violently projected upward they revert or fall down again by reason of the magnetique Attraction of the Earth and it now remains onely that we consider the Reasons of that other species of motion Reflex or Rebounding whereby Bodies being also violently moved or projected any way are impeded in their course and Diverted from the line of their Direction by other bodies encountring them Concerning this Theorem therefore be pleased to know that among all Reflexions by way of Rebound or Resilition that is the Chiefest when a body projected and impinged against another body is returned from thence directly or in the same line toward the place from whence it was projected which always happens when the Projection is made to right Angles or in regular line such as that in which a Heavy body descends upon an horizontal plane And all other Reflections are in dignity inferior thereunto as such whereby the thing projected doth not rebound in a direct line toward the same point from whence it was projected but to some other region by other lines according as it is projected in lines more or less oblique Because with what inclination a body falls upon a plane with the very same inclination doth it rebound from the plane especially a Globe and such as is of an uniform matter and consequently hath the Centre of magnitude and that of Gravity coincident in the same point so that by how much the more oblique the projection is and how much the less is the Angle made of its line with the line of the plane called the Angle of Incidence so much the more oblique is the reflexion made and so much the less the Angle made of its line with the line of the plane continued called the Angle of Reflexion and that so long as till the line of projection shall become parallel to the plane and so no body occurring to or encountring the projectum no reflexion at all be made Know moreover that betwixt No Reflexion at all and the Least Reflexion that is possible there may be assigned as it were a certain Medium and that is the Emersion or Rising up again of a weight appensed to a thread or Lutestring when performing a vibration or swing from one side to the other it ascends from the perpendicular Line to which by descending it had reduced it self For in that case no â—â—â—lecting body doth occur a simple Arch is described and yâ—â—â—here is as a certain Procidence or falling down to the lowest point of the Arch so also a certain Resilition or rising up again from â—he lowest point of the Arch toward the contrary side Again having conceived a direct line touching the lowest point of the Arch so as that the weight suspended by a string may in its vibration glance upon it with its lowest extreme and onely in a point touch the horizontal line you shall have on each side an Angle madâ— from the Arch and the line touching it which is therefore called the Angle of Contingence and because Geometricians demonstrateâ— that the Angle of Contingence which truly differs from a right line is less than any Rectilinear Angle however acute therefore may each of those Angles be said to be Median betwixt the right line and the Angle either of Incidenceâ— or of Reflexion how small soever it be and consequently the Emersion of the weight in Vibration may as justly be said to be Median betwixt the smallest Reflexion and none at all However this Emersion seems to 〈◊〉 the Rule of all Reflection whatever for as in the Vibration of a weight appensed to a string and describing a simple Arch the Aâ—gle of its Emersion is always equal to the Angle of its Procidenâ—â— so in Projection describing an Angular line the Angle of Reflection is always quantum ex se est equal to the Angle of Incidence We say quantum ex se est for otherwise whether it be sensible or not because so long as the Projectum is transferred it is aâ—ways somewhat depressed toward the earth for the reason formerly alleadged thence comes it that the Reflexion can neither be so strong or smart as the Incidence nor make as great an angle 〈◊〉 arise to as great an altitude Which we insinuate that we might not insist upon this advertisement that the Aequality of the Angle of the Reflexion to that of the Incidence may be so much thâ— less by how much the less the projected body comes to a spherical figure or doth consist of matter the less uniform For to attain to that Aequality of the Angels of Incidence and Reflexion necessary it is that the body projected be exactly spherical and of Uniâ—orm matter and so having the Centre of Gravity and the Centre of magnitude coincident in one and the same point as we have formerly intimated it being as well against Reason as Experience that bodies wanting those conditions should arise to that aequaliâ—â— which that we may the better understanâ— let us consider that 〈◊〉 in a Globe or Ball Falling down we regard onely that Gravity which it acquires in its descent from the magnetique Attraction of the Earth so in a Globe or Ball Projected we are to regard onely that Impetus or Force which being imprest upon it by the Projicient supplies the place of Gravity and in respect whereof the Centre of its Gravity may be conceived to be one with that of its magnitude Let a Ball therefore be projected Directly or to right Angles upon a plane and because in that case that Fibre must be the Axis of its Gravity whose extreme going foremost is impinged against the plane thence is it manifest that the Repression must be made in a direct line along that Axis the parallel Fibres in equal number on each part invironing that Axis and so not swaying or diverting the ball more to one part than to another by reason of any the least disproportion of quantity on either side Then lâ—t the same Ball be projected Obliquely against the same plane and because in this case not that middle Fibre which constituteth the Axis of Gravity but some one or other of the Fibres circumstant about it must with one of its extreams strike against the plane therefore is it necessary that that same Fibre be repressed by that impulse and by that repression compelled to give backward toward its contrary extream and thereby in some measure to oppose the motion begun which it wholly overcome and so the ball would rebound from the plane the same way it came if the Fibres on that side the Axis of Gravity which is neerest to the plane were equal in number to that are on the farther or contrary side of it but because those Fibres that are on the farther side or on the part of the Centre and Axis are far more in number and so theâ—e is a greater quantity of matter and consequently a greater force imprest than on the side neerer to the plane
to their Exhalation Thus is Water much sooner evaporated then Oyl and Lead then Silver 3 Anti-Atomist If Atoms be unequal in their superfice and have angular and hamous processes then are they capable of having their rugosities planed by detrition and their hooks and points taken off by amputation contrary to their principle propriety Indivisibility Atomist the hooks angles asperities and processes of Atoms are as insecable and infrangible as the residue of their bodies in respect an equal solidity belongs to them by reason of their defect of Inanity interspersed the intermixture of Inanity being the Cause of all Divisibility Haec quae sunt rerum primordia nulla potest vis Stringere nam solido vincunt ea corpore demum 4 Anti-Atomist That Bodies of small circumscription such as grains of sand may be amassed from a syndrome and coagmentation of Atoms seems indeed to stand in some proportion to probability but to conceive a possibility that so vast a Bulk as the adspectable World bears may arise out of things but one degree above nothing such insensible materials convened and conglobated is a symptome of such madness as Melancholy adust cannot excuse and for which Physitians are yet to study a cure Atomist To doubt the possibility nay dispute the probability of it is certainly the greater madness For since a small stone may be made up of a Coagmentation of grains of Sand a multitude of small stones by coacervation make up a Rock many Rocks by aggregation make a Mountain many Mountains by coaptation make up the Globe of Earth since the Sun the Heavens nay the World may arise from the conjunction of parts of dimensions equal to the Terrestrial Globe what impossibility doth he incurr who conceives the Universe to be amassed out of Atoms Doubtless no Bulk can be imagined of such immense Dimensions as that the greatest parts thereof may not be divided into less and those again be subdivided into less so that by a successive degradation down the scale of Magnitude we may not at last arrive at the foot thereof which cannot be conceived other then Atoms Should it appear unconceivable to any that a Pismire may perform a perambulation round the terrestrial Globe we advise him to institute this Climax of Dimensions and consider first that the ambite of the Earth is defined by miles that miles are commensurated by paces paces consist of feet feet of digits digits of grains c. and then He may soon be convinced that the step of a Pismire holds no great disproportion to a grain and that a grain holds a manifest proportion to a digit a digit to a foot a foot to a pace a pace to a perch a perch to a furlong a furlong to a mile and so to the circumference of the whole Earth yea by multiplication to the convexity of the whole World If any expect a further illustration of this point it can cost him no more but the pains of reading the 45. page of our Treatise against Atheism and of Archimeds book de Arenarum Numero 5 Anti-Atomist If all peices of Nature derived their origine from Individual Particles then would there be no need of Seminalities to specifie each production but every thing would arise indiscriminately from Atoms accidentally concurring and cohaering so that Vegetables might spring up without the praeactivity of seeds without the assistance of moysture without the fructifying influence of the Sun without the nutrication of the Earth and all Animals be generated spontaneously or without the prolification of distinct sexes Atomist This inference is ingenuine because unnecessary since all Atoms are not Consimilar or of one sort nor have they an equal aptitude to the Conformation of all Bodies Hence comes it that of them are first composed certain Moleculae small masses of various figures which are the seminaries of various productions and then from those determinate seminaries do all specifical Generations receive their contexture and Constitution so praecisely that they cannot owe their Configuration to any others And therefore since the Earth impraegnated with Fertility by the sacred Magick of the Creators Benediction contains the seeds of all Vegetables they cannot arise but from the Earth nor subsist or augment without roots by the mediation of which other small consimilar Masses of Atoms are continually allected for their nutrition nor without moysture by the benefit of which those minute masses are diluted and so adapted for transportation and final assimilation nor without the influence of the Sun by vertue whereof their vegetative Faculty is conserved cherished and promoted in its operations Which Reason is aequivalent also to the Generation Nutrition and Increment of Animals 6 Anti-Atomist If your Proto-Element Atoms be the Principle of our 4 common Elements according to the various Configurations of it into Moleculae or small masses and that those are the Seminaries of all things then may it be thence inferred that the Seeds of Fire are invisibly contained in Flints nay more in a Sphaerical Glass of Water exposed to the directly incident rayes of the Sun our sense convincing that Fire is usually kindled either way Atomist Allowing the legality of your Illation we affirm that in a Flint are concealed not only the Atoms but Moleculae or Seeds of Fire which wanting only retection or liberty of Exsilition to their apparence in the forme of fire acquire it by excussion and pursuing their own rapid motion undiquaque discover themselves both by affecting the sight and accension of any easily combustible matter on which they shall pitch and into whose pores they shall with exceeding Celerity penetrate Nor can any man solve this eminent Phaenomenon so well as by conceiving that the body of a Flint being composed of many igneous i. e. most exile sphaerical and agile Atoms wedged in among others of different dimensions and figures which contexture is the Cause of its Hardness Rigidity and Friability upon percussion by some other body conveniently hard the insensible Particles thereof suffering extraordinary stress and violence in regard it hath but little and few Vacuola or empty spaces intermixt and so wanting room to recede and disperse are conglomorated and agitated among themselves with such impetuositie as determinately causeth the constitution of Fire It being manifest that violent motion generateth Heat and confessed even by Aristotle 1. Meteor 3. that Fire is nothing but the Hyperbole or last degree of Heat Secondly That the seeds of Fire are not contained either in the sphaerical Glass or the the Water included therein but in the Beams of the Sun whose Composition is altogether of Igneous Atoms which being deradiated in dispersed lines want only Concurse and Coition to their investment in the visible form of Fire and that the Figure of the Glass naturally induceth it being the nature of either a Convex or Concave Glass to transmit many Beams variously incident towards one and the same point which the virtue of Union advanceth to the force of
therefore doth the begun motion persever as praevailing upon the repression and renitency of the Fibre impinged against the plane and since it cannot be continued in a direct line because of the impediment ariseing from the parts cohaerent it is continued by that way it can i. e. by the open and free obliquity of the plane But this of necessity must be done with some certain Evolution of the Ball and with the contact of the Fibres posited in order both toward the Axis and beyond it and while this is in doing every Fibre strives to give back but because the farther part doth yet praevail over the neerer therefore doth the neerer part still follow the sway and conform to the inclination and conduct of the farther and all the toucht Fibres change their situation nor are they any longer capable of returning by the same way they came because they no longer respect that part from whence they came We say with the Contact of the plane by the Fibres posited toward the Axis and beyond it because since in that Evolution or Turn of the Ball the extream of the Axis toucheth the plane yet nevertheless no Resilition or Rebound is therefore caused in that instant and if there were a resilition at that time it would be to a perpendicular as well the Axis as all the circumstant Fibres being erected perpendicularly upon the face of the plane but the Resilition there must be beyond it because the force of the farther part of the Fibres doth yet praevail over that of the neerer For the Force of the farther part doth yet continue direct and intire but that of the neerer is reflected and by the repression somewhat debilitated and therefore the Resilition cannot be made until so much of Repression and Debilitation be made in the further part as was made at first in the neerer And that must of necessity be done so soon as ever the plane is touched by some one Fibre which is distant from the Axis as much beyond as that Fibre which first touched the plane is distant from the Axis on this side for then do the two forces become equal and so one part of the Fibres having no reason any longer to praevail over the other by counter inclination the Ball instantly ceaseth to touch the plane and flies off from it toward that region to which the Axis and all the circumstant Fibres are then i. e. after the Evolution directed Now because the Ball is after this manner reflected from the plane with the same inclination or obliquity with which it was impinged against it it is an evident consequence that the Angle of its Reflexion must be commensurable by the Angle of its Incidence and that each of them must be so much the more Obtuse by how much less the line of projection doth recede from a perpendicular and contrariwise so much the more Acute by how much more the line of projection doth recede from a perpendicular or how much neerer it approacheth to a parallel with the plane From these Considerations we may infer Two Observables The One that the oblique projection of a Globe against a plane is composed of a double Parallel the one with the Perpendicular the other with the plane for the Globe at one and the same time tends both to the plane and to that part toward which the plane runs out forward The Other that Nature loseth nothing of her right by the Reflexion of bodies forasmuch as she may nevertheless be allowed still to affect and pursue the shortest or neerest way for because the Angle of Reflexion above the plane is equal to that Angle which would have been below the plane in case the plane had not hinderd the progress of the line of projection beyond it by reason of the Angles Equal at the Vertex as Geometricians speak therefore is the Reflex way equal to the Direct and consequently to the shortest in which the ball projected could have tended from this to that place Here to bring up the rear of this Section we might advance a discourse concerning the Aptitude and Ineptitude of Bodies to Reflexion but the dulness of our Pen with long writing as well as the Confidence we have of our Readers Collective Abilities inclining us to all possible brevity we judge it sufficient onely to advertise that what we have formerly said concerning the Aptitude and Ineptitude of Bodies to Projection hath anticipated that Disquisition For certain it is in the General that such Bodies which are More Compact Cohaerent and Hard as they may be with more vehemence and to greater distance Projected so may they with more vehemence and to greater distance Rebound or be Reflected provided they be impinged against other bodies of requisite Compactness Cohaerence and Hardness And the Reason why a Tennis-ball doth make a far greater Rebound than a Globe of Brass of the same magnitude and thrown with equal force is onely this that there is not a proportion betwixt the Force imprest by the Projicient and the Gravity of each of them or betwixt the Gravity of each and the Resistence of the Plane Which holds true also concerning other bodies of different Contextures CONCLUSION Ingenious Reader I Have kept you long at Sea I confess and such was the Unskilfulness of my Pen though steered for the most part according to the lines drawn on those excellent Charts of Epicurus and Gassendus often shipwrackt your Patience But be pleased to consider that our way was very Long and taedious insomuch as we had no less than the whole of that vast and deep Ocean of Sublunary Corporeal Natures to sayl over that our passage was full of Difficulties as well in respect of those sundry Rocks of Incertitude which the great Obscurity of most of those Arguments whose discovery we attempted inevitably cast us upon as of those frequent Mists and Foggs which the exceeding Variety of mens Opinions concerning them surrounded and almost benighted our judgement withal and chiefly that if by the voyage your Understanding is brought home not only safe but inriched though in the least measure with that inestimable Wealth the Knowledge of Truth or what is so Like to Truth as to satisfie your Curiosity as fully as I have reason to congratulate my self for the happiness of my Care and Industry in being your Pilot so must you to esteem the adventure of your Time and Attention compensated with good Advantage And now you are on Land agen give me leave at parting to tell you That all the Fare I shall ever demand of you is only a Candid sentiment of my Good-will and cordial Devotion to the Commonwealth of Philosophy Which indeed doth so strongly Animate me on to enterprizes of Publique Utility though but to those in the Second Form of Scholars that I can be well contented not only to neglect opportunities of Temporal advantages to my self while I am imployed in the study how to contribute to the
the larger and consequently the Coacervate Vacuum apparent in the superior region of the Tube becomes so much the greater And because the Resistence made against the subingression dilating or distending it self is in the instant overcome by reason of a greater impulse caused by the Cylindre of Mercury descending from a greater altitude and that resistence remains which could not be overcome by the remnant of the Mercury in the Tube at the height of 27 digits therefore is this Remaining Degree of resistence the manifest Cause why the Mercury is Aequilibrated here at the point of 27 digits aswell when it falls from a high as a low perpendicular This may receive a degree of perspicuity more from the transitory observation of those frequent Reciprocations of the Quicksilver at the first deflux of it into the restagnant before it acquiesce and fix at the point of Aequiponderancy no otherwise then a Ball bounds and rebounds many times upon a pavement and is by successive subsultations uncessantly agitated up and down untill they gradually diminish and determine in a cessation or quiet The Cause of which can be no other then this that the extreme or remotest subingression of the insensible particles of the Aer is we confess propagated somewhat farther then the necessity of the Aequipondiâ—m requireth by reason of a new access of Gravity in the Quicksilver but instantly the insensible particles of the Aer being so violently and beyond the rate of subingressibility prest upon and made as it were more powerful by their necessary Reflexion then the reâ—idue of Quicksilver remaining in the Tube result back to their former station of liberty with that vehemency as they not only praevent any further subingression and reduce the even-now-superior and conquering force of the Quicksilver to an equality but also repell the Quicksilver delapsed up again into the Tube above the point of the Aequipondium and again when the Quicksilver defluxeth but not from so great an altitude as at first then is the Aer again compelled to double her files in a countermarch and recede from the restagnant Quicksilver though not so far as at first charge And thus the force of each being by reciprocal conquests gradually decreased they come to that Equality as that the Quicksilver subsists in that point of altitude wherein the Aâ—quilibrium is SECT VI. The Fifth Capital Difficulty WHat Force that is whereby the Aer admitted into the lower orifice of the Tube at the total eduction thereof out of the restagnant Quicksilver and Water is impelled so violently as sufficeth not only to the elevation of the remaining Liquors in the Tube but even to the discharge of them through the sealed extreme to a considerable height in the Aer Solution The immediate Cause of this impetuous motion appears to be only the Reflux or Resilition of the so much compressed Basis of the Cylindre of Aer impendent on the surface of the Restagnant Liquors Quicksilver and Water to the natural Laxity of its insensible particles upon the cessation of the force Compressive the Principle and manner of which Restorative or Reâ—lexive Motion may be perspicuously deprehended upon a serious recognition of the Contents of the last Article in the praecedent Chapter of a Disseminate Vacuum and most accommodately Exemplified in the discharge or explosion of a bullet from a Wind-Gun For as the insensible particles of the Aer included in the Tube of a Wind-Gun being by the Embolus or Rammer from a more lax and rare contexture or order reduced to a more dense and close which is effected when they are made more contiguous in the points of their superfice and so compelled to diminish the inane spaces interjacent betwixt them by subingression are in a manner so many Springs or Elaters each whereof so soon as the external Force that compressed them ceaseth which is at the remove of the Diaphragme or Partition plate in the chamber of the Tube reflecteth or is at least reflected by the impulse of another contiguous particle therefore is it that while they are all at one and the same instant executing that Restorative Motion they impel the Bullet gaged in the canale of the Tube before them with so much violence as enables it to transfix a plank of two or three digits thickness So also do the insensible Particles of the Base of the Cylindre of Aer incumbent on the surface of the Restagnant Liquors remain exceedingly compressed by them as so many Springs bent by external Force and so soon as that Force ceaseth the Quicksilver in the Tube after its eduction no longer pressing the Restagnant Mass of Quicksilver underneath and so that by his tumefaction no longer pressing the impendent Aer they with united forces reflect themselves into their natural rare and liberal contexture and in that Restorative motion drive up the remainder of Quicksilver in the canale of the Tube to the upper extreme thereof with such violence as sufficeth to explode all impediments and shiver the glass For in this case we are to conceive the Aer to be aequally distressed betwixt two opposite Forces on one side by the Gravity of the long Cylindre of Aer from the summity of the Atmosphere down to the Base impendent on the superfice of the Restagnant Liquors on the other by the ascendent Liquors in the subjacent vessel which are impelled by the Cylindre of Quicksilver in the tube descending by reason of its Gravity and consequently that so soon as the obex Barricade or impediment of the Restagnant Quicksilver is removed the distressed Aer instantly converteth that resistent force which is inferior to the Gravity of the incumbent aereal Cylindre upon the remainder of the Quicksilver in the Tube as the now more superable Opponent of the two and so countervailing its Gravity by the motion of Reflexion or Restoration hoyseth it up with so rapid a violence as the easily frangible body of the Glass cannot sustain Which Reason doth also satisfie another Collateral Scruple viz. Why Water superaffused upon the Restagnant Quicksilver doth intrude it self as it were creeping up the side of the Tube and replenish the Desert Space therein so soon as the inferior orifice of the Tube is educed out of the Restagnant Quicksilver into the region of Water For it is impelled by the Base of the Aereal Cylindre exceedingly compressed and relaxing it self the resistence of it which was not potent enough to praevail upon the greater Gravity of the Quicksilver in the Tube so as to impel it above the point of Aequiponderancy being yet potent enough to elevate the Water as that whose Gravity is by 13 parts of 14 less then that of the Quicksilver Here the Inquisitive may bid us stand and observe a second subordinate Doubt so considerable as the omission of it together with a rational solution must have rendred this whole Discourse not only imperfect but a more absolute Vacuum i. e.
times according to the compute of the great Mersennus reflect physicomath pag. 104 who exceedingly differs from the opinion of Galilaeo Dialog al. moviment pag. 81. and Marinus Ghetaldus in Archimed promot both which demonstrate Aer to be only 400 times lighter then Water and Water 14 times lighter then Quicksilver hence we may conclude 1 That Aer is 14000 times lighter then Quicksilver 2 That the Cylindre of Aer aequiponderant to the Cylindre of Quicksilver of the altitude of 27 digits is 14000 times higher and 3 That the altitude of the Cylindre of Aer amounts to 21 Leucae or Leagues Since 14000 times 27 digits i. e. 378000 digits divided by 180000 digits so many amounting to a French League that consisteth of 15000 feet the Quotient will be 21. From the so much discrepant opinions of these so excellent Mathematitians and most strict Votaries of Truth Galilaeo and Mersennus each of which conceived his way for the exploration of the exact proportions of Gravity betwixt Aer and Water absolutely Apodictical we cannot omit the opportunity of observing how insuperable a difficulty it is to conciliate Aristotle to Euclid to accommodate those Axioms which concern Quantity abstract from Matter to Matter united in one notion to Quantity to erect a solid fabrick of Physiology on Foundations Mathematical Which Difficulty the ingenious Magnenus well resenting made this a chief praeparatory Axiom to his second Disputation concerning the Verisimility of Democritus Hypothesis of Atoms Non sunt expendendae Actiones Physicae regulis Geometricis subnecting this ponderous Reason Cum Demonstrationes Geometricae procedant ab Hypothesi quam probare non est Mathematici sed alterius Facultatis quae eam refellit id eo lineis Mathematicis regulisque strictè Geometricis Actiones Physicae non sunt expendendae Democrit Reviviscent p. 318. And now at length having run over these six stages in as direct a course and with as much celerity as the intricacy and roughness of the way would tolerate hath our Pen attained to the end of our Digression wherein whether we have gratified our Reader with so much either of satisfaction or Delight as may compensate his time and patience we may not praesume to determine However this praesumption we dare be guilty of and own that no Hypothesis hitherto communicated can be a better Clue to extricate our reason from the mysterious Labyrinth of this Experiment by solving all its stupendious Apparences with more verisimility then this of a Disseminate Vacuity to which we have adhaered But before we revert into the straight tract of our Physiological journey the praecaution of a small scruple deduceable from that we have consigned a Cylindrical Figure to the portion of Aer impendent on the surface of the Restagnant Liquors adviseth us to make a short stand while we advertise That though we confess the Diametre of the Sphere of Aer to be very much larger then that of the Terraqueous Globe and so that the Aer from the Convex to the Concave thereof incumbent on the surface of the Restagnant Liquors in the vessel placed on the Convex of the Earth doth make out the Section or Frustum of a Cone whose Basis is in the summity of the Atmosphere and point at the Centre of the Earth as this Diagram exhibiteth Note that neither Earth Aer Vessel nor Tube are delineated according to their due proportions since so the Earth would have appeared too great and the rest too small for requisite inspection Yet insomuch as the Aer is Aequiponderant to the Cylindre of Quicksilver contained in the Tube the only requisite to our praesent purpose no less in the Figure of a Cone then in that of a Cylindre and since both Mersennus and Gassendus to either of which we are not worthy to have been a meer Amanuensis have waved that nicety and declared themselves our Praecedents in this particular we have thought our selves excusable for being constant to the most usual Apprehension when the main interest of Truth was therein unconcerned CHAP. VI. OF PLACE SECT I. THat Inanity and Locality bear one and the same Notion Essentially and cannot be rightly apprehended under different conceptions but Respectively or more expresly that the same Space when possessed by a Body is a Place but when left destitute of any corporeal Tenent whatever then it is a Vacuum we have formerly insinuated in the third Article Sect. 1. of our Chap. concerning a Vacuum in Nature Which essential Identy or only relative Alterity of a Vacuum and Place is manifestly the Reason why we thus subnect our praesent Enquiry into the Nature or Formality of Place immediately to our praecedent Discourse of a Vacuum we conceiving it the duty of a Physiologist to derive his Method from Nature and not to separate those Things in his Speculation which she hath constituted of so near Affinity in Essence Among those numerous and importune Altercations concerning the Quiddity or formal reason of Place in which the too contentious Schools usually lose their Time their breath their wits and their Auditors attention we shall select only one Quaestion of so much and so general importance that if rightly stated calmly and aequitably debated and judiciously determined it must singly suffice to imbue the mind of any the most Curious Explorator with the perspicuous and adaequate Notion thereof Epicurus in Epist. ad Herodot◠understands Place to be 〈◊〉 〈◊〉 〈◊〉 〈◊〉 〈◊〉 Intervallum illud quod privatum Corpore dicitur INANE oppletum corpore LOCUS That Interval or Space which being destitute of any body is called a Vacuum and possessed by a body is called Place And Aristotle in 3. Auscult Natur. cap. 6. thinks He hath hit the white when He defines Place to be 〈◊〉 〈◊〉 〈◊〉 〈◊〉 〈◊〉 Circumdantis Corporis extremum immobile primum Concava nempe seu proxima immediataque ipsum locatum contingens corporis ambientis superficies the concave proxime immediate superfice of the body circumambient touching the Locatum Now the Difficulty in Quaestion is only this Whether this Definition of Aristotle or that modest Description of Epicurus doth with the greater measure of verisimility and perspicuity respond to the nature of what we ought to understand in propriety of conception signified by the word Place In order to our impartial perpension of the moments of reason on each side requisite it is that we first strictly ponder the Hypothesis or Ground on which Aristotle erected his assertion which is this Praeter dimensiones Corporis locati ipsam ambientis superficiem nullas alias dari in 4. Physic 1. that in nature are none but Corporeal Dimensions for if we can discover any other Dimensions abstruct from Corporiety such wherein the formal reason of Space may best and most intelligibly be radicated it can no longer remain in the suspence of controversie how unsafe it is for the Schools to recurr to that superstructure as a
Calcined Lead and Water are actually Cold and no third Nature is admixt and nothing more can be said to be in them when commixt that was in them during their state of separation whence can we deduce that intense Heat that so powerfully affecteth indeed misaffecteth the sense of Touching Quaestionless only from this our triple fountain i. e. from hence that upon the accession of humidity the acute or pointed particle of the spirit of Vinegre whereby the fixed salt of the Lead was by potential Calcination dissolved and the Sulphur liquated change their order and situation and after various convolutions or the motions of Fermentations obvert their points unto and penetrate the skin and so cause a dolorous Compunction or discover themselves to the Organ of Touching in that species of Quality which men call Heat The reason of this Phaenomenon is clearly the same with that of a heap of Needles which when confused in oblique transverse c. irregular positions on every side prick the hand that graspeth them but if disposed into uniform order like sticks in a Fagot they may be laterally handled without any asperity or puncture or that of the Bristles of an Urchine which when depressed or ported may be stroked from head to tayle without offence to the hand but when erected or advanced become intractable By the same reason also may we comprehend why Aqua Fortis whose Ingredients in their simple natures are all gentle and innoxious is so fiery and almost invincible a poyson to all that take it why the Spirit of Vitriol freshly extracted kindles into a fire if confused with the Salt of Tartar why the Filings of Steel when irrigated with Spirit of Salt suffer an aestuation ebullition and dissolution into a kind of Gelly or Paste with all other mutations sensible observed by Apothecaries and Chymists in their Compositions of Dissimilar natures from which some third or neutral Quality doth result Secondly that in the parts of an Apple whose one half is rotten the other sound what strange disparity there is in the points of Colour Odour Sapour Softness c. Qualities The sound half is sweet in taste fresh and fragrant in smell white in Colour and hard to the touch the Corrupt bitter earthy or cadaverous duskish or inclinining to black and soft Now to what Cause can we adscribe this manifest dissimilitude but only this that the Particles of the Putrid half by occasion either of Contusion or Corrosion as the Procatarctick Cause have suffered a change of position among themselves and admitted almost a Contrary Contexture so as to exhibite themselves to the several Organs of Sense in the species of Qualities almost contrary to those resulting from the sound half which upon a farther incroachment of putrefaction must also be deturbed from their natural Order and Situations in like manner and consequently put on the same Apparences or Qualities For can it be admitted that the sound moâ—ty when it shall have undergone Corruption doth consist of other Particles then before if it be answered that some particles thereof are exhaled and others of the aer succeeded into their rooms our assertion will be rather ratified then impugned because it praesumes that from the egression of some particles the subingression of others of aer and the total transposition of the remaining Corruption is introduced thereupon and thereby that general change of Qualities mentioned These Instances and the insufficiency of any other Dihoties to the rational explanation of them with due attention and impartiality perpended we cannot but highly applaud the perspicacity of Epicurus who constantly held 〈◊〉 〈◊〉 〈◊〉 〈◊〉 〈◊〉 that the Motion of Mutation was a species of Local Transition and 〈◊〉 〈◊〉 〈◊〉 〈◊〉 〈◊〉 Concretum quod secundum Quâ—litatem mutatur omnino mutatur Locali transitivo motu eorum corporum ratione intelligibilium quae in ipsum concreverint Which Empiricus 2. advers Phys. descanting upon saith thus Exempli caussâ ut ex dulci fiat aliquid amarum aut ex albo nigrum oportet moleculas seu Corpuscula quae ipsum constituunt transponi alium vice alterius ordinem suscipere Hoc autem non contigerit nisi ipsae moleculae motione transitus moveantur Et rursus ut ex molli fiat quid Durum ex duro molle oportet eas quae illud constituunt particulas secundum locum moveri quippe earum extensione mollitur coitione verò condensatione durescit c. All which is most adaequately exemplified in a rotten Apple And this we conceive may suffice in the General for our Enquiry into the possible Origine of sensible Qualities CHAP. II. That Species Visible are SUBSTANTIAL EMANATIONS SECT I. SEnsus non suscipere SUBSTANTIAS though the constant assertion of Aristotle and admitted into his Definition of Sense 〈◊〉 〈◊〉 〈◊〉 〈◊〉 〈◊〉 Sensus est id quod est capax sensibilium specierum sine materia lib. 2. de Anima cap. ultim and swallowed as an Axiome by most of his Commentators is yet so far from being indisputable that an intent examination of it by reason may not only suspect but convict it of manifest absurdity Witness only one and the noblest of Senses the SIGHT which discerns the exterior Forms of Objects by the reception either of certain Substantial or Corporeal Emanations by the sollicitation of Light incident upon and reflected from them as it were Direpted from their superficial parts and trajected through a diaphanous Medium in a direct line to the eye or of Light it self proceeding in streight lines from Lucid bodies or in reflex from opace in such contextures as exactly respond in order and position of parts to the superficial Figure of the object obverted to the eye For the FIRST of these Positions Epicurus hath left us so rational â— Ground that deserves besides our admiration of His Perspicacity if not our plenary Adhaerence yet at least our calm Allowance of its Verisimility and due praelation to that jejune and frothy Doctrine of the Schools that Species Visible are Forms without Matter and immaterial not only in their admission into the Retina Tunica or proper and immediate Organ of sight but even in their Trajection through the Medium interjacent betwixt the object and the eye Which Argument since too weighty to be entrusted to the support of a Gratis or simple Affirmation we shall endeavour to prop up with more then one solid Reason And this that we may with method requisite to perspicuity effect we are to begin at the faithful recital of Epicurus Text and then proceed to the Explanation and Examination of it Reputandum est esse in mundo quasdam Effigies ad Visionem inservienteis quae corporibus solidis delineatione consimiles superant longè sua tenuitate quicquid est rerum conspicabilium Neque enim formari repugnat etiam in medio aere circumfusove spatio hujusmodi quasdam Contexturas uti neque repugnat esse
Rhegium at the usual time of the Apparition I examined all the Circumstances thereof together with the situation of the place the nature and propriety of the soyl and the constitution of the vapours arising from the Sea and examining my observations by Physical and Optical reasons I soon detected the Causes of the whole Phaenomenon First I observed the Mountain called Tinna on the Sicilian side directly confronting Rhegium to run along in a duskish obscure tract upon Pelorus and the shores subjacent as also the bottom of the Sea to be covered with shining sand being the fragments of Selenites Antimony and other pellucid Concretions devolved from the eminent parts of the land the contiguous Hills that are richly fraught with veins of those Minerals Then I observed that these translucid sands being together with vapors from the Sea and Shore exhaled into the aer by the intense fervor of the Sun did coalesce into a Cloud in all points respondent to a perfect Polyedrical or Multangular Looking-glass the various superficies of the resplendent Granules making a multiplication of the species and that these being opacated behind by crass and impervious vapours directly facing the Mountains did make reflection of the various Images of objects respective to their various positions to the eye The several Rows of Pillars in the aereal Scene are caused by one single Pillar erected on the Shore for being by a manifold reflection from the various superficies of the tralucent particles opacated on the hinder part by dense Vapours in the speculary Meteor it is multiplyed even to infinity No otherwise then as one single Image posited betwixt two polyedrical Looking-glasses confrontingly disposed is so often repercussed or reflected from superfice to superfice that it exhibiteth to the eye almost an infinite multitude of Images exactly consimilar Thus also doth one man standing on the shore become a whole Army in the Cloud one Beast a whole Herd and one Tree a thick-set Grove As for the vanishing of this first Scene and the succession of a second adorned with the representations of Castles and other magnificent structures the Cause hereof is this since the eye of the Spectator hath its sight variously terminated in the several speculary superficies of the Cloud that is in perpetual motion according to the impulse of the Wind it comes to pass that according to the rules of the Angles of Incidence and Reflection divers Species are beheld under the same constitute Angle and as the speculary Vapour doth reflect them toward the eye which divers species are projected from objects conveniently situate and particularly from the Castle on the ascent towards Rhegium from the place of our prospect Some perhaps may judge our affirmation of the Elevation of those shining Grains of Vitreous Minerals into the aer by the meer attraction of the Sun and the Coalition of them there with the Cloud of Vapours to be too large a morsel to be swallowed by any throat but that Cormorant one of Credulity If so all we require of them is only to consider that Hairs Straws grains of Sand fragments of Wood and such like Festucous Bodies are frequently found immured in Hailstones which doubtless are sufficient arguments that those things were first elevated by the beams of the Sun recoyling from the earth into the middle region of the aer and there coagmentated with the vapours condensed into a Cloud and frozen in its descent Now this solution of the Morgana acquires the more of Certitude and Auctority from hence that in imitation of this Natural Prodigious Ostent or Aereal Representation Kircher invented a way of exhibiting an Artificial one by the Fragments of Glass Selenites Antimony c. stewed in an iron trough and vapours ascending from Water superaffused and terminated by a black Curtain superextended The full description of which Artifice He hath made the Subject of his 2. parastasis in Magia Parastat cap. 1. CHAP. III. CONCERNING THE MANNER and REASON OF VISION SECT I. AMong the many different Conceptions of Philosophers both Ancient and Modern touching the Manner and Reason of the Discernment of the Magnitude Figure c. of Visible Objects by the Visive Faculty in the Eye the most Considerable are these 1 The STOICKS affirmed that certain Visory Rayes deradiated from the brain through the slender perforations of the Optick Nerves into the eye and from thence in a continued fluor to the object do by a kind of Procusion and Compression dispose the whole Aer intermediate in a direct line into a Cone whose Point consisteth in the superfice of the Eye and Base in the superfice of the Object And that as the Hand by the mediation of a staff imposed on a body doth according to the degrees of resistence made thereby either directly or laterally deprehend the Tactile Qualities thereof i. e. whether it be Hard or Soft Smooth or Rough whether it be Clay or Wood Iron or Stone Cloth or Leather c. So likewise doth the Eye by the mediation of this Aereal staff discern whether the Adspectable Object on which the Basis of it resteth be White or Black Green or Red Symetrical or Asymetrical in the Figure of its parts and consequently Beautiful or Deformed 2 ARISTOTLE though his judgment never acquiesced in any one point as to this particular doth yet seem to have most constantly inclined to this that the Colour of the Visible doth move the Perspicuum actu i. e. that Illustrate Nature in the Aer Water or any other 〈◊〉 〈◊〉 〈◊〉 〈◊〉 〈◊〉 Transparent body and that by reason of its Continuity from the extremes of the Object to the Eye doth move the Eye and by the mediation thereof the Internal Sensorium or Visive Faculty and so inform it of the visible Qualities thereof So that according to the Descant of those who pretend to be his most faithful Interpreters we may understand Him to have imagined the Colour of the object to be as it were the Hand the diaphanous Medium as it were the Staff and the Eye as it were the Body on which it is imposed and imprest è diametro opposite to the conceit of the Stoicks who suppose the Eye to supply the place of the Hand the Aer to analogize the Staff and the Object to respond to the Body on which it is imposed and imprest 3 The PYTHAGOREANS determined the reason of Vision on the Reflexion of the Visive Rayes in a continued stream emitted from the internal Eye to the visible back again into the eye or more plainly that the radious Emanations from the Eye arriving at the superfice of the object are thereby immediately Repercussed in an uninterrupted stream home again to the eye in their return bringing along with them a perfect representation thereof as to Colour Figure and Magnitude 4 EMPEDOCLES though admitting as we hinted in the next praeceding Chapter substantial Effluxes from the Visible to the Organ of Sight doth also assume the
parts of both Liquors and yet most certain it is that the particles of Wine possess not the same Invisible Loculaments or Receptaries that are replete with the particles of Water but others absolutely distinct because otherwise there would be as much of Water or Wine alone in the Vial as there is of both Water and Wine which in that Continent is impossible And hereupon we Conclude that to admit every distinct species to replenish the whole medium is no less dangerous then to admit that each of two Liquors confused doth singly replenish the whole Capacity or the Continent the parity of reasons justifying the Parallelism Assumption the Fifth That the visible Image being trajected through the Pupil and having suffered its ultimate refraction in that Convex Mirror the Chrystalline Humor is received and determined in that principal seat of Vision which holds no remote analogy to a Concave Mirror the Retina Tunica or Expansion of the Optick Nerve in the bottom of the eye and therein represents the Object from whence it was deradiated in all particulars to the life i. e. with the same Colour Figure and Situation of parts which it really beareth provided the Distance be not excessive The First part of this eminent Proposition that excellent Mathematician Christopher Scheinerus hath so evicted by Physical Reasons Optical Demonstrations and singular Experiments as no truth can seem capable of greater illustration and less opposition and therefore the greatest right we can do our selves or you in this point is to remit you to the observant lecture of his whole Third Book de Fundament Opticis which we dare commend with this just Elogie that it is the most Elaborate and Satisfying investigation of the Principal Seat of Vision that ever the World was enriched with and He who shall desire a more accomplisht Discourse on that formerly abstruse Theorem must encounter the censure of being either scarce Ingenious enough to comprehend or scarce Ingenuous enough to acknowledge the convincing Energy of the Arguments and Demonstrations therein alledged for the confirmation of his Thesis Radij formalitèr visorij nativam sedem esse tunicam retinam And the other is sufficiently evincible even from hence That the Sight or if you please the Interior Faculty doth alwayes judge of tâ—e adspectable form of an Object according to the Condition of the Image emanant from it at least according as it is represented by the Image at the impression thereof on the principal visory part Which is a position of Eminent Certitude For no other Cause can be assigned why the Visive Faculty doth deprehend and pronounce an object to be of this or that particular Colour but only this that the Image imprest on the Net-work Coat doth represent it in that particular Colour and no other Why when half of the Object is eclipsed by some opace body interposed the eye can speculate nor the faculty judge of no more then the unobscured half but only this that the Image is mutilated and so consisteth of onely those radii that are emitted from the unobscured half and consequently can inferr the similitude of no more Why an Object of whatever Colour appeareth Red when speculated through Glass of that Tincture but only because the Image in its trajection through that Medium being infected with redness retains the same even to its sigillation on the Expansion of the Optick Nerve Why the sight in some cases especially in that of immoderate distance and when the object is beheld through a Reversing Glass deprehends the object under a false figure but because the Image represents it under that dissimilar figure having either its angles â—etused by reason of a too long trajection through the Medium or the situation of its parts inverted by decussation of its rayes in the Glass CONSECTARY the First Now it being no less Evident then Certain that the Image is the sole cause of the Objects apparence under such or such a determinate Colour and of this or that determinate Figure it is of pure Consequence that the Image must also be the Cause of the Objects appearance in this or that determinate Magnitude especially since Figure is essenced in the Termination of Magnitude according to Euclid lib. 1. def 14. Figura est quae sub aliquo vel aliquibus terminis comprehenditur For why doth the object appear to be of great small or mean dimensions if not because the Image arriving at the sentient is great small or mean Why doth the whole object appear greater then a part of it self unless because the whole Image is greater then a part of it self To speak more profoundly and as men not altogether ignorant of the Mysteries in Opticks demonstrable it is that the Magnitude of a thing speculated may be commensurated by the proportion of the Image deradiated from it to the distance of the Common Intersection For as the Diametre of the Image projected through a perspective or Astronomical Tube on a sheet of white paper is in proportion to the Axis of the Pyramid Eversed so is the diameter of the basis of the Object to the Axis of the Pyramid Direct And hereby also come we to apprehend the Distance of the Object from the Eye for having obtained the Latitude of the object we cannot want the knowledge of its Distance and by conversion the knowledge of its distance both assists and facilitates the comprehension of its Magnitude Which comes not much short of absolute necessity since as Des Cartes Dioptrices cap. 6. hath excellently observed in these words Quoniam autem longitudo longius decurrentiam radiorum non exquisite salis ex modo impulsus cognosci potest praecedens Distantiae scientia hic in auxilium est vocanda Sic ex Gr. sâ— distantia cognoscatur esse magna Angulus visionis sit parvus res objecta longius distans judicatur magna sin verò distantia sciatur esse parva angulus Visionis sit magnus objectum judicatur esse parvum si verò distantia objecti longius dissiti sit in cognita nihilcerti de ejus magnitudine decerni potest if the Distance of an object far removed be unknown the judgment concerning the magnitude thereof must be uncertain CONSECTARY the Second Again insomuch as the Receptary of the Visible Image is that Concave Mirrour the Retina tunica we call it a Concave Mirrour not only in respect of its Figure and Use but also in imitation of that grand Master of the Opticks Alhazen who in lib. 1. cap. 2. saith thus Et sequitur ex hoc at corpus sentiens quod est in Concavo Nervi retina nimirum sit aliquantulùm Diaphanum ut appareant in eo formae lucis coloris c. Hence is it that no Image can totally fill that Receptary unless it be derived from an object of an almost Hemispherical ambite or Compass so that the rayes tending from it to the eye may bear the form of a Cone
those things to be Contiguous or Continued whose Rayes are received into the Eye as Contiguous or Continued none of the spaces interjacent affording one raye Of which truth Des Cartes seems to have had a glimpse when in Dioptrices cap. 6. Sect. 15. he conceds objectorum quae intuemur praecedaneam cognitionem ipsorum distantiae melius dignoscendae inservire that a certain praecognition of the object doth much conduce to the more certain dignotion of its Distance And on this branch may we ingraft a PARADOX that one and the same object speculated by the same man in the same degree of light doth alwayes appear greater to one Eye than to the other The truth of this is evincible by the joint testimony of those incorruptible Witnesses of Certitude Experience and Reason 1 Of Experience because no man can make the vision of both his eyes equally perfect but beholding a thing first with one eye the other being closed or eclipsed and then with the other the former being closed or eclipsed shall constantly discover it to be greater in dimensions in the apprehension of one Eye than of the other and Gassendus making a perfect and strict Experiment hereof testifies of himself in Epist. 2. de Apparent Magnitud Solis c. Sect. 17. that the Characters of his Book appeared to his right Eye by a fifth part greater in dimensions though somewhat more obscure than to his left 2 Of Reason because of all Twin Parts in the body as Ears Hands Leggs Testicles c. one is alwayes more vigorous and perfect in the performance of its action than the other Which Inaequality of Vigour if it be not the Bastard of Custom may rightfully be Fathered upon either this that one part is invigorated with a more liberal afflux of Spirits than the other or this that the Orgaganical Constitution of one Part is more perfect and firm than that of the other And therefore one Eye having its Pupill wider or the figure of the Chrystalline more Convex or the Retina Tunica more concave than the other must apprehend an object to be either larger in Dimensions or more Distinct in Parts than the other whose parts are of a different configuration either of these Causes necessitating a respective Disparity in the Action If this sound strange in the ears of any man how will he startle at the mention of that much more Paradoxical Thesis of Ioh. Baptista Porta lib. 6. de Refraâ—tion cap. 1. That no man can see distinctly but with one eye at once Which though seemingly repugnant not only to common persuasion but also to that high and mighty Axiom of Alhazen Vitellio Franc. Bacon Niceron and other the most eminent Professors of the Optiques That the Visive Axes of both eyes concurr and unite in the object speculated is yet a verity well worthy our admission and assertion For the Axes of the Eyes are so ordained by Nature that when one is intended the other is relaxed when one is imployed the other is idle and unconcerned nor can they be both intended at once or imployed though both may be at once relaxed or unimployed as is Experimented when with both eyes open we look on the leaf of a Book for we then perceive the lines and print thereof but do not distinctly discern the Characters so as to read one word till we fix the Axe of one eye thereon and at that instant we feel a certain suddain subsultation or gentle impulse in the Centre of that eye arising doubtless from the rushing in of more spirits through the Optick Nerve for the more efficacious performance of its action The Cause of the impossibility of the intention of both Visive Axes at one object may be desumed from the Parallelism of the Motion of the Eyes which being most evident to sense gives us just ground to admire how so many subtle Mathematicians and exquisite Oculists have not discovered the Coition and Union of the Visive Axes in the object speculated which they so confidently build upon to be an absolute Impossibility For though man hath two Eyes yet doth he use but one at once in the case of Distinct inspection the right eye to discern objects on the right side and the left to view objects on the left nor is there more necessity why he should use both Eyes at once than both Arms or Leggs or Testicles at once And for an Experiment to assist this Reason we shall desire you only to look at the top of your own Nose and you shall soon be convicted that you cannot discern it with both eyes at once but the right side with the right eye and afterward the left side with the left eye and at the instant of changing the Axe of the first eye you shall be sensible of that impulse of Spirits newly mentioned Noâ— indeed is it possible that while your right eye is levelled at the right side of your nose your left should be levelled at the left side but on the contrary averted quite â—rom it because the motion of the eyes being Conjugate or Parallel when the Axe of the right eye is converted to the right side of the nose the Axe of the left must be converted toward the left Ear. And therefore since the Visive Axes of both Eyes cannot Concurr and Unite in the Tipp of the Nose what can remain to persuade that they must Concurr and unite in the same Letter or Word in a book which is not many inches more remote than the Nose And that you may satisfie your self that the Visive Axes doe never meet but run on in a perpetual Parallelism i. e. in direct lines as far distant each from other as are the Eyes themselves having fixed a staff or launce upright in the ground and retreated from it to the distance of 10 or 20 paces more or less look as earnestly as you can on it with your right eye closing your left and you shall perceive it to eclipse a certain part of the wall tree or other body situate beyond it Then look on it again with your left eye closing your right and you shall observe it to eclipse another part of the wall that space being intercepted which is called the Parallaxe This done look on it with both eyes open and if the Axes of both did meet and unite in the staff as is generally supposed then of necessity would you observe the staff to eclipse either both parts of the Wall together or the middle of the Parallaxe but you shall observe it to do neither for the middle shall never be eclipsed but only one of the parts and that on which you shall fix one of your eyes more intently than the other This considered we dare second Gassendus in his promise to Gunners that they shall shoot as right with both eyes open as only with one for levelling the mouth of the Peece directly at the mark with one eye their other must be wholly unconcerned therein nor is
the interior angle and is called the Trochlea or Pully These two Circumactors are sirnamed Amatorij the Lovers Muscles for these are they that roul about the eye in wanton or amorous Glances And thus much of the Conformation of the Eye Now as to the Solution of our Problem viz. How the SITUATION of an object is perceived by the sight Since it is an indisputable Canon Omnem sensum deprehendere rem ad eam regionem è qua ultimò directa metione feritur that every sense doth apprehend its proper object to be situate in that part of Space from whence by direct motion it was thereby affected we may safely inferr that the Visible Object alwayes appears situate in that part of space from whence the Image thereof in a direct line invadeth the Eye and enters the Pupil thereof Which is true and manifest not only in the intuition of an object by immediate or Direct rayes but also in the inspection of Looking-Glasses that represent the object by Reflex and a pure Consequence that a Visible Object by impression of its rayes proceeding from a certain place or region must of necessity be perceived by the sight in its genuine position or Erect Form though we have the testimony both of Reason and Autopsie that the Image of every Visible is pourtraid in the Amphiblestroides in an unnatural position or Everse Form And as for that of Autopsie or Ocular Experiment Take the Eye of an Oxe or if the Anatomick Theatre be open of a man for in that the species are represented more to the life than in the Eye of any other Animal as Des Cartes in dioptrices cap. 5. Sect. 11. and having gently stript off the three Coats in the bottome in that part directly behind the Chrystalline so that the Pellucidity thereof become visible place it in a hole of proportionate magnitude in the wall of your Closet made obscure by excluding all other light so that the Anterior part theaeof may respect the light This done admoving your Eye towards the denudated part of the Chrystalline you may behold the Species of any thing obverted to the outside of the Eye to enter through the Chrystalline to the bottom thereof and there represented in a most lively figure as if pourtrayed by the exquisite Pencil of Apelles but whoâ—ly Eversed as in this following Iconisme Finally an object appears either in Motion or Quiet according as the Image thereof represented on the Retina Tunica is moved or Quiet only because according to the Canon in the praecedent Article touching the reason of the perception of the situation of an object the Visible is alwayes judged to be in that part of Space from which in a direct line the last impression is made upon the Sensorium And this Reason is of extent sufficient to include the full Solution also of that PROBLEM by Alexander 2. de Anima 34. so insulting proposed to the Defendants of Epicurus Material Actinobolisme Visive or the Emanation of substantial Images from the Object to the Eye viz. Why doth tâ—e Image of a man move when reflected from a Mirrour according as the man moves For this Phaenomenon we are to referr to the Variation of the parts of the Mirrour from each of which it is necessary that a fresh Reflexion of the Species be made into the Eye and consequently that the Image appear moved according to the various motions of the object The necessity of this is evident from hence if you stand beholding your face in a Glass and there be divers others standing by one at your right hand another at your left a third looking over your head in the same Glass they shall all behold your image but each in a distinct part of the Glass Whence you may also understand that in the Looking-glass is not only that Image which you behold but also innumerable others and those so mutually communicant that in the same place where you behold your nose another shall see your chin a third your forehead a fourth your mouth a fifth your Eyes c. and yet doth no one see other then a simple and distinct Image Moreover you may hence inferr that in the medium is no point oâ— Space in which there is not formed a perfect Image of the â—ayeâ— concurring therein and advenient from the same object though not from the same parts or particles thereof and consequently that in the whole Medium there are no two Images perfectly alike as also that what the Vulgar Philosophers teach that the whole Image is in the whole Space or Medium and whole in every part thereof is a manifest Falsity For though it may be said justly enough that the whole Image i. e. the Aggregate of all the Images is in the whole Space yet is there no part of that Space in which the whole Image can be To this place belongs also that PROBLEM Why doth not the right hand of the Image respond to the right of the object but contrariwise the left to the right and right to the left The Cause whereof consisteth onely in the Images Confronting the Object or as Plato in Timaeo most perspicuously expresseth it quia contrarijs visus partibus ad contrarias partes â—it contactus Understand it by supposing a second person posited in the place of the Mirrour and confronting the first for his right hand must be opposed to the others left Nor is the reason of the Inversion of the parts of the Image other than this that the rayes emitted from the right side of the object are reflected on the left and â— Contra. Just as in all Impressions or Sigillations the right side of the Antitype responds to the left of the type Consule Aquilonium lib. 1. opt proposit 46. And as for the reason of the Restitution of the parts of the Image to the right position of the parts of the object by two Mirrours confrontingly positeâ— it may most easily and satisfactorily be explained by the Decussation of the reflected rayes To Conclude We need not advertise that the Optical Problems referrible to this place are if not infinite so numerous as to require a larger Volume to their orderly Proposition and Solution than what we have designed to the whole of this our Physiology Nor remember you that our principal Scope in this Chapter was only to evince the Praeâ—â—inence of Epicurus Hypothesis above all others concerning the Reason and Manner of Vision and this by accommodating it to the Verisimilous Explanation of the most Capital Difâ—â—culties occurring to a profound inquest into that abstruse subject All therefore that remains unpaid of our praesent Debt is modestly to referr it to your equitable Arbitration Whether we have deserted the Doctrine of the Aristoteleans touching this theorem and addicted ourselves to the Sect of the Epicureans on any other Interest but that sacred one of Verity which once to decline or neglect upon the sinister praetext of vindicating any Human
mighty hand or most potent Energy in the production of Colours For supposing three kinds of Salt in all natural Concretions the first a Fixt and Terrestrial the second a Sal Nitre allied to Sulphur the Third a Volatile or Armoniac referrible to Mercury and that all bodies receive degrees of Perspicuity or Opacity respondent to the degrees of Volatility or Terrestriety in the Salts that amass them they thereupon deduce their various Colours or visible Glosses from the various Commistion of Volatile or Tralucent Salts with Fixt or obscure Now notwithstanding all these Sects are as remote each from other as the Zenith from the Nadir in their opinions touching the Nature and Causes of Colours as to all other respects yet do they generally Concur in this one particular 〈◊〉 〈◊〉 〈◊〉 〈◊〉 〈◊〉 Colores esse Cohâ—rentes corporibus that Colours are CONGENITE or COHAERENT to bodies Which being manifestly repugnant to reason as may be clearly evinced as well from the Arguments alledged by Plutarch 1. advers Colot to that purpose as from the result of our whole subsequent discourse concerning this theorem we need no other justification of our Desertion of them and Adhaerence to that more verisimilous Doctrine of Democritus and Epicurus 〈◊〉 〈◊〉 〈◊〉 〈◊〉 〈◊〉 Colorem Lege esse or more plainly in the words of Epicurus 〈◊〉 〈◊〉 〈◊〉 〈◊〉 〈◊〉 Colores in corporibus gigni juxta quosdam respectu visus ordines positusque The Probability of which opiâ—â—â—n that we may with due strictness and aequâ—nâ—mity examine and 〈◊〉 whâ—t we formerly delivered in our Oâ—igine of Qualities touching thâ— possible Causes of an inassignable Variety of Colours We are briefly to advertise First That by the word 〈◊〉 〈◊〉 〈◊〉 〈◊〉 〈◊〉 Bodies we are not to understand Atoms or simple bodies for those are generally praesumed to be devoyd of all Colour but 〈◊〉 〈◊〉 〈◊〉 〈◊〉 〈◊〉 Concretions or Compounds Secondly that Epicurus in this text according to the litteral importance thereof and the Exposition of Gassendus his most judicious and copious Interpreter had this and no other meaning That in the Extrems or superficies of all Concretions there are such certain Coordinations and Dispositions of their component particles which according to our First Assumption in the immediately praecedent Chapter borrowed from the incomparable Bullialdus are never contexed without more or less of Inaequality as that upon the incidence of Light they do and must exhibit some certain Colour or other respective to their determinate Reflection and Refraction or Modification of the rayes thereof and the position of the Eye that receives them That from these superficial Extancies and and Cavities of bodies are emitted those substantial Effluviaes constituting the visible Image which striking upon the primary Organ of Vision in a certain Order and Position of particles causeth therein a sensation or Perception of that particular Colour But that these Colours are not really Cohaerent to those superficial particles so as not to be actually separated from them upon the abscedence of Light and consequently that Colours have no Existence in the Dark Moreover that the substance of Light or the minute particles of which its beams consist are necessarily to be superadded to the superficial particles of bodies as the Complement nay the Principal part of Colour as may be inferred from these words of Epicurus registred by Plutarch 1. advers Colot Quinetiam hâc parte luce viz. seclusa noâ— video qui dicere liceat corpora quae in tenebris in conspicua sunt colorem habere Of which persuasion was also that admirable Mathematician Samius Aristarchus who positively affirmed apud Stobaeum in Ecl. Phys. 19. Incidentem in subjectas res Lucem Colorem esse ideoque constituta in tenebris corpora colore prorsùs destitui To which doubtless Virgil ingeniously alluded in his Ubi Coelum condidit Umbra Iupiter rebus nox abstulit atra Colorem And Lucretius in his Qualis enim coecis poterit Color esse tenebris Lumine qui mutatur in ipso propterea quod Recta aut obliqua percussus luce refulget c. And lastly that Light doth create and vary Colours according to the various condition of the minute Faces or sides of the Particles in the superfice which receive and reflect the incident rayes thereof in various Angles toward the Eye SECT II. HAving thus recited explicated and espoused the Conceptions of Epicurus of the Creation of Colours it behoves us to advance to the Examination of its Consistency with right reason not only in its General capacity but deduction and accommodation to Particulars But First to praevent the excess of your wonder at that so Paradoxical assertion of his That there are no Colours in the dark or that all colours vanish upon the Amotion or defection of Light we are to observe that it is one thing to be Actually Colorate and another to be only Potentially or to have a Disposition to exhibit this or that particular Colour upon the access of the Producent Light For as the several Pipes in an Organ though in themselves all aequally Insonorous or destitute of sound have yet an equal Disposition in respect of their Figuration to yield a sound upon the inflation of Wind from the Bellows and as the seeds of Tulips in Winter are all equally Exflorous or destitute of Flowers but yet contain in their seminal Virtues a Capacity or Disposition to emit various coloured flowers upon the access of fructifying heat and moysture in the Spring so likewise may all Bodies though we allow them to be actually Excolor in the Dark yet retain a Capacity whereby each one upon the access and sollicitation of Light may appear clad in this or that particular Colour respective to the determinate Ordination and Position of its superficial particles To inculcate this yet farther we desire you to take a yard of Scarlet Cloth and having extended it in an uniform light observe most exactly the Colour which in all parts it bears Then extend one half thereof in a primary light i. e. the immediately incident or direct rayes of the Sun and the other in a secondary or once reflected light and then though perhaps through the praeoccupation of your judgment you may apprehend it to be all of one colour yet if you engage a skilful Painter to pourtray it to the life as it is then posited He must represent the Directly illuminate half with one Colour viz. a bright and lightsome Red and the Reflexly illuminate half with another i. e. with a Duskish or more obscure Red or shamefully betray his ignorance of Albert Durers excellent Rules of shadowing and fall much short of your Expectation This done gently move the extended Cloth through various degrees of Light and shadow and you shall confess the Colour thereof to be varied upon each remove respondent to the degree of Light striking thereupon Afterward fold the Cloth as Boyes do paper for Lanterns or lay it
in waves or pleights of different magnitude and you shall admire the variety of Colours apparent thereon the lâ—minent and directly illustrate parts projecting a lively Câ—â—nation the Lateral and averted yeilding an obscure sanguine clouded with Murrey and the Profound or unillustrate putting on so perfect sables as no colour drawn on a picture can counterfeit it to the life but the deadest Black Your Sense thus satisfied be pleased to exercise your Reason a while with the same Example and demand of your self Whether any one of all those different Colours can be really inhaerent in the Cloth If you pitch upon the Scarlet as the most likely and proper then must you either confess that Colour not to be really inhaerent since it may in less than a moment be varied into sables only by an interception of Light or admit that all the other Colours exhibited are aequally inhaerent which is more we praesume then you will easily allow And therefore you may attain more of satisfaction by concluding that indeed no one of all those Colours is really so inhaerent in the cloth as to remain the same in the absence of Light but that the superficial particles of the Cloth have inhaerent in them ratione Figurae Coordinationis Positus such a Disposition as that in one degree of Light it must present to the eye such a particular colour in another degree a second gradually different from that in another a third discriminate from both until it arrive at perfect obscurity or Black And if your Assent hereto be obstructed by this DOUBT Why that Cloth doth most constantly appear Red rather then Green Blew Willow c. you may easily expede it by admitting that the Reason consisteth only herein that the Cloth is tincted in a certain Liquor whose minute Particles are by reason of their Figure Ordination and Disposition comparate or adapted to Refract and Reflect the incident rayes of Light in such a manner temperation or modification as must present to the eye the species of such a Colour viz. Scarlet rather then a Green Blew Willow or any other For every man well knows that in the Liquor or Tincture wherein the Cloth was dyed there were several ingredients dissolved into minute pâ—rticles and that there is no one Hair or rather no sensible part in the superfice thereof whereunto Myriads of those dissolved particles do not constantly adhere being agglutinated by those Fixative Salts such as Sal Gemmae Alum calcined Talk Alablaster Sal Armoniack c. wherewith Dyers use to graduate and engrain their Tinctures And therefore of pure necessity it must be that according to the determinate Figures and Contexture of those adhaerent Granules to the villous particles in the superfice of the Cloth such a determinate Refraction and Reflection of the rayes of Light should be caused and consequently such a determinate species of Colour and no other result therefrom Now insomuch as it is demonstrated by Sense that one and the same superfice doth shift it self into various Colours according to its position in various degrees of Light and Shadow and the various Angles in which it reflecteth the incident rayes of Light respective to the Eye of the Spectator and justly inferrible from thence by Reason that no one of those Colours can be said to be more really inhaerent than other therein all being equally produced by Light and Shadow gradually intermixt and each one by a determinate Modification thereof What can remain to interdict our total Explosion of that Distinction of Colours into Real or Inhaerent and False or only â—pparent so much celebrated by the Schools For since it is the Genuine and Inseparable Propriety of Colours in General to be Apparent â—o suppose that any Colour Apparent can be False or less Real than other is an open Contradiction not to be dissembled by the most specious Sophistry as Des Cartes hath well observed in Meteor cap. 8. art 8. Besides as for those Evanid Colours which they call 〈◊〉 〈◊〉 〈◊〉 〈◊〉 〈◊〉 meerly Apparent ones such as those in the Rainbow Parheliaes Paraselens the trains of Peacocks necks of Doves Mallards c. we are not to account them Evanid because they are not True but because the Disposition of those superficial particles in the Clouds and Feathers that is necessary to the Causation of them is not Constant but most easily mutable in respect whereof those Colours are no more permanent in them than those in the Scarlet cloth upon the various position extension plication thereof And Charity would not dispense should we suppose any man so obnoxious to absurdity as to admit that the greater or less Duration of a thing doth alter the Nature of it Grant we for Example that the particles of Water constituting the rorid Cloud wherein the Rainbow shews it self were so constant in that determinate position and mutuall coordination as constantly to refract and reflect the incident beams of the Sun in one and the same manner and then we must also grant that they would as constantly exhibite the same Species of Colours as a Râ—inbow painted on a table but because they are not and so cannot constantly refract and reflect the irradiating light in one and the same manner it is repugnant to reason thereupon to conclude that the Instability of the Colours doth detract from the Verity or Reality of their Nature For it is only Accidental or Unessential to them either to be varied or totally disappear So that if you admit that Sea Green observed in the Rainbow to be less True than the Green of an Herb because its Duration is scarce momentany in comparison of that in the Herb you must also admit that Green in the Herb which in a short progress of time degenerates into an obscure yellow to be less true than that of an Emrauld because its Duration is scarce momentany in comparison of thâ—â— of the Emrauld But perhaps Praejudice makes you yet inflexible and therefore you 'l farther urge thâ—t the Difficulty doth cheifly concern those Evanid Colours which â—â—e appinged on Bodies reflecting light by Prisms or Triangular Glasseâ— vulgarly called Fools Paradises because these seem to have the least of Reality among all other reputed meerly Apparent And in case yâ—â— assault us with this your last Reserve we shall not desert our station for want of strength to maintain it For that those Colours are as Real as any other the most Durable is evident even from hence that they have the very same Materials with all other i. e. they are the substance of Light it self reflected from those objected Bodies â—nd what happens not to those eyes that speculate them without a Prism twice refracted Experience dâ—monstrates that if a man look intently upon a polite Globe in â—hat part of it superfice from which the incident Light is reflecteâ— in direct lines toward his eye He shall perceive it to appear clad in another Colour than when He looks upon it from
any other part of the Medium toward which the Light is not reflected and 〈…〉 He have no reason why He should not account both those Difâ—â—â—ent Colours to be True the Reflection of light which varieth the Apparition according to the various Position of the eye in several parts of the Medium nothing diminishing their Verity If so why should not those Colours created by the Prism be also reputed Real the Refraction of Light which exhibiteth other Colours in the objected Bodies than appear in them without that Refraction nothing diminishing their Reality By way of COROLLARY let us here observe that the Colours created by Light reflected from objects on the Prism and therein twice refracted are Geminated on both sides thereof For insomuch as those Colours are not appinged but on the Extremes of the Object or where the supâ—rfice is unequal for if that be Plane and Smooth it admits only an Uniform Colour and the same that appears thereon when beheld without the Prism therefore are two Colours alwayes observed in that Extreme of the Object which respecteth the Base of the Triangle in the Glass and those are a Vermillion and a Yellow and two other Colours in that extreme which respecteth the Top of the Triangle and those are a Violet blew and a Grass green And hence comes it that if the Latitude of the Superfice be so small as that the extremes approach each other sufficiently near then are the two innermost Colours the Yellow and Green connected in the middle of the Superfice and all the four Colours constantly observe this order beginning from the Base of the Triangle a Vermillion Yellow Green and Violet beside the inassignable variety of other Intermediate Colours about the Borders and Commissures We say Beginning from the Base of the Triangle because which way soever you convert the Prism whether upward or downward to the right or to the left yet still shall the four Colours distinguishably succeed each other in the same method from the Base however all the rayes of Light reflected from the object on the Prism and trajected through it are carried on in lines parallel to the Base after their incidence on one side thereof with the obliquity or inclination of near upon thirty degrees and Refraction therein to an Angle of the same dimensions that issuing forth on the other side they are again Refracted in an Angle of near upon 30 degrees and with the like obliquity or inclination These Reasons equitably valued it is purely Consequent that no other Difference ought to be allowed between these Emphatick or as the Peripatetick False Colours and the Durable or True ones than only this that the Apparent deduce their Creation for the most part from Light Refracted in Diaphanous Bodies respectively Figurated and Disposed and sometimes from light only reflected but the Inhaerent or True as they call them deduce theirs from Light variously Reflexed in opace bodies whose superficial particles or Extancies and Cavities are of this or that Figure Ordination and Disposition Not that we admit the Durable Colours no more than the Evanid to be Formally as the Schools affirm Inhaerent in Opace bodies whose superficial Particles are determinately configurate and disposed to the production of this or that particular species of colouâ—â— and no other but only Materially or Effectively For the several species of Colours depend on the several Manners in which the minute particles of Light strike upon and affect the Retina Tunica and therefore are we to conceive that opâ—â—e Bodies reflecting Light do create Colours only by a certain Modification or Temperation of the reflected light and respondent Impression thereof on the Sensory no otherwise than as a Needle which though it contain not in it self the Formal Reason of Pain doth yet Materially or Effectively produce it when thrust into the skin of an Animal for by reason oâ— its Motion Hardness and Acuteness it causeth a dolorous sensation in the part perforated To diminish tâ—â— Difficulty yet more we are to recognize thâ—t the First Matter or Catholique Principles of all Material Natures are absolutely devoyd of all Sensible Qualities and that the Qualities of Concretions such as Colour Sound Odour Sapor Heat Cold Humidity Siccity Asperity Smoothness Haâ—dness Softness c. are really nothing else but various MODIFICATIONS of the insensible particles of the First Matter relative to the vaâ—ious Organs of the Senses For since the Orgâ—ns of the Sight Hearing â—asting Smelling and Touching have each a peculiar Contexture of the insensible particles that compose them requisite it is that in Concretions there should be various sorts of Atoms some of such a special Magniâ—â—â—â— Figure and Motion as that falling into the Eye they may conveniently move or affect the Principal Sensory and therein produce a sensation of themselves and that either Grateful or Ingratefull according as they are Commodious or Incommodious to the small Receptaries thereof for the Gratefulness or Ingratefulness of Colours ariseth from the Congruity or Incongruity of the particles of the Visible Species to the Receptaries or smâ—ll Pores in the Retina Tunica Some in like mâ—nner that may be convâ—nient to the Organ of Hearing Others to that of smelling c. So that though Atoms of all sorts of Magnitude Figure and Motion contexed into most minute Masses arrive at all the Organs of Sense yet may the Eye only be sensible of Colour the Ear of Sound the Nostrils of Odour c. Again that Colour Sound Odour and all other sensible Qualities are 〈◊〉 according to the various situation order addition detraction transposition of Atoms in the same manner as Words whereof an almost infinite â—ariety may be composed of no more then 24 Letters by their various sitâ—â—tion order addition detraction transposition as we have more copâ—â—â—sly discoursed in our precedent Original of Qualities SECT III. TO descend to Particulars It being more than probable that the various species of Colours have their Origine from only the various Manners in which the incident particles of Light reflected from the exteriours of Objects strike and affect the principal sensory it cannot be improbable that the sense of a White Colour is caused in the Optick Nerve when such Atoms of light or rayes consisting of them strike upon the Retina Tunica as come Directly from the Lucid Fountain the Sun or pure Flame or Reflexedly from a body whose superficial particles are Polite and Sphaerical such as we have formerly conjectured in the smallest and hardly distinguishable Bubbles of Froth and the minute particles of Snow And as for the perception of its Contrary Black generally though scarce warrantably reputed a Colour we have very ground for our conjecture that it ariseth rather from a meer Privation of Light than any Material Impression on the sensory For Blackness seems identical or coessential with Shadow and all of it that is positively perceptible consisteth in its participation of Light which alone
interspersed among the lines of a less Light and as certain that the Vermillion appeareth on that side of the Prisme where the Light is more copious as therein meeting with fewer retundent impervious particles in the substance of the Glass and the Caerule in that part where the Light is diminished as meeting with more impervious particles and being by them repercussed it must inevitably follow thereupon that if an opacous body be posited within the bounds of this light so that the light may fall on each side thereof and as it were fringe it a symptome quite contrary to the former shall evene i. e. the Vermillion will appear on that side of the species which is over against the Caerule and the Caerule will be transposed to that side of the species which confronteth the Vermillion This is easily Experimented with a piece of narrow black Ribbon affixt longwise to either side of the Prisme For in that case the light is bipartited into two Borders or Fringes the opace part veyled by the Ribbon on each side environed with light and each border of light environed with two shadows or more plainly between each border of shadows conterminate to each extreme of Light trajected through the unopacate parts of the Glass and therefore in the commissure of each of the two lights with each of the conterminous shadows there must be Vermillion on one side and Caerule on the other Now to drive this home to the head the solution of the present Problem the Reason why when the light of a Candle is trajected through a Prism on a White paper or Wall posited at convenient distance beyond it and there transformed into these two luminous Colours Vermillion and Caerule if you put your eye in that place of the Paper or Wall whereon the Vermillion shines you shall perceive only the Caerule in the Glass and è contra we say the Reason of this alteration of site in the Colours seems to be only this that the circumstant Aer about the flame of the Candle being opacous and so serving in stead of two Blacks to environ the borders of light causeth that side of the Candle which is seen through the thicker part of the Glass to appear Blew and that which is seen through the thinner to appear Red according to the constant Phaenomenon in Prismes But if the species be beheld by Reflection from any illustrate and repercussing Body such as the paper or wall then must the series or method of the borders of light and shadow be inverted for the reason immediately praecedent and consequently the situation of the Colours emergent from their various contemperations be also inverted And thus have we by the twilight of Rational Conjecture given you a glimpse of the abstruse Original of the Extreme and Simple Colours and should now continue our Attempt to the discovery of the Reasons of each of those many COMPOUND ones wherewith both Nature and Art so delightfully imbellish most of their peices but since they are as Generally as rightly praesumed to be only the multiplied removes of Light and Darkness i. e. to be educed from the various Commixtures of the Extreme or Simple or both and so it cannot require but a short exercise of the Intellect to investigate the determinate proportions of any two or more of the Simple ones necessary to the creation of any Compound Colour assigned especially when those excellent Rules of that Modern Apelles Albertus Durerus praescribed in his Art of Limning and the common Experience of Painters in the Confection of their several Pigments afford so clear a light toward the remove of their remaining obscurity and the singling out their particular Natures we cannot but suppose that any greater superstructure on this Foundation would be lookt upon rather as Ornamental and Superfluous than Necessary to the entertainment of moderate Curiosity Especially when we design it only as a decent Refuge for the shelter of ingenious Heads from the Whirlwind of Admiration and not as a constant Mansion for Belief For as we cautiously praemonished in the First Article the Foundation of it is not layed in the rock of absolute Demonstration or deâ—umed a Priori but in the softer mould of meer Conjeâ—ture and that no deeper than a Posteriori And this we judge expedient to profess because we would not leave it in the mercy of Censure to determine whether or no we pretend to understand What are the proper Figures and other essential Qualities of the insensible Particles of Light with what kind of Vibration or Evolution they are deradiated from their Fountain What are the determinate Ordinations Positions and Figures of those Reflectent and Refringent particles in the extreams of Bodies Diaphanous and Opace which modifie the Light into this or that species of Colour What sort of Reflection or Refraction whether simple or multiplyed is required to the creation of this or that Colour What are the praecise proportions of shadows interwoven with Light which disguise it into this or that colour Besides had we a clear and apodictical theory of all these niceâ—ies yet would it be a superlative Difficulty for us to advance to the genuine Reasons Why Light in such a manner striking on the superfice of such a body therein suffering such a Reflection or Refraction or both and commixt with such a proportion of shadows in the medium should be transformed into a Vermillion rather then a Blew Green or any other Colour Again were our Understanding arrived at this sublimity yet would it come much short of the top of the mystery and it might hazard a dangerous Vertigo in our brains to aspire to the Causes Why by the appulse of Light so or so modified there is caused in the Eye so fair and delightful a Sensation as that of Vision and why the sentient Faculty or soul therein operating becomes sensible not only of the particular stroak of the species but also of the Colour of it For where is that Oedipus that can discover any Analogy betwixt the Retina Tunica Optick Nerve Brain or Soul therein resident and any one Colour and yet no man can deny that there is some certain Analogy betwixt the Species and Sensory since otherwise there could be no Patibility on the one part nor Agency on the other We are not ignorant that the aspiring Wit of Des Cartes hath made a towring flight at all these sublime Abstrusities and boldly fastned the hooks of his Mechanick Principles upon them thinking to stoop them down to the familiar view of our reason But supposing that all Colours arise from the various proportions of the process and circumvolutions of the particles of Light in bodies respective to various Dispositions of their superficial particles which accordingly more or less Accelerate or Retard them as He hath copiously declared in Dioptric cap. 1. Meteor cap. 8. and erecting this upon his corner stone or grand Hypothesis that Light is nothing but an
sensory ordained for the apprehension of it the Mammillary Processes of the brain or two nervous productions derived to the basis of the nose yet could they never agree about the chief subject of their dispute the Quiddity or Form of an Odour or the Commensuration betwixt the same and the odoratory Nerves the theory whereof seems most necessary to the explanation of the Reason and Manner of its Perception and Distinction by them Thus on one side of the schools Heraclitus cited by Aristotle de sensu sensili cap. 5. is positive that the smell is not affected with only an Incorporeal Quality or spiritual species but that a certain subtle substance 〈◊〉 〈◊〉 〈◊〉 〈◊〉 〈◊〉 or Corporeal Exhalation emitted from the odorous object doth really and materially invade and affect the sensory 2 And Epicurus in Epist ad Herodot apud Diogen Laertium lib. 10. seconds him with somewhat a louder voice Existimandum est Odorem non facturum ullam sui impressionem nisi ab odora re usque deferrentur moleculae seâ— Corpuscula quaedam ea ratione Commensurata ipsi olfactâ—â— sensorio uâ— ipsum moveant afficiant ve alia quidem perturbate ac discrepanter ex quo odores Ingrati sunt alia placide accommodate ex quo Iucundi sunt odores men are to conceive that an Odour could make no sensible impression of it self unless there were transferred from the odorous object certain substantial Effluxes or minute Bodies so Commensurate or Analogous to the peculiar Contexture of the Organ of smelling as to be capable of affecting the same and those either perturbdly and discordantly whence some Odours are Ingrateful or amicably and conveniently and those Odours are Grateful 3 And Galâ—n attended on by most of the Aesculapian Tribe sings the same tune and in as high a key as either of the Former saying in lib. de instrum olfact cap 2. Id quod a rerum corporibus exhalat Odoris substantia est though Casserius Placentinus de fabric Nasi Sect. 2. cap. 3. hath endeavoured to corrupt the genuine sense of those words by converting substantia into subjectum as if Galen intended only that the Exhalation from an odorous body was only the subjectum inhaesionis and the odour it self meerly the Quality inhaerent therein Contrary to the rules of Fidelity and Ingenuity because incongruous both the Letter of the Text and the Syntaxis thereof with his whole Enquiry 4 And the Lord St. Alban though a modern yet not unworthy to enter the Chorus with the noblest among the Ancients though He had too frequently used his tongue to the Dialect of Immaterial Qualities and spiritual Images in his discourses of the other senses doth yet make a perfect unison with Galen in this particular delivering his judgement in most full and definite termes thus Certain it is that no smell issueth from a body but with emission of some Corporeal substance Sylva sylvar Cent. 9. experim 834. On the other side we hear the great Genius of Nature as his Idolaters miscall him Aristotle and that most numerous of Sects the Peripatetick vehemently contending that an Odour belongs to the classis of simple or Immaterial Qualities and that though it be wafted or transported on the wings of an Exhalation from the Odorate body to the Sensory yet is the sensory affected onely with the meer Image or Intentional species thereof Now the moments of Authority being thus equal on both sides our province is to determine the scales by the praepondium of Reason i. e with an even hand to examine the weight of the Arguments on which each of these contrary Opinions is grounded To begin with the Later as the most Epidemical and generally entertained we find the principal Base of it to be only that common Axiome Sensus non percipiunt substantias sed tantum earum Accidentia that no sense is invaded and actuated into sensation by the Real or Material but onely the intentional species of the Object which being weak of it self and by us frequently subverted in our praecedent Discourses the whole superstructure thereon relying is already ruined and they who will reaedifie it must lay a new foundation But as to the Former that an Odour is a perfect substance by material impression on the Sensory causing a sensation of it self therein this seems a Truth standing upon such firm feet of its own that it contemns the crutches of sophistry For 1 No Academick can be so obstinate as not to acknowledge that there is a certain Effluvium or Corporeal Exhalation from all odorous bodies diffused and transmitted through the aer as well because his own observation doth ascertain him that all Aromatiques and other odorous bodies in tract of a few years confess a substantial Contabescence or decay of Quantity which makes our Druggists and Apothecaries conserve their parcels of Ambre Grise Musk Civit and other rich Perfumes in bladders and those immured in Glasses to praevent the exhaustion of them by spontaneous emanation as for this that the odour doth most commonly continue vigorous in the medium a good while after the remove of the source or body from which it was effused And Aristotle himself after his peremptory Negative Odorem non esse 〈◊〉 〈◊〉 〈◊〉 〈◊〉 〈◊〉 Effluxionem could not but let slip this Affirmative 〈◊〉 〈◊〉 〈◊〉 〈◊〉 〈◊〉 quod effluit ex corporibus ipsa est odorum substantia 2 Common Experience confirms that odours are vigorous and potent not only in the production of sundry Affections in the brain good or evil according to their vehemency and Gratefulness or Noysomness by the refocillation or pollution of the spirits but also in the Vellication and frequently the Corrosion of tender investment of the Nostrills Thus much the reverend Oracle of Cous well observed in 28 Aphorisme 5 Sect. Odoramentorum suffitus muliebria educit ad alia plaerumque utilis esset nisi gravitatem capitis inferret and Galen supports with his opinion and arguments that pleasant Odours are a kinde of Nourishment of the spirits Besides Plutarch reports that He observed Catts grow mad onely by the smell of certain odoriferous Unguents and Levinus Lemnius de Natur. miracul hath a memorable story of certain Travellers who passing through large fields of Beans in the Flower in Holland become Phrantick meerly with the strength of their smell And all Physicians dayly finde that good smels by a recreation of the languid spirits speedily restore men from swooning fits as evil scents often induce Vomitings syncopes Vertigoes and other suddain symptomes Nay scarce an Author who hath written of the Plague and its Causes but abounds in relations of those accursed miscreants who have kindled most mortal infections by certain Veneficious practices and Compositions of putrid and noysom Odours witness Petrus Droetus de pestilentia cap. 10. Wierus de Venificiis lib. 3. cap. 37 Horatius Augenius lib. de peste cap. 3 Hercules Saxonia de plica cap. 2. 11.
the more Opace by how much more Dense and that the Reason of Perspicuity can hardly be understood but by assuming certain small Vacuities in the Body interposed betwixt the object and the eye such as may give free passage to the visible Species nor that of Opacity but by conceding a certain Corpulency to the space or thing therein interposed such as may terminate the sight therefore cannot this place be judged incompetent to the Consideration of their severall originals By a Perspicuum 〈◊〉 〈◊〉 〈◊〉 〈◊〉 〈◊〉 we suppose that every man understands that Body or Space which though interposed betwixt the Eye and a Lucid or Colorate Object doth nevertheless not hinder the Transition of the Visible species from it to the Eye and by an Opacum that which obstructing the passage of the Visible Species terminates the sight in it self We suppose also that according to our praecedent Theory the Species Visible consist of certain Corporeal Rayes emitted from the Object in direct lines toward the Eye and that where the Medium or interjacent space is free those Rayes are delated through it without impediment but where the space is praepossessed by any solid or Impervious substance they are repercussed from it toward their Original the Object And hence we inferr that because the total Freedom of their Transmission depends only upon the total Inanity of the Space intermediate and so the more or less of freedome trajective depends upon the more or less of Inanity in the Space intermediate therefore must every Concretion be so much more Perspicuous by how much the more and more ample Inane Spaces it hath intercepted among its Component particles which permit the Rayes freely to continue on their progress home to the Eye This we affirm not Universally but under the due limitation of a Caeteris Paribus as we have formerly hinted Because notwithstanding a piece of Lawn is more or less Perspicuous according as the Contexture of its Threads is more or less Rare and the Aer in like manner is more or less pellucid according as it is perfused with more or fewer Vapours yet do we not want Bodies as Paper Sponges c. Which though more then meanly Rare are nevertheless Indiaphanous and on the contrary we see many Bodies sufficiently Dense as Horn Muscovy-glass common glass c. which are yet considerably Diaphanous Now that you may clearly comprehend the Cause of this Difference be pleased to hold your right hand before your eye with your fingers somewhat distant each from other and then looking at some object you may behold it through the chinks or intervals of your fingers this done put your left hand also over your right so as the fingers of it may be in the same position with the former and then may you perceive the object at least as many parts of it as before But if you dispose the fingers of your left hand so as to fill up the spaces or intervals betwixt those of your right the object shall be wholly eclipsed Thus also if you look at an object through a Lawn or Hair Sieve and then put another Sieve over that so as the holes or pores of the second be parallel to those of the first you may as plainly discern it through both as one but if the twists of the second sieve be objected to the pores of the first then shall you perceive no part of the object at least so much the fewer parts by how much greater a number of pores in the first are confronted by threads in the second And hence you cannot but acknowledge that the Liberty of inspection doth depend immediately and necessarily upon the Inanity of the pores the Impediment of it upon the Bodies that hinder the trajection of the Rayes emitted from the Object and yet that to Diaphanity is required a certain orderly and alternate Position of the Pores and Bodies or Particles This considered it is manifest that the Reason why Glass though much more Dense is yet much more perspicuous than Paper is only this that the Contexture of the small filaments composing the substance of Paper is so confused as that the Pores that are open on one side or superfice thereof are not continued through to the other but variously intercepted with cross-running filaments as is more sensible in the Coâ—texture of a Spunge whose holes are not continued quite thorow but determined at half way some more some less so that frequently the bottome of one hole is the cover of another as the Cells in a Hony-comb but Glass in regard of the uniform and regular Contexture of its particles which are ranged as it were in distinct ranks and files with pores or intervals orderly and directly remaining betwixt them hath its pores not so soon determined by particles oppositely disposed but continued to a greater depth in its substance Though this make the whole matter sufficiently intelligible yet may it receive a degree more of illustration if we admit the same Conditions to be in the substance of Glass that are in a Mist or Cloud through which we may behold and object so long as the small passages or intervals betwixt the particles of the Vapours through which the rayes of the visible species may be trajected remain unobstructed but yet perceive the same so much the more obscurely by how much the more remote it is because in that case more impervious particles are variously opposed to those small thorow-fares that obstruct them and so impede the progress of most of the rayes For thus also Glass if thin doth hinder the sight of an object very little or nothing at all but if very thick it wholly terminates the progress of the species and by how much the thicker it is by so much the more it obscures the object And this only because Glass consisting of small solid Particles or Granules and insensible Pores alternately situate hath many of its pores running on in direct lines through its substance to some certain distance but sometimes these sometimes those are obturated by small solid particles succedent when at such a determinate Crassitude it becomes wholly opace And this gives us an opportunity to refute that vulgar Error That the substance of Glass is totally Diaphanous or that all and every Ray of the the Visive Species is trajected through it without impediment To demonstrate the contrary therefore we advise you to hold a piece of the finest and thinnest Venice Glass against the Sun with two sheets of white paper one betwixt the Sun and the Glass the other betwixt the Glass and your Eye for then shall all the Trajected Rayes be received on the paper on this side of the glass and the Reflected ones be received on that beyond it Now insomuch as that paper which is betwixt your eye and the glass doth receive the Trajected rayes with a certain apparence of many small shadows intercepted among them and that paper beyond
several proportions which substance hath to Quantity Much more plausible were their Explication had they derived the Extension of a thing meerly from Space or Place because whenever any thing is said to be Extense the mind instantly layes hold of some determinate part of space referring the Extension of it simply and entirely to the Place wherein it is or may be contained and which is exaequate to its Dimensions nor is it indeed easie to wean the Understanding from this habitual manner of Conception Whereof if we be urged to render a satisfactory Reason we confess we know no better than this that by the Law of Nature every Body in the Universe is consigned to its peculiar Place i. e. such a canton of space as is exactly respondent to its Dimensions so that whether a Body quiesce or be moved we alwayes understand the Place wherein it is Extense to be one and the same i. e. equal to its Dimensions We say By the Lay of Nature because if we convert to the Omnipotence of its Author and consider that the Creator did not circumscribe his own Energy by those fundamental Constitutions which his Wisedom imposed upon the Creature we must wind up the nerves of our Mind to a higher key of Conception and let our Reason learn of our Faith to admit the possibility of a Body existent without Extension and the Extension of a Body consistent without the Body it self as in the sacred mystery of our Saviours Apparition to his Apostles after his Resurrection 〈◊〉 〈◊〉 〈◊〉 〈◊〉 〈◊〉 the dores being shut Not that we can comprehend the manner of either i. e. the Existence of a Body without Extension and of Extension without a Body for our narrow intellectuals which cannot take the altitude of the smallest effect in Nature must be confest an incompetent measure of supernaturals but that whoever allowes the power of God to have formed a Body out of no praeexistent matter cannot deny the same power to extend to the reduction of the same Body to nothing of matter again Which the most pious S. August Epist. 3. and yet this hinders not but a Body which is not actually divided into parts may be said to be Continued insomuch as it so appears to the sense which cannot discern the several Commissures of its particles Again forasmuch as Aristotle defines a Continuum to be that whose Parts are conjoyned by some Common mean or Term it is requisite we observe how far forth his definition is consistent with right reason We allow it to be true Physically so far forth as there are no two parts assignable which are conjoyned by some third intermediate part either sensible as in a magnitude of three feet the two extreme feet are copulated together by the third intermediate or Insensible as in the magnitude of two feet which are joyned together by some interjacent particle so small as to evade the detection of sense But if with Him we accept that Common Mean or Terme for a Mathematical Point or individual for He expresly affirms that the parts of a Line are copulated by a Point the parts of a Superfice by a Line the parts of a Body by a Line or Superfice t is plain that our Conceptions must be inconsistent with Physical verity because such Insectiles or Individuals are not real but only Imaginary as we have copiously asserted in our Discourse concerning the Impossible Division of a Continuum into parts infinitely subdivisible Besides who can conceive that to be a Caement or Glew to unite two parts into one Continued substance which hath it self no parts designable either by sense or reason Nor can any thing be rightly admitted to conjoyn two Bodies unless it hath two sides Extremes or faces one whereof may adhaere to one of the two Bodies the other to the other so as to make a sensible Continuity Concerning the Quality of a Body called FIGURE that which is chiefly worthy our praesent adversion is onely this that if Figure be considered Physically it is nothing but the superficies or terminant Extreames of a Body We say Physically because Geometricians distinguish Figures into Superficial or Plane and Profound or Solid but the Physiologist knows no other Figure properly but the Superficial because in strict truth the Profound or Solid one seems to Him to be rather the Magnitude or Corpulency of a thing circumscribed or terminated by its Figure than the Figure it self abstractedly intended Nay if we insist upon the rigour of verity the Figure of a Body is really nothing but the Body it self at least the meer Manner of its Extreme parts according to which our sense deprehends it to be smooth or rough elated or depressed This may be most fully evinced by only one Example viz. the figure made upon Wax by the impression of a Seal For that Figure really is nothing but the very substance of the Wax in some parts made more Eminent in others more deprest or profound according to the Reverse of its Type ingraven in some hard substance and that without Adjection or Detraction oâ— any Entity whatever And what we affirm of the Figure made in Wax by Sigillation is of equal truth proportionately if accommodated to any other Figure whatever noâ— doth it imply a Difference whether the Figure be Natural such as in Animals Vegetables Minerals or Artificial such as in Aedifices Statues Characters c. SECT II. THe 〈◊〉 of Magnitude and Figure in Concretions being thus 〈…〉 follows that we explore their Effects i. e. the Qualities which seem so immediately cohaerent to the Magnitude and Figure of Bodies as that reason cannot consigne them to more likely and probable Principles than the two First Proprieties of the Universal Matter Atoms The 〈◊〉 therefore of Magnitude are SUBTILITY and its 〈…〉 Not that the Emergency of a Great Body from Atoms the 〈◊〉 Exile or of a small body from great Atoms is impossibl◠〈…〉 formerly intimated but that a Body consisting of more Exil◠〈…〉 Aâ—omâ— hath a greater subtility or obtains a Faculty of penâ—â—â—ating the contexture of another body by subingression into the pores 〈…〉 â—hereoâ— and a body consisting of grosser Atoms must have more of 〈…〉 Hebeâ—ude and so hath not the like Faculty of penetrating the Coâ—â—â—xtures of other bodies by subingression into the mane spaces oâ— inteâ—â—â—â—â— betwixt their particles This may be Exemplified in Fire and 〈…〉 and Oyle Aqua Fortis and Milk c. We are 〈◊〉 now to learn the truth of that Chymical Canon Cuique 〈…〉 vel extrahendae eligendum esse idoneum menstruum quod 〈…〉 respondeat experience having frequently ascertained us that Aqu◠〈◊〉 which soon dissolves the most compact of bodies Gold will no◠〈…〉 Reâ—ine Pitch Wax and many other Unctuous and Reâ—inous 〈◊〉 which yeild almost at first touch to the separatory â—acuâ—ty 〈…〉 that Mercurial Waters expeditely insinuate into the substance of Gold dissolve the Continuity of its
stiffly cohaerent particles and 〈◊〉 from a most solid into an oyly substance not so much by 〈…〉 â—ymbolisme or Affinity of nature that Salt Nitre and Sulphur whicâ—â—eing added to Sand Flints and many Metals promote the solution 〈…〉 fire have yet no accelerating but a retarding energy upoâ— Turpentine Balsome Myrrh c. in the extraction of their Oyls or 〈◊〉 that all Waters or Spirits extracted from Saâ—ine and Metalline nature are most convenient Menstruaes for the solution of Metals Minerals not 〈◊〉 much in respect of their Corrosion as similitude of pores and particles and consequently that every Concretion requires to its dissolution some 〈◊〉 dissolvent that holds some respondency or analogy to its contexture 〈◊〉 yet have we no reason therefore to abandon our Assumption that 〈◊〉 dissolution of one body by the subingression or insinuation 〈…〉 another must arise from the greater subtility of particles 〈…〉 until it be commonstrated to us that a Body whose 〈…〉 can penetrate another Body whose Pores are more 〈…〉 whereto is demonstrated to us by the frequent Experimentâ— of 〈◊〉 And therefore the Reason Why Oyle Olive doth pervade some Bodies which yet are impenetrable even by spirit of Wine by â—aimundus Lullius and after him by Libavius and Quercetan accounted the true Sulphur and Mercury of Hermetical Philosophers extracted from a Vegetable for the solution of Gold into a Potable substance and the Confection of the Great Elixir and as General a Dissolvent as that admired but hardly understood Liquor Alkahest of Paracelsus if not the same can be no other but this that in the substance of Oyle are some Particles much more subtile and penetrative than any contained in the substance of Wine though those subtile particles are thinly interspersed among a far greater number of Hamous or Hooked particles which retard their penetration Thus also in that affrighting and Atheist-converting Meteor Lightning seem to be contained many particles much more exile and searching than those of our Culinary Fires because it sometimes dissolves the hardest of Metals in a moment which preserveâ— its integrity for some hours in our fiercest reverberatory furnaces Which Lucretius well expresseth in this Tetrastich Dicere enim possis caelestem Fulminis ignem Subtilem magis e parvis constare Figuris Atque ideo transire foramina quae nequit ignis Noster hic elignis ortus taedaque creatus Secondly the Qualities Consequent to Figure are SMOOTHNESSE and its contrary ASPERITY Not that if we appeal to the judgement of the sense the superfice of a Body may not be smooth though it consist of angulouâ— Atoms or rough though composed of plain and polite Atoms for all Atoms as well as their Figures are so Exile as that many of them that are angular may cohaere into a mass without any inequality in the superfice deprehensible by the sense and on the contrary many of those that are plane and polite may be convened and concreted into such masses as to make angles edges and other inequalities sufficiently sensible But that if we refer the matter partly to the judicature of Reason partly to the evidence of our senses in General we cannot but determine it to arise from the Figuration of Atoms alone First to the judicature of Reason for as the mind admits nothing to be perfectly continued besides an Atom so can it admit nothing to be exquisitely smooth besides either the whole superfice of an Atom â—f the same be orbicular oval or of the like Figure or som parts of it if the same be tetrahedical hexahedrical or of some such poligone figure Because look by what reason the mind doth conclude the superfice of no Concretion in nature to be perfectly continued by the same reason doth 〈◊〉 â—â—nclude the superfice of every thing seemingly most equal and polite to be â—â—râ—â—usly interrupted with asperities or eminent and deprest particles and 〈…〉 refers immediately and soleâ—y to many small masses of Atoms in 〈◊〉 Contexture coadunated like as it referrs the interruptions in the superfice of a piece of Lawne or Cambrique which to the eye and touch appears most smooth and united to the small masses of Filaments interwoven in the webb And here the Experiment of a Microscope is opportune for when a man looks through it upon a â—heet of the finest and â—mooâ—hest Venice Paper which seems to the naked eye and most exquisite touch to be equal and â—erse in all parts of it superfice He shall discern it to be so full of Eminences and Cavities or small Hills and Valleys as the most praegnant and praepared Imagination cannot suppose any thing more unequal and impolite Seâ—ondly to the Evidence of our senses in General because the very Afâ—â—ction of Pleasure or Pain arising to the sensory from the contact of the sâ—â—â—ible object doth sufficiently demonstrate that smoothness is a Quality 〈◊〉 either from such Atoms or such small masses of Atoms contexed as 〈◊〉 smooth and pleasant to the sense by reason of their correspondence 〈◊〉 â—he pores and particles of the Organ and contrariwise that â—sperity is a â—uality resulting either from such single Atoms or such most minute masses of Atoms concreted as dilacerate or exasperate the sense by reason of 〈◊〉 incongruity or Disproportion to the Contexture of the Organ as w◠〈◊〉 even to redundancy Exemplified in the Grateful and Ungrateful 〈◊〉 of each sense CHAP. XI OF THE Motive Vertue Habit Gravity and Levity OF CONCRETIONS SECT I. THe Third Propriety of the Universal Matter Atoms is Mobility or Gravity and from that fountain is it that all Concretions derive their Virtue Motive For though our deceptable sense inform us that the minute Particles of Bodies are fixt in the act of their Coadunation wedged up together and as it were fast bound to the peace by reciprocal concatenation and revinction yet from the Dâ—ssolution of all Compound natures in process oâ— time caused by the intestine Commotions of their Elementary Principles without the hostility of any External Contraries may our more judicious Reason well inferr that Atoms are never totally deprived of that their essential Faculty Mobility but are anceâ—santly agitated thereby even in the centrals of Concretions the most soâ—id and compact some tending one way others another in a perpetual 〈◊〉 of Eruption and when the Major part of them chance to â—ffect 〈…〉 the same way of emancipation then is their united force determimined â—o one part of the Concretion and motion likewise determined to one region respecting that Part. That same MOTIVE VIRTUE thereâ—ore wherewith every Compound Bodie is naturally endowed must owe â—ts â—rigine to the innate and co-essential Mobility oâ— its component particles being really the same thing with their Gravity or Impetus which yet receives its determinate manner and degree from their mutual Combination In respect whereof it necessarily comes to paâ—s that when Atoms mutually adhâ—ering vnto 〈…〉 other caâ—â—ot obey the â—mpuâ—â—e of 〈◊〉 â—â—ndency singly they are not
moved with that pernicity as if each were aâ—â—â—solute liberty but impeding and retarding each other in their progress arâ—â—â—rried with a flower motion But that more or less slow according to 〈◊〉 rate or proportion of common Resistence because always some of them are carryed to an opposite others transversly others obliquely to a difâ—â—rent region An◠〈◊〉 is it that because Atoms are at most freedom of range in 〈…〉 Concretions every degree of Density and Compactness causin◠〈◊〉 â—â—oportionate degree of Tardity in their spontaneous motions 〈…〉 the Motive Faculty not more generally than rightly conceived 〈…〉 chiefly in the spiritual or as vulgar Philosophy Aethereal Parts 〈◊〉 Concretions And whether the spirits of a thing are principaâ— deâ—â—â—mined to move thither do they not only themselves contend 〈…〉 and speed but also carry along with them the more 〈…〉 less movâ—able parts oâ— the Concretion as is superlatively 〈…〉 Voluntary motions oâ— Animals W◠〈◊〉 not here insist upon the Redargution of that Blasphemous and Absur◠〈◊〉 the formeâ— Epiâ—hitâ— always implies the later dream of 〈…〉 Atoms werâ— not only the First Matter but also the First and 〈…〉 of all things and consequently that all Motions and so all 〈…〉 â—niverse and Caused meerly by the inhaerent Mobility of them be 〈…〉 have expresly refuted the same in our Treatise against Atheism 〈…〉 1. artic ultim Especially since it is more opportune for us her◠〈…〉 that insomuch as the motion of all Atoms is supposed 〈…〉 Dâ—rect and most rapid therefore doth the Deviation as 〈…〉 of Concretions seem to arise from the Deflection Repercussion 〈…〉 Repression of the Atoms composing them For the 〈…〉 meeting of two Atoms may be in direct lines so that among 〈…〉 singlâ— percussion or repercussion overcomâ—ng the first begun 〈…〉 assembly oâ— Conventiâ—n will bear there may be caused some 〈…〉 â—hough more or less slow and their Occursations may be 〈…〉 Oblique angles and so by the same reason may ensue a 〈…〉 more or less slow but also more or less Oblique Moreâ—ve◠〈…〉 repeâ—cussion made to oblique angles there chance to 〈…〉 repercussion to angles equally oblique then must the 〈…〉 â—blâ—quity multangular according to the multiplicity 〈…〉 the Angles be very frequent and indistant the 〈…〉 at least to appearance to be of an uniform Curvity and 〈…〉 be termed a motion Circular Elliptical Helicoâ—â—al 〈…〉 aâ—cording to the condition of its Deflection and Crookedâ—â—â—◠〈…〉 observâ— thaâ— every Body whether Simple or 〈…〉 Concretion frâ—m which a Repercussion is made must 〈…〉 bâ— moveâ— the same way as is the repercust or not 〈…〉 because otherwise there can be no mutual 〈…〉 impingent body rebound from the repercutiâ—◠〈…〉 why â—excepting only the motion 〈…〉 of all Concretions doth ever suppose something that remains Unmoved or that in respect of its less motion is tantamount to a thing Unmoved because otherwise there could be no reciprocal Resistence and so all motion might both begin and repair it self Having thus premised these few fundamental Laws of Motion in General opportunity commands us to descend to the consideration of the FACULTY of Motion insomuch as it seems not to be any thing distinct from that Motive Force inhaerent in all Concretions which we have now both described and deduced from its immediate origine the Mobility of Atoms and that it is well known to all Book-men to appertain to the second species of Qualities according to the method of Aristotle To which we may add these lessons also that it comprehends the Third species of Qualities and obtains the First or Habit as its proper appendix Know we therefore that the Faculty or Power of Motion doth therefore seem to be one and the same thing with the coessential Mobility now described because every thing in Nature is judged to have just so much of Efficacy or Activity as it hath of Capacity to move either it self or any other thing And hence is it that in Nature there is no Faculty properly but what is Active because though the motions of things be really the same with their Actions yet must all motion have its beginning only from the Movent or Agent Nor can it avail to the contrary that all Philosophers have allowed a Passive Faculty to be inhaerent in all Concretions since in the strict dialect of truth that Passiveness is no other than a certain Impotency of Resistence or the Privation of an Active Power in defect whereof the subject is compelled to obey the Energy of another If you suppose an obscure Contradiction in this our Assertion and accordingly Object that therefore there must be a Faculty of Resistence in some proportion and that that Resistence is Passive we are provided of a satisfactory salvo which is that though the Active Virtue which is in the Resistent doth sometimes scarce discover it self yet is it manifest that there are very many things which make resistence only by motion which no man can deny to be an Active Faculty as when we rowe against wind and tide or strive with a Bowe in the drawing of it for all these evidently oppose our force by contrary moton And as for other things which seem to quiesce and yet make some resistence such we may conceive to make that resistence by a kinde of motion which Physicians denominate a Tonick motion like that of the Eye of an Animal when by the Contraction of all its muscles at once it is held in one fixt position Thus not only the whole Globe of the Earth but all its parts are held unmoved and first by mutual cohaerence and resist motions as they are parts of the whole and thus also may all Concretions be conceived to be made Immote not that the Principles of which they consist are not in perpetual inquietude and motion but because their parâ—â—cles reciprocally wedge and implicate each other and while some impede â—nd â—ppose the motions of others they all conspire to the Consistence of â—he whole However the more Learned and Judicious shall further dispute â—his paradoxical Argument yet dare we determine the Common Notiâ—n of a Faculty to be this that there is inherent in every thing a Prinâ—â—ple of Moving itself or Acting if not Primaryâ—which â—which the schools terme the Forme yet Secondary at least or profluent from the Forme being as it were the immediate Instrument thereof And here we cannot conceal our wonder that the Peripatetick hath not for so many ages together discovered himself to be intangled in a manifest Contradiction while on one part He affirms that there are certain Faculties flowing â tota substantia from the whole substance of a thing as if they were derived from the matter of Concretions and on the other concludes as indisputable that the Matter is absolutely devoid of all Activity as if it were not certain that the Faculties frequently perish when yet not the whole and intire substance of the thing perisheth but only the
either Actually as Frost snowe the North-wind c. or Potentially as Nitre Hemlock Night-shade and all other simples aswel Medical as Toxical or Poysonous whose Alterative Virtue consisteth cheifly in Cold. Now as for the determinate Figure of Frigorifick Atoms our enquiries can hope for but small light from the almost consumed vaper of Antiquity For though Philoponus in 1 physic Magnenus de Atomis disput 2. cap. 3. confidently deliver that Democritus assigned a Cubical Figure to the Atoms of Cold and endeavour to justifie that assignation by sundry Mathematical reasons yet Aristotle a man aswell acquainted with the doctrines of his Predecessors as either of those expresly affirms that nor Democritus nor Leucippus nor Epicurus determined the Atoms of Cold to any particular Figure at all for His words are these 3 de caelo cap. 4. 〈◊〉 〈◊〉 〈◊〉 〈◊〉 〈◊〉 Nihilpendâ— determinarunt So that rather than remain altogether in the dark we must strike fire out of that learned Conjecture of our Master Gaâ—sendus and taking our indication from the rule of Contrariety infer that the Atoms of Heat being spherical those of Cold in all reason must be Tetrahedical or Pyramidal consisting of 4 sides or equilateral Triangles To make the reasonableness of this supposition duly evident let us consider 1. That as Heat hath its origine from Atoms most exile in magnitude spherical in figure and so most swift of motion so must its Contrary Cold be derived from principles of Contrary proprieties viz. Atoms not so exile in magnitude of a Figure most opposite to a sphere and so of most slow motion 2. That none but Tetrahedical Atoms can justly challenge to themselves these proprieties that are requisite to the Essensification of Cold. For 1. If we regard their Magnitude a Tetrahedical Atom may be Greater than a Spherical by its whole Angles because a Sphere may be circumscribed within a Tetrahedon 2. If the Figure it self none is more opposed to a Sphere than a Tetrahedon because it is Angular and farthest recedeth from that infinity or rather innumerability of small insensible sides which a profound Geometrician may speculate in a Sphere 3. If their Mobility no body can be more unapt for motion than a Tetrahedical one for what vulgar Mathematicians impute to a Cube viz. that it challengeth the palme from all other Figures for Ineptitude to motion doth indeed more rightfully belong to a Tetrahedon as will soon appear to any equitable consideration upon the perpension of the reasons alleagable on both parts But here we are to signifie that this ineptitude to motion proper to Tetrahedical Atoms is not meant of Atoms at liberty and injoying freedom of motion in the Inane space since in that state all Atoms are praesumed to be of equal velocity but only of Atoms wanting that liberty such as are included in Concretions and by intestine evolutions continually attempt Emancipation and Exsilition 4. It cannot impugne at least not stagger the reasonableness of this conjectural Assignation of a Tetrahedical figure to the Atoms of Cold that Plato in Timaeo definitely adscribeth a Pyramidal Figure to Fire not to the Aer i. e. to the Atoms of Heat not to those of Cold because if any shall thereupon conceive that a Pyramid is most capable of penetrating the skin of a man and consequently of producing therein the sense of Heat rather than Cold He may be soon converted by considering a passage in our former section of this Chapter that the Atoms of Heat may though spherical as well in respect of their extreme Exility which the point of no Pyramid can exceed as of the velocity of their Motion prick as sharply and penetrate as deeply as the Angles of the smallest Pyramid imaginable To which may be conjoyned that the Atoms of Cold according to our supposition are also capable of Pungency and Penetration and consequently that a kind of Adustion is also assignable to great Cold according to that expression of Virgil 1 Georg. Boceae penetrabile frigus adurit For in fervent Frosts to use the same Epithite as the sweet-tongued Ovid in the same case when our hands are as the English phrase is Benumm'd with Cold if we hold them to the fire we instantly feel a sharp and pricking pain in them Which ariseth from hence that the Atoms of Heat while by their agility and constant supplies they are dispelling those of Cold which had entred and possessed the pores of our hands do variously commove and invert them they are hastily driven forth and in their contention and egress cut and dilacerate the flesh and skin as well with their small points as edges lying betwixt their points and so produce an acute and pungitive pain Whereupon the sage Sennertus de Atomis grounds his advice that in extreme cold weather when our hands are so stupified as that an Extinction of their vital heat may be feared we either immerse them into cold water or rub them in snow that the Atoms of Cold which have wedged each other into the pores may be gently and gradually called forth before we hold them to the fire and this least not only grievous pain be caused but a Gangrene ensue from the totall dissolution of the Contexture of our hands by the violent intrusion of the Cold Atoms when they are forcibly impelled and agitated by the igneous as the sad experience of many in Ruscia Groenland the Alps and other Regions obnoxious to the tyranny of Cold hath taught Concerning this Helmâ—nt also was in the right when He said Mechanicè namque videmus membrum fere congelatum sub nive recalescere à syderatione praeservari quod alias aer mox totaliter congelare pergeret vel si repente ad ignem sit delatum moritur propter extremi alterius festinam actionem c. in cap. de Aere articul 8. 5. Nor doth it hinder that Philoponus and Magnenus affirm that the Atoms of Cold ought to be Cubical in respect of the eminent aptitude of that figure for Constipation and Compingency the General Effects of Cold because a Pyramid also hath its plane sides or faces which empower it to perform as much as a Cube in that respect and if common Salt be Constrictive only because being Hexahedrical in form it hath square plane sides as a Cube certainly Alum must be more Constrictive because being Octahedrical in form it hath triangular plane sides as a Pyramid Besides it is manifest that these plane sides must so much the more press upon and wedge in the particles of a body by how much more of the body or greater number of its particles they touch and that by how much more they are entangled by their Angles so much more hardly are they Expeded and so remain cohaerent so much more pertinaciously Hence comes it that all Concretions consisting for the most part of such figurated Atoms are Adstâ—ictive Effectually for interposing their particles amongst those of other bodies that are Fluid
Habit to which any Act can 〈…〉 attributed but as a meer Privation for to be Dry is nothing else 〈…〉 want moisture yet because a Moistned body may contain more 〈…〉 Humidity therefore may it be said to be more or less Dry 〈◊〉 and a body that is imbued with less moisture be said to be dry 〈…〉 one imbued with more Thus Green Wood or such as hath 〈◊〉 extraneous moisture is commonly said to grow more and more 〈…〉 degrees as it is more and more Dehumectâ—ted and then at lengâ—◠〈◊〉 be perfectly dry when all the Aqueous moisture as well natura◠〈◊〉 â—mbibed is consumed though then also it contain a certain 〈◊〉 moâ—sture which Philosophers call the Humidum Primigentum 〈◊〉 this only Comparatively or in respect to its forme◠〈…〉 was imbueâ— with a greater proportion of Humidity For the 〈◊〉 of this we are to observe that there are Two sorts 〈…〉 compact bodies are usually humectated the one 〈…〉 â—he other Oleag nous and Fat The First is easily 〈…〉 by heat but not inflammable the other though it 〈…〉 and is as easily inflammable in regard of the many 〈…〉 is not easily exsoluble nor attenuable into 〈…〉 cohaerence of its particles To the First 〈…〉 that mâ—â—sture in Concretions which Chymists extracting 〈…〉 Vegetables because though it moâ—stens as Wate◠〈…〉 incapable of inflâ—mmation yet is it much more volatile 〈…〉 And to eâ—ther or both sorts though in a diverse respect belong 〈…〉 they call Aqua Vitae or the spirits of a Vegetable such 〈…〉 because though it doth moisten as Water yet is 〈…〉 evaporable by heat and as inflammable as 〈…〉 learn in the School of Sense that such bodie◠〈…〉 Aqueous and Lean moisture are easily 〈…〉 are humectate with the Unctuous 〈…〉 hardly Why because the Atoms of which the Aqueous doth consist are more laevigated or smooth in their superfice and so having no hooks or clawes whereby to cohaere among themselves or adhaere to the concretion are soon disgregated but those which compose the Oleaginous being entangled as well among themselves as with the particles of the body to which they are admixt by their Hamous angles are not to be expeded and disengaged without great and long agitation and after many unsuccessfull attempts of evolution Thus Wood is sooner reduced to Ashes than a stone because that is compacted by much of Aqueous Humidity this by much of Unctuous For the same reason is it likewise that a clodd of Earth or peice of Cloth which hath imbibed Water is far more easily resiccated than that Earth or Cloth which hath been dippt in oyle or melted fat And this gives us somewhat more than a meer Hint toward the clear Solution of Two PROBLEMS frequently occurring but rarely examined The one is Why pure or simple Water cannot wash out spots of Oyle or Fat from a Cloth or silk Garment which yet Water wherein Ashes have been boyled or soap dissolved easily doth For the Cause hereof most probably is this that though Water of it self cannot penetrate the unctuous body of oyle nor dissociate its tenaciously cohaerent particles and consequently not incorporate the oyle to it self so as to carry it off in its fluid arms when it is expressed or wrung out from the cloth yet when it is impraegnated with Salt such as is abundantly contained in Ashes and from them extracted in decoction the salt with the sharp angles and points of its insensible particles penetrating pervading cutting and dividing the oyle in minimas particulas the Water following the particles of salt at the heels incorporates the oyle into it self and so being wrung out from the cloth again brings the same wholly off together with it self Which dâ—ubtless was in some part understood by the Inventor of soap which being compounded 〈◊〉 Water Salt and Oyle most perfectly commixt is the most general Abstersive for the cleansing of Cloathes polluted with oyle grease turpentine sweat and the like unctuous natures for the particleâ— of oyle ambuscadoed in the soap encountring those oyly or pâ—nguous particleâ— which adhaere to the hairs and filaments of Cloth and stâ—â—n it become easily united to them and bring them off together with themselves when they are dissolved and set afloat in the Water by the incisive and diâ—â—â—ciating particles of the Salt which also is brought off at the same time by the Water which serveth only as a common vehicle to aâ—l the rest The other Why stains of Ink are not Delible with Water though decocted to a Lixirium or Lee with Ashes or commixt with soap but wiâ—◠〈◊〉 Acid juice such as of Limons Oranges Crabbs Vinegre c. 〈◊〉 Reason hereof seems to be only this that the Viâ—â—ioâ— or 〈◊〉 which â—trâ—kes the black in the Decoction of Galls Sumach or other 〈◊〉 Ingredients being Acid and so consisting of particles congenerâ—â—s â—n figure and other proprieties to those which constitute the 〈…〉 whenever the spot of Ink is throughly moystned with an acid 〈◊〉 the vitrioâ—â—s soon united thereto and so educed together with â—t upâ—n expression the union arising propter 〈◊〉 〈◊〉 〈◊〉 〈◊〉 〈◊〉 from the Similitude of their two natures For there always is the most easy and perfect union where is a Similitude of Essences or formal proprieties as is notably experimented in the eduction of Cold from a mans hands or other benummed parts by rubbing them with snow in the evocation of fire by fire in the extraction of some Venoms from the central to the outward parts of the body by the application of other Venoms to the skin which is the principal cause why some Poysons are the Antidotes to others the alliciency and â—â—â—â—uation of Choler by Rhubarb c. Lastly in 〈◊〉 place we might pertinently insist upon the Causes and Manner of Coâ—â—osion and Dissolution of Metals and other Compact and Firmâ— bodies 〈◊〉 Aqua Fortis Aqua Regis and other Chymical Waters the 〈◊〉 of Salt Alume Nitre Vitriol Sugar and other Salin concreted 〈◊〉 by Water the Exhalability or Evaporability of Humid and 〈◊〉 substances and other useful speculations of the like obscure naturâ— but 〈◊〉 of these deserves a more exact and prolix Disquisition than the 〈…〉 signed to our praesent province will afford and what we have already 〈◊〉 sufficiently dischargeâ—h our debt to the Title of this Chapter CHAP. XIV Softness Hardness Flexility Tractility Ductility c. SECT I. THe two First of this Rank of Secunâ—darie Qualities HARDNESS and SOFTNESS beâ—ng so neer of Extraction and Semblance that mâ—ny have confounded them with Firmness and Fluidâ—ty in a General and looser acceptâ—tion forâ— so Virgil gives the Epitheâ—e of Soft to Water Lucretius to Aer Vaporâ— Clouds c. because a Firme bodie or such whose parts are reciprocâ—lly cohaerent and superfice more 〈…〉 apparently continued as 〈◊〉 may be Soft and on the other side a Fluid body or such whose 〈…〉 not reciprocally cohaerent nor 〈◊〉 really continued as 〈…〉 be Hard
〈◊〉 Experiments some whereof are recited by the Lord St. Alban in â—â—lva sylvarum Cent. 1. But this one will serve the turne When an Oyster or Tortois shell is let fall from a sufficient altitude upon a stone 〈◊〉 is usually shattered into many peices and that for no other Reason but this that the lower side whether Convex or Concave being vehemently impinged against the stone the particles thereof immediately knockt by the stone as vehemently give back and in their quick Retrocession impell the particles situate immediately above them whereupon those impelled particles with the same violence impell others next in order above them until the percussion being propagated from part to part successively quite home to the upper superfice it comes to pass that each percussed part giving back the whole shell is shattered into small Fragments All which may seem but a genuine Paraphrase upon the Text of Mersennus Harmonicor lib 2. propos 43. Duritiei verò proprietas appellatur Rigiditas quae fit ab Atomis ita sibi invicem cohaerentibus ut Deflexionem impediant quod contingit in Corporibus quae constant Atomis Cubicis octuedris tetruedis ex quibus resultat perfecta superficiecularum inter se cohaesio hinc â—it ut Rigida Corpora Fructilia sint non autem Sectilia ictu impacto tota in frusta dissiliant Qui adum praedictae superficiunculae se invicem premunt quae sunt ex una parte dimoventur ab iis quae ex alia adeo ut unico impetu externo Corpori impresso Contusio sentiatur per totum partium eodem momento fit separatio There yet remains a Quality which is the Ofspring neither of Softness alone nor Hardness alone but ought to be referred partly to the one partly to the other and that is RUPTILITY For not only such Bodies as challenge the Attribute of Softness are subject to Ruption when they are distressed beyond the tenour of their Contexture either by too much Inflexion as a Bow over bent or too much Distention as Leather or Parchment over strained or too much Malleation as a plate of Lead Iron or other Metal over hammerd but such also as claim the title of Hardness and that in an eminent proportion as Marble for a Pillar of Marble if long and slender and laid transversly or horizontally so as to rest only upon its two extrems is easily broken asunder by its own Weight For as Soft bodies when rackt or deduced beyond the râ—te of mutual Cohaerence among their parts must yeeld to the External Force which distresâ—eth them and so suffer total discontinuity so Hard ones when the Internal Force or their owne Weight is too great to be resisted by their Compactness as in the example of a long Marble Pillar not supported in the middle then must they likewise yeeld to that superior force and break asunder And here the Archer and Musician put in for a Solution of that PROBLEM which so frequently troubles them viz. Cur Chordae faciliâ—â—s circa Exâ—rema quam circa Medium frangantur cum vi vel pondere sive horizontaliter sive verticaliter trahuntur Why Bowstrings Lutestrings and other Chords though of uniforme Contexture throughout and equally distended in all parts do yet usually break asunder not in the middle or neer it but at one End where they are fastned The Cause certainly must be this that the Weight or drawing force doth alwayes first act upon the parts of the string which are neerest to it and successively upon those which are farthest off i. e. in the Middle so that the string suffering the greatest stress neer the Extrems is more subject to break there than in any other part Wherefore whenever a Bowstring breaks in or neer the middle it may safely be concluded that the string was weakest in that place To which we may add this also that Experienced Archers to praevent the frequent breaking of their strings and the danger of breaking the Bow thereby injoyn their String-makers to add a Link of Flax or Twist more at the Ends of each string than in any other parts of it and that they call the Forcing because Experience hath taught them that the Force of the Bow is most violently discharged upon those parts of the string which are neerest to the Horns CHAP. XV. OCCULT QUALITIES made MANIFEST SECT I. HAving thus long entertained it self with the most probable Reasons of the several wayes and means whereby Compound Bodies exhibite their several Attributes and Proprieties to the judicature of the Sensitive Faculties in Animals and principally in Man the Rule Perfection and grand Exemplar of all the rest t is high time for our Curiosity to turn a new leaf and sedulously address it self to the speculation of Another Order or Classis of Qualities such as are vulgarly distinguished from all those which have hitherto been the subject of our Disquisitions by the unhappy and discouraging Epithite OCCULT Wherein we use the scarce perfect Dialect of the Schools who too boldly praesuming that all those Qualities of Concretions which belong to the jurisdiction of the senses are dependent upon Known Causes and deprehended by Known Faculties have therefore termed them Manifest and as incircumspectly concluding that all those Proprieties of Bodies which fall not under the Cognizance of either of the Senses are derived from obscure and undiscoverable Causes and perceived by Unknown Faculties have accordingly determined them to be Immanifest or Occult. Not that we dare be guilty of such unpardonable Vanity and Arrogance as not most willingly to confess that to Ourselves all the Operations of Nature are meer Secrets that in all her ample catalogue of Qualities we have not met with so much as one which is not really Immanifest and Abstruse when we convert our thoughts either upon its Genuine and Proxime Causes or upon the Reason and Manner of its perception by that Sense whose proper Object it is and consequently that as the Sensibility of a thing doth noe way praesuppose its Intelligibility but that many things which are most obvious and open to the Sense as to their Effects may yet be remote and in the dark to the Understanding as to their Causes so on the Contrary doth not the Insensibility of a thing necessitate nay nor aggravate the Unintelligibility thereof but that many things which are above the sphere of the Senses may yet be as much within the reach of our Reason as the most sensible whatever Which being praecogitated as when we look back upon our praecedent Discourses touching the Originals and Perception of Sensible Qualities we have just ground to fear that they have not attained the happy shoar of verity but remain upon the wide and fluctuating ocean of meer Verisimility So also when we look forward upon our immediately subsequent Disquisitions into the Causes of many Insensible Qualities are we not destitute of good reason to hope that though we herein attempt the consignation of