole body of the wine the cold receiued first but in the outward partes of it and by pressing to make that without haue a more forcible ingression But the whole doctrine of Meteores is so amply so ingeniously and so exactely performed by that neuer enough praysed Gentleman Monsieur Des Cartes in his Meteorologicall discourses as I should wrong my selfe and my Reader if I dwelled any longer vpon this subiect And whose Physicall discourses had they beene diuulged before I had entered vpon this worke I am persuaded would haue excused the greatest part of my paines in deliuering the nature of bodies It were a fault to passe from treating of condensation without noting so ordinary an effect of it as is the ioyning together of partes of the same body or of diuers bodies In which we see for the most part that the solide bodies which are to be ioyned together are first eyther heated or moistened that is they are rarifyed and then they are left to cold ayre or to other cold bodies to thicken and condense as aboue we mentioned of syrupes and gellies and so they are brought to sticke firmely together In the like manner we see that when two mettalls are heated till they be almost brought to runninge and then are pressed together by the hammer they become one continued body The like we see in glasse the like in waxe and in diuers other thinges On the contrary side when a broken stone is to be pieced together the pieces of it must be wetted and the ciment must be likewise moistened and then ioyning them aptly and drying them they sticke fast together Glew is moistened that it may by drying afterwardes hold pieces of wood together And the spectaclemakers haue a composition which must be both heated and moistened to ioyne vnto handles of wood the glasses which they are to grinde And broken glasses are cimented with cheese and chalke or with garlike All these effects our sense euidently sheweth vs arise out of condēsation but to our reasō it belōgeth to examine particularly by what steppes they are performed Frst then we know that heate doth subtilise the little bodies which are in the pores of the heated body and partly also it openeth the pores of the body it selfe if it be of a nature that permitteth it as it seemeth those bodies are which by heate are mollifyed or are liquefactible Againe we know that moysture is more subtile to enter into small creekes then dry bodies are especially
they can not soddainely be so much rarifyed as the subtiler partes of ayre that are there and therefore the more those subtiler partes are rarifyed and thereby happen to be carried vp the stronger and the thicker the heauyer atomes must descend And thus this concurse of ayre from the polar partes mainetayneth grauity vnder the zodiake where otherwise all would be turned into fire and so haue no grauity Now who coÌ„sidereth the two hemispheres which by the aequator are diuided will find that they are not altogether of equall complexions but that our hemisphere in which the Northpole is comprised is much dryer then the other by reason of the greater coÌ„tinent of land in this and the vaster tract of sea in the other and therefore the supply which cometh froÌ„ the diuers hemispheres must needes be of differeÌ„t natures that which cometh from towardes the Southpole being compared to that which cometh froÌ„ towardes the North as the more wett to the more dry Yet of how different coÌ„plexions soeuer they be you see they are the emanations of one and the same body Not vnlike vnto what nature hath instituted in the ranke of animals among whom the male and the female are so distinguished by heate and cold moysture and drought that neuerthelesse all belongeth but to one nature and that in degrees though manifestly different yet so neere together that the body of one is in a manner the same thing as the body of the other Euen so the complexions of the two hemispheres are in such sort different in the same qualities that neuerthelesse they are of the same nature and are vnequall partes of the same body which we call the earth Now Alchymistes assure vs that if two extractions of one body do meete together they will incorporate one with the other especially if there be some little difference in the complexion of the extractions Whence it followeth that these two streames of ayre making vp one continuate floud of various currents from one end of the world to the other each streame that cometh to the equator from its owne Pole by the extraction of the sunne and that is still supplyed with new matter flowing from its owne pole to the aequator before the sunne can sufficiently rarify and lift vp the atomes that came first perpendicularly vnder its beames as it vseth to happen in the effects of Physicall causes which can not be rigorously aiusted but must haue some latitude in which nature inclineth euer rather to aboundance then to defect will passe euen to the other pole by the conduct of his fellow in case he be by some occasion driuen backe homewardes For as we see in a boule or paile full of water or rather in a pipe through which the water runneth along if there be a little hole att the bottome or side of it the water will wriggle and change its course to creepe out att that pipe especially if there be a little spigott or quill att the outside of the hole that by the narrow length of it helpeth in some sort as it were to sucke it So if any of the files of the army or flould of atomes sucked from one of the Poles to the aequator do there find any gappes or chinkes or lanes of retiring files in the front of the other poles batalia of atomes they will presse in there in such manner as we haue aboue declared that water doth by the helpe of a labell of cotton and as is exemplyfied in all the attractions of venime by venimous bodies whereof we haue giuen many examples aboue and they will go along with them the course they goe For as when a thicke short guilded ingott of siluer is drawne out into a long subtile wyre the wyre continuing still perfectly guilded all ouer doth manifestly shew that the outside and the inside of the ingott do strangely meete together and intermixe in the drawing out so this little streame which like an eddy current runneth backe from the aequator towardes its owne Pole will continue to the end still tincted with the mixture of the other Poles atomes it was incorporated with att its coming to the aequator Now that some little riuolets of ayre and atomes should runne backe to their owne Pole contrary to the course of their maine streame will be easily enough to conceiue if we but consider that att certaine times of the yeare windes do blow more violently and strongly from some determinate part or Rombe of the world then they do att other times and from other partes As for example our East India Mariners tell vs of the famous Monâ—ones they find in those partes which are strong windes that raigne constantly six monthes of the yeare from one polewardes and the other six monthes from the other pole and beginne precisely about the sunnes entering into such a signe or degree of the zodiake and continue till about its entrance into the opposite degree And in our partes of the world certaine smart Easterly or Northeasterly windes do raigne about the end of March and beginning of Aprill when it seemeth that some snowes are melted by the spring heates of the sunne And other windes haue their courses in other seasons vpon other causes All which do euidently conuince that the course of the ayre and of vapors from the poles to the equator can not be so regular and vniforme but that many impediments and crosses do light in the way to make breaches in it and thereby to force it in some places to an opposite course In such sort as we see happeneth in eddy waters and in the course of a tide wherein the streame running swiftly in the middle beateth the edges of the water to the shore and thereby maketh it runne backe att the shore And hence we may conclude that although the maine course of ayre and atomes for example from north to south in our hemisphere can neuer faile of going on towardes the aequator constantly att the same rate in grosse neuerthlesse in seuerall particular little partes of it and especially att the edges of those streames that are driuen on faster then the rest by an extraordinary and accidentall violent cause it is variously interrupted and sometimes entirely stopped and other times euen driuen backe to the northwardes And if peraduenture any man should thinke that this will not fall out because each streame seemeth to be alwayes coming from his owne Pole to the aequator and therefore will oppose and driue backe any bodies that with lesse force should striue to swimme against it or if they sticke vnto them will carry them backe to the aequator We answere that we must not conceiue that the whole ayre in body doth euery where equally encroach from the polewardes vpon the torride zone but as it were in certaine brookes or riuolets according as the contingency of all causes putt together doth make it fall out Now then out of what we haue said it will follow that since
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
and giue the like motion to any body they find in their way if it be susceptible of such a motion which it is euident that all bodies are vnlesse they be strucken by some contrary impulse For since that a bodies being in a place is nothing else but the continuity of its outside to the inside of the body that containeth it and is its place it can haue no other repugnance to locall motion which is nothing else but a successiue changing of place besides this continuity Now the nature of density being the power of diuiding and euery least power hauing some force and efficacy as we haue shewed aboue it followeth that the stroake of euery atome eyther descending or ascending will worke some thing vpon any body though neuer so bigge it chanceth to encounter with and strike vpon in its way vnlesse there be as strong an impulse the contrary way to oppose it But it being determined that the descending atomes are denser then those that ascend it followeth that the descending ones will preuayle And consequently all dense bodies must necessarily tend downewardes to the center which is to be Heauy if some other more dense body do not hinder them Out of this discourse we may conclude that there is no such thing among bodies as positiue grauity or leuity but that their course vpwardes or downewardes happeneth vnto them by the order of nature which by outward causes giueth them an impulse one of these wayes without which they would rest quietly wheresoeuer they are as being of themselues indifferent to any motion But because our wordes expresse our notions and they are framed according to what appeareth vnto vs when we obserue any body to descend constantly towardes our earth we call it heauy and if it mooue contrarywise we call it light But we must take heed of considering such grauity and leuity as if they were Entities that worke such effects since vpon examination it appeareth that these wordes are but short expressions of the effects themselues the causes whereof the vulgar of mankinde who impose names to thinges do not consider but leaue that worke vnto Philosophers to examine whiles they onely obserue what they see done and agree vpon wordes to expresse that Which wordes neither will in all circumstances alwayes agree to the same thing for as corke doth descend in ayre and ascend in water so also will any other body descend if it lighteth among others more rare then it selfe and will ascend if it lighteth among bodies that are more dense then it And we terme bodies light and heauy onely according to the course which we vsually see them take Now proceeding further on and considering how there are various degrees of density or grauity it were irrationall to conceiue that all bodies should descend att the same rate and keepe equall pace with one an other in their iourney downewardes For as two knifes whereof one hath a keener edge then the other being pressed with equall strength into like yielding matter the sharper will cutt deeper then the other so if of two bodies one be more dense then the other that which is so will cutt the ayre more powerfully and will descend faster then the other for in this case density may be compared to the knifes edge since in it consisteth the power of diuiding as we haue heretofore determined And therefore the pressing them downewardes by the descending atomes being equall in both or peraduenture greater in the more dense body as anone we shall haue occasion to touch and there being no other cause to determine them that way the effect of diuision must be the greater where the diuider is the more powerfull Which the more dense body is and therefore cutteth more strongly through the resistance of the ayre and consequently passeth more swiftly that way it is determined to mooue I do not meane that the velocities of their descent shall be in the same proportion to one an other as their densities are for besides their density those other considerations which we haue discoursed of aboue when we examined the causes of velocity in motion must likewise be ballanced And out of the comparison of all them not out of the consideration of any one alone resulteth the differences of their velocities and that neither but in as much as concerneth the consideration of the mooueables for to make the calculation exact the medium must likewise be considered as by and by we shall declare for since the motion dependeth of all them together although there should be difference betweene the mooueables in regard of one onely and that the rest were equall yet the proportion of the difference of their motions must not follow the proportion of their difference in that one regard because their difference considered single in that regard will haue one proportion and with the addition of the other considerations though alike in both to their difference in this they will haue an other As for example reckon the density of one mooueable to be double the density of an other mooueable so that in that regard it hath two degrees of power to descend whereas the other hath but one suppose then the other causes of their descent to be alike in both and reckon them all three and then ioyne these three to the one which is caused by the density in one of the mooueables as likewise to the two which is caused by the density in the other mooueable and you will find that thus altogether their difference of power to descend is no longer in a double proportion as it would be if nothing but their density were considered but is in the proportion of fiue to foure But after we haue considered all that concerneth the mooueables we are then to cast an eye vpon the medium they are to mooue in and we shall find the addition of that to decrease the proportion of their difference exceedingly more according to the cessibility of the medium Which if it be ayre the great disproportion of its weight to the weight of those bodies which men vse to take in making experiences of their descent in that yielding medium will cause their difference of velocity in descending to be hardly perceptible Euen as the difference of a sharpe or dull knife which is easily perceiued in cutting of flesh or bread is not to be distinguished in diuiding of water or oyle And likewise in weights a pound and a scruple will beare downe a dramme in no sensible proportion of velocity more then a pound alone would do and yet putt a pound in that scale instead of the dramme and then the difference of the scruple will be very notable So then those bodies whose difference of descending in water is very sensible because of the greater proportion of weight in water to the bodies that descend in it will yield no sensible difference of velocity when they descend in ayre by reason of the great disproportion of weight betweene
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
it be in the streame of a riuer and notwithstanding it will still mooue downewardes we may answere that considering the litle decliuity of the bed of such a streame the strongest motion of the partes of the streame must necessarily be downewardes and consequently they will beate the stone downewardes And if they do not the like to a feather or other light body it is because other partes of the streame do gett vnder the light body and beate it vpwardes which they haue not power enough to do to the stone Sixthly it may be obiected that if Elements do not weigh in their owne spheres then their grauity and descending must proceede from some other cause and not from this percussion of the atomes we attribute it to which percussion we haue determined goeth through all bodies whatsoeuer and beateth vpon euery sensible part of them But that Elements weigh not in their owne spheres appeareth out of the experience of a syphon for though one legge of the syphon be suncke neuer so much deeper into the body of the water then the other legge reacheth below the superficies of the water neuerthelesse if once the outward legge become full of water it will draw it out of the other longer legge which it should not do if the partes of water that are comprised within their whole bulke did weigh seeing that the bulke of water is much greater in the sunke legge then in the other and therefore these should rather draw backe the other water into the cisterne then be themselues drawne out of it into the ayre To this we answere that it is euident the Elements do weigh in their owne spheres att least as farre as we can reach to their spheres for we see that a ballone stuffed hard with ayre is heauyer then an empty one Againe more water would not be heauyer then lesse if the inward partes of it did not weigh and if a hole were digged in the bottome of the sea the water would not runne into it and fill it if it did not grauitate ouer it Lastly there are those who vndertake to distinguish in a deepe water the diuers weights which seuerall partes of it haue as they grow still heauyer and heauyer towardes the bottome and they are so cunning in this art that they professe to make instruments which by their equality of their weight to a determinate part of the water shall stand iust in that part and neyther rise nor fall higher or lower but if it be putt lower it shall ascend to its exact equally weighing orbe of the water and if it be putt higher it shall descend vntill it cometh to rest precisely in that place Whence it is euident that partes of water do weigh within the bulke of their maine body and of the like we haue no reason to doubt in the other two weighty Elements As for the opposition of the syphon we referre that point to where we shall haue occasion to declare the nature of that engine of sett purpose And there we shall shew that it could not succeede in its operation vnlesse the partes of water did grauitate in their maine bulke into which one legge of the syphon is sunke Lastly it may be obiected that if there were such a course of atomes as we say and that their stroakes were the cause of so notable an effect as the grauity of heauy bodies we should feele it palpably in our owne bodies which experience sheweth vs we do not To this we answere first that their is no necessity we should feele this course of atomes since by their subtility they penetrate all bodies and consequently do not giue such stroakes as are sensible Secondly if we consider that dustes and strawes and feathers do light vpon vs without causing any sense in vs much more we may cōceiue that atomes which are infinitely more subtile and light can not cause in vs any feeling of them Thirdly we see that what is continuall with vs and mingled in all thinges doth not make vs take any especiall notice of it and this is the case of the smiting of atomes Neuerthelesse peraduenture we feele them in truth as often as we feele hoat and cold weather and in all catarres or other such changes which do as it were sinke into our body without our perceiuing any sensible cause of them for no question but these atomes are the immediate causes of all good and bad qualities in the ayre Lastly when we consider that we can not long together hold out our arme att length or our foote from the ground and reflect vpon such like impotencies of our resisting the grauity of our owne body we can not doubt but that in these cases we feele the effect of these atomes working vpon those partes although we can not by our sense discerne immediately that these are the causes of it But now it is time to draw our Reader out of a difficulty which may peraduenture haue perplexed him in the greatest part of what he hath hitherto gone ouer In our inuestigation of the Elements we tooke for a principle therevnto that grauity is sometimes more sometimes lesse then the density of the body in which it is But in our explication of rarity and density and againe in our explication of grauity we seeme to putt that grauity and density is all one This thorne I apprehend may in all this distance haue putt some to paine but it was impossible for mee to remedy it because I had not yet deliuered the manner of grauitation Here then I will do my best to asswage their greefe by reconciling these appearing repugnancies We are therefore to consider that density in it selfe doth signify a difficultie to haue the partes of its subiect in which it is seperated one from an other and that grauity likewise in it selfe doth signify a quality by which a heauy body doth descend towardes the center or which is consequent therevnto a force to make an other body descend Now this power we haue shewed doth belong vnto density so farre forth as a dense body being strucken by an other doth not yield by suffering its partes to be diuided but with its whole bulke striketh the next before it and diuideth it if it be more diuisible then it selfe is So that you see density hath the name of density in consideration of a passiue quality or rather of an impassibility which it hath and the same density is called grauity in respect of an actiue quality it hath which followeth this impassibility And both of them are estimated by the different respects which the same body or subiect in which they are haue vnto different bodies that are the termes whereunto it is compared for the actiue quality or grauity of a dense body is esteemed by its respect to the body it striketh vpon whereas its density includeth a respect singly to the body that striketh it Now it is no wonder that this change of comparison worketh a disparity
in the denominations and that thereby the same body may be conceiued to be more or lesse impartible then it is actiue or heauy As for example lett vs of a dense Element take any one least part which must of necessity be in its owne nature and kind absolutely impartible and yet it is euident that the grauity of this part must be exceeding litle by reason of the litlenesse of its quantity so that thus you see an extremity of the effect of density ioyned together in one body by the accident of the litlenesse of it with a contrary extremity of the effect of grauity or rather with the want of it each of them within the limits of the same species In like manner it happeneth that the same body in one circumstance is more weighty in an other or rather in the contrary is more partible so water when it is in a payle because it is thereby hindered froÌ„ spreading abroad hath the effect of grauity predominating in it but if it be poured out it hath the effect of partibility more And thus it happeneth that meerely by the gradation of rarity and density one dense body may be apt out of the generall course of naturall causes to be more diuisible theÌ„ to be a diuider though according to the nature of the degrees considered absolutely in theÌ„selues what is more powerfull to diuide is also more resisteÌ„t and harder to be diuided And this arriueth in that degree which maketh water for the falling and beating of the atomes vpon water hath the power both to diuide it and to makâ— it descend but so that by making it descend it diuideth it And therefore we say that it hath more grautty then density though it be the very density of it which is the cause that maketh it partible by the working of one part vpon an other for if the atomes did not find the body so dense as it is they could not by their beating vpon one part make an other be diuided So that a dense body to be more heauy then dense signifyeth nothing else but that it is in such a degree of density â—hat some of its owne partes by their being assisted and sett on worke by a generall cause which is the fall of the atomes are powerfull enough to diuide other adioyning partes of the same density with them one from an other in such sort as we see that water poured out of an eawer into a basen where there is already other water hath the power to diuide the water in the basen by the assistance of the celerity which it getteth in descending And now I hope the reader is fully satisfyed that there is no contradiction in putting Density and Grauity to be the same thing materially and that neuerthelesse the same thing may be more heauy then dense or more dense then heauy as we tooke it to our seuerall purposes in the inuestigation of the Elements Hauing thus layed an intelligible ground to discouer how these motions that are generall to all bodies and are naturall in chiefe are contriued by nature we will now endeauour to shew that the contrary position is not onely voluntary but also impossible Lett vs therefore suppose that a body hath a quality to mooue it downewardes And first wee shall aske what downewardes signifyeth for eyther it signifyeth towardes a fixed point of imaginary space or towardes a fixed point of the vniuerse or towardes some mooueable point As for the first who would maintaine it must haue more imagination then iudgment to thinke that a naturall quality could haue an essence determined by a nothing because we can frame a conceit of that nothing As for the second it is very vncertaine whether any such point be in nature for as for the center of the earth it is cleare that if the earth be carryed about the center of it can not be a fixed point Againe if the center signifyeth a determinate point in the earth that is the medium of grauity or of quantity it is changed as often as any dust lighteth vnequally vpon any one side of the earth which would make that side bigger then it was and I doubt a quality can not haue morall considerations to thinke that so litle doth no harme As for the third position likewise it is not intelligible how a quality should change its inclination or essence according to the change that should light to make now one point now an other be the center vnto which it should tend Againe lett vs consider that a quality hath a determinate essence Then seeing its power is to mooue and to moue signifyeth to cutt the mediuÌ„ it is mooued in it belongeth vnto it of its nature to cutt so much of such a medium in such a time So that if no other cause be added but that you take precisely and in abstracto that quality that medium and that time this effect will follow that so much motion is made And if this effect should not follow it is cleare that the being able to cutt so much of such a medium in such a time is not the essence of this quality as it was supposed to be Diuiding then the time and the medium halfe the motion should de made in halfe the time a quarter of the motion in a quarter of the time and so without end as farre as you can diuide But this is demonstratiuely impossible sithhence it is demonstrated that a mooueable coming from rest must of necessity passe through all degrees of tardity and therefore by the demonstration cited out of Galileus we may take a part in which this grauity can not mooue its body in a proportionate part of time through a proportionate part of the mediuÌ„ But because in naturall Theorems experiences are naturally required lett vs see whether nature giueth vs any testimony of this verity To that purpose we may consider a plummet hanged in a small string from a beame which being lifted vp gentlely on the one side att the extent of the string and permitted to fall meerely by the power of grauity it will ascend very neere as high on the contrary side as the place it was held in from whence it fell In this experiment we may note two thinges the first that if grauity be a quality it worketh against its owne nature in lifting vp the plumett seing its nature is onely to carry it downe For though it may be answered that it is not the grauity but an other quality called vis impressa which carrieth it vp neuerthelesse it can not be denyed but that grauity is either the immediate or at least the mediate cause which maketh this vis impressa the effect whereof being contrary to the nature of grauity it is absurd to make grauity the cause of it that is the cause of an essence whose nature is contrary to its owne And the same argument will proceede though you putt not vis impressa but suppose some other thing to be
the cause of the plummets remounting as long as grauity is said to be a quality for still grauity must be the cause of an effect contrary to its owne inclination by setting on foote the immediate cause to produce it The second thing we are to note in this experiment of the plummets ascent is that if grauity be a quality there must bee as much resistance to its going vp as there was force to its coming downe Therefore there must be twice as much force to make it ascend as there was to make it descend that is to say there must be twice as much force as the naturall force of the grauity is for there must be once as much to equalise the resistance of the grauity and then an other time as much to carry it as farre through the same medium in the same time But it is impossible that any cause should produce an effect greater then it selfe Againe the grauity must needes be in a determinate degree and the vertue that maketh the plummett remount whatsoeuer it be may be putt as litle as we please and consequently not able to ouersway the grauity alone if it be an intrinsecall quality and yet the plummet will remount in which case you putt an effect without a cause An other experience we may take from the force of sucking for take the barrell of a long gunne perfectly bored and sett it vpright with the breech vpon the ground and take a bullett that is exactly fitt for it but so as it sticke not any where both the barrell and it being perfectly polished and then if you sucke att the mouth of the barrell though neuer so gently the bullett will come vp so forcibly that it will hazard the striking out of your teeth Now lett vs consider what force were necessary to sucke the bullett vp and how very slowly it would ascend if in the barrell it had as much resistance to ascend as in the free ayre it hath inclination to goe downe But if it had a quality of grauity naturall to it it must of necessity haue such resistance whereas in our experiment we see it cometh as easily as the very ayre So that in this example as well as in the other nature teacheth vs that grauity is no quality And all or most of the arguments which we haue vrged against the quality of grauity in that explication we haue considered it in haue force likewise against it although it be said to be an inclination of its subiect to mooue it selfe vnto vnity with the maine stocke of its owne nature as diuers witty men do putt it for this supposition doth but chāge the intention or end of grauity and is but to make it an other kind of intellectuall or knowing Entity that determineth it selfe to an other end which is as impossible for a naturall quality to do as to determine it selfe to the former endes And thus much the arguments we haue proposed do conuince euidently if they be applyed against this opinion THE TWELTH CHAPTER Of Violent Motion ANd thus we haue giuen a short scātling whereby to vnderstand in some measure the causes of that motion which we call naturall by reason it hath its birth from the vniuersall oeconomy of nature here among vs that is from the generall working of the sunne whereby all naturall thinges haue their course and by reason that the cause of it is att all times and in all places constantly the same Next vnto which the order of discourse leadeth vs to take a suruay of those forced motions whose first causes the more apparent they are the more obscurity they leaue vs in to determine by what meanes they are continued When a tennis ball is strucken by a rackett or an arrow is shott from a bow we plainely see the causes of their motion namely the stringes which first yielding and then returning with a greater celerity do cause the missiues to speed so fast towardes their appoynted homes Experience informeth vs what qualities the missiues must be endued withall to mooue fast and steadily They must be so heauy that the ayre may not breake their course and yet so light that they may be within the command of the stroake which giueth them motion the striker must be dense and in its best velocity the angle which the missiue is to mount by if we will haue it goe to its furthest randome must be the halfe of a right one and lastly the figure of the missiue must be such as may giue scope vnto the ayre to beare it vp and yet not hinder its course by taking too much hold of it All this we see but when withall wee see that the moouer deserteth the moueable as soone as he hath giuen the blow wee are att a stand and know not where to seeke for that which afterwardes maketh it flye for motion being a transient not a permanent thing as soone as the cause ceaseth that begott it in that very point it must be att an end and as long as the motion continueth there must be some permanent cause to make it do so so that as soone as the rackett or bowstring goe backe and leaue the ball or arrow why should not they presently fall straight downe to the ground Aristotle and his followers haue attributed the cause hereof to the ayre but Galileo relisheth not this conception His arguments against it are as I remember to this tenor first ayre by reason of its rarity and diuisibility seemeth not apt to conserue motion next we see that light thinges are best carried by the ayre and it hath no power ouer weighty ones lastly it is euident that ayre taketh most hold of the broadest superficies and therefore an arrow would flye faster broadwayes then longwayes if this were true Neuerthelesse since euery effect must haue a proportionable cause from whence it immediately floweth and that a body must haue an other body to thrust it on as long as it mooueth lett vs examine what bodies do touch a moueable whilest it is in motion as the onely meanes to find an issue out of this difficulty for to haue recourse vnto a quality or impressed force for deliuerance out of this straight is a shift that will not serue the turne in this way of discourse we vse In this Philosophy no knott admitteth such a solution If then we enquire what body it is that immediately toucheth the ball or arrow whiles it flyeth we shall find that none other doth so but the ayre and the atomes in it after the stringes haue giuen their stroake and are parted from the missiue And although we haue Galileos authority and arguments to discourage vs from beleeuing that the ayre can worke this effect yet since there is no other body besides it left for vs to consider in this case lett vs att the least examine how the ayre behaueth it selfe after the stroake is giuen by the stringes First then it is euident that as soone
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
we may remember how in the close of the fourth we remitted a question concerning the existence of the Elements that is whether in any places of the world there were any pure Elements eyther in bulke or in little partes as being not ready to resolue it till we had declared the manner of working of bodies one vpon an other Here then will be a fitt place to determine that out of what we haue discoursed concerning the actions whereby bodies are made and corrupted for considering the vniuersall action of fire that runneth through all the bodies we haue commerce withall by reason of the sunnes influence into them and operation vpon them with his light and beames which reacheth farre and neere and looking vpon the effects which we haue shewed do follow thence it is manifest there can not be any great quantity of any body whatsoeuer in which fire is not intrinsecally mixed And on the other side we see that where fire is once mixed it is very hard to seperate it totally from thence Againe we see it is impossible that pure fire should be conserued without being adioyned to some other body both because of its violent natiuity still streaming forth with a great impetuosity as also because it is so easily ouercome by any obsident body when it is dilated And therefore we may safely conclude that no simple Element can consist in any great quantity in this course of nature which we liue in and take a suruay of Neyther doth it appeare to what purpose nature should haue placed any such storehouses of simples seeing she can make all needefull complexions by the dissolutions of mixed bodies into other mixed bodies sauouring of the nature of the Elements without needing their purity to beginne vpon But on the other side it is as euident that the Elements must remaine pure in euery compounded body in such extreme small partes as we vse to call atomes for if they did not the variety of bodies would be nothing else but so many degrees of rarity and density or so many pure homogeneall Elements and not bodies composed of heterogeneall partes and consequently would not be able to shew that variety of partes which we see in bodies nor could produce the complicated effects which proceede from them And accordingly we are sure that the least partes which our senses can arriue to discouer haue many varieties in them euen so much that a whole liuing creature whose organicall partes must needes be of exceeding different natures may be so litle as vnto our eyes to seeme indiuisible we not distinguishing any difference of partes in it without the helpe of a multiplying glasse as in the least kind of mites and in wormes picked out of Childrens handes we dayly experience So as it is euident that no sensible part can be vnmingled But then againe when we call to mind how we haue shewed that the qualities which we find in bodies do result out of the composition and mixtion of the Elements we must needes conclude that they must of necessity remaine in their owne essences in the mixed body And so out of the whole discourse determine that they are not there in any visible quantity but in those least atomes that are too subtile for our senses to discerne Which position we do not vnderstand so Metaphysically as to say that their substantiall formes remaine actually in the mixed body but onely that their accidentall qualities are found in the compound remitting that other question vnto Metaphysicians those spirituall Anatomistes to decide THE SEVENTEENTH CHAPTER Of Rarefaction and Condensation the two first motions of particular bodies OVr intention in this discourse concerning the natures and motions of bodies ayming no further then att the discouery of what is or may be done by corporeall Agents thereby to determine what is the worke of immateriall and spirituall substances it can not be expected att our handes that we should deliuer here an entire and complete body of naturall Philosophy But onely that we should take so much of it in our way as is needfull to carry vs with truth and euidence to our iourneys end It belongeth not then to vs to meddle with those sublime contemplations which search into the nature of the vast Vniuerse and that determine the vnity and limitation of it and that shew by what stringes and vpon what pinnes and wheeles and hinges the whole world moueth and that from thence do ascend vnto an awfull acknowledgment and humble admiration of the primary cause from whence and of which both the being of it and the beginning of the first motion and the continuance of all others doth proceed and depend Nor in deede would it be to the purpose for anyman to sayle in this Ocean and to beginne a new voyage of nauigation vpon it vnlesse he were assured he had ballast enough in his shippe to make her sinke deepe into the water and to carry her steadily through those vnruly waues and that he were furnished with skill and prouision sufficient to go through without eyther loosing his course by steering after a wrong compasse or being forced backe againe with shorte and obscure relations of discoueries since others that went out before him are returned with a large account to such as are able to vnderstand and summe it vp Which surely our learned countryman and my best and most honoured frend and to whom of all men liuing I am most obliged for to him I owe that litle which I know and what I haue and shall sett downe in all this discourse is but a few sparkes kindled by me att his greate fire hath both profoundly and acutely and in euery regard iudiciously performed in his Dialogues of the world Our taske then in a lower straine and more proportionate to so weake shoulders is to looke no further then among those bodies we conuerse withall Of which hauing declared by what course and engines nature gouerneth their common motions that are found euen in the Elements and from thence are deriued to all bodies composed of them we intend now to consider such motions as accompany diuers particular bodies and are much admired by whosoeuer vnderstandeth not the causes of them To beginne from the easiest and most connexed with the actions of the Elements the handsell of our labour will light vpon the motions of Rarefaction and Condensation as they are the passions of mixed bodies And first for Rarefaction we may remember how it proceedeth originally from fire and dependeth of heate as is declared in the former chapter and wheresoeuer we find Rarefaction we may be confident the body which suffereth it is not without fire working vpon it From hence we may gather that when the ayre imprisoned in a baloone or bladder swelleth against what cōtaineth it and stretcheth its case and seeketh to breake out this effect must proceed from fire or heate though we see not the fire working eyther within the very bowels of the ayre
as they partake more or lesse of this heate which is the Architect that mouldeth and frameth them all Vndoubtedly this can be none other but the hart whose motion and manner of working euidently appeareth in the twinckling of the first red spotte which is the first change in the egge and in the first matter of other liuing creatures Yet I do not intend to say that the hart is perfectly framed and completely made vp with all its partes and instruments before any other part be begunne to be made but only the most vertuous part and as it were the marrow of it which serueth as a shoppe or a hoat forge to mould spirits in from whence they are dispersed abroad to forme and nourish other partes that stand in neede of them to that effect The shootings or litle red stringes that streame out from it must surely be arteries through which the bloud issuing from the hart and there made and imbued with the nature of the seede doth runne till encountring with fitt matter it engrosseth it selfe into braine liuer lightes c. From the braine cheifely groweth the marrow and by consequent the bones containing it which seeme to be originally but the outward part of the marrow baked and hardened into a strong cruste by the great heate that is kept in as also the sinnewes which are the next principall bodies of strength after the bones The marrow being very hoat dryeth the bones and yet with its actuall moysture it humecteth and nourisheth them too in some sort The spirits that are sent from the braine do the like to the sinewes And lastly the arteries and veines by their bloud to cherish and bedew the flesh And thus the whole liuing creature is begunne framed and made vp THE FIVE AND TWENTIETH CHAPTER How a Plant or Animal cometh to that figure it hath BVt before we goe any further and search into the operations of this animall a wonderfull effect calleth our consideration vnto it which is how a plant or animal cometh by the figure it hath both in the whole and in euery part of it Aristotle after he had beaten his thoughts as farre as he could vpon this question pronunced that this effect could not possibly be wrought by the vertue of the first qualites but that it sprung from a more diuine origine And most of the contemplators of nature since him do seeme to agree that no cause can be rendered of it but that it is to be referred meerely to the specificall nature of the thing Neyther do we intend to derogate from eyther of these causes since that both diuine prouidence is eminently shewne in contriuing all circumstances necessary for this worke and likewise the first temperament that is in the seede must needes be the principall immediate cause of this admirable effect This latter then being supposed our labour and endeauour will be to vnfold as farre as so weake and dimme eyes can reach the excellency and exactnesse of Gods prouidence which can not be enough adored when it is reflected vpon and marked in the apt laying of adequate causes to produce such a figure out of such a mixture first layed From them so artificially ranged we shall see this miracle of nature to proceed and not from an immediate working of God or nature without conuenient and ordinary instruments to mediate and effect this configuration through the force and vertue of their owne particular natures Such a necessity to interest the cheife workeman att euery turne in particular effects would argue him of want of skill and prouidence in the first laying of the foundations of his designed machine he were an improuident clockemaker that should haue cast his worke so as when it were wound vp and going it would require the masters hand att euery houre to make the hammer strike vpon the bell Lett vs not then too familiarly and irreuerently ingage the Almighty Architect his immediate handy worke in euery particular effect of nature Tali non est dignus vindice nodus But lett vs take principles within our owne kenning and consider how a body hath of its owne nature three dimensions as Mathematicians vse to demonstrate and that the variety which we see of figures in bodies proceedeth out of the defect of some of these dimensions in proportion to the rest As for example that a thing be in the forme of a square tablette is for that the cause which gaue it length and breadth could not also giue it thickenesse in the same proportion for had it beene able to giue profundity as well as the other two it had made a cube instead of a tablette In like manner the forme of a lamine or very long square is occasioned by some accident which hindereth the cause from giuing breadth and thickenesse proportionable to the length And so other figures are made by reason that their causes are somewayes bound to giue more of some dimension to one part then to an other As for example when water falleth out of the skye it hath all the litle corners or extancies of its body grated of by the ayre as it rouleth and tumbleth downe in it so that it becometh round and continueth in that forme vntill that settling vpon some flatt body as grasse or a leafe it receiueth a litle plainenesse to the proportion of its weight mastering the continuity of it And therefore if the droppe be great vpon that plaine body it seemeth to be halfe a sphere or some lesse portion of one but if it be a litle droppe then the flatt part of it which is that next vnto the grasse is very litle and vndiscernable because it hath not weight enough to presse it much and spread it broad vpon the grasse and so the whole seemeth in a manner to be a sphere but if the externe causes had pressed vpon this droppe only broadwayes and thickewayes as when a turner maketh a round pillar of a square one then it would haue proued a cylinder nothing working vpon it to grate off any of its length but only the corners of the breadth and thickenesse of it And thus you see how the fundamentall figures vpon which all the rest are grounded are contriued by nature not by the worke of any particular Agent that immediately imprinteth a determinate figure into a particular body as though it wrought it there att once according to a foreconceiued designe or intelligent ayme of producing such a figure in such a body but by the concurrence of seuerall accidentall causes that do all of them ioyne in bringing the body they file and worke vpon into such a shape Only we had like to haue forgotten the reason and cause of the concaue figure in some partes of plantes which in the ordinary course of nature we shall find to grow from hence that a round outside being filled with some liquor which maketh it grow higher and higher it happeneth that the succeeding causes do contract this liquor and do
the glasse and each side of the opacous bodies shadow Wherefore in each of these lights or rather in each of their commixtions with darkenesse there must be red on the one side and blew on the other according to the course of light which we haue explicated And thus it falleth out agreable to the rule we haue giuen that blew cometh to be on that side of the opacous bodies shadow on which the glasse casteth red and red on that side of it on which the glasse casteth blew likewise when light going through a conuexe glasse maketh two cones the edges of the cone betwixt the glasse and the point of concurse will appeare red if the roome be darke enough and the edges of the further cone will appeare blew both for the reason giuen for in this case the point of concurse is the strong light betwixt the two cones of which that betwixt the glasse and the point is the stronger that beyond the point the weaker and for this very reason if an opacous body be put in the axis of thâ—se two cones both the sides of its picture will be red if it be held in the first cone which is next to the glasse and both will be blew if the body be situated in the further cone for both sides being equally situated to the course of the light within its owne cone there is nothing to vary the colours but only the strength and the weakenesse of the two lights of the cones on this side and on that side the point of concurse which point being in this case the strong and cleare light whereof we made generall mention in our precedent note the cone towardes the glasse and the illuminant is the stronger side and the cone from the glasse is the weaker In those cases where this reason is not concerned we shall see the victory carried in the question of colours by the shady side of the opacous body that is the blew colour will still appeare on that side of thâ— opacous bodies shadow that is furthest from the illuminant But where both causes do concurre and contrast for precedence there the course of the light carryeth it that is to say the red will be on that side of the opacous bodies shadow where it is thicker and darker and blew on the other side where the shadow is not so strong although the shadow be cast that way that the red appeareth as is to be seene when a slender body is placed betwixt the prisme and the reflectent body vpon which the light and colours are cast through the prisme and it is euident that this cause of the course of the shadow is in it selfe a weaker cause then the other of the course of light and must giue way vnto it whensoeuer they encounter as it can not be expected but that in all circumstances shadowes should to light because the colours which the glasse casteth in this case are much more faint and dusky then in the other For effects of this later cause we see that when an opacous body lyeth crosse the prisme whiles it standeth endwayes the red or blew colour will appeare on the vpper or lower side of its picture according as the illuminant is higher or lower theÌ„ the transuerse opacous body the blew euer keeping to that side of the picture that is furthest from the body and the illuminant that make it and the red the contrary likewise if an opacous body be placed out of the axis in eyther of the cones we haue explicated before the blew will appeare on that side of the picture which is furthest aduanced in the way that the shadow is cast and the red on the contrary and so if the opacous body be placed in the first cone beside the axis the red will appeare on that side of the picture in the basis of the second cone which is next to the circumference and the blew on that side which is next the axis but if it be placed on one side of the axis in the second cone then the blew will appeare on that side the picture which is next the circumference and the red on that side which is next the center of the basis of the cone There remayneth yet one difficulty of moment to be determined which is why when through a glasse two colours namely blew and red are cast from a candle vpon a paper or wall if you put your eye in the place of one of the colours that shineth vpon the wall and so that colour cometh to shine vpon your eye in such sort that an other man who looketh vpon it will see that colour plainely vpon your eye neuerthelesse you shall see the other colour in the glasse As for example if on your eye there shineth a red you shall see a blew in the glasse and if a blew shineth vpon your eye you shall see a red The reason hereof is that the colours which appeare in the glasse are of the nature of those luminous colours which we first explicated that arise from looking vpon white and blacke bordering together for a candle standing in the ayre is as it were a white situated betweene two blackes the circumstant dusky ayre hauing the nature of a blacke so then that side of the candle which is seene through the thicker part of the glasse appeareth red and that which is seene through the thinner appeareth blew in the same manner as when we looke through the glasse whereas the colours shine coÌ„trarywise vpon a paper or reflecting obiect as we haue already declared together with the reasons of both these appearances each fitted to its proper case of looking through the glasse vpon the luminous obiect serrownded with darkenesse in the one and of obseruing the effect wrought by the same luminous obiect in some medium or vpon some reflectent superficies in the other And to confirme this if a white paper be sett standing hollow before the glasse like halfe a hollow pillar whose flatt standeth edgewayes towardes the glasse so as both the edges may be seene through it the further edge will seeme blew and the neerer will be red and the like will happen if the paper be held in the free ayre parallele to the lower superficies of the glasse without any blacke carpet to limit both endes of it which serueth to make the colours the smarter so that in both cases the ayre serueth manifestly for a blacke in the first betweene the two white edges and in the second limiting the two white endes and by consequence the ayre about the candle must likewise serue for two blackes including the light candle betweene them Seuerall other delightfull experiments of luminous colours I might produce to confirme the groundes I haue layed for the nature and making of them But I conceiue that these I haue mentioned are aboundantly enough for the end I propose vnto my selfe therefore I will take my leaue of this supple and nice subiect referring
my Reader if he be curious to entertaine himselfe with a full variety of such shining wonders to our ingenious countryman and my worthy frend Mr. Hall who at my last being at Liege shewed me there most of the experiences I haue mentioned together with seuerall other very fine and remarkable curiosities concerning light which he promised me he would shortly publish in a worke that he had already cast and almost finished vpon that subiect and in it I doubt not but he will giue entire satisfaction to all the doubts and Problemes that may occurre in this subiect whereas my litle exercise formerly in making experiments of this kind and my lesse conueniency of attempting any now maketh me content my selfe with thus spinning of a course thridde froÌ„ wooll carded me by others that may runne through the whole doctrine of colours whose causes haue hitherto beene so much admired and that it will do so I am stroÌ„gly persuaded both because if I looke vpoÌ„ the causes which I haue assigned a priori me thinkes they appeare very agreeable to nature and to reason and if I apply them to the seuerall PhoenomeÌ„s which Mr. Hall shewed me and to as many others as I haue otherwise mett with I find they agree exactly with them and render a full account of them And thus you haue the whole nature of luminous colours resolued into the mixtion of light and darkenesse by the due ordering of which who hath skill therein may produce any middle colour he pleaseth as I my selfe haue seene the experience of infinite changes in such sort made so that it seemeth vnto me nothing can be more manifest then that luminous colours are generated in the way that is here deliuered Of which how that gentle and obedient Philosophy of Qualities readily obedient to what hard taske soeuer you assigne it will render a rationall account and what discreet vertue it will giue the same thinges to produce different colours and to make different appearances meerely by such nice changes of situation I do not well vnderstand but peraduenture the Patrones of it may say that euery such circumstance is a Conditio sine qua non and therewith no doubt their Auditors will be much the wiser in comprehending the particular nature of light and of the colours that haue their origine from it The Rainebow for whose sake most men handle this matter of luminous colours is generated in the first of the two wayes we haue deliuered for the production of such colours and hath its origine from refraction when the eye being at a conuenient distance from the refracting body looketh vpon it to discerne what appeareth in it The speculation of which may be found in that excellent discourse of Monsieur des Cartes which is the sixt of his Meteors where he hath with great acuratenesse deliuered a most ingenious doctrine of this mystery had not his bad chance of missing in a former principle as I conceiue somewhat obscured it For he there giueth the cause so neate and so iustly calculated to the appearances as no man can doubt but that he hath found out the true reason of this wonder of nature which hath perplexed so many great witts as may almost be seene with our very eyes when looking vpon the fresh deaw in a sunneshiny morning we may in due positions perceiue the raynebow colours not three yardes distant from vs in which we may distinguish euen single droppes with their effects But he hauing determined the nature of light to consist in motion and proceeding consequently he concludeth colours to be but certaine kindes of motion by which I feare it is impossible that any good account should be giuen of the experiences we see But what we haue already said in that point I conceiue is sufficient to giue the reader satisfaction therein and to secure him that the generation of the colours in the rainebow as well as all other coulours is likewise reduced to the mingling of light and darkenesse which is our principall intent to proue adding therevnto by way of aduertissement for others whose leisure may permitt them to make vse thereof that who shall ballance the proportions of luminous colours may peraduenture make himselfe a steppe to iudge of the natures of those bodies which really and constantly do weare like dyes for the figures of the least partes of such bodies ioyntly with the connexion or mingling of them with pores must of necessity be that which maketh them reflect light vnto our eyes in such proportions as the luminous colours of their tincture and semblance do For two thinges are to be considered in bodies in order to reflecting of light eyther the extancies and cauities of them or their hardenesse and softenesse As for the first the proportions of light mingled with darkenesse will be varied according as the extancies or the cauities do exceed and as each of them is great or small since cauities haue the nature of darknesse in respect of extancies as our moderne Astronomers do shew when they giue account of the face as some call it in the orbe of the moone Likewise in regard of soft or of resistent partes light will be reflected by them more or lesse strongly that is more or lesse mingled with darkenesse for whereas it reboundeth smartly backe if it striketh vpon a hard and a resistent body and accordingly 〈◊〉 â—hew it selfe in a bright colour it must of necessity not reflect at all 〈…〉 very fâ—ebly if it penetrateth into a body of much humidity or if â—â—â—oseth it selfe in the pores of it and that litle which cometh so weakely from it must consequently appeare of a dusky dye and these two being all the causes of the great variety of colours we see in bodies according to the quality of the body in which the reall colour appeareth it may easily be determined from which of them it proceedeth and then by the colour you may iudge of the composition and mixture of the rare and dense partes which by reflecting light begetteth it In fine out of all we haue hitherto said in this Chapter we may conclude the primary intent of our so long discourse which is that as well the senses of liuing creatures as the sensible qualities in bodies are made by the mixtion of rarity and density as well as the naturall qualities we spoke of in their place for it can not be denyed but that heate and cold and the other couples or payres which beate vpon our touch are the very same as we see in other bodies the qualities which moue our tast and smell are manifestly a kinne and ioyned with them lighâ— we haue concluded to be fire and of motion which affecteth our eare it is not disputable so that it is euident how all sensible qualities are as truly bodies as those other qualities which we call naturall To this we may adde that the proprieties of these sensible qualities are such as proceed euidently from rarity and
part of the braine where knowledge resideth but that it is indeed the driuing thither of solide materiall bodies exceeding litle ones that come from the obiects theÌ„selues Which position if it be true it followeth that these bodies must rebound from thence vpon other partes of the braine where at the length they find some vacant cell in which they keepe their rankes and files in great quiett and order all such sticking together and keeping company with one an other that entered in together and there they lye still and are at rest vntill they be stirred vp eyther by the naturall appetite which is the ordinary course of beastes or by chance or by the will of the man in whom they are vpon the occasions he meeteth with of searching into them Any of these three causes rayseth them vp and giueth them the motion that is proper to them which is the same with that whereby they came in at the first for as Galilaeus teacheth vs euery body hath a particular motion peculiarly proper to it when nothing diuerteth it and then they slide successiuely through the fantasie in the same manner as when they presented themselues to it the first time After which if it require them no more they returne gently to their quiett habitation in some other part of the braine from whence they were called and summoned by the fantasies messengers the spirits but if it haue longer vse of them and would view them better then once passing through permitteth then they are turned backe againe and lead a new ouer their course as often as is requisite like a horse that a rider paceth sundry times along by him that he sheweth him to whiles he is attentiue to marke euery part and motion in him But lett vs examine a litle more particularly how the causes we haue assigned do raise these bodies that rest in the memory and do bring them to the fantasie The middlemost of them namely chance needeth no looking into because the principles that gouerne it are vncertaine ones But the first and the last which are the appetite and the will haue a power which we will explicate hereafter of mouing the braine and the nerues depending of it conueniently and agreably to their disposition Out of which it followeth that the litle similitudes which are in the caues of the braine wheeling and swimming about almost in such sort as you see in the washing of currantes or of rise by the winding about and circular turning of the cookes hand diuers sortes of bodies do go their courses for a pretty while so that the most ordinary obiects can not choose but present themselues quickely because there are many of them and are euery where scattered about but others that are fewer are longer ere they come in view much like as in a paire of beades that containing more litle ones then great ones if you plucke to you the string they all hang vpon you shall meete with many more of one sort then of the other Now as soone as the braine hath lighted on any of those it seeketh for it putteth as it were a stoppe vpon the motion of that or at the least it moueth it so that it goeth not farre away and is reuocable at will and seemeth like a baite to draw into the fantasie others belonging vnto the same thing eyther through similitude of nature or by their connexion in the impression and by this meanes hindereth other obiects not pertinent to the worke the fansie hath in hand from offering themselues vnseasonably in the multitudes that otherwise they would do But if the fansie should haue mistaken one obiect for an other by reason of some resemblance they haue betweene themselues then it shaketh againe the liquid medium they all floate in and rooseth euery species luâ—king in remotest corners and runneth ouer the whole beaderoule of them and continueth this inquisition and motion till eyther it be satisfyed with retriuing at length what it required or that it be growne weary with tossing about the multitude of litle inhabitants in its numerous empire and so giueth ouer the search vnwillingly and displeasedly Now that these thinges be as we haue declared will appeare out of the following considerations first we see that thinges of quite different natures if they come in together are remembred together vpon which principle the whole art of memory dependeth such thinges can not any way be comprised vnder certaine heades nor be linked together by order and consequence or by any resemblance to one an other and therefore all their connexion must be that as they came in together into the fantasie so they remaine together in the same place in the memory and their first coupling must proceed from the action that bound them together in driuing them in together Next we may obserue that when a man seeketh and tumbleth in his memory for any thing he would retriue he hath first some common and confused notion of it and sometimes he hath a kind of flasking or fadeing likenesse of it much what as when in striuing ro remember a name men vse to say it is at their tongues end and this sheweth that he attracteth those thinges he desireth and hath vse of by the likenesse of something belonging to them In like manner when hunger maketh one think of meat or thirst maketh one dreame of drinke or in other such occasions wherein the naturall appetite stirreth obiects in the memory and bringeth theÌ„ to the fantasie it is manifest that the spirits informing the braine of the defect and paine which seuerall partes of the body do endure for want of their due nourishment it giueth a motion to the hart which sendeth other spirits vp to supply the braine for what seruice it will order them by which the braine being fortifyed it followeth the pursuite of what the liuing creature is in want of vntill the distempered partes be reduced into their due state by a more solide enioying of it Now why obiects that are drawne out of the memory do vse to appeare in the fantasie with all the same circumstances which accompanyed them at the time when the sense did send them thither as when in the remembrance of a frend we consider him in some place and at a certaine time and doing some determinate action the reason is that the same body being in the same medium must necessarily haue the same kind of motion and so consequently must make the same impression vpon the same subiect The medium which these bodies moue in that is the memory is a liquid vaporous substance in which they floate and swimme at liberty Now in such a kind of medium all the bodies that are of one nature will easily gather together if nothing disturbe them for as when a tuned lute string is strucken that string by communicating a determinate species of vibration to the ayre round about it shaketh other stringes within the compasse of the moued ayre not all
the name of Feare and the other that carrieth one to the pursuite of the obiect we call Hope Anger or Audaciâ—y is mixed of both these for it seeketh to auoyde an euill by embracing and ouercoming it and proceedeth out of aboundance of spirits Now if the proportion of spirits sent from the hart be too great for the braine it hindereth or peruerteth the due operation both in man and beast All which it will not be amisse to open a litle more particularly and first why painefull or displeasing obiects do contract the spirits and gratefull ones do contrary wise dilate them It is because the good of the hart consisteth in life that is in heate and moysture and it is the nature of heate to dilate it selfe in moysture whereas cold and drie thinges do contract the bodies they worke vpon and such are enemyes to the nature of men and beasts and accordingly experience as well as reason teacheth vs that all obiects which be naturally good are such as be hoat and moyst in the due proportion to the creature that is affected and pleased with them Now the liuing creature being composed of the same principles as the world round about him is and the hart being an abridgement of the whole sensible creature and being moreouer full of bloud and that very hoat it cometh to passe that if any of these little extracts of the outward world do arriue to the hoat bloud about the hart it worketh in this bloud such like an effect as we see a droppe of water falling into a glasse of wine which is presently dispersed into a competent compasse of the wine so that any little obiect must needes make a notable motion in the bloud about the hart This motion according to the nature of the obiect will be eyther conformable or contrary vnlesse it be so little a one as no effect will follow of it and then it is of that kind which aboue we called indifferent If the ensuing effect be connaturall to the hart there riseth a motion of a certaine fume about the hart which motion we call pleasure and it neuer fayleth of accompanying all those motions which are good as Ioy Loue Hope and the like but if the motion be displeasing there is likewise a common sense of a heauynesse about the hart which we call griefe and it is common to sorrow feare hate and the like Now it is manifest by experience that thâ—se motions are all of them different ones and do strike against diuers of those partes of our body which encompasse the hart out of which striking followeth that the spirits sent from the hart do affect the braine diuersly and are by it conueyed into diuers nerues and so do sett diuers members in action Whence followeth that certaine members are generally moued vpon the motion of such a passion in the hart especially in beaste â—ho haue a more determinate course of working then man hath and if â—ometimes we see variety euen in beasts vpon knowledge of the circumstances we may easily guesse at the causes of that variety the particularities of all which motions we remitt to Physitians and to Anatomistes aduertising only that the fume of pleasure and the heauinesse of griefe do plainely shew that the first motions do participate of dilatation and the latter of compression Thus you see how by the senses a liuing creature becometh iudge of what is good and of what is bad for him which operation is performed more perfectly in beasts and especially in those who liue in the free ayre remote from humane conuersation for their senses are fresh and vntaynted as nature made them then in men Yet without doubt nature hath beene as fauourable in this particular to men as vnto them were it not that with disorder and excesse we corrupt and oppresse our senses as appeareth euidently by the story we haue recorded of Iohn of Liege as also by the ordinary practise of some Hermites in the diserts who by their tast or smell would presently be informed whether the herbes and rootes and fruits thâ—y mett withall were good or hurtfull for them though they neuer before had had triall of them Of which excellency of the senses there remaineth in vs only some dimme sparkes in those qualities which we call sympathies and antipathies whereof the reasons are plaine out of our late discourse and are nothing elâ—e but a conformity or opposition of a liuing creature by some indiuiduall property of it vnto some body without it in such sort as its conformity or opposition vnto thinges by its specificall qualities is termed naturall or against nature But of this we shall discourse more at large hereafter Thus it appeareth how the senses are seated in vs principally for the end of mouing vs to or from obiects that are good for vs or hurtfull to vs. But though our Reader be content to allow this intent of nature in our three inferiour senses yet he may peraduenture not be satisfyed how the two more noble ones the hearing and the seeing do cause such motions to or from obiects as are requisite to be in liuing creatures for the preseruation of them for may he say how can a man by only seeing an obiect or by hearing the sound of it tell what qualities it is embued withall Or what motion of liking or disliking can be caused in his hart by his meere receiuing the visible species of an obiect at his eyes or by his eares hearing some noyse it maketh And if there be no such motion there what should occasion him to prosecute or auoyd that obiect When he tasteth or smelleth or toucheth a thing he findeth it sweet or bitter or stincking or hoat or cold and is therewith eyther pleased or displeased but when he only seeth or heareth it what liking or disliking can he haue of it in order to the preseruation of his nature The solution of this difficulty may in part appeare out of what we haue already said But for the most part the obiects of thâ—se two nobler senses dâ—â—moue vs by being ioyned in the memory with some other thing that did eyther please or displease some of the other three senses And from thence it is that the motion of going to embrace the obiect or â—uersion from it doth immediately proceed as when a dogg seeth a man that vseth to giue him meate the species of the man coming into his fansie calleth out of his memory the others which are of the same nature and are former participations of that man as well as this fâ—esh one is but these are ioyned with specieses of meate because at other times they did vse to come in together and therefore the meate being a good vnto him and causing him in the manner we haue said to moue towardes it it will follow that the dogg will presently moue towardes that man and expresse a contentednesse in being with him And this is the ground of all assuefaction in beasts and
they are Lett vs then in the next place consider what will follow in the rest of the body out of these varieties of passions once raysed in the hart and sent into the braine It is euidēt that according to the nature and quality of these motions the hart must needes in euery one of them voyde out of it selfe into the arteries a greater or lesser quantity of bloud and that in diuers fashions and the arteries which lye fittest to receiue these suddaine egestions of bloud are those which goe into the braine whose course being directly vpwardes we can not doubt but that it is the hoatest and subtilest part of the bloud and the fullest of spirits that flyeth that way These spirits then running a lōg and perplexed iourney vp and downe in the braine by various meanders and anfractuosities are there mingled with the humide steame of the braine it selfe and are therewith cooled and do come at the last to smoake at liberty in the hollow ventricles of the braine by reeking out of the little arteriall branches that do weaue the plexus choroides or nette we spoke of ere while and they being now growne heauy do fall by their naturall course into that part or processe of the braine which is called medulla spinalis or the marrow of the backe bone which being all besett by the nerues that runne through the body it can not happen otherwise but that these thickened and descending spirits must eyther fall themselues into those nerues or else presse into them other spirits which are before them that without such new force to driue them violently forwardes would haue slided downe more leisurely Now this motion being downewardes and meeting with no obstacle till it arriue vnto its vtmost periode that way the lowest nerues are those which naturally do feele the communication of these spirits first But it is true if the flowing tide of them be great and plentifull all the other nerues will also be so suddainely filled vpon the filling of the lowermost that the succession of their swellings will hardly be perceptible as a suddaine and violent inundation of water seemeth to rise on the sides of the channell as it doth at the milldamme though reason assureth vs it must beginne there because there it is first stopped On the contrary side if the spirits be few they may be in such a proportion as to fill only the lower nerues and to cōmunicate little of thēselues to any of the others And this is the case in the passion of feare which being stored with fewer spirits thē any other passiō that causeth a motiō in the body it moueth the legges most and so carryeth the animal that is affrayd with violence from the obiect that affrighteth him Although in truth it is a faint hope of escaping mingled with feare which begetteth this motion for when feare is single and at its height it stoppeth all motion by contracting the spirits and thence is called stupor as well as griefe for the same reason and accordingly we see extreme cowardes in the extremity of their feare haue not the courage to runne away no more then to defend or helpe themselues by any other motions But if there be more aboundance of spirits then the vpper partes are also moued as well as the legges whose motion contributeth to defense but the braine it selfe and the senses which are in the head being the first in the course of this flood of spirits that is sent from the hart to the head it is impossible but that some part of them should be pressed into the nerues of those senses and so will make the animal vigilant and attentiue to the cause of its feare or griefe But if the feare be so great that it contracteth all the spirits and quite hindereth their motion as in the case we touched aboue then it leaueth also the nerues of the senses destitute of spirits and so by too strong apprehension of a danger the animall neyther seeth nor apprehendeth it but as easily precipitateth it selfe into it as it happeneth to auoyde it being meerely gouerned by chance and may peraduenture seeme valiant through extremity of feare And thus you see in common how all the naturall operations of the body do follow by naturall consequence out of the passions of the mind without needing to attribute discourse or reason eyther to men or beastes to performe them Although at the first sight some of them may appeare vnto those that looke not into their principles and true causes to flow from a source of intelligence whereas it is euident by what wee haue layed open they all proceed from the due ranging and ordering of quantitatiue partes so or so proportioned by rarity and density And there is no doubt but who would follow this search deepely might certainly retriue the reasons of all those externall motions which wee see vse to accompany the seuerall passions in men and Beastes But for our intent wee haue said enough to shew by what kind or order and course of nature they may be effected without confining our selues ouer scrupulously to euery circumstance that we haue touched and to giue a hinte whereby others that will make this inquiry their taske may compile an intire and well grounded and intelligible doctrine of this matter Only we will adde one aduertissement more which is that these externall motions caused by passion are of two kindes for some of them are as it were the beginnings of the actions which nature intendeth to haue follow out of the passions that cause them but others are only bare signes of the passions that produce them and are made by the cōnexion of partes vnnecessary for the maine action that is to follow out of the passion with other partes that by the passion are necessarily moued as for example when an hungry mans mouth watereth at the sight of good meate it is a kind of beginning of eating or of preparation for eating for when we eate nature draweth a moysture into our mouth to humectate our meate and to conuey the tast of it into the nerues of the tongue which are to make report of it vnto the braine but when we laugh the motion of our face aymeth at no further end and followeth only by the connexion of those muscles which draw the face in such a sort vnto some inward partes that are moued by the passion out of which laughing proceedeth But we must not leaue this subiect without some mention of the diaphragma into which the other branch of those nerues that are called of the sixth coniugation doth come for the first branch we haue said goeth into the hart and carryeth thither the obiects that come into the braine and this we shall find carryeth backe to the braine the passion or motion which by the obiect is raysed in the hart Concerning this part of our body you are to note that it is a muscolous membrane which in the middle of it hath a
do cause a swelling or a contraction of it against this or that part doth stoppe and hinder the the entrance of the spirits into some sinewes and doth open others and driueth the spirits into them so as in the end by a result of a chaine of swellinges and contractions of seuerall partes successiuely one against an other the due motions of prosecution or auersion are brought about As for example an obiect that affecteth the hart with liking by dilating the spirits about the hart sendeth some into the optâ—ke nerues and maketh the liuing creature turne his eye towardes it and keepe it steady vpon what he desireth as contrariwise if he dislike and feare it he naturally turneth his eye and head from it Now of this motion of the eye and head may depend the running to the thing in one case and the running from it in the other for the turning of the necke one way may open a passage for the spirits into those sinewes which carry the rest of the body towardes the obiect and the turning of it to the other side may open other sinewes which shall worke a contrary effect and carry the animal from the obiect and the mouing of those sinewes which at the first do turne the necke doth proceed from the quality and number of the spirits that ascend from the hart and from the region of the hart from whence they are sent according to the variety whereof there are diuers sinewes fitted to receiue them To make vp which discourse we may call to mind what we haue said a litle aboue concerning the motions caused in the externall partes of the body by passion mouing within as when feare mingled with hope giueth a motion to the legges anger to the armes and handes and all the rest of the body as well as to the legges and all of them an attention in the outward senses which neuerthelesse peruerteth euery one of their functions if the passion be in extremity And then surely we may satisfy our selues that eyther this or some way like it which I leaue vnto the curious in Anatomy to settle with exactenesse for it is enough for my intent to shew in grosse how these operations may be done without calling in some incomprehensible qualities to our ayde is the course of nature in motions where no other cause interueneth besides the obiect working vpon the sense which all the while it doth it is the office of the eye of fantasy or of common sense to lye euer open still watching to obserue what warninges the outward senses do send vnto him that accordingly he may direct and change the motions of the hart and of the whole body But if the obiect do make violent impressions vpon the sense and the hart being then vehemently moued do there vpon send abouÌ„dance of spirits vp to the braine this multitude of spirits thronging vpon the common sense oppresseth it as we haue already said in such sort that the notice which the sense giueth of particular circumstances can not preuayle to any effect in the braine and thus by the misguidance of the hart the worke of nature is disordered which when it happeneth we expresse in short by saying that passion blindeth the creature in whom such violent and disorderly motions haue course for passion is nothing else but a motion of the bloud and spirits about the hart and is the preparation or beginning of the animals working as we haue aboue particularly displayed And thus you see in common how the circuite is made from the obiect to the sense and from it by the common sense and fantasy to the hart and from the hart backe againe to the braine which then setteth on worke those organes or partes the animal is to make vse of in that occasion and they eyther bring him to or carry him from the obiect that at the first caused all this motion and in the end becometh the periode of it THE SIX AND THERTIETH CHAPTER Of some actions of beastes that seeme to be formall actes of reason as doubting resoluing inuenting IN the last Chapter the foundations are layed and the way is opened for the discouering how all operations which proceed from nature and passion are performed among liuing creatures and therefore I conceiue I haue thereby sufficiently complyed with the obligation of my intention which is but to expresse and shew in common how all the actions of sensible bodies may be reduced to locall motion and to materiall application of one boy vnto an other in a like manner though in a different degree as those motions which we see in liueliest bodies Yet because among such animals as passe for irrationall there happen some operations of so admirable a straine as resemble very much the highest effects which proceed from a man I thinke it not amisse to giue some further light by extending my discourse to some more particulars then hitherto I haue done whereby the course and way how they are performed may be more clearely and easily looked into and the rather because I haue mette with some men who eyther wanting patience to bestow on thoughts of this kind so much time as is necessary for the due scanning of them or else through a promptitude of nature passing swiftly from the effect they looke vpon in grosse to the most obuious seeming cause do suddainely and strongly resolue that beastes vse discourse vpon occasions and are endewed with reason This I intend not to doe quite in particular for that were to write the history of euery particular animal but will content my selfe with touching the causes in common yet in such sort that the indifferent Reader may be satisfyed of a possibility that these effects may proceed from materiall causes and that I haue poynted out the way to those who are more curious and haue the patience and leisure to obserue diligently what passeth among beastes how they may trace these effects from steppe to steppe vntill at length they discouer their true causes To beginne then I conceiue we may reduce all those actions of beastes which seeme admirable and aboue the reach of an irrationall animal vnto three or foure seuerall heades The first may be of such as seeme to be the very practise of reason as doubting resoluing inuenting and the like The next shall be of such as by docility or practise beastes do oftentimes arriue vnto In the third place we will consider certaine continuate actions of a long tract of time so orderly performed by them as that discourse and rationall knowledge seeme clearely to shine through them And lastly we will cast our eye vpon some others which seeme to be euen aboue the reason that is in man himselfe as the knowing of thinges which the sense neuer had impression of before a prescience of future euents prouidences and the like As for the first the doubting of beasts and their long wauering sometimes betweene obiects that draw them seuerall wayes and at the
nestes and in doing such other actions as may be compared to the strickings of the clocke and the ringing of the allarum at due times And as that king of China vpon his first seeing a watch thought it a liuing a iuditious creature because it moued so regularly of it selfe and beleeued it to be dead when it was runne out till the opening of it and the winding it vp discouered vnto him the artifice of it so any man may be excused that looking vpon these strange actions and this admirable oeconomy of some liuing creatures should beleeue them endewed with reason vntill he haue well reflected vpon euery particular circumstance of their nature and operations for then he will discerne how these are but materiall instruments of a rationall Agent working by them from whose orderly prescriptions they haue not power to swarue in the least circumstance that is Euery one of which considered singly by it selfe hath a face of no more difficulty then that for example an ingenier should so order his matters that a mine should be ready to play exactly at such an houre by leauing such a proportion of kindled match hanging out of one of the barrels of pouder whiles in the meane time he eyther sleepeth or attendeth to something else And when you haue once gayned thus much of your selfe to grâ—ee vnto an orderly course and generation of any single effect by the power of a materiall cause working it raise but your discourse a straine higher and looke with reuerence and duty vpon the immensity of that prouident Architect out of whose handes these masterpieces issue and vnto whom it is as easy to make a chaine of causes of a thousand or of a million of linkes as to make one linke alone and then you will no longer sticke at allowing the whole oeconomy of those actions to be nothing else but a production of materiall effects by a due ranging and ordering of materiall causes But lett vs returne to our theame as we see that milke coming into the brestes of liuebearing female creatures when thâ—y grow wery bigge heateth and maketh them seeke the mouthes of their yong ones to disburthen and coole them so the carriage and biggenesse of the egges heateth exceedingly the brestes and bodies of the birdes and this causeth them to be still rubbing of their brestes against the sides of their nestes where vnto their vnwieldinesse then confineth them very much and with their beakes to be still picking their feathers which being then apt to fall off and me we as we see the haire of women with childe is apt to shedde it happeneth that by then they are ready to lay their egges they haue a soft bed of their owne feathers made in their nestes ouer their courser mattrasse of strawes they first brought thither and then the egges powerfull attracting of the annoying heate from the hennes brest whose imbibing of the warmeth and stonelike shell can not choose but coole her much inuiteth her to sitt constantly vpon them vntill sitting hatcheth them and it is euideÌ„t that this sitting must proceed from their temper at that time or from some other immediate cause which worketh that effect and not from a iudgement that doth it for a remote end for housewifes tell vs that at such a season their hennes will be sitting in euery conuenient place they come vnto as though they had egges to hatch when neuer a one is vnder them so as it seemeth that at such time there is some inconuenience in their bodies which by sitting is eased When the chickens are hatched what woÌ„der is it if the litle crying of tender creatures of a like nature and laÌ„guage with their daÌ„mes do moue those affectioÌ„s or passions in her bosome which causeth her to feede theÌ„ and to defend and breede them till they be able to shift for themselues For all this there needeth no discourse or reason but only the motion of the bloud about the hart which we haue determined to be passioÌ„ stirred by the yong ones chirpinges in such sort as may carry them vnto those actions which by nature the supreme intellect are ordered for their preseruation Wherein the birdes as we haue already said are but passiue instruments and know not why they do those actions but do them they must whensoeuer such and such obiects which infaillibly woâ—ke in their due times do make such and such impressions vpon their fantasies like the allarum that necessarilly striketh when the hand of the dyall cometh to such a point or the gunnepouder that necessarily maketh a ruine and breach in the wall when the burning of the match reacheth to it Now this loue in the damme growing by litle and litle wearisome and troublesome to her and at last fading quite away and she not being able to supply their encreased needes which they grow euery day stronger to prouide for of themselues the straight commerce beginneth to dye on both sides and by these degrees the damme leaueth her yong ones to their owne conduct And thus you see how this long series of actions may haue orderly causes made and chained together by him that knew what was fitting for the worke he went about Of which though it is likely I haue missed of the right ones as it can not choose but happen in all disquisitions where one is the first to breake the yce and is so slenderly informed of the particular circumstances of the matter in question as I professe to be in this yet I conceiue this discourse doth plainely shew that he who hath done more then we are able to comprehend and vnderstand may haue sett causes sufficient for all these effects in a better order and in compleater rankes then those which we haue here expressed and yet in them so coursely hewed out appeareth a possibility of hauing the worke done by corporeall agents Surely it were very well worth the while for some curious and iuditious person to obserue carefully and often the seuerall steppes of nature in this progresse for I am strongly persuaded that by such industry we might in time arriue to very particular knowledge of the immediate and precise causes that worke all these effects And I coÌ„ceiue that such obseruation needeth not be very troublesome as not requiring any great variety of creatures to institute it vpon for by maâ—king carefully all that passeth among our homebred hennes I beleeue it were easy to guesse very neerely at all the rest THE EIGHT AND THERTIETH CHAPTER Of prescience of future euentes prouidencies the knowing of thinges neuer seene bâ—fore and such other actions obserued in some liuing creatures which seeme to be euen aboue the reason that is in man himselfe THe fourth and last kind of actions which we may with astonishment obserue among beastes I conceiue will auayle litle to inferre out of them that the creatures which do them are endewed with reason and vnderstanding for such they are as if we should admitt that yet we
tender skinne of it the bloud in some measure piercing the skinne and not returning wholy into its naturall course which effect is not permanent in the mother because her skinne being harder doth not receiue the bloud into it but sendeth it backe againe without receiuing a tincture from it Farre more easy is it to discouer the secret cause of many antipathies or sympathies which are seene in children and endure with them the greatest part if not the whole terme of their life without any apparent ground for them as some do not loue cheese others garlike others duckes others diuers other kindes of meate which their parents loued well and yet in token that this auersion is naturall vnto them and not arising from some dislike accidentally taken and imprinted in their fantasy they will be much harmed if they chance to eate any such meate though by the much disguising it they neither know nor so much as suspect they haue done so The story of the Lady HeÌ„nage who was of the bedchamber to the late Queene Elizabeth that had her checke blistered by laying a rose vpon it whiles she was a sleepe to try if her antipathy against that flower were so great as she vsed to pretend is famous in the Court of England A kinsman of mine whiles he was a childe had like to haue dyed of drought before his nurse came to vnderstand that he had an antipathy against beere or wine vntill the tender nature in him before he could speake taught him to make earnest signes for water that by accident he saw the greedy drinking of which cured presently his long languishing and pining sickenesse and such examples are very frequent The cause of these effects many times is that their mothers vpon their first suppression of their vsuall euacuations by reason of their being with child toke some strong dislike to such thinges their stomackes being then oppressed by vnnaturall humours which ouerflow their bodies vpon such retentions and which make them oftentimes sicke and prone to vomiting especially in the mornings whiles they are fasting and sometimes to desire earnestly which they call longing to feede vpon some vnwholesome as well as some particular wholesome thinges and otherwhiles to take auersion against meates which at other seasons they affected well Now the child being nourished by the so imbued bloud of the mother no wonder if it taketh affections or dislikes conformable to those which at that present raigne in the mother the which for the most part vsed to be purged away or are ouerwhelmed by the mastering qualities of better aliments succeding but if by some mischance they become too much grafted in the childes stomacke or in some other part through which the masse of bloud must passe then the child getteth an auersion from those meates and we often see that people retaine a strong conuersion to such meates or drinkes as their mothers affected much or longed for whiles they bred child of them And thus we will leaue this particular adding only one note why there are more persoÌ„s generally who haue antipathy against cheese theÌ„ against any one sort of meate besides whatsoeuer A principal reason of which symptome where the precedent one hath not place I coÌ„ceiue to be that their nurses proued with child whiles they gaue them sucke for I haue by experience found it to haue beene so in as many as I haue made inquiry into And it is very conformable to reason for the nurses milke curdling in her brest vpon her breeding of child and becoming very offensiue to the childes tender stomacke whose being sicke obligeth the parents to change the nurse though peraduenture they know nothing of the true reason that maketh her milke vnnaturall he hath a dislike of cheese which is strong curdled milke euer after settled in him as people that haue once surfeted violently of any meate seldome arriue to brooke it againe Now as concerning those animals who lay vp in store for winter and seeme therein to exercise a rationall prouidence who seeth not that it is the same humour which moueth rich misers to heape vp wealth euen at their last gaspe when they haue no child nor frend to giue it to nor think of making any body their heires Which actions because they haue no reason in them are to be imputed to the passion or motion of the materiall appetite In the doing of them these steppes may be obserued first the obiect presenting it selfe to the eye prouoketh loue and desire of it especially if it be ioyned with the memoâ—y of former want then this desire stirreth vp the animal after he hath fedde himselfe to gather into the place of his chiefe residence as much of that desired obiect as he meeteth withall and whensoeuer his hunger returning bringeth backe into his fantasy the memory of his meate it being ioyned with the memory of that place if he be absent from it he presently repaireth thither for reliefe of what presseth him and thus dogges whâ—n they are hungry do rake for bones they had hidden when â—heir bellies were full Now if this foode gathered by such prouidence which is nothing else but the conformity of it working vpon him by his sense and layâ—d vp in the place where the owner of it resideth as the corne is which the auntes gather in summer be easily portable he will carry it abroad wiâ—h him the first time he stirreth after a long keeping in for then nothing worketh so powerfully in his fantasy as his store and he will not easily part from it though other circumstances inuite him abroad From hence it proceedeth that when a faire day cometh after long foule weather the auntes who all that while kept close in their dennes with their corne lying by them do then come abroad into the sunne and do carry their graine along with them or peraduenture it happeneth because the precedent wett weather hath made it grow hoat or musty or otherwise offensiue within and therefore they carry it out as soone as themselues dare peepe abroad which is when the faire weather and heate of the day inuiteth them out into the open ayre and before night that they returne into their holes the offensiue vapours of the corne are exhaled and dryed vp and moue their fantasies no longer to auersion wherevpon they carry it backe againe hauing then nothing but their long contracted loue vnto it to worke vpon them The like whereof men doing by discourse to ayre their corne and to keepe it sweete and the same effect following herein they will presently haue it that this is done by the auntes for the same reason and by designe Then the moysture of the earth swelling the graine and consequently making it beginne to shoote at the endes as we declared when we spoke of the generation of plantes and as we see in the moystening of corne to make malt of it those litle creatures finding that part of it more tender and iuicy then the
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
A to B is the proportion of CB to CA that is it goeth in the same time faster towardes D then it doth towardes M in the proportion which CB hath to CA. By which account the resistance it hath in the way towardes D must also be greater then the resistance it hath in the way towardes M in the proportion which CB hath to CA and therefore the more tardity must be in the way to D and not in the way to M and consequently the declination must be from Ewardes and to Mwardes For where there is most resistance that way likewise must the tardity be greatest and the declination must be from that way but which way the thickenesse to be passed in the same time is most that way the resistance is greatest and the thickenesse is clearely greater towardes E then towardes M therefore the resistance must be greatest towardes E and consequently the declination from the line BL must be towardes M and not towardes E. But the truth is that in his doctrine the ball would goe in a straight line as if there were no resistance vnlesse peraduenture towardes the contrary side of the cloth att which it goeth out into the free ayre for as the resistance of the cloth is greater in the way towardes D then in the way towardes M because it passeth a longer line in the same time as also it did formerly in the ayre so likewise is the force that mooueth it that way greater then the force which mooueth it the other And therefore the same proportions that were in the motion before it came to the resisting passage will remaine also in it att the least vntill coming neere the side att which it goeth out the resistance be weakned by the thinnenesse of the resistent there which because it must needes happen on the side that hath least thicknesse the ball must consequently turne the other way where it findeth greatest yielding and so att its getting out into the free ayre it will bend from the greater resistance in such manner as we haue said aboue Neither do the examples brought by Monsieur Des Cartes and others in maintenance of this doctrine any thing auayle them for when a canon bullett shott into a riuer hurteth the people on the other side it is not caused by refraction but by reflexion as Monsieur Des Cartes himselfe acknowledgeth and therefore hath no force to prooue any thing in refraction whose lawes are diuers from those of pure reflexion And the same answere serueth against the instance of a muskett bullett shott att a marke vnder water which perpetually lighteth higher then the marke though it be exactly iust aymed att For we knowing that it is the nature of water by sinking in one place to rise round about it must of necessity follow that the bullett which in entring hath pressed downe the first partes of the water hath withall thereby putt others further off in a motion of rising and therefore the bullet in its goeing on must meete with some water swelling vpwardes and must from it receiue a ply that way which can not faile of carrying it aboue the marke it was leuelled att And so we see this effect proceedeth from reflection or the bounding of the water and not from refraction Besides that it may iustly be suspected the shooter tooke his ayme too high by reason of the markes appearing in the water higher then in truth it is vnlesse such false ayming were duly preuented Neither is Monsieur Des Cartes his excuse to be admitted when he sayth that light goeth otherwise then a ball would do because that in a glasse or in water the etheriall substance which he supposeth to runne through all bodies is more efficaciously mooued then in ayre and that therefore light must go faster in the glasse then in the ayre and so turne on that side of the straight line which is contrary to the side that the ball taketh because the ball goeth not so swiftly For not to dispute of the verity of this proposition the effect he pretendeth is impossible for if the etheriall substance in the ayre before the glasse be slowly mooued the motion of which he calleth light it is impossible that the etheriall substance in the glasse or in the water should be more smartly mooued then it Well it may be lesse but without all doubt the impulse of the etheriall substance in the glasse can not be greater then its adequate cause which is the motion of the other partes that are in the ayre precedent to the glasse Againe after it is passed the glasse it should returne to be a straight line with the line that it made in the ayre precedent to the glasse seeing that the subsequent ayre must take off iust as much and no more as the glasse did adde the contrary whereof experience sheweth vs. Thirdly in this explication it would alwayes go one way in the ayre and an other way in the glasse whereas all experience testifyeth that in a glasse conuexe on both sides it still goeth in the ayre after its going out to the same side as it did in the glasse but more And the like happeneth in glasses on both sides concaue Wherefore it is euident that it is the superficies of the glasse that is the worker on both sides and not the substance of the ayre on the one side and of the glasse on the other And lastly his answere doth no wayes solue our obiection which prooueth that the resistance both wayes is proportionate to the force that mooueth and by consequence that the thing moued must go straight As we may imagine would happen if a bullett were shott sloaping through a greene mudde wall in which there were many round stickes so thinne sett that the bullett mighr passe with ease through them for as long as the bullett touched none of them which expresseth his case it would go straight but if it touched any of them which resembleth ours as by and by will appeare it would glance according to the quality of the touch and mooue from the sticke in an other line Some peraduenture may answere for Monsieur Des Cartes that this subtile body which he supposeth to runne through all thinges is stiffe and no wayes plyable But that is so repugnant to the nature of rarity and so many insuperable inconueniencies do follow out of it as I can not imagine he will owne it and therefore I will not spend any time in replying therevnto We must therefore seeke some other cause of the refraction of light which is made att the entrance of it into a diaphanous body Which is plainely as we said before because the ray striking against the inside of a body it can not penetrate turneth by reflexion towardes that side on which the illuminant standeth and if it findeth cleare passage through the whole resistent it followeth the course it first taketh if not then it is lost by many reflexions too and
fro And taking a body of concaue surfaces we shall according to this doctrine of ours find the causes of refraction iust contrary and accordingly experience likewise sheweth vs the effects to be so too And therefore since experience agreeth exactly with our rules we can not doubt but that the principles vpon which we goe are well layd But because crooked surfaces may haue many irregularities it will not be amisse to giue a rule by which all of them may be brought vnto a certainety And this it is that reflexions from crooked superficieses are equall to the reflexions that are made from such plaine superficieses as are tangents to the crooked ones in that point from whence the reflexions are made Which principall the Masters of Optikes do take out of a Mathematicall supposition of the vnity of the reflecting point in both the surfaces the crooked and the plaine But we take it out of the insensibility of the difference of so litle a part in the two different surfaces as serueth to reflect a ray of light for where the difference is insensible in the causes there likewise the difference is so litle in the effects as sense can not iudge of them which is as much as is requisite to our purpose Now seeing that in the Mathematicall supposition the point where the reflexion is made is indifferent to both the surfaces it followeth that it importeth not whether superficies you take to know the quality of reflexion by This principle then being settled that the reflexion must follow the nature of the tangent surfaces and it being prooued that in plaine surfaces it will happen in such sort as we haue explicated it followeth that in any crooked superficies of what figure soeuer the same also will happen Now seeing we haue formerly declared that refractions are but a certaine kind of reflexions what we haue said here of reflexions may be applyed to refractions But there remaineth yet vntouched one affection more of refractions which is that some diaphanous bodies do in their inward partes reflect more then others which is that which we call refraction as experience sheweth vs. Concerning which effect we are to consider that diaphanous bodies may in their composition haue two differences for some are composed of greater partes and greater pores others of lesser partes and lesser pores It is true there may be other combinations of pores and partes yet by these two the rest may be esteemed As for the first combination we see that because the pores are greater a greater multitude of partes of light may passe together through one pore and because the partes are greater likewise a greater multitude of rayes may reflect from the same part and may find the same passage quite throughout the diaphanous body On the contrary side in the second combination where both the pores and the partes of the diaphanous body are litle the light must be but litle that findeth the same passage Now that refraction is greater or lesser happeneth two wayes for it is eyther when one diaphanous body reflecteth light att more angles then an other and by consequence in a greater extent of the superficies or else when one body reflecteth light from the same point of incidence in a shorter line and in a greater angle then an other doth In both these wayes it is apparant that a body composed of greater partes and greater pores exceedeth bodies of the opposite kind for by reason that in the first kind more light may beate against one part a body in which that happeneth will make an appearance from a further part of its superficies whereas in a body of the other sort the light that beateth against one of the litle partes of it will be so litle as it will presently vanish Againe because in the first the part att the incidence is greater the surface from which the reflexion is made inwardes hath more of a plaine and straight superficies and consequently doth reflect att a greater angle then that whose superficies hath more of inclining But we must not passe from this question without looking a litle into the nature of those bodies in which refraction is made for if they as well as the immediate causes of refraction do likewise fauour vs it will not a litle aduance the certainety of our determination To this purpose we may call to mind how experience sheweth vs that great refractions are made in smoake and in mistes and in glasses and in thicke bodied waters and Monsieur Des Cartes addeth certaine oyles and spirits or strong waters Now most of these we see are composed of litle consistent bodies swimming in an other liquide body As is plaine in smoake and mistes for the litle bubbles which rise in the water before they gett out of it and that are smoake when they gett into the ayre do assure vs that smoake is nothing else but a company of litle round bodies swimming in the ayre and the round consistence of water vpon herbes leafes and twigges in a rynde or dew giueth vs also to vnderstand that a mist is likewise a company of litle round bodies that sometimes stand sometimes floate in the ayre as the wind driueth them Our very eyes beare wittnesse to vs that the thicker sort of waters are full of litle bodies which is the cause of their not being cleare As for glasse the blowing of it conuinceth that the litle dartes of fire which pierce it euery way do naturally in the melting of it conuert it into litle round hollow bodies which in their cooling must settle into partes of the like figure Then for crystall and other transparent stones which are found in cold places it can not be otherwise but that the nature of cold piercing into the maine body and contracting euery litle part in it selfe this contraction must needes leaue vacant pores betweene part and part And that such transparent stones as are made by heate haue the like effect and property may be iudged out of what we see in brickes and tiles which are left full of holes by the operation of the fire And I haue seene in bones that haue layne a long time in the sunne a multitude of sensible litle pores close to one an other as if they had beene formerly stucke all ouer with subtile sharpe needles as close as they could be thrust in by one other The Chymicall oyles and spirits which Monsieur Des Cartes speaketh of are likely to be of the same composition since that such vse to be extracted by violent fires for a violent fire is made by the coniunction of many rayes together and that must needes cause great pores in the body it worketh vpon and the sticking nature of these spirits is capable of conseruing them Out of all these obseruations it followeth that the bodies in which greatest refractions do happen are compounded as we haue said of great partes and great pores And therefore by onely taking light to be