in bulk but the small ones very hardly Next the smalness and well-working of the parts by means of the airs penetrating every dense one and sticking close to every one of them and consequently joyning them without any unevenness causes that there can be no ruggedness in it and therfore 't is glibb in like manner as we see plaister or starch become smooth when they are well wrought Then the humidity of it causes it to be catching and the shortness of every part makes that where it sticks it is not easily parted thence Now the rarity of air next to fire admits it to be of all the other Elements most easily brought to the height of fire by the operation of fire upon it And therfore oyls are the proper food of that Element And accordingly we see if a drop of oyl be spill'd upon a sheet of paper and the paper set on fire at a corner as the fire comes near the oyl the oyl will disperse and spread it self upon the paper to a broader compass then it had because the heat rarifies it and so in Oyl it self the fire rarifying the air makes it penetrate the earthy parts adjoynd to it more then it did and so subtilizes them till they be reduced to such a height as they are within the power of fire to communicate its own nature to them and thus it turns them into fire and carries them up in its flame But if fire be predominant over earth and air in a watry compound it makes the body so proportion'd to be subtile rare penetrative hot in operation light in weight and subject to burn Of this kind are all sorts of wines and distil'd Spirits commonly called strong waters or Aquavites in Latine Aquaeardentes These will lose their virtues meerly by remaining uncover'd in the air for fire doth not incorporate strongly with water but if it find means raises it self into the air As we see in the smoke of boyling water which is nothing else but little bodies of fire that entring into the water rarifie some parts of it but have no inclination to stay there and therefore as fast as they can get out fly away but the humide parts of the water which they have rarified being of a sticking nature joyn themselves to them and ascend in the air as high as the fiery atomes have strength to carry them which when it fails them that smoke falls down in a dew and so becomes water again as it was All which one may easily discern in a glasse-vessel of water set over the fire in which one may observe the fire come in at the bottome and presently swim up to the top like a little bubble and immediately rise from thence in smoke and that will at last convert it self into drops and settle upon some solid substance thereabouts Of these fiery spirits some are so subtile as of themselves they will vanish and leave no residue of a body behind them and Alchymists profess to make them so etherial and volatile that being pour'd out of a glass from some reasonable height they shall never reach the ground but before they come thither be so rarified by that little motion as they shall grow invisible like the air and dispersing themselves all about in it fill the chamber with the smell of that body which can no longer be seen The last excess in watery bodies must be of water it self which is when so little a proportion of any of the other is mingled with it as is hardly perceptible Out of this composition arise all those several sorts of juices or liquors we commonly call Waters which by their mixture with the other three Elements have peculiar properties beyond simple Elemental water The general quality whereof we shall not need any further to express because by what we have already said of water in common they are sufficiently known In our next survey we will take Earth for our ground to work upon as hitherto we have done water which if in any body it be in the utmost excess beyond all the other three then rocks and stones will grow out of it whose driness and hardness may assure us that Earth sways in their composition with the least allay that may be Nor doth their lightness in respect of some other earthy compositions impeach this resolution for that proceeds from the greatness and multiplicity of pores wherwith their driness causes them to aboundâ— and hinders not but that their real solid parts may be very heavy Now if we mingle a considerable proportion of water with earth so as to exceed the fire and air but still inferiour to the earth we shall poduce metals whose great weight with their ductility and malleability plainly tells us that the smallest of waters gross parts are the glew that holds the earthy dense ones together such weight belonging to earth and that easie changing of parts being most proper to water Quick-silver that is the general matter wherof all the metals are immediately composed gives us evidence hereof for fire works upon it with the same effect as upon water And the calcination of most of the metals proves that fire can easily part and consume the glew by which they were closed and held together which therfore must be rather of a watry then of an aiery substance Likewise the glibness of Mercury and of melted metals without catching or sticking to other substances gives us to understand that this great temper of a moist Element with earth is water and not air and that the watry parts are comprised and as it were shut up within the earthy ones for air catches and sticks notably to all things it touches and will not be imprisoned the divisibility of it being excceeding great though in never so short parts Now if air mingles it self with earth and be prodominant over water and fire it makes such an oily and fat soil as Husbandmen account their best mould which receiving a betterment from the Sun temperate heat assures us of the concourse of the aire for wherever such heat is air cannot fail of accompanying or being effected by it and the richest of such earth as pot-earth and marl will with much fire grow more compacted and stick closer together then it did as we see in baking them into pots or fine bricks Whereas if water were the glew between the dense parts fire would consume it and crumble them asunder as it doth in those bodies it calcines And excesse of fire will bring them to vitrification which still confirms that air abounds in them for it is the nature of air to stick so close where once it is kneaded in as it cannot be separated without extreme difficulty And to this purpose the viscuous holding together of the parts of glass when it is melted shews evidently that air abounds in vitrified bodies The last mixture we are to meddle with is of fire with earth in an over-ruling
which two never misses to reign whenever the water freezes and both of them argue great store of little earthy dry bodies abounding in them which sweeping over all those that ly in their way and course must of necessity be mixed with such as give them admittance which water doth very easily And accordingly we see that when in the freezing of water the Ice grows any thing deep it either shrinks about the borders or at least lies very loose so as we cannot doubt but there is a free passage more of such subtile bodies to get still to the water and freez it deeper To his second argument we ask How he knows that Ice quantity for quantity is lighter then water For though of a Spunge that is ful of water it be easie to know what the spunge weighs and what the water that was soaked into it because we can part the one of them from the other and keep each apart to examine their weights yet to do the like between Ice and water if Ice be throughout full of air as of necessity it must be we believe impossible And therfore it may be lighter in the bulk then water by reason of the great pores caus'd in it through the shrinking up of the parts of water together which pores must then necessarily be fill'd with air and yet every part by it self in which no air is be heavier then so much water And by this it appears that his last argument grounded upon the the swiming of Ice in water has no more force then if he would prove that an iron or earthen dish were lighter and consequently more rare then water because it swims upon it which is an effect of the airs being contain'd in the belly of it as it is in Ice not a sign of the metals being more rare then water Wheras on the contrary side the proof is positive and clear for us For it cannot be denied but the mingling of the water with other bodies more dense then it must of necessity make the compound also the water it self become more dense then it was alone And accordingly we see that Ice half thaw'd for then much of the air is driven out and the water begins to fill the pores wherin the air resided before sinks to the bottom as an Iron dish with holes in it wherby the water might get into it would do And besides we see that water is more Diaphanous then Ice and Ice more consistent then water Therfore I hope we shall be excused if in this particular we be of a contrary opinion to this great personage But to return to the thrid of our discourse The same that passes here before us passes also in the Sky with Snow Hail Rain Wind. Which that we may the better understand let us consider how Winds are made for they have a main influence into all the rest When the Sun by some particular occurrent raises great multitudes of Atoms from some one place and they either by the attraction of the Sun or some other occasion take their course a certain way this motion of those atoms we call a wind which according to the continuance of the matter from whence these atoms rise endures a longer or a shorter time and goes a farther or a shorter way like a river or rather like those eruptions of waters which in the Northern parts of England they call Gypsies which break out at uncertain times and upon uncertain causes and flow likewise with an uncertain duration So these winds being composed of bodies in a determinate proportion heavier then the air run their course from their height to the ground where they are supported as water is by the floor of its channel whiles they perform their carreer that is till they be wasted either by the drawing of the Sun or by their sticking and incorporating into grosser bodies Some of these winds according to the complexion of the body out of which they are extracted are dry as those which come from barren mountains cover'd with snow others are moist as those that come out of marrishy or watry places others have other qualities as of heat or cold of wholsomness or unwholsomness and the like partly from the source and partly from the bodies they are mingled within their way Such then being the nature and origine of wind if a cold one meet in the air with that moist body wherof otherwise rain would have been made it changes that moist body into Snow or into Hail if a dry wind meet with a wet body it makes it more dry and so hinders the rain that was likely to be but if the wet body overcome the dry wind it brings the wind down along with it as we see when a showre of rain allays a great wind And that all this is so experience will in some particulars instruct us as well as reason from whence the rest may be evidently infer'd For we see that those who in imitation of nature would convert water into Ice take snow or ice mingle it with some active dry body that may force the cold parts of the snow from it and then they set the water in some fit vessel in the way that those little bodies are to take which by that means entring into it strait incorporate themselves therewith and of a suden convert it into ice Which process you may easily try by mingling Salt Armoniacke with snow but much more powerfully by setting the snow over the fire whiles the glass of water to be congealed stands in it after the manner of an egg in salt And thus fire it self though it be the enemy destroyer of all cold is made the instrument of freezing And the same reason holds in the cooling of wine with snow or ice when after it has been a competent time in the snow they whose charge it is use to give the vessel that contains the wine three or four turns in the snow so to mingle through the whole body of the wine the cold receiv'd first but in the outward parts of it and by pressing too make that without to have a more forcible ingression But the whole doctrin of Meteors is so amply so ingeniously and so exactly perform'd by that never-enough-praised Gentleman Mounsir Des Cartes in his Meteorological discourses as I should wrong my self and my Reader if I dwell any longer upon this subject And whose Physical discourses had they been divulged before I had entred upon this work I am perswaded would have excused the greatest part of my pains in delivering the nature of bodies It were a fault to pass from treating of Condensation without noting so ordinary an effect of it as is the joyning together parts of the same body or of divers bodies In which we see for the most part that the solide bodies which are to be joyn'd together are first either heated or moistned that is they are rarified and then they are left to cold
refraction 6. An answer to the arguments brought in favour of Monsieur des Cartes his opinion 7. The true cause of refraction of light both at its entrance and at its going out from the refleing body 8. A general rule to know the nature of reflection and refractions in all sorts of surface 9. A body of greater parts and greater pores makes a greater refraction than one of lesser parts and lesser pores 10. A confirmation of the former doctrine out of the nature of bodies that refract light CHAP. XIV Of the composition qualities Generation of mixed Bodies 1. The connexion of this chapter with the rest and the Authours intent in it 2. That there is a least sise of bodies and that this least sise is found in fire 3. The first conjunction of parts is in bodies of least sise and it is made by the force of Quantity 4. The second sort of conjunction is compactedness in simple Elements and it proceeds from density 5. The third conjunction is of parts of different Elements and it proceeds from quantity and density together 6. The reason why liquid bodies do easily joyn together and dry ones difficultly 7. That no two hard bodies can touch one another immediately 8. How mixed bodies are framed in general 9. The cause of the several degrees of solidity in mixed bodies 10. The Rule whereto are reduced all the several 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 over the other two 13. Of those bodies where water being the basis air 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 excess 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 excess over the other three Elements 17. Of those bodies where earth is the basis water is the predominant element over the other two 18. Of those bodies where earth being the basis air 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 several combinations of the first qualities and are at last resolv'd into several degrees of rarity density 21. That in the Planets Stars there is a like variety of mixed bodies caused by light as here on earth 22. In what manner the Elements work on one another in the composition of mixed bodies and in particular fire which is the most active 23. A particular declaration touching the generation of Metals CHAP. XV. Of the Dissolution of Mixed Bodies 1. Why some bodies are brittle and others tough or apt to withstand outward violence the first instrument to dissolve mixed bodies 2. How outward violence doth work on the most compacted bodies 3. The several effects of fire the second and chiefest instrument to dissolve all compounded bodies 4. The reason why some bodies are not dissolved by fire 5. The reason why fire melteth gold but cannot consume it 6. Why Lead is easily consumed and calcinted by fire 7. Why and how some bodies are divided by fire into Spirits Waters Oyls Salts and Earth And what those parts are 8. How water the third instrument to dissolve bodies dissolvs calx into salt and so into terra damnata 9. How water mingled with salt becomes a most powerful Agent to dissolve other bodies 10. How putrefaction is caused CHAP. XVI An Explication of certain Maxims touching the operations and qualies of bodies and whether the Elements be found pure in any part of the world 1. What is the Sphere of activity in corporeal agents 2. The reason why no body can work in distance 3. An objection answer'd against the manner of explicating the former axiome 4. Of re-action and first in pure local motion that each Agent must suffer in acting and act in suffering 5. The former Doctrine applyed to other local motions design'd by particular names And that Suisseths argument is of no force against this way of doctrine 6. Why some notions do admit of intension and remission and others not 7. That in every part of our habitable world all the four elements are found pure in small atoms but not in any great bulk CHAP. XVII Of Rarefaction and Condensation the two first motions of Particular bodies 1. The Authours intent in this and the following chapters 2. That bodies may be rarified both by outward and inward heart and how this is perform'd 3. Of the great effects of Rarefaction 4. The first manner of condensation by heat 5. The second manner of condensation by cold 6. That Ice is not water rarified but condensed 7. How Wind Snow and Hail are made and wind by rain allaid 8. How parts of the same or divers bodies are joyn'd more strongly together by condensation 9. Vacuities cannot be the reason why water impregnated to the full with one kind of salt will notwithstanding receive more of another 10. The true reason of the former effect 11. The reason why bodies of the same nature do joyn more easily together than others CHAP. XVIII Of another motion belonging to Particular bodies called Attraction and of certain operations term'd Magical 1. What Attraction is and from whence it proceeds 2. The true sense of the Maxime that Nature abhors from vacuitys 3. The true reason of attraction 4. Water may be brought by the force of attraction to what height soever 5. The doctrine touching the attraction of water in Syphons 6. That the Syphon doth not prove water to weigh in its own orb 7. Concerning attraction caus'd by fire 8. Concerning attraction made by virture of hot bodies amulets c 9. The natural reason given for divers operations esteem'd by some to be magical CHAP. XIX Of three other motions belonging to particular bodies Filtration Restitution and Electrical attraction 1. What is Filtration and how it is effected 2. What causes the water in Filtration to ascend 3. Why the filter will not drop unless the label hang lower than the water 4. Of the motion of Restitution and why some bodies stand bent others not 5. Why some bodies return only in part to their natural figure others entirely 6. Concerning the nature of those bodies which shrink aand stretch 7. How great and wonderful effects proceed from small plain and simple principles 8. Concerning Electrical attratâ—on and the causes of it 9. Cabeus his opinion refuted concerning the cause of Electrical motions CHAP. XX. Of the Loadstones generation and its particulas motions 1. The extreme heat of the Sun under the Zodiack draws a stream of air from each Pole into the torrid Zone 2. The atomes of these two streams coming together are apt to incorporate with one another 3. By the meeting and mingling together
will pierce cut out the water almost into as little parts as themselves and mingling themselves with them they will flie away together and so convert the whole body of water into subtile smoke whereas the same Agent after long working upon lead will bring it into no less parts then small grains of dust which it calcines it into And gold that is more dense then lead resists peremptorily all the dividing power of fire and will not at all be reduced into a calx or lime by such operation as reduced lead into it So that remembring how the nature of Quantity is Divisibility and considering that rare things are more divisible then dense ones we must needs acknowledge that the nature of Quantity is some way more perfectly in things that are Rare then in those that are Dense On the other side more compacted and dense things may haply seem to some to have more Quantity then those that are rare and that is but shrunk together which may be stretch'd out and driven into much greater dimensions then the Quantity of rare things taking the quantities of each equal in outward appearance As gold may be beaten into much more and thiner leaf then an equal bulk of silver or lead A wax candle will burn longer with a small light then a tallow candle of the same bigness and consequently be converted into a greater quantity of fire and air Oyl will make much more flame then spirit of wine that is far rarer then it These and such like considerations have much perplex'd Philosophers and driven them into diverse thoughts to find out the reasons of them Some observing that the dividing of a body into little parts makes it less apt to descend then when it is in greater have believ'd the whole cause of lightness and rarity to be derived from division As for example they find that lead cut into little pieces will not go down so fast in water as when it is in bulk and it may be reduced into so smal atomes that it will for some space swim upon the water like dust of wood Which assumption is prov'd by the great Galileus to whose excellent wit and admirable industry the world is beholding not only for his wonderful discoveries made in the Heavens but also for his acurate and learned declaring of those very things that lye under our feet He about the 90. page of his first Dialogue of Motion clearly demonstrates how any real medium must of necessity resist more the descent of a little piece of lead or any other weighty matter than it would a greater piece and the resistance will be greater and greater as the pieces are lesser and lesser So that as the pieces are made less they will in the same medium sink the flower and seem to have acquired a new nature of lightness by the diminution not only of having less weight in them than they had as half an ounce is less than a whole ounce but also of having in themselvs a less proportion of weight to their bulk than they had as a pound of Cork is in regard of its magnitude lighter than a pound of Lead So as they conclude that the thing whose continued parts are the lesser is in its own nature the lighter and the rarer and other things whose continued parts are greater be heavier and denser But this discourse reaches not home for by it the weight of any body being discovered by the proportion it has to the medium in which it descends it must ever suppose a body lighter than it self in which it may sink and go to the bottome Now of that lighter body I enquire what makes it be so and you must answer by what you have concluded that it is lighter then the other because the parts of it are lesse and moreseverd from one another for if they be as close together their division avails them nothing since things sticking fast together work as if they were but one and so a pound of lead though it be filed into small dust if it be compacted hard together will sink as fast as if it were one bulk Now then allowingthe little parts to be seperated I ask what other body fills up the spaces between those little parts of the medium in which your heavy body descends For if the parts of water are more sever'd then the parts of lead there must be some other substance to keep the parts of it asunder let us suppose this to be air and I ask Whether an equal part of air be as heavy as so much water or whether it be not If you say it is then the compound of water and air must be as heavy as lead since their parts one with another are as much compacted as the parts of lead are For there is no difference whether those bodies whose little parts are compacted together be of the same substance or of divers or whether the one be divided into smaller parts then the other or not so they be of equal weights in regard of making the whole equally heavy as you may experience if you mingle pin-dust with a sand of equal weight though it be beaten into far smaller divisions then the pin-dust and put them in a bag together But if you say that air is not so heavy as water it must be because every part of air hath again its parts more sever'd by some other body then the parts of water are sever'd by air And then I make the same instance of that body which severs the parts of air And so at last since there cannot actually be an infinite process of bodies one lighter then another you must come to one whose little parts filling the pores and spaces between the parts of the others have no spaces in themselves to be fil'd up But as soon as you acknowledge such a body to be lighter and rarer then all the rest you contradict and destroy all you said before For by reason of its having no pores it follows by your rule that the little parts of it must be as heavy if not heavier then the little parts of the same bigness of that body whose pores it fills and consequently it is proved by the experience we alledg'd of pin-dust mingled with sand that the little parts of it cannot by their mingling with the parts of the body in which it is immediately contain'd make that lighter then it would be if these little parts were not mingled with it Nor would both their parts mingled with the body which immediately contains them make that body lighter And so proceeding on in the same sort through all the mingled bodies till you come to the last that is immediately mingled with water you will make water nothing the lighter for being mingled with all these and by consequence it should be as heavy and as dense as lead Now that which deceiv'd the Authors of this opinion was that they had not a right intelligence of the causes
the essence of Rarity and Density stands in the proportion of quantity to substance if we believe Aristole the greatest master that ever was of finding out definitions and notions and trust to the uncontroulable reasons we have brought in the precedent discourse This explication of Rarity and Density by the composition of substance with quantity may peradventure give little satisfaction to such as are not used to raise their thoughts above Physical and natural speculations who are apt to conceive there it no other composition or resolution but such as our senses shew us in compounding and dividing bodies according to quantitive parts Now this obliges us to shew that such a kind of composition and division as this must necessarily be allow'd of even in that course of doctrine which seems most contrary to ours To which purpose let us suppose that the position of Democritus or of Epicurus is true to wit that the original compositions of all bodies is out of very little ones of various figures all of them indivisible not Mathematically but Physically and that this infinite number of indivisibles floats in an immense ocean of vacuum or imaginary space In this position let any man who conceives their grounds may be maintained explicate how one of these little bodies is moved For taking two parts of vacuum in which this body successively is 't is clear that really and not only in my understanding 't is a difference in the said body to be now here now there wherfore when the body is gone thither the notion of being here is no more in the body and consequently is divided from the body And therfore when the body was here there was a composition between the body and its being here which seeing it cannot be betwixt two parts of Quantity must of necessity be such a kind of composition as we put between quantity and substance And certainly let men wrack their brains never so much they will never be able to shew how motion is made without some such composition and division upon what grounds soever they proceed And if then they tell us that they understand not how there can be a divisibility between substance and quantity we may reply that to such a divisibility two things are required first that the Notions of Substance and Quantity be different secondly that one of them may be Chang'd without the other As for the First 't is most evident we make an absolute distinction between their two notions both when we say that Socrates was bigger a Man than a Boy and when we conceive that milk or water while it boyles or wine while it works so as they run over the vessels they are in are greater and possess more place then when they were cool and quiet and fill'd not the vessel to the brim For however witty explications may seem to evade that the Same thing is now greater now lesser yet it cannot be avoided but that ordinary men who look not into Philosophy both conceive it to be so and in their familiar discourse express it so which they could not do if they had not different notions of the Substance and of the Quantity of the thing they speak of And though we had no such evidences the very names and definitions of them would put it beyond strife all men calling substance a Thing quantity Bigness and refering a Thing to Being as who would say that which is but Bigness to some other of like nature to which it is compar'd as that it is half as big twice as big or the like This then being unavoidable that the Notions are distinguish'd there remains no difficulty but only in the Second namely that the one may be Chang'd and the other not Which reason and demonstration convince as we have shew'd Wherfore if any shall yet further reply that they do not understand how such change is made we shall answer by asking them whether they know how the change of being sometimes here sometimes there is made by local motion in vacuum without a change in the body moved Which question if they cannot satisfie they must either deny that there is any local motion in vacuum or else admit a change in quantity without a change in substance for this latter is as evidently true as they suppose the former to be though the manner how they are effected be alike obscure in both and the reason of the obscurity the same in both With which we will conclude the present Chapter adding onely this note That if all Physical things and natural changes proceed out of the constitution of rare and dense bodies in this manner as we put them which the work we have in hand intends to shew then so manifold effects will so convince the truth of this doctrine we have declared that there can remain no doubt of it nor can there be any of the divisibility of quantity from substance without which this doctrine cannot consist For it cannot be understood how there is a greater proportion of quantity than of substance or contrariwise of substance then of quantity if there be not a real divisibility between quantity and substance And much less can it be conceiv'd that the same thing hath at one time a greater proportion of Quantity and at another time a less if the greater or lesser proportion be not separable from it that is if there be not a divisibility betwixt it and substance as well as there are different notions of them Which to prove by the proper principle belonging to this matter would require us to make a greater inrode into the very bowels of Metathysicks and to take a larger circuit then is fitting either for the subject or for the intended brevity of this Treatise CHAP. IV. Of the four first Qualities and of the four Elements THe subject of our discourse hitherto hath been three simple notions Quantity Rarity and Density Now it shall be to enquire if by compounding these with Gravity or Weight which is one of the specieses of Quantity above mentioned and of which I shall speak at large hereafter we may beget any further qualities and so produce the Four first Bodies call'd Elements Inimitation of Logitians who by compounding such propositions as of themselves are evident to mans nature as soon as they are proposed bring forth new knowledges which threds they still entermix and weave together till they grow into a fair piece And thus the Sciences they so much labour for and that have so great an extent result out of few and simple notions in their beginnings But before we fall to mingling and comparing them together I think it will not be amiss to set down and determine what kind of things we mean by rare and what by dense that when the names are agreed on we may slip into no errour by mistaking them So then though there be several considerations in regard of which rarity and density may be differently attributed to bodies yet
man that seeing the Divider is the agent in division and in Local motion and dense bodies are by their nature dividers the Earth must in that regard be the most active among the Elements since it is the most dense of them all But this seems to be against the Common judgment of all the searchers of nature who unamimously agree that Fire is the most active Element As also it seems to impugne what we our selves have determin'd when we said there were two active qualities heat and cold whereof the first was in its greatest excess in Fire and the latter in water To reconcile these we are to consider that the action of Cold in its greatest height is composed of two parts the one is a kind of pressing and the other is penetration which requires applicability Of which two the former arises out of density but the latter out of moderation of density as I have declared in the precedent Chapter Wherefore the former will exceed more in Earth though the whole be more eminent in Water For though considering only the force of moving which is a a more simple and abstracted notion then the determination and particularization of the Elements and is precedent to it therein Earth hath a precedency over water yet taking the action as it is determin'd to be the action of a particular Element and as it concurs to the composition or dissolution of mixed bodies in that consideration which is the chief work of Elements and requires an intime application of the Agents Water hath the principality and excess over Earth As for Fire it is more active then either of them as will appear clearly if we consider how when Fire is applyed to fewel and the violence of blowing is added to its own motion it incorporates it self with the fewel and in a small time converts a great part of it into its own nature and shatters the rest into smoak and ashes All which proceeds from the exceeding smallness and dryness of the parts of fire which being moved with violence against the fewel and thronging in multitudes upon it easily pierce the porous substance of it like so many extreme sharp Needles And that the force of Fire is as great and greater then of Earth we may gather out of our former discourse where having resolved that density is the virtue by which a body is moved and cuts the medium and again considering that celerity of motion is a kind of density as we shall by and by declare 't is evident that since blowing must of necessity press violently and with a rapid motion the parts of fire against the fewel and so condense them exceedingly there both by their celerity by bringing very many parts together there it must needs also give them activity and vertue to pierce the body they are beaten against New that Celerity is a kind of Density will appear by comparing their natures For if we consider that a dense body may be dilated so as to possess and fill the place of a rare body that exceeded it in bigness and by that dilatation may be divided into as many and as great parts as the rare body was divisible into we may conceive that the substance of those parts was by a secret power of nature folded up in that little extension in which it was before And even so if we reflect upon two Rivers of equal channels and depths whereof the one goes swifter then the other and determine a certain length of each channel and a common measure of Time we shall see that in the same measure of time there passes a greater bulk of water in the designed part of the channel of the swifter stream then in the designed part of the flower though those parts be equal Nor imports it that in Velocity we take a part of time whereas in Density it seems that an instant is sufficient and consequently there would be no proportion between them For knowing Philosophers all agree that there are no Instants in time and that the apprehension of them proceeds meerly from the manner of our understanding And as for parts in time there cannot be assumed any so little in which the comparison is not true and so in this regard it is absolutely good And if the Reader have difficulty at the disparity of the things which are pressed together in Density and in Celerity for that in Density there is only Substance in Celerity there is also Quantity crowded up with the substence he will soon receive satisfaction when he shall consider that this disparity is to the advantage of what we say and makes the nature of density more perfect in celerity and consequently more powerful in fire then in earth Besides if there were no disparity it would be a distinct species of density but the very same By what we have spoken above it appears how fire gets into fewel now let us consider how it comes out for the activity of that fierce body will not let it lie still and rest as long as it has so many enemies round about it to rouse it up We see then that as soon as it has incoporated it self with the fewel and is grown master of it by introducing into it so many of its own parts like so many Souldiers into an Enemies Town they break out again on every side with as much violence as they came in For by reason of the former resistance of the fewel their continual streaming of new parts upon it and one overtaking another there where their journey was stop'd all which is increas'd by the blowing doth so exceedingly condense them into a narrower room then their nature effects that as soon as they get liberty and grow masters of the fewel which at the first was their prison they enlarge their place and consequently come out and flie abroad ever aiming right forwards from the point where they begin their journey for the violence wherewith they seek to extend themselves into a larger room when they have liberty to do so will admit no motion but the shortest which is by a straight line So that if in our phantasie we frame an image of a round body all of fire we must withall presently conceive that the flame proceeding from it would diffuse it self every way indifferently in straight lines so that the source serving for the Center there would be round about it an huge Sphere and of fire and light unless some accidental and extern cause should determine its motion more to one part then to another Which compass because it is round and has the figure of a Sphere is by Philosophers term'd the Sphere of its activity So that it is evident the most simple and primary motition of fire is a flux in a direct line from the center of it to its circumference taking the fewel for its center as also that when 't is beaten against a harder body it may be able to destroy it though that
occur other arguments of no less importance to prove this verity than these we have already proposed CHAP. VII Two objections answer'd against light being fire with a more ample proof of its being such HAving then said thus much to perswade us of the corporeity of this subtile thing that so queintly plays with our eyes we will in the next place examine those objections that at the beginning we set down against its being a body and if after a through discussion of them we find they do in truth conclude nothing of what at the first sight they bear so great a shew of but that we shall be able perfectly to solve and enerve their force no body will think it rashness in us to crave leave of Aristotle that we may dissent from him in a matter that he has not look'd to the bottom of and whose opinion therin cannot be defended from plain contradictions and impossibilities 'T is true never any one man looked fo far as he into the bowels of nature he may be rightly termed the Genius of it and whoever follows his principles in the main cannot be led into errour but we must not believe that he or any man else who relies upon the strength and negotiation of his own reason ever had a priviledge of infallibility entail'd to all he said Let us then admire him for what he has deliver'd us and where he falls short or is weary in his search and suffers himself to be born down by popular opinions against his own principles which happens very seldom to him let us seek to supply and relieve him But to pursue our intent We will begin with answerin the third objection which is that if light were fire it must heat as well as enlighten where it shines There 's no doubt but it doth so as is evident by the weather-glasses and other artificiall musical instruments as Organs and Virginals that played by themselvs wâ—ch Cornelius Drebbel That admirable master of Mechanicks made to shew the King All which depends upon the rarefaction and condensation of some subtile body conserv'd in a cavity within the bulk of the whole instrument for assoon as the Sun shined they would have motion and play their parts And questionless that grew out of the rarefaction of the subtile liquor he made use of which was dilated assoon as the air was warmd by the Sun-beams Of whose operation it was so sensible that they no sooner left the Horizon but its motion ceased And if but a cloud came between the instrument and them the musick would presently go slower time And the ancient miracle of Memnons statue seems to be a juggling of the Ethiopian priests made by the like invention But though he and they found some spirituall and refined natter that would receive such notable impressions from so small alterations of temper yet it is no wonder that our gross bodies are not sensible of them for we cannot feel heat unless it be greater then that which is in our sense And the heat there must be in proportion to the heat of our bloud which is an high degree of warmth and therfore 't is very possible that an exceeding rarified fire may cause a far lesse impression of heat then we are able to feel Consider how if you set pure spirit of wine on fire and so convert it into actual flame yet it will not burn nor scarce warm your hand and then can you expect that the light of a candle which fills a great room should burn or warm you as far as it shines If you would exactly know what degree of heat and power of burning that light has which for example shines upon the wall in a great chamber in the midst wherof there stands a candle do but calculate what overproportion of quantitie all the light in the whole room bears to the quantity of the little flame at the top of the candle and that is the overproportion of the force of burning which is in the candle to the force of burning which is in so much light at the wall as in extension is equall to the flame of the candle Which when you have considered you will not quarrel at its not warming you at that distance although you grant it to be fire streaming out from â—e flame as from the spring that feeds it and extreamly dilated according to the nature of fire when it is at liberty by going so far without any other grosse body to imprison or clog it 'T is manifest that this rule of examining the proportion of burning in so much of the light as the flame is by calculating the proportion of the quantity or extension of all the light in the room to the extension of the flame of the candle and then comparing the flame of the candle to a part of light equall in extension unto it is a good and infallible one if we abstract from accidental inequalities since both the light and the flame are in a perpetual flux and all the light was first in the flame which is the spring from whence it continually flows As in a river where every part runs with a settled stream though one place be straighter and another broader yet of necessity since all the water that is in the broad place came out of the narrow it must follow that in equal portions of time there is no more water where it has the liberty of a larg channel then where the banks press it into a narrow bed so that there be no inequalities in the bottome In like manner if in a large stove a basin of water be converted into steam that rarified water which then fills the whole Stove is no more then what the Basin contain'd before and consequently the power of moistening which is in a foot 's extension for example of the stove wherein that steam is must be in proportion to the vertue of wetting in the foot extension of water as the quantity of that great room which the steam fills is to the quantity of the water contain'd in the basin For although the rarified water be not in every least part of that great place it seems to take up by reason that there is Air in which it must swim yet the power of wetting that was in the Basin of water is dilated through the whole room by the conjunction of the Myst or Dew to all the sensible parts of the Air that is in the room and consequently the power of wetting which is in any foot of that room is in a manner as much less then the power of wetting which was in the foot of water as if the water were rarified to the quantity of the whole room and no air were left with it And in the same manner it fares with dilated fire as it doth with dilated water with only this difference peradventure that Fire grows purer and more towards its own nature by dilatation whereas water becomes more mix'd and is carried
of fewel to maintain the same light for a great company of years But I should not easily be perswaded that either flame or light could be made without any manner of consuming the body which serves them for fewel CHAP. VIII An Answer to three other Objectious formerly proposed against Light being a Substance HAving thus defended our selves from their Objections who would not allow light to be fire and having satisfied their inquisition who would know what becomes of it when it dyes if it be a body we will now apply our selves to answer their difficulties who will not let it pass for a body because it is in the same place with another body as when the Sun-beams enlighten all the air and when the several lights of two distinct Candles are both of them every where in the same room Which is the substance of the second main objection This of the justling of the aire is easily answered thus that the aire being a very divisible body doth without resistance yield as much place as is requisite for light And that light though our eyes judge it diffused every where yet is not truly in every point or atome of air but to make us see it every where it suffices that it be in every part of the air which is as big as the black or sight of our eye so that we cannot set our eye in any position where it receives not impressions of light In the same manner as Perfumes which though they be so gross bodies that they may be sensibly wasted by the wind yet â—o fill the air that we can put our nose in no part of the room where a perfume is burned but we shall smell it And the like is of mists as also of the sprouted water to make a perfume which we mention'd above But because pure discourses in such small thrids as these 〈◊〉 but weakly bind such Readers as are not accustom'd to them and I would if possible render this Treatise intelligible to every rational man how ever little vers'd in Scholastick learning among whom I expect it will have a fairer passage then among those that are already deeply imbued with other principles let us try if we can herein inform our selves by our sense and bring our eyes for witness of what we say He then that is desirous to satisfie himself in this particular may put himself in a dark room through which the Sun sends his beams by a cranie or little hole in the wall and he will discover a multitude of little atomes flying about in that little stream of light which his eye cannot discern when he is environ'd on all sides with a full light Then let him examine whether or no there be light in the midst of those little bodies and his own reason will easily till him that if those bodies were as perspicuous as the air they would not reflect upon our eyes the beams by which we see them And therefore he will boldly conclude that at the least such parts of them as reflect light to us do not admit it nor let it sink into them Then let him consider the multitude of them and the little distance betwixt one another and how nevertheless they hinder not our sight but we have it free to discover all objects beyond them in what position soever we place our eye And when he thus perceives that these opacous bodies which are every where do not hinder the eye from judging light to have an equal plenary diffusion through the whole place that it irradiates he can have no difficulty to allow air that is diaphanous and more subtile far then they and consequently divisible into lesser atomes and having lesser pores gives less scope to our eyes to miss light then they do to be every where mingled with light though we see nothing but light and cannot discern any breach of it Especially when he shall adde to this consideration that the subtile body which thus fills the air is the most visible thing in the world and that whereby all other things are seen and that the air it mingles it self with is not at all visible by reason of the extreme diaphaneity of it and easie reception of the light in every pore of it without any resistance or reflection and that such is the nature of light as it easily drowns an obscure body if it be not too big and not onely such but even other light bodies for so we know as well the fixed Stars as the Planets are conceal'd from our sight by the nearness to the Sun neither the lightness of the one nor the bigness of the other prevailing against the darkning of an exuperant light and we have daily experience of the same in very pure chrystal glasses and in very clear water which though we cannot discern by our sight if they be certain positions nevertheless by experience we find that they reflect much light and consequently have great store of opacous parts And then he cannot choose but conclude that it is impossible but light should appear as it doth to be every where and to be one continued thing though his discourse withal assure him it is every where mingled with air And this very answer I think will draw with it by consequence the solution of the other part of the same objection which is of many lights joyning in the same place and the same is likewise concerning the images of colours every where crossing one another without hindrance But to raise this contemplation a strain higher let us consider how light being the most rare of all known bodies is of its own nature by reason of the divisibility that followeth rarity divisible into lesser parts then any other and particularly then flame which being mixed with smoke and other corpulency falls very short of light And this to the proportion in which it is more rare then the body 't is compared to Now a great Mathematician having devised how to measure the rarefaction of Gun-powder into flame found the Diameter fifty times increased and so concluded that the body of the flame was in proportion to the body of the Gun-powder it was made of as 125000. is to one Wherfore by the immediately proceeding consequence we find that 125000 parts of flame may be couched in the room of one least part of gunpowder and peradventure many more considering how porous a body Gun-powder is Which being admitted 't is evident that although light were as gross as the flame of Gun-powder and Gun-powder were as solid as gold yet there might pass 125000. rayes of light in the space wherin one least part of Gun-powder might be contained which space would be absolutely invisible to us and be contained many times in the bigness of the sight of a mans eye Out of which we may gather what an infinity of objects may seem to us to cross themselvs in the same indivisible place and yet may have room sufficient for every one
to pass his way without hindring his fellow Wherfore seeing that one single light could not send rayes enough to fil every little space of aire that is capable of light and the less the further it is from the flame 't is obvious enough to conceive how in the space where the air is there is capacity for the rays of many candles Which being well sum'd up will take away the great admiration how the beams of light though they be corporeall can in such great multitudes without hindering one another enter into bodies and come to our eye and will shew that 't is the narrowness of our capacities and not the defect of nature which makes these difficulties seem so great For she hath sufficiently provided for all these subtile operations of fire as also for the entrance of it into glass and into all other solid bodies that are Diaphanous upon which was grounded the last instance the second objection pressed for all such bodies being constituted by the operation of fire which is alwaies in motion there must needs be ways left for it both to enter in and to evaporate out And this is most evident in glass which being wrought by an extreme violent fire and swelling with it as water and other things do by the mixture of fire must necessarily have great store fire in it self whiles it is boyling as we see by its being red hot And hence it is that the workmen are forced to let it cool by degrees in such relentings of fire as they call their nealing heats lest it should shiver in pieces by a violent succeeding of air in the room of the fire for that being of greater parts then the fire would strain the pore of the glass too suddenly and break it all in pieces to get ingressions whereas in those nealing heats the air being rarer lesser parts of it succeed to the fire and leisurely stretch the pores without hurt And therefore we need not wonder that light passes so easily through glass and much less that it gets through other bodies seeing the experience of Alchymists assures us 't is hard to find any other body so impenitrable as glass But now to come to the answer of the first and in appearance most powerful objection against the corporeity of light which urges that its motion is perform'd in an instant and therefore cannot belong to what is material and cloth'd with quantity We will endeavour to shew how unable the sense is to judge of sundry sorts of motions of Bodies and how grosly it is mistaken in them And then when it shall appear that the motion of light must necessarily be harder to be observed then those others I conceive all that is rais'd against our opinion by so incompetent a judge will fall flat to the ground First then let me put the Reader in mind how if ever he mark'd children when they play with firesticks they move and whirle them round so fast that the motion will cosen their eyes and represent an entire circle of Fire to them and were it somewhat distant in a dark night that one play'd so with a lighted Torck it would appear a constant Wheele of fire without any discerning of motion in it And then let him consider how slow a motion that is in respect of what 't is possible a body may participate of and he may safely conclude that 't is no wonder though the motion of light be not descried and that indeed no argument can be made from thence to prove that light is not a body But let us examine this consideration a little further and compare it to the motion of the earth or heavens Let the appearing circle of the fire be some three foot Diameter and the time of one entire circulation of it be the sixtieth part of a minute of which minutes there are 60. in an hour so that in a whole day there will but be 86400. of these parts of time Now the Diameter of the wheel of fire being but of three foot the whole quantity of space that it moves in that atome of time will be at the most ten foot which is three paces and a foot of which parts there are near eleven millions in the compass of the earth so that if the earth be moved round in 24. hours it must go near 130. times as fast as the Boy 's stick which by its swift motion deceives our eye But if we allow the Sun the Moon and the fixed Stars to move how extreme swift must their flight be and how imperceptible would their motion be in such a compass as our sight would reach to And this being certain that whether the earth or they move the appearances to us are the same 't is evident that as now they cannot be perceiv'd to move as peradventure they do not so it would be the very same in shew to us although they did move If the Sun were near us and gallop'd at that rate surely we could not distinguish between the beginning and ending of his race but there would appear one permanent Line of light from East to West without any motion at all as the Torch seems to make with so much a slower motion one permanent immoveable wheel of fire But contrary to this effect we see that the Sun and Stars by onely being removed further from our eyes do cosen our sight so grossely that we cannot discern them to be moved at all One would imagine that so rapid and swift a motion should be perceiv'd in some sort or other which whether it be in the earth or in them is all one to this purpose Either we should see them change their places whiles we look upon them as Arrows and Birds do when they fly in the Aire or else they should make a stream of light bigger then themselvs as the Torch doth But none of all this happens Let us gaze upon them so long and so attentively that our eyes be dazled with looking and all that while they seem to stand immovable and our eyes can give us no account of their journey till it be ended They discern it not while it is in doing So that if we consult with no better counsellour then them we may wonder to see that body at night setting in the West which in the morning we beheld rising in the East But that which seems to be yet more strange is that these bodies move cross us and nevertheless are not perceiv'd to have any motion at all Consider then how much easier it is for a thing that moves towards us to be with us before we are aware A nimble Fencer will put in a thrust so quick that the â—oil will be in your bosome when you thought it a yard off because in the same moment you saw his point so far distant and could not discerne it to move towards you till you felt the rude salutation it gave you If then you will compare the body of light with
by descending so that as long as it boyls 't is in a perpetual confused motion up and down Now having formerly concluded that fire is light and light is fire it cannot be doubted but that the Sun serves instead of fire to our Globe of Earth and water which may be fitly compared to the boyling pot and all the day long draws vapours from those bodies that his beams strike upon For he shooting his little darts of fire in multitudes and in continued streams from his own center against the Python the earth we live on they there overtake one another and cause some degrees of heat as far as they sink in But not being able by reason of their great expansion in their long journey to convert it into their own nature and set it on fire which requires a high degree of condensation of the beams they but pierce and divide it very subtilly and cut some of the outwardparts of it into extreme little atomes To which sticking very close and being in a manner incorporated with them by reason of the moisture that is in them they in their rebound back from the earth carry them along with them like a ball that struck against a moist wall in its return from it brings back some of the mortar sticking upon it For the distance of the Earth from the Sun is not the utmost period of these nimble bodie 's flight so that when by this solid body they are stop'd in their course forwards on they leap back from it and carry some little parts of it with them som of them a farther some of them a shorter journey according to their littleness and rarity make them fit to ascend As is manifest by the consent of all Authors that write of the Regions of the Air who determine the Lower Region to reach as far as the reflection of the Sun and conclude this Region to be very hot For if we mark how the heat of fire is greatest when it is incorporated in some dense body as in Iron or in Sea-coal we shall easily conceive that the heat of this Region proceeds mainly out of the incorporation of light with those little bodies which stick to it in its reflection And experience testifies the same both in our soultry days which we see are of a gross temper and ordinarily go before rain as also in the hot Springs of extreme cold countrys where the first heats are unsufferable which proceed out of the resolution of humidity congeal'd in hot winds which the Spaniards call Bochornos from Boca de horno by allusion to the breathing stream of an Oven when it is open'd which manifestly shew that the heat of the Sun is incorporated in the little bodies which compose the steam of that wind And by the principles we have already laid the same would be evident though we had no experience to instruct us for seeing that the body of fire is dry the wet parts which are easiest resolved by fire must needs stick to them and accompany them in their return from the earth Now whiles these ascend the air must needs cause others that are of a grosser complexion to descend as fast to make room for the former and to fill the places they left that there may be no vacuity in nature And to find what parts they are and from whence they come that succeed in the room of light and atomes glew'd together that thus ascend we may take a hint from the Maxime of the Opticks that Light reflecting makes equal angles whence supposing the Superficies of the earth to be circular it will follow that a Perpendicular to the center passes just in the middle between the two rayes the incident and the reflected Wherefore the air between these two rayes and such bodies as are in it being equally pressed on both sides those bodies which are just in the middle are nearest and likeliest to succeed immediately in the room of the light and atomes which ascend from the Superficies of the earth and their motion to that point is upon the Perpendicular Hence 't is evident that the Air and all such bodies as descend to supply the place of light and atomes which ascend from the Earth descend perpendicularly towards the center of the earth And again such bodies as by the force of light being cut from the earth or water do not ascend in form of light but incorporate a hidden light and heat within them and thereby are rarer then these descending bodies must of necessity be lifted up by the descent of those denser bodies that go downwards because they by reason of their density are moved with a greater force And this lifting up must be in a perpendicular line because the others descending on all sides perpendicularly must needs raise those that are between them equally from all sides that is perpendicularly from the center of the earth And thus we see a motion set on foot of some bodies continually descending and others continually ascending all in perpendicular lines excepting those which follow the course of lights reflexion Again as soon as the declining Sun grows weaker or leaves our Horizon and his beams vanishing leave the little hors-men which rode upon them to their own temper and nature from whence they forced them they finding themselvs surrounded by a smart descending stream tumble down again in the night as fast as in the day they were carried up and crowding into their former habitations exclude those they find had usurped them in their absence And thus all bodies within reach of the Suns power but especially our air are in perpetual motion the more rarified ones ascending and the dense ones descending Now then because no bodies wherever they be as we have already shew'd have any inclination to move towards a particular place otherwise then as they are directed and impel'd by extrinsecal Agents let us suppose that a body were placed at liberty in the open air And then casting whether it would be moved from the place we suppose it in and which way it would be moved we shall find it must of necessity happen that it shall descend and fall down till it meet with some other gross body to stay and support it For though of it self it would move no way yet if we find that any other body strikes efficaciously enough upon it we cannot doubt but it will move that way which the striking body impels it Now it is strucken upon on both sides above and below by the ascending and the descending atoms the rare ones striking upon the bottome of it and driving it upwards and the denser ones pressing upon the top of it and bearing it downwards But if you compare the the impressions the denser atoms make with those that proceed from the rare ones 't is evident the dense ones must be the more powerful and therfore will assuredly determine the motion of the body in the air that way they go which is
as positive gravity or levity but that their course upwards or downwards happens to them by the order of nature which by outward causes gives them an impulse one of these wayes without which they would rest quietly wherever they are as being of themselvs indifferent to any motion But because our words express our notions and they are fram'd according to what appears to us when we observe any body to descend constantly towards our earth we call it heavie and if it move contrarywise we call it light But we must take heed of considering such gravity and levity as if they were Entities that work such effects since upon examination it appears that these words are but short expressions of the effects themselves the causes whereof the vulgar of mankind who impose names to things do not consider but leave that work to Philosophers to examine whiles they onely observe what they see done and agree upon words to express that Which words neither will in all circumstances always agree to the same thing for as cork descends in aire and ascends in water so also will any other body descend if it lights among others more rare then it self and will ascend if it lights among others that are more dense then it And we term Bodies light and heavy only according to the course which we usually see them take Now proceeding further on and considering how there are various degrees of density or gravity it were irrational to conceive that all bodies should descend at the same rate and keep equal pace with one another in their journey downwards For as two knives whereof one hath a keener edge then the other being press'd with equal strength into like yielding matter the sharper will cut deeper then the other so if of two bodies one be more dense then the others that which is so will cut the air more powerfully and descend faster then the other for in this case density may be compared to the kniefs edge since in it consists the power of dividing as we have heretofore determin'd And therefore the pressing them downwards by the descending atomes being equal in both or peradventure greater in the more dense body as anon we shall have occasion to touch and there being no other cause to determine them that way the effect of division must be the greater where the divider is the more powerful Which the more dense body is and therefore cuts more strongly through the resistance of the air and consequently passes more swiftly that way 't is determin'd to move I do not mean that the velocities of their descent shall be in the same proportion to one another as their densities are for besides their density those other considerations which we have discours'd of above when we examin'd the causes of velocity in motion must likewise be ballanced And out of the comparisons of all them not out of the consideration of any one alone results the differences of their velocities nor that neither but in as much as concerns the consideration of the moveables for to make the calculation exact the Medium must likewise be considered as by and by we shall declare For since the motion depends of all them together though there should be difference between the moveables in regard of one only and that the rest were equal yet the proportion of the difference of their motions must not follow the proportion of their difference in that one regard because their difference consider'd single in that regard will have one proportion and with the addition of the other considerations though alike in both to their difference in this they will have another As for example reckon the density of one moveable to be double the density of another moveable so that in that regard it has two degrees of power to descend whereas the other has but one suppose then the other causes of thier descent to be alike in both and reckon them all three and then joyn these three to the one which is caused by the density in one of the moveables as likewise to the two which is caused by the density in the other moveable 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 five to four But after we have consider'd all that concerns the moveables we are then to cast an eye upon the Medium they are to move in and we shall find the addition of that decreases the proportion of their difference exceedingly more according to the cessibility of the Medium Which if it be Air the great disproportion of its weight to the weight of those bodies which men use to take in making experiences of their descent in that yeelding Medium will cause their difference of velocity in descending to be hardly perceptible Even as the difference of a sharp or dull knife which is easily perceiv'd in cutting of flesh or bread is not to be distinguish'd in dividing of water or oyl And likewise in Weights a pound and a scruple will bear down a dram in no sensible proportion of velocity more then a pound alone would do and yet put a pound in that scale in stead of the dram 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 air by reason of the great disproportion of weight between air and the bodies that descend in it The reason of this will clearly shew it self in abstracted proportions Thus Suppose air to have one degree of density and water to have 400 then let the moveable A. have 410 degrees of density and the moveable B. have 500. Now compare their motion to one another in the several mediums of air and water The exuperance of the density of A. to water is 10 degrees but the exuperance of B. to the same water is 100 degrees so that B. must have in water swifter then A in the proportion of 103 to ten that is of 10 to one Then let us compare the exuperance of the two moveables over air A is 409 times more dense then air but B is 499 times more dense then it by which account the motion of B. must be in that medium swifter then the motion of A in the proportion of 499 to 409 that is about 50 to 41 which to avoid fractions we may account as 10 to 8. But in water they exceed one another as 10 to one so that their difference of velocity must be scarce perceptible in air in respect of what it is in water Out of all which discourse I only infer in common that a greater velocity in motion will follow the greater density of the moveable without determining
notable degree as for example to water makes then a great difference of a heavy bodies gravitation in it and accordingly we see a great difference between heavy bodies descending in water and in air though between two kinds of air none is to be observ'd their difference is so smal in respect of the density of the body that descends in them And therfore since an assured and certain difference in circumstances makes no sensible inequality in the affect we cannot expect any from such circumstances as we may reasonably doubt whether there be any inequality among them or no. Besides that if in any of the proposed cases a heavy body should gravitate more and be heavier one time than another yet by weighing it we could not discern it since the counterpoise which is to determine its weight must likewise be in the same proportion heavier then it was And besides weighing no other means remains to discover its greater graviation but to compare it to Time in its descent and I believe that in all such distances as we can try it in its inequalities will be no whit less difficult to be observ'd that way then any other Lastly to bend our discourse particularly to that instance of the objection where it is conceiv'd that if gravity or descending downwards of bodies proceeded from atoms striking on them as they move downwards it would follow that a stone or other dense body lying under shelter of a thick hard and impenetrable adamantine rock would have no impulse downwards and consequently would not weigh there We may note that no body whatever compacted by physical causes and agents can be so dense and imporous but that such atoms as these we speak of must be in them and in every part of them and every where pass through and through them as water doth through a sieve or through a spunge and this universal maxime must extend as far as the Sun or any other heat communicating with the Sun reaches and is found The reason whereof is because these atoms are no other thing but such extreme little bodies as are resolved by heat out of the main stock of those massie bodies upon which the Sun and heat do work Now then it being certain out of what we have heretofore said that all mixt bodies have their temper and consistence and generation from the mingling of fire with the rest of the Elements that compose them and from the concoction or digestion which fire makes in those bodies 't is evident that no mixt body whatever nor any sensible part of a mixt body can be void of pores capable of such atoms or be without such atoms passing through those pores which atoms by mediation of the air that likewise hath its share in such pores must have communication with the rest of the great sea of air and with the motions that pass in it And consequently in all and every sensible part of any such extreme dense and pretended inpenetrable body to the notice wherof we can arrive this percussion of atoms must be found and they will have no difficulty in running through nor by means of it in striking any other body lying under the shelter of it and thus both in from that hard body there must be stil an uninterrupted continuation of gravity or of descending towards the centre To which we may adde that the stone or dense body cannot lie so close to the rock that covers it but that some air must be between for if nothing were between they would be united and become one continued body and in that air which is a Creek of the great Ocean of air spread over the world that is every where bestrew'd with moving atoms and which is continually fed like a running stream with new air that drives on the air it overtakes no doubt but there are descending atoms as well as in all the rest of its main body and these descending atoms meeting with the stone must needs give some stroke upon it and that stroke be it never so little cannot chuse but work some effect in making the stone remove a little that way they go and that motion wherby the space is inlarg'd between the stone and the shelt'ring rock must draw in a greater quantity of air and atoms to strike upon it And thus by little and little the stone passes through all the degrees of tardity by which a descending body parts from rest which is by so much the more speedily done by how much the body is more eminent in density But this difference of time in regard of the atoms strokes only and abstracting from the bodies density will be insensible to us seeing as we have said no more is required of them but to give a determination downwards And out of this we clearly see the reason why the same atoms striking upon one body lying on the water make it sink and upon another they do not As for example if you lay upon the superficies of some water a piece of iron and a piece of cork of equal bigness and of the same figure the iron will be beaten down to the bottom and the cork will float at the top The reason wherof is the different proportions of the comparison of their densities with the density of water for as we have said the efficacy and force of descending is to be measured by that So then the strokes of the atoms being more efficatious upon water then upon cork because the density of water is greater then the density of cork considering the abundance of air that is harbor'd in the large pores of it it followes that the atoms will make the water go down more forcibly then they will cork But the density of iron exceeding the density of water the same strokes will make the iron descend faster then the water and consequently the iron must sink in the water and the cork will swim upon it And this same is the cause why if a piece of cork be held by force at the bottom of the water it will rise up to the top as soon as the violence is taken away that kept it down for the atoms strokes having more force on the water then on the cork they make the water sink and slide under it first a little thin plate of water and then another a little thicker and so by degrees more and more till it hath lifted the cork quite up to the top Fifthly it may be objected that these atoms do not descend always perpendicularly but somtimes slopingly and in that case if their strokes be the cause of dense bodies moving they should move sloping and not downward Now that these atoms descend somtimes slopingly is evident as when for example they meet with a stream of water or with a strong wind or even with any other little motion of the air such as carries feathers up and down hither and thither which must needs waft the atoms in some measure along
with them their way Seeing then that such a gentle motion of the air is able to put a feather out of its way notwithstanding the percussions of the atoms upon it why shall it not likewise put a piece of iron out of its way downwards since the iron hath nothing from the atoms but a determination to its way But much more why should not a strong wind or a currant of water do it since the atoms themselv's that give the iron its determination must needs be hurried along with them To this we answer that we must consider how any wind or water which runs in that sort is it self originally full of such atoms which continually and every where press into and cut through it in pursuing their constant perpetual course of descending in such sort as we shewed in their running through any hard rock or other densest body And these atoms make the wind or water primarily tend downwards though other accidental causes impel them secundarily to a sloping motion And still their primary natural motion will be in truth strongest though their not having scope to obey that but having enough to obey the violent motion makes this become the more observeable Which appears evidently out of this that if there be a hole in the bottome of the pipe that conveys water slopingly be the pipe never so long and consequently the sloping motion never so forcible yet the water will run out at that hole to obey its more powerful impulse to the centrewards rather then continue the violent motion in which it had arrived to a great degree of celerity Which being so 't is easie to conceive that the atoms in the wind or water which move perpendicularly downwards will still continue the irons motion downwards notwithstanding the Mediums sloping motion since the prevailing force determines both the iron and the Medium downward and the iron has a superproportion of density to cut its way according as the prevalent motion determines it But if the descending atoms be in part carried along down the stream by the current of wind or water yet still the current brings with it new atoms into the place of those that are carried away and these atoms in every point or place wherever they are of themselvs tend perpendicularly downwards though they are forced from the compleat effect of their tendance by the violence of the current so that in this case they are moved by a declining motion compounded of their own natural motion and the force one with which the stream carries them Now then if a dense body fall into such a current where these different motions give their several impulses it will be carried in such sort as we say of the atoms but in another proportion not in a perpendicular but in a mixt declining line compounded of the several impulses which the atoms and current give it in which also 't is to be remembred how the current gives an impulse downwards as well as sloping and peradventure the strongest downwards and the declination will be more or less according as the violent impulse prevails more or less against the natural motion But this is not all that is to be consider'd 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 self has a particular virtue of its own namely its density by which it receivs and prosecutes more fully its determination downwards and therfore the force of that body in cutting its way through the Medium is also to be considered in this case as well as above calculating its declining from the perpendicular and out of all these causes will result a middle declination compounded of the motion of the water or wind both ways and of its own motion by the perpendicular line And since of these three causes of a dense bodies motion it s own virtue in prosecuting by its density the determination it requires is the most efficacious by much after it has once receiv'd a determination from without its declination will be but little if it be very dense and heavy But if it recede much from density as so have some near proportion to the density of the Medium the declination will be great And in a word according as the body is heavier or lighter the declination will be more or less in the some 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 such a superproportion as we have declared heretofore makes the Mediums operation upon 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 a feather because the stones motion downwards is greater and stronger then the motion of a feather downwards And by consequence the force that can turn a feather from its course downwards is not able to deturn a stone And if it be repli'd that it may be so order'd that the stone shall have no motion before it be in the stream of a river and notwithstanding it will still move downwards we may answer that considering the little declivity of the bed of such a stream the strongest motion of the parts of the stream must necessiariy be downwards and consequently they will beat the stone downwards And if they do not the like to a feather or other light body 't is because other parts of the stream get under the light body and beat it upwards which they have not power enough to do to the stone Sixthly it may be objected that if Elements do not weigh in their own Spheres then their gravity and descending must proceed from some other cause and not from this percussion of the atoms we attribute to it which percussion we have determin'd goes through all bodies whatever and beats upon every sensible part of them But that Elements weigh not in their own Spheres appears out of the experience of a Syphon for though one leg of a Syphon be sunk never so much deeper into the body of the water then the other leg reaches below the superficies of the water nevertheless if once the outward leg become full of water it will draw it out of the other longer leg Which it should not do if the parts of water that are comprised within their whole bulk did weigh since the bulk of water is much greater in the sunk leg then in the other and therfore these should rather draw back the other water into the Cistern then be themselves drawn out of it into the air To this we answer that 't is evident the Elements do weigh in their own Spheres at least as far as we can reach to their Spheres for we see that a ball once stuff'd hard with air is heavier then an empty one Again more water would not be heavier then less if the inward
water by sinking in one place to rise round about it must of necessity follow that the bullet which in entring has press'd down the first parts of the water has withal therby put others further off in a motion of rising and therfore the bullet in its going on must meet with some water swelling upwards and from it receive a ply that way which cannot fail of carrying it above the mark it was level'd at And so we see this effect proceeds from reflection or the bounding of the water and not from refraction Besides that it may justly be suspected the shooter took his aim too high by reason of the marks appearing in the water higher than in truth it is unless such false aiming were duly prevented Neither is Monsir des Cartes his excuse to be admitted when he saies that light goes otherwise than a ball would do because in a glass or water the etherial substance which he surposes to run through all bodies is more efficaciously moved than in air and thersore light must go faster in the glass than in the air and so turn on that side of the straight line which is contrary to the side that the ball takes because the ball goes not so swiftly For not to dispute the verity of this proposition the effect he pretends is impossible for if the etherial suhstance in the air before the glass be flowly moved the motion of which he calls light 't is impossible that the etherial substance in the glass or in the water should be more smartly moved than it Well it may be less but without all doubt the impulse of the etherial substance in the Glass cannot be greater than its adequate cause which is the motion of the other parts that are in the air precedent to glass Again after it is pass'd the glass it should return to be a straight line with the line that it made in the air precedent to the glass in the subsequent air must take off just as much and no more as the glas did add the contrary wherof experience shews us Thirdly in this explication it would always go one way in the air and another way in the glass wheras all experience testifies that in a glass convex on both sides it still goes in the air after its going out to the same side as it did in the glass but more And the like happens in glasses on both sides concave Wherfore 't is evident that 't is the snperficies of the Glass that is the worker on both sides and not the substance of the air on one side and of the glass on the other And lastly his answer no way solvs our objection which proves that the resistance both ways is proportionate to the force that moves and by consequence that the thing moved must go straight As we may imagine would happen if a bullet were shot stoping through a green mud wall in which there were many round sticks so thin set that the bullet might pass with ease through them for as long as the bullet touched none of them which express his case it would go straight but if it touch'd any which resembles ours as by and by will apperar it would glance according to the quality of the touch and move from the stick in another line Some peradventure may answer for Monsieur des Cartes that this subtile body which he supposes to run through all things is stiff and no ways pliable But that is so repugnant to the nature of rarity and so many insuperable inconveniences follow out of it as I cannot imagin he will own it and therfore I will not spend any time in replying therto We must therfore seek some other cause of the refraction of light which is made at the entrance of it into a Diaphanous body Which is plainly as we said before because the ray striking against the inside of a body it cannot penetrate turns by reflection towards that side on which the illuminant stands and if it findes clear passage through the whole resistent it follows the course it first takes if not then 't is lost by many reflections to and fro But because crooked surfaces may have many irregulalities it will not be amiss to give a rule by which all of them may be brought to a certainty And this it is that Reflections from crooked superficieses are equal to the reflections that are made from such plain superficieses as are tangents to the crooked ones in that point from whence the reflections are made Which Principle the Masters of Opticks take out of a Mathematecal supposition of the Unity of the reflecting point in both the surfaces the crooked and the plain But we take it out of the insensibility of the difference of so little a part in the two different surfaces as serves to reflect a ray of light For where the difference is insensible in the causes there likewise the difference is so little in the effects as sense cannot judge of them which is as much as is requisite to our purpose Now since in the Mathematical supposition the point where the reflection is made is indifferent to both the surfaces it follows that it imports not whether superficies you take to know the quality of reflection by This principle then being setled that the reflection must follow the nature of the tangent surfaces and it being proved that in plain surfaces it will happen as we have explicated it follows that in any crooked supersicies of what Figure soever the same also will happen Now seeing we have formerly declared that refractions are but a certain kind of reflexions what we have said here of reflections may be apply'd to refractions But there remains yet untouch'd one affection more of refractions which is that some Diaphanous bodies in their inward parts reflect more than others which is that we call refraction as experience shews us Concerning which effect we are to consider that Diaphanous bodies may in their composition have two differences for some are composed of greater parts and greater pores others of lesser parts and lesser pores 'T is true there may be other combinations of pores and parts yet by these two the rest may be esteem'd As for the first combination we see that because the pores are greater a greater multitude of parts of light may pass together through one pore and because the parts are greater likewise a greater multitude of rays may reflect from the same part and find the same passage quite throughout the Diaphanous body On the contrary side in the second combination where both the pores and the parts of the Diaphanous body are little the light must be but little that finds the same passage Now that refraction is greater or lesser happens two ways for 't is either when one Diaphanous body reflects light at more angles than another and by consequence in a greater extent of the superficies or else when one body reflects light from the
soft and liquid bodies easily joyn and incorporate into one continued body but hard and dry bodies so difficultly as by experience we find to be true Water with water or wine either with other wine or with water so unites that 't is very hard to part them but sand or stones cannot be made to stick together without very great force and industry The reasons whereof must necessarily depend of what we have said above To wit that two bodies cannot touch one another without becoming one and that if two bodies of one degree of density do touch they must stick together according to the force of that degree of density Out of which two is manifestly infer'd that if two hard things should come to touch they must needs be more difficultly separated then two liquid things And consequently they cannot come to touch without as much difficulty as that wherby they are made one But to deduce this more particularly let us consider that all the little surfaces by which one hard body may be conceiv'd to touch another as for example when a stone lies upon a stone must of necessity be either plain or concave or convex Now if a plain superficies should be supposed to touch another plain one coming perpendicularly to it it must of necessity be granted to touch it as soon in the middle as on the sides Wherfore if there were any air as of necessity there must be betwixt the two surfaces before they touch'd it will follow that the air which was in the midle must have fled quite out from between the two surfaces as soon as any part of the surfaces touch that is as soon as the air which was between the utmost edges of the surfaces did fly out and by consequence it must have moved in an instant But if a plain surface be said to touch a convex surface it touches it only by a line as Mathematicians demonstrate or a point But to touch by a line or a point is in truth not to touch by the form or motion of Quantity which requires divisibility in all that belongs to it and by consequence among bodies it is not-to-touch and so one such surface doth not touch the other Now for a plain surface to touch a concave every man sees is impossible Likewise for two convex surfaces to touch one another they must be allow'd to touch either in a line or in a point which we have shew'd not to be a physical touching And if a convex surface should be said to touch a concave they must touch all at once as we said of plain surfaces and therfore the same impossibility will arise therein So that 't is evident no two surfaces moving perpendicularly towards one another can come to touch one another if neither of them yields and changes its hew Now then if it be supposed they come slidingly one over another in the same line wherby first the very tips of the edges come to touch one another and still as you shove the uppermost on forwards and it slides over more of the nether surface it gains to touch more of it I say that neither in this case do they touch immediately one another For as soon as the two first parts should meet if they did touch and there were no air between them they must presently become one quantity or body as we have declared and must stick firmly together according to their degree of density and consequenly could not be moved on without still breaking asunder at every impulse as much of the massie body as were already made one by their touching And if you should say they did not become one and yet allow them to touch immediately one another without having any air or fluid body between them then if you suppose them to move onwards upon these terms they would be changed locally without any intrinsecal change which in the book De Mundo as we have formerly alledg'd is demonstrated impossible There remains only a third way for two hard surfaces to come together which is that first they should rest sloping one upon another and make an angle where they meet as two lines that cut one another doe in the point of their intersection and so contain as it were a wedge of air between them which wedge they should lessen by little and little through their moving towards one another at their most distant edges whiles the touching edges are like immoveable centers that the others turn upon till at length they shut out all the air and close together like the two legs of a compass But neither is it possible that this way they should touch For after their first touch by one line which neither is in effect a touching as we have shewed no other parts of them can touch though still they approach nearer and nearer till their whole surfaces entirely touch at once and therefore the air must in this case leap out in an instant a greater space then if the surfaces came perpendicularly to one another for here it must flie from one extremity to the other whereas in the former case it was to go but from the middle to each side And thus 't is evident that no two bodies can arrive to touch one another unless one of them at the least have a superficies plyable to the superficies of the other that is unless one of them be soft which is to be liquid in some degree Seeing then that by touching bodies become one and liquidity is the cause and means whereby bodies arrive to touch we may boldly conclude that two liquid bodies most easily and readily become one and next to two such a liquid and a hard body are soonest united but two hard ones most difficultly To proceed then with our reflections upon the composition of Bodies and upon what results out of the joyning and mixture of their first differences Rarity and Density we see how if a liquid substance happens to touch a dry body it sticks easily thereto Then consider there may be so small a quantity of such a liquid body as it may be almost impossible for any natural agent to divide it further into less parts and suppose that such a liquid part is between two dry parts of a dense body and sticking to them both becomes like a glew to hold them together will it not follow out of what we have said that these two dense parts will be as hard to be severed from one another as the small liquid part by which they stick together is to be divided So that when the viscuous ligaments which in a body hold together the dense parts are so small and subtile as no force we can apply can divide them the adhesion of the parts must needs grow then inseparable And therefore we use to moisten dry bodies to make them more easily be divided whereas those that are over-moist are of themselves ready to fall in pieces And thus you see how in general
bodies are framed Out of which discourse we may ballance the degrees of solidity in bodies For all bodies being composed of humide and dry parts we may conceive either kind of those parts to be bigger or lesser or to be more rare or more dense Now if the dry parts of any body be extreme little and dense and the moist parts that joyn the dry ones together be very great and rare then that body will be very easie to be dissolv'd But if the moist parts which glew together such extreme little and dense dry parts be either lesser in bulk or not so rare then the body composed of them will be in a stronger degree of consistence And if the moist parts which serve for this effect be in an excess of littleness and withal dense then the body they compose will be in the highest degree of consistence that nature can frame On the other side if you glew together great dry parts which are moderately dense great by the admixtion of humid parts that are of the least size in bulk and dense withal then the consistence will decrease from its height by how much the parts are greater and the density less But if to dry parts of the greatest size and in the greatest remisness of density you add humid parts both very great and very rare then the composed body will prove the most easily dissolveable of all that nature affords After this casting our eyes a little further towards the composition of particular bodies we shall find still greater mixtures the further we go for as the first and simplest compounded bodies are made of the four Elements so others are made of these and again a third sort of them and so on-wards according as by motion the parts of every one are broken in sunder and mingled with others Those of the first order must be of various tempers according to the proportions of the Elements whereof they are immediatly made As for example such a proportion of Fire to the other three Elements will make one kind of simple body and another proportion will make another kind and so throughout by various combinations and proportions among all the Elements In the effecting of which work it will not be amiss to look a little upon nature and observe how she mingles and tempers different bodies one with another wherby she begets that great variety of creatures we see in the World But because the degrees of composition are infinite according to the encrease of number we will contain our selves within the common notions of excess in the four primary components for if we should descend once to specifie any determinate proportions we should endanger losing our selvs in a wood of particular natures which belong not to us at present to examin Then taking the four Elements as materials to work upon let us first consider how they may be varied that differing compositions may result out of their mixtures I conceive that all the ways of varying the Elements in this regard may be reduced to the several sizes of Bigness of the Parts of each Element that enter into the composition of any body and to the Number of those Parts for certainly no other can be imagin'd unless it were variety of Figure But that cannot be admited to belong in any constant manner to those least particulars wherof bodies are framed as if determinate figures were in every degree of quantity due to the natures of Elements and therfore the Elements would conserve themselves in those figures as well in their least atoms as massie bulk For seeing how these little parts are shuffled together without any order and that all liquids easily joyn and take the figures which the dense ones give them and that they again justling one another crush themselves into new shapes to which their mixture with the liquid ones makes them yield the more easily t is impossible the elements should have any other natural figure in these their least parts then such as chance gives them But that one part must be bigger then another is evident for the nature of rarity and density gives it the first of them causing divisibility into little parts and the latter hindring it Having then settled in what manner the Elements may be varied in the composition of bodies let us now begin our mixture In which our ground to work upon must be Earth and Water For only these two are the Basis of permanent bodies that suffer our senses to take hold of them and submit themselvs to trial Wheras if we should make the predominant Element to be Air or Fire and bring in the other two solid ones under their jurisdiction only to make up the mixture the compound resulting out of them would be either in continual consumption as ordinary fire is or else through too much subtlety imperceptible to our eyes or touch therfore not a fit subject for us to discourse of especially since the other two Elements afford us enough to speculate on Peradventure our Smel might take some cognisance of a body so composed or the effect of it taken in by respiration might in time shew it self upon our health but it concerns not us now to look so far our design requires more maniable substances Of these then let Water be the first and with it we will mingle the other three elements in excess over one another by turns but stil all of them oversway'd by a predominant quantity of water and then let us see what kind of bodies will result out of such proportions First if earth prevail above fire and air and arrive next in proportion to the water a body of such a composition must needs prove hardly liquid and not easie to let its parts run a sunder by reason of the great proportion of so dense a body as earth that holds it together Yet some inclination it will have to fluidness by reason the water is predominant over all which also will make it be easily divisible and give every little resistance to any hard thing that shall be apply'd to make way through it In a word this mixture makes the constitution of Mud Dirt Honey Butter and such like things where the main parts are great ones And such are the parts of earth and water in themselvs Let the next proportion of excess in a watry compound be of air which when it prevails incorporates it self chiefly with earth for the other Elements would not so well retain it Now because its parts are subtile by reason of the rarity it hath and sticking because of its humidity it drives the earth and water likewise into lesser parts The result of such a mixture is that the parts of a body compounded by it are close catching flowing slowly glibb and generally it will burn and be easily converted into flame Of this kind are those we call Oyly or unctuous bodies whose great parts are easily separated that is easily divisible
continual application to the body it thus anatomises hath harden'd as it were rosted some parts into such greatness and driness as they will not flie nor can be carried up with any moderate heat But great quantity of fire being mingled with the subtiler parts of his baked earth makes them very pungent and acrimonious in tast so that they are of the nature of ordinary Salt and so called and by the help of water may easily be separated from the more gross parts which then remain a dead and useless earth By this discourse 't is apparent that fire has been the instrument which hath wrought all these parts of an entire body into the forms they are in for whiles it carried away the fiery parts it swel'd the watry ones and whiles it lifted up them it digested the Aerial parts and whiles it drove up the Oyle it baked the earth and salt Again all these retaining for the most part the proper nature of the substance from whence they are extracted 't is evident that the substance is not dissolv'd for so the nature of the whole would be dissolv'd and quite destroy'd extinguish'd in every part but that onely some parts containing the whole substance or rather the nature of the whole substance in them are separated fromo ther parts that have likewise the same nature in them The third instrument for the separation and dissolution of bodies is Water whose proper matter to work upon is Salt and it serves to supply what the fire could not perform which is the separation of the salt from the earth in calcined bodies All the other parts fire was able to sever but in these he hath so baked the little humidity he hath left in them with their much earth as he cannot divide them any further and so though he incorporates himself with them yet he can carry nothing away with him If then pure water be put upon that chalk the subtilest dry parts of it easily joyn to the supervenient moysture and sticking close to it draw it down to them But because they are the lighter it happens to them as when a man in a boat pulls the land to him that comes not to him but he removes himself and his boat to it so these ascend in the water as they dissolve And the water more and more penetrating them and by addition of its parts making the humidity which glews their earthy parts together greater and greater makes a wider and wider separation between those little earthy parts and so imbues the whole body of the water with them into which they are dispersed in little atomes Those that are of biggest bulk remain lowest in the water and in the same measure as their quantities dissolve into less and less they ascend higher and higher till at length the water is fully replenish'd with them and they are diffused through the whole body of it whiles the more gross and heavy earthy parts having nothing in them to make a present combination between them and the water fall down to the bottome and settle under the water in dust In which because earth alone predominates in a very great excess we can expect no other virtue to be in it but that which is proper to mere earth to wit driness and weight Which ordinary Alchimists look not after and therfore call it Terra damnata but others find a fixing quality in it by which they perform very admirable operations Now if you prove the impregnated water from the Terra damnata and then evaporate it you will find a pure white substance remaining Which by its bulk shews it self to be very earthy and by its pricking and corrasive taste will inform you much fire is in it and by its easie dissolution in a moist place that water had a great share in the production of it And thus the salts of bodies are made and extracted Now as water dissolves salt so by the incorporation and virtue of that corrosive substance it doth more then salt it self can do for having gotten acrimony and more weight by the mixture and dissolution of salt in it it makes it self away into solide bodies even into metalls as we see in brass and iron which are easily rusted by salt dissolving upon them And according as the salts are stronger so this corrasive virtue encreases in them even so much as neither silver nor gold are free from their eating quality But they as well as the rest are divided into most small parts and made to swim in water in such sort as we have explicated above and wherof every ordinary Alchymist teaches the practise But this is not all salts help as well to melt hard bodies and metalls as to corrode them For fome fusible salts flowing upon them by the heat of the fire and others dissolv'd by the steam of the metal that incorporates with them as soon as they are in flux mingle with the natural juice of the metals and penetrate deeper then without them the fire could do and swell them and make them fit to run These are the principal ways of the two last instruments in dissolving of bodies taking each of them by it self But there remains one more of very great importance as well in the works of nature as of art in which both the former are joyned and concur and that is putrefaction Whose way of working is by gentle heat and moisture to wet and pierce the body it works upon wherby 't is made to swel and the hot parts of it being loosen'd they are at length drunk up and drown'd in the moist ones from whence by fire they are easily separated as we have already declared and those moist parts afterwards leaving it the substance remaines dry and falls in pieces for want of the glew that held it together CHAP. XVI An explication of certain Maxims touching the operations and qualities of bodies and whether the Elements be found pure in any part of the World OUt of what we have determin'd concerning the natural actions of bodies in their making and destroying one another 't is easie to understand the right meaning of some terms and the true reason of some maxims much used in the Schools As first when Philosophers attribute to all sorts of corporeal Agents a Sphere of Activity The sense of that manner of expression in fire appears plainly by what we have already declared of the nature and manner of operation of that Element And in like manner if we consider how the force of cold consists in a compression of the body that is made cold we may perceive that if in the cooled body there be any subtile parts which can break forth from the rest such compression wil make them do so Especially if the compression be of little parts of the compressed body within themselvs as well as of the outward bulk of the whole body round about For at first the compression of such causes in the body
either losing his course by steering after a wrong compass or being forced back again with short and obscure relations of discoveries since others that went out before him are return'd with a large account to such as are able to understand and sum it up Which surely our learned Countryman and my best and most honoured Friend and to whom of all men living I am most obliged for to him I ow that little which I know and what I have and shall set down in all this discourse is but a few sparks kindled by me at his great fire has both profoundly and accutely and in every regard judiciously performed in his Dialogues of the World Our task then in a lower strain and more proportionate to so weak shoulders is to look no further then among those bodies we converse with Of which having declared by what course and Engines Nature governs their common motions that are found even in the Elements and from thence are derived to all bodies composed of them we intend now to consider such motions as accompany divers particular bodies and are much admired by whoever understands not the the causes of them To begin from the easiest and most connexed with the actions of the Elements the handsel of our labour will light upon the motions of Rarefaction and Condensation as they are the passions of mixed bodies And first for Rarefaction we may remember how it proceeds originally from fire and depends of heat as is declared in the former Chapter and wherever we find Rarefaction we may be confident the body which suffers it is not without fire working upon it From hence we may gather that when the Air imprison'd in a baloon or bladder swells against what contains it and stretches its case and seeks to break out this effect must proceed from fire or heat though we see not the fire working either within the very bowels of the air or without by pressing upon what contains it and so making it self a way to it And that this latter way is able to work this effect may be convinced by the contrary effect from a contrary cause for ' take a bladder stretch'd out to its greatest extent by air shut up within it and hang it in a cold place you will see it presently contract it self into a less room and the bladder will grow wrinckled and become too big for the air within it But for immediate proof of this position we see that the addition of a very smal degree of heat rarifies the air in a Weather-glass the air receiving the impression of heat sooner then water and so makes it extend it self into a greater place and consequently it presses upon the water and forces it down into a less room then formerly it possessed And likewise we see Quicksilver and other liquors if they be shut up in glasses close stop'd and set in sufficient heat and a little is sufficient for this effect will swell and fill their glasses and at the last break them rather then not find a way to give themselvs more room which is then grown too straight in the glass by reason of the rarefaction of the liquors by the fire working upon them Now again that this effect may be wrought by the inward heat that is inclosed in the bowels of the substance thus shut up both reason and experience assure us For they teach us that if a body which is not extremely compacted but that by its loosness is easily divisible into little parts such a one as Wine or other spiritual liquors be inclosed in a vessel the little atoms that perpetually move up and down in every space of the whole World making their way through every body will set on work the little parts in the Wine for example to play their game so that the hot and light parts if they be many not enduring to be compressed and kept in by the heavie and cold ones seek to break out with force and till they can free themselvs from the dense ones that would imprison them they carry them along with them and make them swell out as well as themselvs Now if they be kept in by the vessel so that they have not play enough they drive the dense ones like so many little hammers or wedges against the sides of it and at length break it and so make themselvs way to a larger room But if they have vent the more fiery hot spirits fly away and leave the other grosser parts quiet and at rest On the other side if the hot and light parts in a liquor be not many nor very active and the vessel be so ful that the parts have not free scope to remove and make way for one another there will not follow any great effect in this kind as we see in Bottle Beer or Ale that works little unless there be some space left empty in the bottle And again if the vessel be very much too big for the liquor in it the fiery parts find room first to swel up the heavie ones and at length to get out from them though the vessel be close stopped for they have scope enough to float up and down between the surface of the liquor and the roof of the vessel And this is the reason that if a little beer or small wine be left long in a great cask be it never so close stop'd it will in time grow dead And then if at the opening of the bung after the cask hath been long unstir'd you hold a candle close to it you shall at the instant see a flash of flame environing the vent Which is no other thing but the subtile spirits that parting from the beer or wine have left it dead and flying abroad as soon as they are permited are set on fire by the flame they meet with in their journey as being more combustible because more subtile then that spirit of wine which is kept in form of liquor and yet that likewise though much grosser is set on fire by the touch of flame And this happens not only to Wine and Beer or Ale but even to water As dayly experience shews in the East Indian Ships that having been five or six yeers at Sea when they open some of their casks of Thames Water in their return homewards for they keep that water till the last as being their best and most durable and that grows lighter and purer by the often purifyings through violent motions in storms every one of which makes new gross and earthy parts fall down to the bottom and other volatile ones ascend to the top a flame is seen about their bungs if a candle be near as we said before of wine And to proceed with confirming this doctrine by further experience we dayly see that the little parts of heat being agitated and brought into motion in any body enter and pierce into other parts and incorporate themselvs with them and set them on fire if they be capable
away all the palpable moisture And so when wet cloathes are hang'd either in the Sun or at the fire we see a smoake about the cloathes and heat within them which being all drawn out from them they become dry And this deserves a particular note that although they should be not quite dry when you take them from the fire yet by that time they are cool they will be dry for the fire that is in them when removed from the main stock of fire flying away carries with it the moisture that was incorporated with it And therfore whiles they were hot that is whiles the fire was in them they must also be moist because the fire and the moisture were grown to be one body and could not become through dry with that measure of fire for more would have dry'd them even whiles they were hot until they were also grown through cold And in like manner Syrups Hydromels Gellies and the like grow much thicker after they are taken off from the fire than they were upon the fire and much of their humidity flies away with the fire in their cooling wherby they lessen much of their quantity even after the outward fire hath ceased from working upon them Now if the moist parts that remain after the drying be by the heat well incorporated in the dry parts and so occasion the dry parts to stick close together then that body is condensed and will to the proportion of it be heavier in a less bulk as we see that Metals are heavier than Stones Although this effect be in those examples wrought by heat yet generally speaking it is more proper to cold which is the Second Way of drying a moist body As when in Greenland the extreme cold freeses the Whalefishes Beer into Ice so that the stewards divide it with Axes and Wedges and deliver their portions of drinks to their ships company and their Shallops gings in their bare hands but in the innermost part of the Butt they find some quantity of very strong liquor not inferiour to moderate spirit of Wine At first before custome had made it familiar to them they wonder'd that every time they drew at the tap when first it came from their ships to the shore for the heat of the hold would not let it freese no liquor would come unless they new tap'd it with a longer gimlet but they thought that pains well recompen'd by finding it in the tast to grow stronger and stronger till at last their longest gimlets would bring nothing out and yet the vessel not a quarter drawn off which obliged them then to stave the Cask that so they might make use of the substance that remain'd The reason of this is evident That cold seeking to condense the beer by mingling its dry and cold parts with it those that would indure this mixture were imbibed and shrunk up by them But the other rare and hot parts that were squees'd out by the dense ones which enter'd to congeal the beer and were forced into the middle of the vessel which was the furthest part for them to retire to from their invironing enemies conserv'd themselvs in their liquid form in defiance of the assaulting cold whiles their fellows remaining by their departure more gross and earthy then they were before yielded to the conquerour they could not shift away from and so were dry'd and condens'd in ice which when the Marriners thaw'd they found like fair water without any spirits in it or comforting heat to the stomack This manner of condensation which we have described in the freezing of Beer is the way most practis'd by nature I mean for immediate condensation for condensation is secondarily wherever there is rarefaction which we have determin'd to be an effect of heat And the course of it is that a multitude of earthy and dry bodies being driven against any liquor easily divide it by means of their density their driness and their littleness all which in this case accompany one another and are by us determin'd to be powerful dividers and when they are gotten into it they partly suck into their own pores the wet and diffused parts of the liquid body and partly they make them when themselvs are full stick fast to their dry sides and become as a glew to hold themselves strongly together And thus they dry up the liquor and by the natural pressing of gravity contract it into a lesser room No otherwise then when we force much wind or water into a bottle and by pressing it more and more make it lye closser then of its own nature it would do Or rather as when ashes are mingled with water both those substances stick so close to one another that they take up less room theâ— they did each apart This is the method of Frosts and Snow and Ice both natural and artificial For in natural freezing ordinarily the North or Northeast Wind by its force brings and drives into our liquors such earthy bodies as it has gather'd from rocks cover'd with snow which being mix'd with the light vapours whereof the wind is made easily find way into the liquors and then they dry them into that consistence we call Ice Which in token of the wind it has in it swims upon the water and in the vessel where it is made rises higher then the water did wherof it is composed and ordinarily it breaks from the sides of the vessel so giving way to more wind to come in and freeze deeper and thicker But because Galileus In his Discourses Intorno alle cose che stanno in su l' accqua pag. 4. was of opinion that Ice was water rarified and not condens'd we must not pass over this verity without maintaining it against the opposition of so powerful an adversary His arguments are first that Ice takes up more place then the water did of which it was made which is against the nature of condensation Secondly that quantity for quantity Ice is lighter then water wheras things that are more dense are proportionally more heavie And lastly that Ice swims in water wheras we have aften taught that the more dense desends in the more rare Now to reply to these arguments we say first that We would gladly know how he did to measure the quantity of the Ice with the quantity of the Water of which it was made and then when he hath shew'd it and shew'd withall that Ice holds more place then water we must tell him that his experiment concludes nothing against our doctrine because there is an addition of other bodies mingled with the water to make Ice of it as we touch'd above and therefore that compound may well take up a greater place then the water alone did and yet be denser then it and the water also be denser then it was And that other bodies do come into the water and are mingled with it is evident out of the exceeding coldness of the aire or some very old wind one of
air or other cold bodies to thicken and condense as above we mentioned of Syrups and Jellies and so they are brought to stick firmly together In like manner we see that when two metals are heated till they be almost brought to running and then are pressed together by the hammer they become one continued body The like we see in glass the like in wax and in divers other things Onthe contrary side when a broken stone is to be pieced together the pieces of it must be wetted and the cement must be likewise moistned and then joyning them aptly and drying them they stick fast together Glew is moistned that it may by drying afterwards hold pieces of wood together And the Spectale-makers have a composition which must be both heated and moistned to joyn to handles of wood the glasses they are to grind And broken glasses are cemented with cheese and chalk or with garlick All these effects our sense evidently shews us arise out of condensation but to our reason it belongs to examine particularly by what steps thy are perform'd First then we know that heat subtilizes the little bodies which are in the pores of the heated body and partly also it opens the pores of the body it self if it be of a nature that permits it as it seems those bodies are which by heat are mollified or are liquofactable Again we know that moisture is more subtile to enter into small creeks then dry bodies are especially when it is pressed for then it will be divided into very little parts and will fill up every little chinck and nevertheless if it be of a gross and viscuous nature all the parts of it will stick together Out of these two properties we have that since every body has a kind of orb of its own exhalations or vapours round about it self as is before declared the vapours which are about one of the bodies will more strongly and solidly that is in more abundant and greater parts enter into the pores of the other body against which it is pressed when they are opened and dilated and thus they becoming common to both bodies by flowing from the one and streaming into the other and sticking to them both will make them stick to one another And then as they grow cold dry these little parts shrink on both sides and by their shrinking draw the bodies together and withal leave greater pores by their being compressed together then were there when by heat and moysture they were dilated into which pores the circumstant cold parts enter and therby as it were wedge in the others and consequently make them hold firmly tostether the bodies which they joyn But if art or nature should apply to this juncture any liquor or vapour which had the nature and power to insinuate it self more efficaciously to one of these bodier then the glew which was between them did of necessity in this case these bodies must fall in pieces And so it happens in the separation of metals by corrosive waters as also in the precipitation of metals or salts when they are dissolv'd into such corrosive waters by means of other metals or salts of a different nature in both which cases the entrance of a latter body that penetrates more strongly and unites it self to one of the joyn'd bodies but not to the other tears them asunder and that which the piercing body rejects falls into little pieces and if formerly it were joyn'd with the liquor 't is then precipitated down from it in a dust Out of which discourse we may resolve the question of that learned and ingenious man Petrus Gassendus who by experience found that water impregnated to fulness with ordinary salt would yet receive a quantity of other salt and when it would imbibe no more of that would neverthless take into it a proportion of a third and so of several kinds of salts one after another which effect he attributed to Vacuities or porous spaces of divers figures that he conceived to be in the water wherof some were fit for the figure of one salt and some for the figure of another Very ingeniously yet if I miss not my mark most assuredly he hath missed his For first how could he attribute divers sorts of Vacuities to water without giving it divers figures And this would be against his own discourse by which every body should have one determinate natural figure Secondly I would ask him if he measured his water after every salting and if he did whether he did not find the quantity greater then before that salt was dissolv'd in it Which if he did as without doubt he must then he might safely conclude that his salts were not receiv'd in vacuities but that the very substance of the water gave them place and so encreas'd by the receiving them Thirdly seeing that in his doctrine every substance has a particular figure we must allow a strange multitude of different shapes of vacuities to be naturally in water if we will have every different substance wherwith it may be impregnated by making decoctions extractions solutions and the like to find a fit vacuity in the water to lodg it self in What a difform net with a strange variety of mashes would this be And indeed how extremely uncapable must it be of the quantity of every various kind of vacuity that you will find must be in it if in the dissolution of every particular substance you calculate the proportion between it and the water that dissolveth it and then multiply it according to the number of several kinds of substances that may be dissolved in water By this proceeding you will find the vacuities to exceed infinitely the whole body of the water even so much that it could not afford subtile thrids enough to hold it self together Fourthly if this doctrine were true it would never happen that one body or salt should precipitate down to the bottom of the water by the solution of another in it which every Alchymist knows never fails in due circumstances for seeing that the body which precipitates and the other which remains dissolv'd in the water are of different figures and therfore require dâ—fferent vacuities they might both of them have kept their places in the water without thrusting one another out of it Lastly this doctrine gives no account why one part of salt is separated from another by being put in the water and why the parts are there kept so separated which is the whole effect of that motion we call dissolution The true reason therfore of this effect is as I conceive that one salt makes the water apt to receive another for the lighter salt being incorporated with the water makes the water more proper to stick to an heavier and by dividing the small parts of it to bear them up that otherwise would have sunk in it The truth and reason of which will appear more plain if at every joynt we observe the particular steps of every
may be drawn to what height one pleases However the force which nature applies to maintain the continuity of quantity can have no limit seeing it is grounded upon contradiction And therefore Galileo was much mistaken when he thought to make an instrument wherby to discover the limits of this force We may then conclude that the breaking of the water must depend from the strength of other causes As for example when the gravity is so great by increasing the bulk of the water that it will either overcome the strength of the pipe or else make the sucker of the pump rather yield way to air then draw up so great a weight for which defects if remedies be found the art may surely be inlarged without end This is particular in a Syphon that when that arm of it which hangs out of the water is lower then the superficies of the water then it will run of it self after it is once set on running by sucking The reason whereof is because the weight which is in the water pendant is greater then the weight of the ascending water and therby supplyes the want of a continual suckeâ— But if the nose of that arm that hangs out of the water be put even with the water then the water will stand still in both pipes or arms of the Syphon after thy are filled with sucking But if by the running out of the water the outward pipe grow shorter then to reach as low as the superficies of the water in the fountain from whence it runs in this case the water in each arm of the Syphon will run back into the fountain Withall it is to be noted that though the arm which is out of the water be never so long yet if it reach not lower then the superficies of the fountain the over quantity and weight of the water there more then in the other arm helps it nothing to make it run out Which is because the declivity of the other arm over-recompences this overweight Not that the weight in the shorter pipe has so much force as the weight in the longer pipe but because it has more force then the greater weight exercises therin its running for the greatest part of its force tends another way then to the end of the pipe to wit perpendicularly towards the Centre and so is hindred from effect by the great sloping or little declivity of the pipe upon which it leans But some considering how the water in that longer arm of the Syphon is more in quantity than the water in the other arm of it wherat it runs out admire why the greater quantity of water doth noâ—d raw back the less into the cistern but suffers it self to be lifted up and drain'd away as if it run steeply downwards And they imagine that hence may be deduced that the parts of water in the cistern do not weigh as long as they are within the orb of their own body To whom we answer that they should consider how that to have the greater quantity of water in the longer arme of the Syphon which arm is immersed in the water of the cistern draw back into the cistern the water in the other arm of the Syphon that hangs out in the air it must both raise as much of the water of the cistern as its own bulk is above the level which at present the whole bulk of water has and withal at the same time pull up the water in the other arm Now 't is manifest that these two quantities of water together are heavier then the water in the sunk arm of the Syphon since one of them single is equal unto it And by consequence the more water in the sunk arm cannot weigh back the less water in the hanging arm since to do that it must at the same time weigh up over and above as much more in the cistern as it self weighs But turning the argument I say that if once the arm of the Syphon that is in the air be supposed to draw any water be it never so little out of the cistern whether occasioned by sucking or by whatever other means it follows that as much water as is drawn up above the level of the whole bulk in the cistern must needs press into the sunken arm from the next adjacent parts that is from the bottom to supply its emptying and as much must of it self press down from above according to its natural course when nothing violents it to rest in the place that the ascending water which is lower then it leavs at liberty for it to take possession of And then it cannot be doubted but that this descending water having all its weight in pressing down applied to drive up the rising water in the sunk arm of the Syphon the water in the other arm of the Syphon without having all its weight in ruÌ„ning out appli'd at the same time to draw up the same water in the sunk arm this single resistant must yield to their double mastering force And consequently the water in the arm of the Syphon that is in the air must needs draw the water that is the other immersed arm as long as the end of its pipe reaches lower then the level of the water in the cistern for so long it appears by what we have said it must needs be more weighty since part of the rising water in the sunk arm of the syphon is couÌ„ erpois'd by as much descending water in the cistern And thus 't is evident that out of this experiment it cannot be infer'd that parts of water do not weigh within the orb of their own whole but only that two equal parts of water in their own orb namely that which rises in the sunken arm and that which presses down from the whole bulke in the cistern are of equal weight and ballance one another So that never so little odds between the two counterpoysing parcels of water which are in the air must needs make the water run out at that end of the syphon where the overweight of water is The Attraction whose cause next to this is most manifest is that which is made by the force of heat or fire for we see that fire ever draws air to it so notably that if in a close room there be a good fire a man that stands at the door or window especially without shall hear such a noise that he will think there is a great wind within the chamber The reason of this attraction is that fire rarifying the air next it and withall spending it self perpetually causes the air and his own body mingled together to fly up through the chimney or by some other passage Whence it follows of necessity that the next body must succeed into the place of the body that is flown away The next body generally is air whose mobility and fluidity beyond all other bodies makes it of all others the fittest to be drawn and the more of it
it upon a hedge as that dries away so will their sore amend In other parts they observe that if milk newly come from the cow in the boyling run over into the fire and that this happen often and near together to the same cows milk that cow will have her udder sore inflamed and the prevention is to cast salt immediately into the fire upon the milk The herb Persicaria if it be well rub'd upon Warts and then be laid in some fit place to putrifie causes the Warts to wear away as it rots some say the like of fresh Beef Many examples also there are of hurting living creatures by the like means which I set not down for fear of doing more harm by the evil inclination of some persons into whose hands they may fall then profit by their knowing them to whom I intend this work But to make these operations of nature not incredible let us remember how we have determin'd that every body whatever yields some steam or vents a kind of vapour from it self and consider how they must needs do so most of all that are hot and moist as bloud and milk and all wounds and sores generally are We see that the foot of a Hare or Bear leaves such an impression where the beast has passed as a dog can discern it a long time after and a Fox breaths out so strong a vapour that the hunters themselvs can wind it a great way off and a good while after he is parted from the place Now joyning this to the experiences we have already allow'd of concerning the attraction of heat we may conclude that if any of these vapours light upon a solid warm body which has the nature of a source to them they will naturally congregate and incorporate there and if those vapours be joyn'd with any medicative quality or body they will apply that medicament better then any Chirurgeon can Then if the steam of bloud bloud and spirits carry with it from the weapon or cloth the balsamike qualities of the salve or powder and with them settle upon the wound what can follow but a bettering in it Likewise if the steam of the corruption that is upon the clod carry the drying quality of the wind which sweeps over it when it hangs high in the air to the sore part of the cows foot why is it not possible that it should dry the corruption there as well as it dryes it upon the hedge And if the steam of burned milk can hurt by carrying fire to the dug why should not salt cast upon it be a preservative against it Or rather why should not salt hinder the fire from being carried thither Since the nature of salt always hinders and suppresses the activity of fire as we see by experience when we throw salt into the fire below to hinder the flaming of soot in the top of a chimney which presently ceases when new fire from beneath doth not continue it And thus we might proceed in sundry other effects to declare the reason and possibility were we certain of the truth of them therfore we remit this whole question to the authority of the testimonies CHAP. XIX Of three other motions belonging to particular bodies Filtration Restitution and Electrical attraction AFter these let us cast our eye upon another motion very familiar among Alchymists which they call Filtration It is effected by putting one end of a tongue or label of Flannen or Cotten or Flax into a vessel of water and letting the other end hang over the brim of it And it will by little and little draw all the water out of that vessel so that the end which hangs qâ—t be lower then the superficies of the water and make it all come over into any lower vessel you will reserve it in The end of this operation is when any water is mingled with gross and muddy parts not dissolv'd in the water to separate the pure light ones from the impure By which we are taught that the lighter parts of the water are those which most easily catch And if we will examine in particular how 't is likely this business passes we may conceive that the body or linguet by which the water ascends being a dry one some lighter parts of the water whose chance it is to be near the climbing body of Flax begin to stick fast to it and then they require nothing near so great force nor so much pressing to make them climb up along the flax as they would do to make them mount in the pure air As you may see if you hold a stick in running water shelving against the stream the water will run up along the stick much higher then it could be forced up in the open air without any support though the agent were much stronger then the current of the stream And a ball will on a rebound run much higher upon a shelving board then it would if nothing touch'd it And I have been told that if an egsshell fill'd with dew be set at the foot of a hollow stick the Sun will draw it to the top of the shelving stick wheras without a prop it will not stir it With much more reason then we may conceive that water finding as it were little steps in the Cotton to facilitate its journy upwards must ascend more easily then those other things do so as it once receive any impulse to drive it upwards For the gravity both of that water which is upon the Cotton as also of so many of the confining parts of water as can reach the Cotton is exceedingly allay'd either by sticking to the Cotton and so weighing in one bulk with that dry body or else by not tending down straight to the Center but resting as it were upon a steep plain according to what we said of the arm of a Syphon that hangs very sloping out of the water and therfore draws not after it a less proportion of water in the other arm that is more in a direct line to the Center by which means the water as soon as it begins to climb comes to stand in a kind of cone neither breaking from the water below its bulk being big enough to reach to it nor yet falling down to it But our chief labour must be to finde a cause that may make the water begin to ascend To which purpose consider how water of its own nature compresses it self together to exclude any other body lighter then it is Now in respect of the whole mass of the water those parts which stick to the cotton are to be acounted muchlighter then water not because in their own nature they are so but for the circumstances which accompany and give them a greater disposition to receive a motion upwards then much lighter bodies whiles they are destitute of such helps Wherfore as the bulk of water weighing and striving downwards it follows that if there were any air mingled with it it would to
possess a lesser place drive out the aire so here in this case the water at the foot of the ladder of cotton ready to climb with a very small impulse may be after some sort compared in respect of the water to air by reason of the lightness of it and consequently is forced up by the compressing of the rest of water round about it Which no faster gets up but other parts at the foot of the ladder follow the first and drive them still upwards along the tow and new ones drive the second and others the third and so forth so that with ease they climb up to the top of the filter still driving one another forwards as you may do a fine towel through a musket barrel which though it be too limber to be thrust straight through yet craming still new parts into it at length you will drive the first quite through And thus when these parts of water are got up to the top of the vessel on which the filter hangs and over it on the other side by sticking still to the tow and by their natural gravity against which nothing presses on this side the label they fall down again by little and little and by drops break again into water in the vessel set to receive them But now if you ask why it will not drop unless the end of the label that hangs be lower then the water I conceive it is because the water which is all along upon the flannen is one continued body hanging together as it were a thrid of wire and is subject to like accidents as such a continued body is Now suppose you lay wire upon the edge of the basin which the filter rests on and so make that edge the Centre to ballance it upon if the end that is outermost be heaviest it will weigh down the other otherwise not So fares it with this thrid of water if the end of it that hangs out of the pot be longer and consequently heavier then that which rises it must needs raise the other upwards and fall it self downwards Now the raising of the other implies lifting more water from the Cistern and the sliding of it self further downwards is the cause of its converting into drops So that the water in the cistern serves like the flax upon a distaff and is spun into a thrid of water still as it comes to the flannen by the drawing it up occasion'd by the overweight of the thrid on the other side of the center Which to express better by a similitude in a solid body I remember I have oftentimes seen in a Mercers shop a great heap of massy gold lace lie upon their stall and a little way above it a round smooth pin of wood over which they use to have their lace when they wind it into bottoms Now over this pin I have put one end of the lace as long as it hung no lower then the board upon which the rest of the lace did lie it stird'd not for as the weight of the loose end carried it one way so the weight of the otherside where the whole was drew it the otherway in this manner kept it in equalibrity But as soon as I drew on the hanging end to the heavier then the climbing side for no more weights then is in the air that which lies upon the board having another center then it began to roule to the ground and still drew up new parts of that which lay upon the board till all was tumbled down upon the floor In the same manner it hap'nes to the water in which the thrid of it upon the filter is to be compared fitly to that part of the lace which hung upon the pin and the whole quantity in the cistern is like the bulk of lace upon the Shopboard for as fast as the filter draws it up 't is converted into a thrid like that which is already upon the filter in like manner as the wheel converts the flax into yarn as fast as it draws it out from the distaff Our next consideration will very aptly fall upon the motion of those things which being bent leap with violence to their former figure wheras others return but a little and others stand in that ply wherin the bending hath set them For finding the reason of which effects our first reflection may be to note that a Superficies which is more long then broad contains a less floor then that whose sides are equal or nearer being equal and that of those surfaces whose lines and angles are all equal that which hath most sides and angles contains still the greater floor Whence it is that Mathematicians conclude a circle to be the most capacious of all figures and what they say of lines in respect of a superficies the same with proportion they say of surfaces in respect of the body contained And accordingly we see by consequence that in the making a bag of a long napkin if the napkin be sew'd together longwise it holds a great deal less then if it be sewd together broadwise By this we see plainly that if any body in a thick and short figure be forced into a thinner which by becoming thinner must likewise become either longer or broader for what it loses one way it must get another then that superficies must needs be stretched which in our case is a Physical outside or material part of a solid body not a Mathematical consideration of an indivisible Entity We see also that this change of figures happens in the bending of all those bodies wherof we are now enquiring the reason why some of them restore themselves to their original figures and others stand as they are bent Then to begin with the latter sort we find that they are of a moist nature as among metalls lead and tin and among other bodies those â—which we account soft And we may determine that this effect proceeds partly from the humidity of the body that stands bent and partly from a driness peculiar to it that comprehends and fixes the humidity of it For by the first they are render'd capable of being driven into any figure which nature or art desires and by the second they are preserv'd from having their gravity put them out of what figure they have once receiv'd But because these two conditions are common to all solid bodies we may conclude that if no other circumstance concur'd the effect arising out of them would likewise be common to all such and therfore where we find it otherwise we must seek further for a cause of that transgression As for example if you bend the bodies of young trees or the branches of others they will return to their due figure 'T is true they will somtimes lean towards that way they have been bent as may be seen even in great trees after violent tempests and generally the heads of trees the ears of corn and the grown hedg rows will all bend one way
in some countries where some one wind has a main predominance and reigns most continually as near the Seashore upon the western coast of England where the South-West wind blows constantly the greatest part of the year may be observed but this effect proceeding from a particular and extraordinary cause concerns not our matter in hand We are to examine the reason of the motion of Restitution which we generally see in young trees and branches of others as we said before In such we see that the earthy part which makes them stiff or rather stark abounds more then in the others that stand as they were bent at least in proportion to their natures but I conceive this is not the cause of the effect we enquire about but that 't is a subtile spirit which hath a great proportion of fire in it For as in rarefaction we found that fire which was either within or without the body to be rarified did cause the rarefaction either by entring into it or by working within it so seeing here the question is for a body to go out of a lesser superficies into a greater which is the progress of rarefaction and hapen's in the motion of restitution the work must needs be done by the force of heat And because this effect proceeds evidently out of the nature of the thing in which it is wrought and not from any outward cause we may conclude it has its origine from a heat within the thing it self or else that was in it and may be press'd to the outward parts of it and would sink into it again As for example when a young tree is bended both every mans conceit is and the nature of the thing makes us believe that the force which brings the tree back again to its figure comes from the inner side that is bent which is compress'd together as being shrunk into a circular figure from a straight one for when solid bodies that were plain on both sides are bent so as on each side to make a portion of a Circle the convex superficies will be longer then it was before when it was plain but the concave will be shorter And therfore we may conceive that the spirits which are in the contracted part being there squeez'd into less room then their nature well brooks work themselvs into a greater space or else that the spirits which are crush'd out of the convex side by the extension of it remain besieging it and strive to get in again in such manner as we have declared when we spoke of attraction wherin we shew'd how the emited spirits of any body will move to their own source and settle again in it if they be within a convenient compass and accordingly bring back the extended parts to their former situation or rather that both these causes in their kinds concur to drive the tree into its natural figure But as we see when a stick is broken 't is very hard to replace all the splinters every one in its proper situation so it must of necessity fall out in this bending that certain insensible parts both inward and outward are therby displaced and can hardly be perfectly rejoynted Whence it follows that as you see the splinters of a half broken stick meeting with one another hold the stick somwhat crooked so these invisible parts do the like in such bodies as after bending stand a little that way but because they are very little ones the tree or branch that has been never so much bended may so nothing be broken in it be set strait again by pains without any notable detriment of its strength And thus you see the reason of some bodies returning in part to their natural figures after the force leaves them that bent them Out of which you may proceed to those bodies that restore themselvs entirely whereof steel is the most eminent And of it we know that there is a fiery spirit in it which may be extracted out of it not only by the long operations of calcining digesting and distilling it but even by gross heating and then extinguishing it in wine and other convenient Liquors as Physicians use to do Which is also confirm'd by the burning of steel-dust in the flame of a candle before it has been thus wrought upon which after-wards it will not do wherby we are taught that originally there are store of spirits in steel till they are sucked out Being then assured that in steel there is such abundance of spirits and knowing that it is the nature of spirits to give a quick motion and seeing that duller spirits in trees make this motion of Restitution we need seek no further what it is that doth it in steel or in any other things that have the like nature which through the multitude of spirits that abound in them especially steel returns back with so strong a jerk that their whole body will tremble a great while after by the force of its own motion By what is said the nature of those bodies which shrink and stretch may easily be understood for they are generally composed of stringy parts to which if humidity happen to arrive they grow therby thicker and shorter As we see that drops of water getting into a new rope of a well or into a new cable will swell it much thicker and by consequence make it shorter Galileus notes such wetting to be of so great efficacy that it will shrink a new cable and shorten it notably notwithstanding the violence of a tempest the weight and jerks of a loaden ship strain it what is possible for them to stretch it Of this nature leather seems to be and parchment and divers other things which if they be proportionably moistned and no exteriour force apply'd to extend them will shrink up but if they be overweted they will become flaccide Again if they be suddenly dryed they 'l shrivel up but if they be fairly dried after moderate weting they will extend themselvs again to their first length The way having been open'd by what we have discoursed before we came to the motion of Restitution towards the discovery of the manner how heavy bodies may be forced upward contrary to their natural motion by very smal means in outward appearance let us now examine upon the same grounds if like motions to this of water may not be done in some other bodies in a subtiler manner In which more or less needs not trouble us since we know that neither quantitâ—â—or the operations of it consist in an indivisible or are limited or determin'd by periods they may not pass 'T is enough for us to find a ground for the possibility of the operation and then the perfecting and reducing of it to such a height as at first might seem impossible incredible we may leave to the Oeconomy of wise nature He that learns to read write or play on the Lute is in the beginning ready to lose heart at every step
whom and Dr. Harvey our Nation may claim even in this latter age as deserved a crown for solid Philosophical learning as for many ages together it hath done formerly for acute and subtile speculations in Divinity But before I fall to particulars I think it worth warning my Reader how this Great Man arrived to discover so much of Magnetical Philosophy that he likewise if he be desirous to search into nature may by imitation advance his thoughts and knowledge that way In short then all the knowledg he got of this subject was by forming a little Loadstone into the shape of the earth By which means he compassed a wonderful design which was to make the whole globe of the earth maniable for he found the properties of the whole earth in that little body which he therfore called a Terrella or little earth and which he could manage and try experiences on at his will And in like manner any man that has an aim to advance much in natural Sciences must endeavour to draw the matter he enquires of into some smal model or into some kind of manageable method which he may turn and wind as he pleases and then let him be sure if he hath a competent understanding that he will not miss of his mark But to our intent the first thing we are to prove is that the Loadstone is generated in such sort as we have described For proof wherof the first ground we will lay shall be to consider how in divers other effects it is manifest that the differences of being exposed to the North or to the South cause very great variety in the same thing as hereafter we shall have occasion to touch in the barks and grains of trees and the like Next we find by experience that this virtue of the Loadstone is receivd into other bodies that resemble its nature by heatings and coolings for so it passes in iron bars which being throughly heated and then laid to cool North and South are therby imbued with a Magnetick virtue heat opening their bodies and disposing them to suck in such atoms as are convenient to their nature that flow to them whiles they are cooling So that we cannot doubt but convenient matter fermenting in its warm bed under the earth becomes a Loadstone by the like sucking in of affluent streams of a like complexion to the former And it fares in like manner with those fiery instruments as fireforks tongues shovels and the like which stand constantly upwards and downwards for they by being often heated and cool'd again gain a very strong verticity or turning to the Pole and indeed they cannot stand upwards and downwards so little a while but they will in that short space gain a manifest verticity and change it at every turning Now since the force and vigour of this verticity is in the end that stands downwards 't is evident that this effect proceeds out of an influence receiv'd from the earth And because in a Load-stone made into a globe or consider'd so to the end you may reckon Hemispheres in it as in the great earth either Hemisphere gives to a needle touch'd upon it not only the virtue of that Hemisphere where it is touch'd but likewise the vertue of the contrary Hemisphere we may boldly conclude that the virtue which a Loadstone is impregnated with in the womb or bed of the earth where it is form'd and grows proceeds as well from the contrary Hemisphere of the earth as from that wherin it lyes in such sort as we have above described And as we feel oftentimes in our own bodies that some cold we catch remains in us a long while after the taking it and somtimes seems even to change the nature of some part of our body into which it is chiefly enter'd and hath taken particular possession of so that whenever new atoms of the like nature again range about in the circumstant air that part so deeply affected with the former ones of-kin to these in a particular manner seems to rissent and attract them to it and to have its guests within it as it were waken'd and rous'd up by the strokes of the advenient ones that knock at their doors Even so but much more strongly by reason of the longer time and less hinderances we may conceive that the two virtues or atoms proceeding from the two different Hemisphere constitute a certain permanent and constant nature in the stone that imbibes them which then we call a Loadstone and is exceeding sensible as we shall hereafter declare of the advenience to it of new atoms a like in nature and complexion to those it is impregnated with And this virtue consisting in a kind of softer and tenderer substance then the rest of the stone becomes thereby subject to be consumed by fire From whence we may gather the reason why a Loadstone never recovers its magnetick virtue after it hath once lost it though iron doth for the humidity of iron is inseparable from its substance but the humidity of a Loadstone which makes it capable of this effect may be quite consumed by fire and so the stone may be left too dry for ever being capable of imbibing any new influence from the earth unless it be by a kind of new making it In the next place we are to prove that the Loadstone works in that manner we have shew'd For which end let us consider how the atoms that are drawn from each Pole and Hemisphere of the earth to the Equator making up their course by a manuduction of one another the hindermost cannot chose but still follow on after the formost And as it happens in filtration by a cotton cloath if some one part of the cotton have its disposition to the ascent of the water more perfect and ready then the other parts have the water will assuredly ascend faster in that part then in any of the rest so if the atoms find a greater disposition for their passage in any one part of the Medium they range through then in another they will certainly not fail of taking that way in greater abundance and with more vigour and strength then any other But 't is evident that when they meet with such a stone as we have described the helps by which they advance in their journey are notably encreas'd by the floud of atoms they meet coming out of that stone which being of the nature of their opposite pole they seise greedily upon them and therby pluck themselvs faster on like a Ferry man that draws on his boat the swiftlier the more vigourously he tâ—gs and pulls at the rope that lyes thwart the river for him to hale himself over by And therfore we cannot doubt but this floud of atoms streaming from the pole of the earth must needs pass through that stone with more speed and vigour then they can do any other way And as we see in the running of water if it meets with any lower
of them To come then to the matter Now that we have explicated the natures of those motions by means wherof bodies are made and destroy'd and in which they are to be consider'd chiefly as passive whiles some exterior agent working upon them causes such alterations in them and brings them to such pass as we see in the changes that are daily wrought among substances The next thing we are to imploy our selves about is to take a survey of those motions which some bodies have wherin they seem to be not so much patients as agents and contain within themselvs the principle of their own motion having no relation to any outward object more then to stir up that principle of motion and set it on work which when it is once in act hath as it were within the limits of its own kingdom and sever'd from commerce with all other bodies whatever many other subaltern motions over which it presides To which purpose we may consider that among the compounded bodies whose natures we have explicated there are some in whom the parts of different complexions are so small so wel mingled together that they make a compound which to our sense seems all quite through of one Homogeneous nature and however it be divided each part retains the entire and compleat nature of the whole Others again there are in which 't is easie to discern that the whole is made up of several great parts of very differing natures and tempers And of these there are two kinds one of such as their differing parts seem to have no relation to one another or correspondence together to perform any particular work in which all of them are necessary but rather they seem to be made what they are by chance and accident and if one part be sever'd from another each is an entire thing by it self of the same nature as it was in the whole and no harmony is destroy'd by such division As may be observ'd in some bodies dig'd out of Mines in which one may see lumps of Metal or stone and glass and such different substances in their several distinct situations perfectly compacted into one continuate body which if you divide the glass remains what it was before the Emerald is still an Emerald the silver is good silver and the like of the other substances the causes of which may be easily deduced out of what we have formerly said But there are other bodies in which this manifest and notable difference of parts carries with it such a subordination of one of them to another as we cannot doubt but that nature made such engines if so I may call them by design and intended that this variety should be in One thing whose unity and being what it is should depend of the harmony of the several differing parts and should be destroy'd by their separation As we see in living Creatures whose particular parts and members being once sever'd there is no longer a living creature to be found among them Now of this kind of bodies there are two sorts The first is of those that seem to be one continuate substance wherin we may observe one and the same constant progress throughout from the lowest to the highest part of it so that the operation of one part is not at all different from that of another but the whole body seems to be the course and throughfare of one constant action varying it self in divers occasions and occurrences according to the disposition of the subject The bodies of the second sort have their parts so notably separated one from the other and each have such a peculiar motion proper to them that one might conceive they were every one a complete distinct total thing by it self and that all of them were artificially tied together were it not that the subordination of these parts to one another is so great and the correspondence between them so strict the one not being able to subsist without the other from whom he derives what is needful for him and again being so useful to that other and having its action and motion so fitting and necessary for it as without it that other cannot be as plainly convinces that the compound of all these several parts must needs be one individuol thing I remember that when I travel'd in Spain I saw there two Engines that in some sort express the natures of these two kinds of bodies One at Toledo the other a Segovia both of them set on work by the current of the river in which the foundation of their machine was laid That at Toledo was to force up water at a great height from the river Tagus to the Alcazar the Kings palace that stands upon a high steep hill or rock almost perpendicular over the river In the bottome there was an indented wheel which turning round with the stream gave motion at the same time to the whole engine which consisted of a multitude of little troughs or square ladles set one over another in two parallel rows over against one another from the bottom to the top and upon two several divided frames of timber These troughs were closed at one end with a traverse board to retain the water from running out there which end being bigger then the rest of the trough made it somewhat like a ladle and the rest of it seem'd to be the handle with a channel in it the little end of which channel or trough was open to let the water pass freely away And these troughs were fasten'd by an axletree in the middle of them to the frame of timber that went from the bottome up to the top so that they could upon that center move at liberty either the shut end downwards or the open end like the beam of a ballance Now at a certain position of the root-wheel if so I may call it all one side of the machine sunk down a little lower towards the water and the other was raised a little higher Which motion was changed as soon as the ground-wheel had ended the remnant of his revolution for then the side that was lowest before sprung up and the other sunk down And thus the two sides of the machine were like two legs that by turns trod the water as in the Vintage men press Grapes in a watte Now the troughs that were fast'ned to the timber which descended turn'd that part of them downwards which was like a Box shut to hold the water and consequently the open end was up in the air like the arm of the ballance to which the lightest scale is fasten'd and in the mean time the troughs upon the ascending timber were moved by a contrary motion keeping their boxends aloft and letting the open ends incline downwards so that if any water were in them they would let it run out wher'as the others retain'd any that came into them VVhen you have made an image of this Machine in your phantasie consider what will follow out
while longer fighting would have sunk one another But besides the motions in the air which receiv'd them easily by reason of the fluidity of it we see that even solid bodies participate of it As if you knock never so lightly at one end of the longest beam you can find it will be distinctly heard at the other end The trampling of men and horses in a quiet night wil be heard some miles off if one lay their ear to the ground and more sensibly if one make a little hole in the earth and put ones ear into the mouth of it but most of all if one set a Drum smooth upon the ground and lay ones ear to the upper edge of it for the lower membrane of the Drum is shaked by the motion of the earth and then multiplies that sound by the hollow figure of the Drum in the conveying it to the upper membrane upon which your ear leans Not much unlike the Tympane or Drum of the ear which being shaked by outward motion causes a second motion on the inside of it correspondent to this first and this having a free passage to the brain strikes it immediately and so informes it how things move without which is all the mystery of hearing If any thing break or stop this motion before it shake our ear it is not heard And accordingly we see that the sound of Bells or Artillery is heard much further if it have the conduct of waters then through the pure air because in such bodies the great continuity of them makes that one part cannot shake alone and upon their superficies there is no notable unevenness nor any dense thing in the way to check the motion as in the air hills buildings trees and such like so that the same shaking goes a great way And to confirm that this is the true reason I have several times observ'd that standing by a river side I heard the sound of a ring of Bells much more distinctly and loud then if I went some distance from the water though nearer to the steeple from whence the sound came And it is not only the motion of the air that makes sound in our ears but any motion that hath access to them in such a manner as to shake the quivering membranous Tympane within them will represent to us those motions which are without and so make such a sound there as if it were convey'd onely by the air Which is plainly seen when a man lying a good way under water shall there hear the same sounds as are made above in the air but in a more clumsie manner according as the water by being thicker and more corpulent is more unwieldy in its motions And this I have tryed often staying under water as long as the necessity of breathing would permit me Which shews that the air being smartly moved moves the water also by means of its continuity with it and that liquid element being fluide and getting into the ear makes vibrations upon the drum of it like to those of air But all this is nothing in respect of what I might in some sort say and yet speak truth Which is that I have seen one who could discern sounds with his eyes 'T is admirable how one sense will oftentimes supply the want of another whereof I have seen an other strange example in a different strain from this of a man that by his grosser senses had his want of sight wonderfully made up He was so throughly blind that his eyes could not inform him when the Sun shined for all the cry stalline humour was out in both his eyes yet his other senses instructed him so efficaciously in what was their office to have done as what he wanted in them seem'd to be overpay'd in other abilities To say that he would play at Cards and Tables as well as most men is rather a commendation of his memory phantasie then of any of his outward senses But that he should play wel at Bowles and Shovelbord and other games of aim which in other men require clear sight and an exact level of the hand according to the qualities of the earth or table and to the situation and distance of the place he was to throw at seems to exceed possibility And yet he did all this He would walk in a chamber or long alley in a garden after he had been a while used to them as straight and turn as just at the ends as any seeing man could do He would go up and down every where so confidently and demean himself at table so regularly as strangers have sitten by him several meals and seen him walk about the house without ever observing any want of seeing in him which he endeavour'd what he could to hide by wearing his hat low upon his brows He would at the first abord of a stranger as soon as he spoke to him frame a right apprehension of his stature bulk and manner of making And which is more when he taught his Schollers to declame for he was School-master to my sons and lived in my house or to represent some of Seneca's Tragedies or the like he would by their voice know their gesture and the situation they put their bodies in so that he would be able as soon as they spoke to judge whether they stood or sate or in what posture they were which made them demean themselvs as decently before him whiles they spoke as if he had seen them perfectly Though all this be very stange yet me thinks his discerning of lights is beyond it all He would feel in his body and chiefly in his brain as he hath often told me a certain effect by which he knew when the Sun was up and would discern exactly a clear from a cloudy day This I have known him frequently do without missing when for trial sake he has been lodged in a close chamber whereto the clear light or Sun could not arrive to give him any notice by its actual warmth nor any body could come to him to give him private warnings of the Changes of the weather But this is not the relation I intended when I mention'd one that could hear by his eyes if that expression may be permited me I then reflected upon a Noble man of great quality that I knew in Spain the younger brother of the Constable of Castile But the reflection of his seeing of words call'd into my remembrance the other that felt light in whom I have often remark'd so many strange passages with amazement and delight that I have adventured upon the Readers patience to record some of them conceiving they may be of some use in our course of doctrine But the Spanish Lord was born deaf so deaf that if a Gun were shot off close by his ear he could not hear it and consequently he was dumb for not being able to hear the sound of words he could never imitate nor understand them The loveliness of
of the instrument which is the reason that the concave figure is affected in most and so when it breaks out of the instrument in greater quantity then the string immediately did shake it causes the same undulations in the whole body of Air round about And that striking the Drum of the ear gives notice therin what tenour the string moves whose vibrations if one stop by laying his finger upon it the sound is instantly at an end for then there is no cause on foot that continues the motion of the Air which without a continuation of the impulse returns speedily to quiet through the resistance made to it by other parts of it that are further off Out of all which 't is plain that motion alone is able to effect and give account of all things whatever that are attributed to Sound and that Sound and motion go hand in hand together so that whatever is said of the one is likewise true of the other Wherfore it cannot be deny'd but that hearing is nothing else but the due perception of motion and that motion and sound are in themselvs one and the same thing though expressâ—d by different names and comprised in our understanding under different notions Which proposition seems to be yet further convinced by the ordinary experience of perceiving musick by mediation of a stick for how should a deaf man be capable of musick by holding a stick in his Teeth whose other end lies upon the Vial or Virginals were it not that the proportional shaking of the stick working a like dancing in the mans head make a like motion in his brain without passing through his ear and consequently without being otherwise sound then as bear motion is sound Or if any man will still persist in having sound be some other thing then as we say and that it effects the sense otherwise then purely by motion he must nevertheless acknowledge that whatever it be it hath neither cause nor effect nor breeding nor dying that we either know or can imagine And then if he will let reason sway he will conclude it unreasonable to say or suspect so ill grounded a surmise against so clear and solid proofs which our ears themselvs not a little confirm their whole figure and nature tending to the perfect receiving conserving and multiplying the motions of air which happen without a man as who is curious may plainly see in the Anatomists books and discourses CHAP. XXIX Of Sight and Colours THere is yet left the object of our Sight which we call Colours to take a survey of for as for light we have at large display'd the nature and properties of it from which whether colour be different or no will be the question we shall next discuss For those who are cunning in Opticks will by refractions and reflexions make all sorts of colours out of pure light as we see in Rainbows in those Triangular Glasses or Prisms which some call Fools Paradises and in other inventions for this purpose Wherfore in brief to shew what colour is let us lay for a ground that Light is of all other things in the world the greatest and the most powerful agent upon our eye either by it self or by what comes in with it and that where light is not darkness is Then consider that light may be diversly cast especially through or from a transparent body into which it sinks in part and in part it doth not and you will conclude that it cannot choose but come out from such a body in divers sorts mingled with darkness Which if it be in a sensible quantity accordingly makes divers appearances and those appearances must of necessity have divers hues representing the colours which are middle colours between white and black since white is the colour of light and darkness seems black Thus those colours are ingendred which are call'd apparent ones And they appear somtimes but in some one position as in the Rainbow which changes place as the looker on doth but at other times they may be seen from any part as those which light makes by a double refraction through a Triangular Glass And that this is rightly deliver'd may be gather'd out of the conditions requisite to their production For that Chrystal or water or any refracting body doth not admit light in all its parts is evident by reason of the reflection it makes which is exceeding great and not only from the superficies but even from the middle of the body within as you may see plainly if you put it in a dark place and enlighten but one part of it for then you may perceive as it were a current of light pass quite through the body although your eye be not opposite to the passage so that manifestly it reflects to your eye from all the inward parts which it lights upon Now a more oblique reflection or refractiom more disperses the light and admits more privations of light in its parts then a less oblique one as Galileo hath demonstrated in the First Dialogue of his Systeme Wherefore a less oblique reflection or refraction may receive that in quality of light which a more oblique one makes appear mingled with darkness and consequently the same thing will appear colour in one which shews it self plain light in another for the greater the inclination of an angle is the greater also is the dispersion of the light And as colours are made in this sort by the medium through which light passes so if we conceive the superficies from which the light reflects to be diversly order'd in respect of reflexion it must of necessity follow that it will have a divers lustre and sight as we see by experience in the necks of Pigeons and in certain positions of our eye in which the light passing through our eye-brows makes an appearance as though we saw divers colours streaming from a candle we look upon And accordingly we may observe how some things or rather most appear of a colour more inclining to white when they are irradiated with a great light then when they stand in a lesser And we see Painters heighten their colours and make them appear lighter by placing deep shadows by them even so much that they will make objects appear nearer and further off meerly by their mixtion of their colours Because objects the nearer they are the more strongly and lively they reflect light and therfore appear the clearer as the others do more dusky Wherfore if we put the superficies of one body to have a better disposition for the reflection of light then another hath we cannot but conceive that such difference in the superficies must needs beget variety of permanent colours in the bodies and according as the superficies of the same body is better or worse disposed to reflection of light by polishing or by compressure together or the like so the same body remaining the same in substance will shew it self of a different colour And it being
parts then another whose parts are less Neither doth it import that the pores be supposed as great as the parts for be they never so large the corners of the thick parts they belong to must needs break the course of what will not bow but goes all in straight lines more then if the parts and pores were both less since for so subtile a piercer as light no pores can be too little to give it entrance 'T is true such great ones would better admit a liquid body into them such a one as water or air but the reason of that is because they will bow and take any ply to creep into those cavities if they be large enough which light will not do Therefore 't is clear That freedom of passage can happen to light only there where there is an extreme great multitude of pores and parts in a very little quantity or bulk of body which pores and parts must consequently be extreme little ones for by reason of their multitude there must be great variety in their situation from whence it will happen that many lines must be all of pores quite through and many others all of parts although the most will be mixed of both pores and parts And so we see that although the light pass quite through in many places yet it reflects from more not onely in the superficies but in the very body it self of the Diaphanous substance But in another substance of great parts and pores there can be but few whole lines of pores by which the light may pass from the object to make it be seen and consequently it must be Opacous which is the contrary of Diaphanous that admits many Rays of Light to passe through it from the Object to the Eye wherby It is seen though the Diaphanous hard body intervene between them Now if we consider the generation of these two Colours White and black in bodies we shall find that likewise to justifie and second our doctrine For white things are generally cold and dry and therfore are by nature ordain'd to be receptacles and conservers of heat and of moisture as Physitians note Contrariwise Black as also green which is near of kin to black are growing colours and are the die of heat incorporated in abundance of wet as we see in smoak in pit-coal in garden ground and in Chymical putrefactions all which are black as also in young herbs which are generally green as long as they are young and growing The other colours keeping their standing betwixt these are generated by the mixture of them and according as they partake more or less of either of them are nearer or further off from it So that after all this discourse we may conclude in short that The colour of a body is nothing else but the power which that body hath of reflecting light to the eye in a certain order and position and consequently is nothing else but the very superficies of it with its asperity or smoothness with its pores or inequalities with its hardness or softness and such like The Rules and limits wherof if they were duly observ'd and order'd the whole nature and science of colours would easily be known and described But out of this little we have deliver'd of this subject it may be rightly inser'd that Real Colours proceed from Rarity and Density as even now we touch'd and have their head spring there and are not strange qualities in the air but tractable bodies on the earth as all are which as yet we have found and medled withal and are indeed the very bodies themselves causing such effects upon our eye by reflecting of light which we express by the names of Colours CHAP. XXX Of Luminous or apparent Colours AS for the Luminous Colours whose natures Art hath made more maniable by us than those which are called real Colours and are permanent in bodies their generation is clearly to be seen in the Prism or Triangular glass we formerly mention'd The considering of which will confirm our doctrine That even the colours of bodies are but various mixtures of light and shadows diversly reflected to our eyes For the right understanding of them we are to note That this glass makes apparitions of colours in two sorts one when looking through it there appear various colours in the objects you look on different from their real ones according to the position you hold the glass in when you look on them The other sort is when the beams of light that pass through the Glass are as it were tincted in their passage and are cast by the Glass upon some solid object and appear there in such and such colours which continue still the same in what position soever you stand to look upon them either before or behind or on any side of the Glass Secondly we are to note that these colours are generally made by refraction though somtimes it may happen otherwise as above we have mention'd To discover the reason of the first sort of colours that appear by refraction when one looks through the glass let us suppose two several bodies one black the other white lying close by one another and in the same horisontal parallel but so that that the black be further from us then the white then if we hold the Prism through which we are to see these two oppositely coloured bodies somwhat above them and that side of it at which the coloured bodies must enter into the glass to come to our eye parallel to those bodies 't is evident That the black will come into the Prism by lesser angles then the white I mean that in the line of distance from that face of the glass at which the colours come in a longer line or part of black will subtend an angle no bigger then a lesser line or part of white doth subtend Thirdly we are to note That from the same point of the object there come various beams of light to that whole superficies of the glass so that it may and somtimes doth happen that from the some part of the object beams are reflected to the eye from several parts of that superficies of the glass at which they enter And whenever this happens the object must necessarily be seen in divers parts that is the picture of it will at the same time appear to the eye in divers places And particularly we may plainly observe two pictures one a lively and strong one the other a faint and dim one Of which the dim one will appear nearer us then the lively one and is caus'd by a secondary ray or rather I should say by a longer ray that striking nearer to the hither edge of the glasses superficies which is the furthest from the object makes a more acute angle then a shorter ray doth that strikes upon a part of the glass further from our eye but nearer the object and therfore the image made by this secondary or longer ray must appear
it swells according to the encrease of the Moon which whether it be true or no there can be no doubt but that it being of a substance which is full of skins and strings is capable of being stretch'd and of swelling upon light occasions and of falling or sinking again upon as light as being easily penetrable by vapours and liquors whose nature it is to swell and to extend that which they enter into Out of which it follows that it must be the nature of the Nerves to do the like and indeed so much the more by how much more dry they are than the brain for we see that to a certain measure drier things are more capable of extention by the ingression of wet than moist things are because these are not capable of receiving much more wet into them These things being premised let us imagine that the brain being first swell'd afterwards contracts it self and it must of necessity follow that seeing the Nerves are all open towards the brain though their concavities cannot be discern'd the spirits and moisture in the brain must needs be press'd into the Nerves which being already stored with spirits sufficiently to the proportion of their hard skins this addition will make them swell and grow hard as a Balloon doth which being competently full of air hath nevertheless more air press'd into it Since therfore the Masters of Anatomy teach us that in every muscle there is a nerve which is spread into a number of little branches along that muscle it must follow that if these little branches be swollen the flesh likewise of that muscle must also needs be swollen Now the muscle having both its ends fastned the one in a greater bone the other in a lesser and there being least resistance on that part where the bone is lesser and more movable the swelling of the muscle cannot choose but draw the little bone towards the great one and by consequence move that little bone and this is that which Philosophers usually call Voluntary motion For since our knowledg remains in the brain whatever is done by knowledg must be done by the brain and most of what the brain works for the common service of the living creature proceeds also from knowledg that is from the motion of fansy which we have express'd This matter being thus far declared we may now enter upon the explication of certain effects which peradventure might have challeng'd room in the precedent Chapter but indeed could not well be handled without first supposing this last discourse and it is what is meant by those powers that are call'd Natural Faculties which however in their particulars they be manifold in a living creature yet whenever any of them is resolved it appears to be compounded of some of these five to wit the Attractive the Retentive the Secretive the Concoctive and the Expulsive faculty Of which the Attractive the Secretive and the Concoctive seem not to belong to the nervs for though we may conceive that the part of the Animal turns it self towards the thing which it attracts nevertheless that very turning seems not to be done by vertue of the muscles and nervs but rather in a natural way as the motion of the heart is perform'd in such sort as we have formerly declared As for example if the stomach when it is greedy of meat draws it self up towards the throat it seems rather to be a kind of dryness and wrapping such as we see in bladders or leather either by fire or cold which make them shrivel up and grow hard than a true faculty of the living creature to seek after meat Nor need we extend our discourse any further about these three faculties seeing that we have already declared in common how attraction drying and mixture of active bodies with passive ones is perform'd which needs but applying to these particulars to explicate fully their nature As for example if the Kidneys draw the matter of Urine to them out of the Veinet it may be by any of the following three manners to wit either by draught by wet or by steam For if the serous parts that are in the blood which runs in the Veins touch some dry parts conformable to their nature tending towards the Kidneys they will infallibly adhere more to those dry parts than to the rest of the blood Which if they do in so great a quantity that they reach to other further parts more dry than these they will leave the first parts to go to the second and thus by little and little will draw a line of Urine from the blood if the blood abound with it and the nearer it comes to the Kidneys the stronger still the attraction will be The like will happen if the serosity which is in the blood touch some part weted with a like serosity or where such hath lately passed For as we see water will run more easily upon a wet part of a board or a stone than on a dry one so you cannot doubt but that if the serous part which is mix'd with the blood light upon a current of its own nature it will stick more to that than to the current of the blood and so part from the blood to go that way which the current of its own nature goes Besides it cannot be doubted but that from the Kidnyes and from the passages between the Kidneyes and the Veins in which the blood is convey'd there arises a steam whose nature is to incorporate it self with serous matter out of whose body it hath been extracted This steam therfore flying still to the serous blood which passes by must of necessity precipitate as I may say the serous parts of the blood or rather must filter them out of their main stock and so will make them run in that current from which it self flows And thus you see how Attraction and Secretion are made for the drawing of the serosity without drawing the blood is the parting of the Urine from the blood And this example of the Kidneys operation may be apply'd to the attractions of all the other parts Now the Concoctive faculty which is the last of the three we took together consists of two parts one is as it were a drying of the humour which is to be concocted the other is a mingling the substance of the vessel in which the humour is concocted with the humour it self For as if you boyl divers kinds of liquors in brass pans the pans will taint the liquor with the quality of the brass and therfore Physicians forbid the use of such in the boiling of several medicines so much more in a living creatures body there can be no doubt but that the vessel in which any humour is concocted gives a tincture therto Now concoction consisting in these two 't is evident what the concoctive vertue is to wit heat and the specifical property of vessel which by heat is mingled with the humour There remain yet the
that the effect which we call pain is nothing else but a compression For although this solution of continuity may seem to be a dilatation yet in truth it is a compression in the part where the evil is which happens to it in the same manner as we shew'd when we spoke of the motion of Restitution it doth to stiff bodies that by violence are compress'd and drawn into a lesse capacious figure than their nature affects and return into their own state as soon as the mastring violence leaves them at liberty Pleasure therfore must be contrary to this and consist in a moderate dilatation for an immoderate one would cause a compression in some adherent parts and there would become pain And conformable to this we experience that generally they are hard things which breed pain to us and those which breed pleasure are oily and soft as meats and odours which are sweet to the taste and smell and soft substances which are grateful to the touch the excess of all which proves offensive and painful so that from the extremity of pleasure one enters presently upon the confines of pain Now then let us consider how the little similitudes of bodies which from without come into the fantasy must of necessity work there according to their little power effects proportionable to what they wrought first in the outward senses from whence they were convey'd to the brain For the senses that is the nervs and the Septum lucidum having both of them their origin from the very substance of the brain and differing only in degrees of purity and refinement the same object must needs work like effects in both compressing or dilating them proportionaby to one another Which compression or dilatation is not pain or pleasure as it is in the outward sense but as it is reported to the heart and that being the seat of all pains or pleasures wrought in other parts and that as it were dies them into those qualities is not capable of feeling either it self so that the strokes of any little similitudes upon the fantasie make only compressions or dilatations there not pains or pleasures Now these bodies or similitudes if they be reverberated from the fantasie or Septum Lucidum upon the little roots of the nervs of the fixt couple which go to the heart must needs work there a proportionable impression to what they wrought upon the fansie either compressing or dilating it and the heart being extremely passive by reason of its exceeding tenderness and heat cannot choose but change its motion at least in part if not in whole and this with relation to two causes one the disposition of the heart it self the other the vehemency of the stroke This change of motion and different beating of the heat is that which properly is called Passion and is ever accompanied with pleasure or with grief according to the nature of the impression that either contracts or dilates the heart and the spirits about it and is discovered by the beating of the arteries and of the pulse Conformable wherunto Physicians tell us that every passion hath a distinct pulse The pulses are divided in common by abundance or by want of spirits yet it both kinds they may have common disferences for in abundance the pulse may be quick or slow regular or irregular equal or unequal and the like may happen in defect of spirits according to the motions of the heart which are their causes Again the object by being present or further off makes the stroke greater or lesser and accordingly varies the motion of the heart Let us then call to mind how we have formerly declared that life consists in heat and humidity and that these two join'd together make a thing great and we may conclude that of necessity the motion which is most lively must have a great full and large stroke like the even rolling waves of a wide and smooth sea and not too quick or smart like the breaches of a narrow Fretum agitated by tempestuous winds From this other motions may vary either by excess or by deficiency the first makes the stroke become smart violent and thick the other slackens it and makes it grow little slow weak and thin or seldom And if we look into the motions of our heart we shall see these three differences of them follow three several chief passions The first follows the passion of Joy the second the passion of Anger and the third the passion of Grief Nor need we look any further into the causes of the several motions for we see that Joy and Grief following the stroke of sense the one of them must consist in an oily dilatation that is the spirits about the heart must be dilated by a gentle large great and sweet motion in a moderation between velocity and slowness the other contrariwise following the stroke of sense in pain as the first did in pleasure must contract the spirits and consequently make their motion or stroke become little and deficient from all the properties we have above set down As for Anger the motion following that passion is when the abundance of spirits in the heart is a little check'd by the contrary stroke of sense but presently overcomes that opposition and then as we see a hinder'd water or a man that suddainly or forcibly brake through what withstood their motion go on with a greater violence than they did and as it were precipitately so the heart having overcome the contraction which the sense made in it dilates it self with a fury and makes its motion smart and vehement Whence also it follows that the spirits grow hotter than they were and accordingly it is often seen that in the scoulding of a woman and in the irritation of a dog if ever now and then one thwart them and interpose a little opposition their fury will be so sharpned and heightned that the woman will be transported beyond all limits of reason and the dog will be made mad with nothing else done to him but angring him at convenient times and some men likewise have by slight oppositions iterated speedily upon them before their spirits could relent their vehement motion and therfore must still encrease it been angred into feavors This passion of Anger seems almost to be solitary on the side of excess beyond joy which is as it were the standard and perfection of all passions as light or whiteness is of all colours but on the other side of deficiency there are several middle passions which participate more or less of joy and grief As particularly those two famous ones which govern mans life Hope and Fear Concerning which Physicians tell us that the pulse or beating of Fear is quick hard and unequal to which I conceive we may safely add that it must also be small and feeble the perfection of joy decreasing in it on one side to wit from greatness and largeness but not intirely so that a kind of quickness supplies
the first the doubting of Beasts and their long wavering somtimes between objects that draw them several ways and at last their resolving upon some one of them and their steady pursuance of that afterwards these will not be matter of hard digestion to him that shall have well relished meditated on the contents of the last Chapter For 't is evident that if several objects of different natures at the same time present themselvs to a living creature they must of necessity make divers impressions in the heart of it proportionable to the causes from whence they proceed so that if one of them be a motion of hope and the other of fear it cannot choose but follow thence that what one of them begins the other will presently break off By which means it will come to pass that in the Beasts heart there must needs be such waverings as we may observe in the Sea when at the beginning of a tide of flood it meets with a bank that checks the coming in of the waves and for a while bears them back as fast as they press upon it they offer at getting over it and by and by retire back again from the steepness of it as though they were apprehensive of some danger on the other side and then again attempt it afresh and thus continue labouring one while one way another while another till at length the floud increasing the water seems to grow bolder and breaks amain over the banks and then flows on till it meets with another that resists it as the first did And thus you see how the Sea can doubt and resolve without any discoursing In like manner it fares with the heart of a Beast whose motions steer the rest of the body when it beats betwen hope and fear or between any other two contrary passions without requiring any other principles from whence to deduce it than those we have already explicated But now to speak of their invention I must confess that among several of them there appears so much cunning in laying of their plots which when they have compassed they seem to grow careless and unbend their intention as having obtain'd what with earnestness they desired that one might think they wrought by design and had a distinct view of an end for the effecting of which they used discourse to choose the likeliest means To this purpose the subtilties of the Fox are of most note They say he uses to lie as if he were dead therby to make Hens and Ducks come boldly to him That in the night when his body is unseen he will fix his eyes upon poultry and so make them come down to him from their roost That to rid himself of the fleas that afflict him in the Summer he will sink his body by little and little into the water while the fleas creep up to his head to save themselves from drowning and from thence to a bough he holds in his mouth and will then swim away leaving them there That to cousen the Badger of his earth he will piss in it as knowing that the rank smell of his Urine will drive the other cleanlier beast to quit it That when Dogs are close upon him and catching at him he will piss upon his Tail and by firking that up and down will endeavour you may believe to make their eyes smart and so retard their pursuit that he may escape from them And there are particular stories that express yet more cunning than all these As of a Fox that being sore hunted hang'd himself by the teeth among dead vermin in a Warren till the Doggs were pass'd by him and had lost him Of another that in like distress would take into his mouth a broom bush growing upon a sleep cliff on the side hand neer his Den which had another way to it easie enough of access and by help of that would securely cast himself into his hole while the Dogs that follow'd him hastily and were ignorant of the danger would break their necks down the rocks 'T is said that in Thracia the Countrey people know whether the rivers that are frozen in the winter will bear them or no by marking whether the Foxes venture boldly over them or retire after they have lai'd their ears to the Ice to listen whether they can hear the noise of the water running under it from whence you may imagine they collect that if they hear the current of the stream the Ice must needs be thin and consequently dangerous to trust their weight to it And to busie my self no longer with their subtilties I will conclude with a famous tale of one of these crafty animals that having kill'd a Goose on the other side of the river and being desirous to swim over with it to carry it to his den before he would attempt it lest his prey might prove too heavy for him to swim withal and so he might lose it he first weigh'd the Goose with a piece of wood and then tri'd to carry that over the river whiles he left his Goose behind in a safe place which when he perciev'd he was able to do with ease he then came back again and ventured over with his heavy bird They say it is the nature of the Iacatray to hide it self and imitate the voice of such beasts as it uses to prey upon which makes them come to him as to one of their own fellows and then he seises on and devours them The Iaccal that has a subtile sent hunts after beasts and in the chase by his barking guides the Lion whose nose is not so good till they overtake what they hunt which peradventure would be too strong for the Iaccall but the Lion kills the quarry and having first fed himself leaves the Iaccal his share and so between them both by the ones dexterity and the others strength they get meat for nourishment of them both Like stories are recorded of some Fishes And every day we see the invention of Beasts to save themselvs from catching as Hares when they are hunted seeks always to confound the sent somtimes by taking hedges otherwhiles waters somtimes running among sheep and other beasts of stronger sent somtimes making doubles and treading the same path over and over and somtimes leaping with great jumps hither and thither before they betake themselves to their rest that so the continuateness of the sent may not lead doggs to their form Now to penetrate into the causes of these and of such like actions we may remember how we shew'd in the last Chapter that the beating of the heart works two things one is that it turns about the specieses or little corporeities streaming from outward objects which remain in the memory the other is that it is always pressing on to some motion or other Out of which it happens that when the ordinary ways of getting victuals or escaping from enemies fail a creature whose constitution is active it lights somtimes though
Of the great effects of Rarefaction 4. The first manner of condensation by heat 5. The second manner of condensation by cold 3. That Ice is not water rarifiâ—d but condensed 7. How wind snow and hail are made and wind by rain allayed 8. How parts of the same or divers bodies are joyned more strongly together by condensation 9. Vacuities cannot be the reason why water impregnated to the full with one kind of salt will notwithstanding receive more of another 10. The true reason of the former effect 11. The reason why bodies of the same nature jâ—yn more easily together then others 1. What attraction is and from whence it proceeds 1. The true sense of the Maxime that Nature abhors from vacuity 3. The true rea son of attraction 4. Water may be brought by the force of attraction to what height soever 5. The doctrine touching the attraction of water in Syphons 6. That the Syphon doth not prove water to weigh in its own orb 7. Concerning attraction caused by fire 8. Concerning attraction made by virtue of hot bodies amulets c. 9. The natural reason given for divers operations esteemed by some to be magical 1. What is Filtration and how it is effected 2. What causes the water in filtration to ascend 3. Why the filter will not drop unless the label hang lower then the water 4. Of the motion of Râ—stitution and why some bodies stand bent others not 5. Why some bo dies return only in part to their natural figure others entirely 6. Concerning the nature of those bodies which shrink and stretch 7. How great wonderful effects proceed from smal plain and simple principles 8. Concerning Electrical at action and the causes of it 6. Cabeus his opinion reâ—uted concerning the cause of Electrical motions 1. The extreme heat of the Sun under the Zodiack draws a stream of air from each pole into the Torrid Zone * Chap. 18. Sect. 7. 2. The Atoms of these two streams coming together are apt to incorporate with one another 3. By the meeting and mingling together of these streams at the Equator divers rivolets of Atoms of each Pole are continuated from one Pole to the other 4. Of these Atoms incorporated with some fit matter in the bowels of the earth is made a stone 5. This stone works by emanations joyned with agreeing streams that meet them in the air and in fine it is a Loadstone 6 A methode for making experiences on any subject 7. The Loadstones generation by atoms flowing from both Poles is confirmd by experiments observ'd in the stone it self 8. Experiments to prove that the Loadstone works by emanations meeting with agreeing streames 1. The operations of the loadstone are wrought by bodies and not by qualities 2. Objections against the former position answer'd 3. The Loadstone is imbued with his virtue from another body 4 The virtue of the Loadstone is a double and not one simple virtue 5. The virtue of the Loadstone works more strongly in the poles of it then in any other part 6. The loadstone sends forth its emanations spherically Which are of two kindâ— and each kind is strongest in that Hemisphere through whose polary parts they issue out 7. Putting two loadstones within the sphere of one another every part of one loadstone doth not agree wâ—th every part of the other loadstone 8. Concetning the declination and other respects of a needle towards the loadstone it touches 8. The virtue of the Loadstone goes from end to end in lines almost parallel to the Axis 10. The virtue of the Loadstone is not perfectly spherical though the stone be such 11. The intention of nature in all the operations of the loadstone is to make an union betwixt the attractive and attracted bodies 12. The main globe of the earth is not a Loadstone 13. The loadstone is generated in all parts or Climâ—t's of the earth 14. The conformity betwixt the two motions of magnetick things and of heavy things 1. Which is the North and which the South Pole of a Loadstone 2. Whether any bodies besides magnetick ones be attractive 3. Whether an iron placed perpendicularly towards the earth gets a magnetical virtue of pointing towards the north or towards the south in that end that lies downwards 4. Why loadstones affect iron better than one another 5. Gilberts reason refuted touching a cap'd Loadstone that takes up more iron then one not cap'd and an iron impregnated that in some case draws more strongly then the stone it self Galileus his opinion touching the former effects refuted 7. The Authors solution to the former questions 8. The reason why in the former case a lesser Loadstones draws the interjacent iron from the greater 9. Why the variation of a touched needle from the North is greater the nearer you go to the Pole 10. Whether in the same part of the world a touched needle may it one time vary more fâ—om the North and at another time less 11. The whâ—le doctrine of the loâ—dstone sum'd up in short 1. The connexion of the following Chapters with the precedent ones 2. Concerning several compositions of mixed bodies 3. Two sorts of Living Creatures 4. An engine to express the first sort of living creatures 5. Another Engine by which may be expressed the second sort of living creatures 4. The two former engines and some other comparisons applied to express the two several sorts of living creatures 7. How plants are framed 8. How Sensitive Creatures are formed 1. The opinion that the seed contains formally every part of the parent 2. The former opinion rejected 3. The Authours opinion of this question 4. Their opinion refuted who hold that every thing contains formally all things 5. The Authors opinion concerning the generation of Animals declared and confirm'd That one substance is changed into another 7. Concerning the hatching of Chickens and the generation of the other Animals 8. From whence it happens that the deficiences or excresences of the parents body are often seen in their children 9. The difference between the Authors opinion anâ—â—he former 〈◊〉 10 That the heart is imbued with the general specifike vertues of the whole body wherby is confirm'd the doctrine of the two former Paragraphes 11 That the heart is the first part generated in a living creatures 1. That the figure of an Animal is produced by ordinary second causes as well as any other corporeal effect 2. That the several figures of bodies proceed from a defect in one of three dimensions caused by the circumference of accidental causes 3. The former doctrine is confirmd by several instances 4. The same doctrine applyed to plants 4. The same doctrine declared in leaves of trees 16. The same applied to the bodies of Animals 7. In what sense the Author admits of vis formatrix 1. From whence proceeds the primary motion growth in Plants 2. Mr. des Cartes his opinion touching the motion of the heart 3. The former opinion rejected 4. The Authors opinion
proportion over air and water And this I conceive produces those substāces which we may term co-agulated juyces and which the Latines call succi concreti whos 's first origine seems to have been liquours that have been afterwards dried by the force either of heat or cold Of this nature are all kind of Salts Niters Sulfurs and divers sorts of Bitumens All which easily bewray the relicks and effects of fire left in them some more some less according to their degrees And thus we have in general deduced from their causes the complexions of those bodies whereof the bulk of the world subjected to our use consists and which serve for the production and nourishment of living creatures both animal and vegetable Not so exactly I confess nor so particularly as the matter in it self or as a Treatise confined to that subject would require yet sufficiently for our intent In the performance whereof if more accurate searchers of nature shall find that we have peradventure been mistaken in the minute delivering of some particular bodies complexion their very correction I dare boldly say will justifie our principal scope which is to shew that all the great variety we see among bodies arises out of the commixion of the First Qualities and of the Elements for they will not be able to correct us upon any other grounds then those we have laid As may easily be perceiv'd if we cast a summary view upon the qualities of compounded bodies All which we shall find to spring out of rarity and density and to savour of their origine for the most manifest qualities of bodies may be reduced to certain pairs opposite to one another As namely some are liquid and flowing others are consistent some are soft others hard some are fatty viscuous and smooth others lean gritty and rough some gross others subtile some tough others brittle and the like Of which the liquid the soft the fat and the viscuous are so manifestly derived from rarity that we need not take any further pains to trace out their origine and the like is of their contraries from the contrary cause to wit of those bodies that are consistent hard lean and gritty all which evidently spring from density As for smoothness we have already shew'd how that proceeds from an airy or oily nature and by consequence from a certain degree of rarity And therefore roughness the contrary of it must proceed from a proportionable degree of density Toughness is also a kind of ductility which we have reduced to watriness that is to another degree of rarity and consequently brittleness must arise from the contrary degree of density Lastly grossness and subtilness consist in a difficulty or facility to be divided into small parts which appears to be nothing else but a certain determination of rarity and density And thus we see how the several complexions of bodies are reduced to the four Elements that compound them and the qualities of those bodies to the two primary differences of quantitative things by which the elements are diversified And out of this discourse it will be evident that these complexions and qualities though in diverse degrees must of necessity be found wherever there is any variation in bodies For seeing there can be no variation in bodies but by rarity and density and that the pure degrees of rarity and density make heat cold moisture and driness and in a word the four Elements 't is evident that wherever there is variety of bodies there must be the four Elements though peradventure far unlike these miked bodies which we call Elements And again because these Elements cannot consist without motion and by motion they of necessity produce Mixed bodies and forge out those Qualities which we come from explicating it must by like necessity follow that wherever there is any variety of active and passive bodies there mixed bodies likewise must reside of the same kinds and be indued with qualities of the like natures as those we have treated of though peradventure such as are in other places of the world remote from us may be in a degree far different from ours Since then it cannot be denied but that there must be notable variety of active and passive bodies wherever there is light neither can it be denied but that in all those Great Bodies from which light is reflected to us there must be a like variety of complexions and qualities and of bodies temper'd by them as we find here in the Orb we live in Which Systeme how different it is from that which Aristotle and the most of the School have deliver'd us as well in the evidencies of the proofs for its being so as in the position and model of it I leave to the prudent Readers to consider and judge Out of what has been already said 't is not hard to discover in what manner the composition of bodies is made In effecting which the main hinge wheron that motion depends is fire or heat as it likewise is in all other motions whatever Now because the composition of a mixed body proceeds from the action of one simple body or element upon the others it will not be amiss to declare by some example how this work passes for that purpose let us examine how fire or heat works upon his fellows By what we have formerly deliver'd 't is clear that fire streaming out from its centre and diffusing it self abroad so as to fill the circumference of a larger circle it must needs follow that the beams of it are most condens'd and compacted together near the centre and the further they stream from the centre the more thin and rarified they must grow yet this is with such moderation as we cannot any where discern that one beam doth not touch another and therfore the distances must be very smal Now let us suppose that fire happens to be in a viscuous and tenacious body and then consider what will happen in this case of one side the fire spreads it self abroad on the other side the parts of the tenacious body being moist as I have formerly determin'd their edges on all hands will stick fast to the dry beams of the fire that pass between them Then they stretching wider and wider from one another must needs draw with them the parts of that tenacious body which stick to them and stretch them into a greater widness or largness then they enjoy'd before from whence it follows that seeing there is no other body near therabouts but they two either there must be a vacuity left or else the tenacious body must hold and fill a greater space then it did before and consequently be more rare Contrariwise of any of the other elements be stronger then fire the denser Elements break off from their continu'd stream the little parts of fire which were gotten into their greater parts and sticking on all sides about them so enclose them that they have no more semblance of fire and