Physiologia Epicuro-Gassendo-Charltoniana, or, A fabrick of science natural, upon the hypothesis of atoms founded by Epicurus repaired [by] Petrus Gassendus ; augmented [by] Walter Charleton ...

SECT. II.

* 1.1NOw, of all these Praeconsiderables only the First can be judged Praecarious, by those whose Festination or Inadvertency hath not given them leave to observe the Certitude thereof inseparably connected to the evidence of all the others, by the linkes of genuine Conse∣quence. And therefore, that we may not be wanting to them, or our selves, in a matter of so much importance, as the full Confirmation of it by nervous and apodictical Reasons; especially when the Determina∣tion of that eminent and and long-lived Controversie concerning the QUIDDITY or Entity of Light, Whether it be an Accident, or Substance, a meer Quality, or a perfect Body? seems the most proper and desiderated subject of our praesent speculations, and the whole Theory of all other sensible Qualities (as Vulgar Philosophy calls them) is dependent on that one cardinal pin, since Light is the nearest allied to spiritual natures of all others, and so the most likely to be Incorporeal: we must devote this short Section to the perspicuous Eviction of the CORPORIETY of Light.

* 1.2Not to insist upon the grave Authority either of Empedocles, who, as Aristotle (1. de sensu & sensili: & de Gener. Animal. 1. cap. 8.) testifieth, affirmed Light to be 〈 in non-Latin alphabet 〉〈 in non-Latin alphabet 〉, Effluxionem, a material Emanation, and required certain proportionate Pores, or most slender passages in all Dia∣phanous bodies, for their transition; or Plato, who defined Colour, or Light disguised, to be 〈 in non-Latin alphabet 〉〈 in non-Latin alphabet 〉, Ef••luentem quandam Flammulam; or of Democritus and Epicurus, both which are well known to have been grand Patrons, if not the Authors of that opinion, that Light is corporeal: we judge it alone sufficient to demonstrate the Corporiety of Light, that the Attributes thereof are such, as cannot justly be adscribed to any but a Cor∣poreal Entity.

1 1.3Such are (1) Locomotion; for manifest it is, that some substance, though most tenuious, is deradiated from every Lucidum to the eye of the distant Spectator: nor is a Bullet sent from the mouth of a full charged Cannon with the millionth part of such velocity, as are the arrows shot from the bow of Apollo; since the rayes of the Sun are transformed from one end of the heavens to the other, in a far less division of time, than a Cannon Bullet is flying to its m••••k.

2 1.4(2) Resilition; for the rayes of light are sensibly repercussed from all solid bodies, on which they are projected; and that with such pernicity or rapid motion, as transcends, by inassignable excesses, the rebound of a Can∣non Ball from a Rock of Adamant.

3 1.5(3) Refraction, for our sense confirms, that Light is ever refracted by those Bodies, which allow its rayes a passage, or through-fare, but not an absolute free and direct one.

(4) Coition, or Union, or Corroboration, from bodies either reflecting,4 1.6 or transmitting many rayes to one common point of concurse, where they become so violent as to burn any thing applied.

(5) Disgregation and Debilitation,5 1.7 from the didaction of its rayes re∣flected or trajected: so that those which before during their Union were so vigorous as to cause a conflagration, being one distracted become so lan∣guid as not to warm.

(6) Igniety; since Light seems to be both the Subject,6 1.8 and Vehicle to Heat, and those speak incorrigibly, who call Light, Flame attenuated. Which we shall less doubt, if we consider the natural Parallelism betwixt Flame and Water, Light and a Vapour. For, as Water by Rarefaction, or Attenuation becomes a Vapour; so may we conceive Flame by Attenuation to become Light circumfused in the aer: and as a Vapour is nothing else but Water so rarefied into small discontinued par∣ticles, as that it doth scarce moisten the body on which it is impacted; so is Light nothing else but Flame so dilated by Rarefaction, that it doth hard∣ly warm the body it toucheth. Lastly, as a Vapour how finely soever rarefied, is still substantially Water; because only by the Coition of its dif••used particles it returns again to Water, as in all distillations: so must we account Light however rarefied, to be still substantially Flame; because only by the Coition, or Congregation of its dispersed rayes it is reducible into absolute Flame, as in all Burning-glasses.

These Attributes of Light considered, it is not easie for the most praevaricate judgment not to confess, that Light is a Corporeal substance, and the Rayes of it most tenuious streams of subtle Bodies: since it is impossible they should be deradiated from the Lucid Fountain with such ineffable pernicity, transmitted through the Diaphanum in a mo∣ment, impacted against solid bodies, repercussed, corroborated by Unition, debilitated by Disgregation, &c. without essential Corpulency.

Notwithstanding this apodictical evidence of the Corporiety of Ligh••, the refractary Peripatetick will have it to be a meer Quality, and objects

(1) That his master Aristotle,* 1.9 impugning the doctrine of Demo∣critus, Epicurus, and others, who ascribed Materiality to Light, de∣fined it to be meerly 〈 in non-Latin alphabet 〉〈 in non-Latin alphabet 〉 perspicui, an act of the Perspicuum.

To this we answer, (1) That though Aristotle thought it sufficient barely to deny that light is 〈 in non-Latin alphabet 〉〈 in non-Latin alphabet 〉, ullius corporis Ef••luxum, and to affirm it to be Energian perspicui, ut perspicuum; yet will the judicious discover it to be rather an ambage to circumvent the incircumspect, than a demonstration to satisfie the curious. For, though Philopouus (2. de Anim. 7.) willing to conceal or guild over his Masters error, interpreteth his Perspicuum actu, or illustrate Nature, and so Light to be a kind of Chord, which being continuedly inter∣posed betwixt the object and the eye, causeth that the Colour thereof posited beyond the Medium, doth affect and move the eye to the act of intuition: yet hath He left the Reason and Manner of this supposed Act

of the Perspicuum on the eye, the chief thing necessary to satisfaction, involved in so many and great Difficulties, as proclaim it to be absolute∣ly inexplicable. (2) That albeit we deny not Illumination to be meer∣ly ••cc••dental to opace Bodies; yet therefore to allow the Light, where∣with they are illuminate, to be an Accident, and no Substance, is a ma∣nifest Alogie. And to affirm, that the Aer, Water, or any Diaphanous body is the subject of Inhaesion to Light, is evidently incongruous; because every Medium is simply Passive, and remains unmoved while the Light pervades it: and how can Light pervade it, if it be not Corporeal? or how can the rayes thereof conserve their Tensity and Di∣rectness in the Aer, while it is variously agitated by wind and other causes, if they were not absolutely independent thereupon? (3) What Aristotle saith concerning the Propagation of the species of Light even to infinity in all points of the Medium, besides its incomprehensibili∣ty, is absolut••ly inconsistent to the Pernicity of its motion, which is too ra∣pid and momentany to proceed from a fresh Creation of Light in every point of the medium: since the multitude of fresh productions successively made, would r••quire a far longer time for the transmission of the light of a candle to the eye of a man at the distance of but one yard, than our sense de∣monstrates to be necessary to the transmission of the light of the Sun from one end of Heaven to the other.

(2) That by allowing Light to be Corporeal, we incurr the absurd••ty of admitting two Bodies into one and the same place.* 1.10

Which is soon solved by reflecting on what we have formerly and frequently said, concerning Inanity interspersed, and observing what we shall (God willing) say of those eminent Qualities, Rarity and Perspi∣cuity: from either of which it may be collected, how great a Multitude of Pores are in every Rare and Perspicuous Body, which remain tenantable, or unpossessed.

* 1.11(3) That from the Corporiety of Light it must follow, that a Body ma•• be moved in an Instant. But he hath not yet proved that the motion of Light is instantaneous: and we have, that it is not, but only Momentany, i. e. that Ligh•• is moved in a certain space of time, though imperceptible, yet divisible, and not in one individual point, or Instant.

* 1.12(4) That the Rayes of Light are Invisible in pure Aer, and by conse∣quence Immaterial. Solut. Their Invisibility doth not necessitate their Immateriality; for the Wind, which no man denies to be Corporeal, is invisible: and as it sufficeth that we feel the Wind in its progress through the aer, so also is it sufficient that we perceive Light, in the illumination of Opace Bodies, on which it is impinged, and from which it is reflected. Be∣sides, whoso maketh his sense the measure of Corporiety, doth strain it to a higher subtility, than the constitution of its Organs will bear, and make many more spiritual Entities, than can be found in the Uni∣verse; nay, He implicitely supposeth an Immaterial Being naturally capable of Incorporation meerly by the Unition of its dispersed par∣ticles; since many rayes of Light congregated into one stream become visible.

(5) That the Materiality of Light is repugnant to the Duration of the Sun; which could not have lasted so long, but must have, like a Tapour,* 1.13 ex∣hausted its whole stock of Luminous Matter, and wincked out into perpetual night, long since, if all its Rayes were substantial Emanations, according to our Assumption.

But this Refuge may be battered with either of these two shots. 1 The superlative Tenuity of the Luminous particles continu••lly emitted from the body of the Sun, is such as to prevent any sensible minoration of its orb, in many 1000 yeers. (2) If the Diametre of the Sun were minorated by 100000 miles less than it was observed in the days of Ptolomy; yet would not that so vast Decrement be sensible to our sight: since being in its Apo∣gaeum, in summer, it doth not appear one minute less in Diameter to the strictest astronomical observation, than in winter, in its Perigaeum, and yet Snellius, Bullialdus, and Gassendus, three Astronomers of the highest form, assure us that it is about 300000 miles more remote from us, in its Apogae∣um, than Perigaeum.

(6 and Lastly) That if Light were Flame,* 1.14 then would all Light warm at least: but there are many Lights actually Cold, such as that in the Phospher M••neralis, or Lapis Phenggites, of whose admirable Faculty of imbibing, retaining and emitting a considerable light, the excellent Fortunius Licetus hath written a singular Tract, and Athanas. Kircherus a large chapter (in Art. magn. Lucis & Umbrae lib. ••. part. 1. cap. 8.), in Gloworms, the scales and shells of some Fishes, among which the most eminent are those Dactyli mentioned by Kircher (in libri jam citati part. 1. cap. 6.) in these words, sunt & Dactyli, ostreacei generis, qui vel manibus triti lumen veluti scintillas quasdam ex se spargunt: quemadmodum Melitae, in Sicilia, Calabria, & Ligustici maris oris non sine admiratione à piscatoribus & nautis instructoribus observasse memini; in Rotten Wood, &c. Ergo, &c.

Answer, The Defect of actual Heat in these things, doth arise, in part from the abundant commistion of Gross and Viscid Humidity with those igneous Particles that are Collucent in them; but mostly from the ex∣ceeding Rarety of those Luminous Sparks: which being so thin and lan∣guid, as to disappear even at the approach of a Secondary Light, cannot be expected vigorous enough to infuse an actual warmth into the hand that toucheth them; especially when experience attesteth, that the Rayes of the Sun, after two Reflections, become so languid by Attenuation, as they can hardly affect the tenderest hand with any sensible Heat. And therefore, unless it can be evinced, that the disgregation of the parts of a Body, doth destroy the Corporiety of it; and that the simple Attenuation of Lig••t doth make it to be no Light: we ask leave to retain our p••rsuasion, that the existence of many lights, which are devoyd of Heat, as to the per∣ception of our sense, is no good Argument against the Igniety and Cor∣poriety of Light.

Notes

• * 1.1

  Art. 1. The Necessity of the Authors confirmation of the F••••st Praeconsiderable
• * 1.2

  Art. 2. The CORPO∣RIETY of Light, demon∣strated by its j••st Attributes: viz.
• 1 1.3

  Locomotion.
• 2 1.4

  Resilition.
• 3 1.5

  Refraction.
• 4 1.6

  Coition.
• 5 1.7

  Disgr••gation
• 6 1.8

  Igniety.
• * 1.9

  Art. 3. Aristotles Defi∣nition of Ligh••, a meer Ambage, and incomprehen∣sible.
• * 1.10

  Art. 4. The 〈◊〉〈◊〉 of Light imp••rts not the Coexi∣stence of two B••dies in one Place: contra¦ry to the Peri∣patetick.
• * 1.11

  Art. 5. Nor the moti∣on of a B••dy to be Instanta∣ne••us.
• * 1.12

  Art. 6. The Invisibili∣t•• of ••ight in the limpid me∣dium, no Ar∣gument of its Immateriality: as the Peripa∣tetick prae∣sumes.
• * 1.13

  Art. 7. T••e Corporiety of Light fully consistent with the Du∣ration of the Sun: contrary to the Peripa∣tetick.
• * 1.14

  Art. 8. The in••••nsibi∣lity of Heat in many Lucent B••die•• no va∣lid Argument against the praesent The∣sis, that Light is Flame Atte∣nuated.