and malleable Metal: This may be farther confirmed by the Experiments made on the like Occafion by Mr. Boyle, by which he fhews how fome Bodies, fhut up on every Side in Glass, become more ponderous by the Fire or Light that paffes thro' the Pores of the faid Glafs: But this is proved yet more plainly, and beyond all Difpute, by the following Experiment of the faid Mr. Homberg in the above-mention'd Place, who having reduced four Ounces of Regulis Martis to Powder, placed it about the Distance of 1 Foot from the true Focus of the Burning-Glass of the Duke of Orleans, ftirring it about from time to time with an Iron Spoon; by the Heat of this Light there afcended a great Smoak from the faid Regulus for the fpace of an Hour, and then it ceased: And tho' one might expect, that by the lofs of all thofe Particles which evaporated in Smoak, the Weight whereof would have been diminished; yet the contrary, he found that the Weight of it was increafed quarter of an Ounce, and fome Grains, that it to say, about a tenth part of the whole.

Afterwards he placed the fame in a greater Heat, or in the real Focus, which put the Regulus into Fufion, and then it weighed no more than 3 Ounces; fo that he reckons that this lofs of the half Ounce happening by the Evaporation and Smoaking, one may fafely affirm, that the Light had firft augmented it with almoft the Weight of a whole Ounce, which by melting, and the Operation of fuch great Heat was diffipated again.

Now whether this laft Calculation be just or not, it plainly follows from hence, that this Regulus had in the first of those Experiments gained by the Rays of Light, the Weight of almost half an Ounce over and above all that evavorated in Smoak;

Smoak; which clearly fhews, that Light can conjoyn itself to folid and palpable Bodies, and increase the Subftance thereof.

But the Reader is defired to confider this as the firft Sketch of a new Difcovery: And I fhall not endeavour any farther here to determine, whether we ought with thofe great Men above-mention'd, to confider Light as the chiefest and most active Principle in Nature. This however seems to be unconteftably true, that Light is either a pure and uncompounded Fire, or carries fuch a Matter along with it; and how much ought to be ascribed to the Activity of Fire is fufficiently known to every one. Experience likewife teacheth us, how much all Plants and Animals depend upon the Influence of the Light of the Sun; infomuch, that if it cannot be said to be the only active Principle in Nature, at least it may be certainly reckon'd among the chiefest.

SECT. XXXVIII. Optical Experiments passed over.

I SHALL not amufe my felf here to rehearse the common and known Experiments about Light, which the Science of Optics fuggefts as fo many Wonders, tho' they furnish us with one of the greatest Proofs to demonftrate that there is a God who dire&s this miraculous Matter of Light, rendering it subject to fuch Laws, notwithftanding the amazing Velocity of its Motions, that even the greatest Mathematicians muft ftand aftonished, when they fee that all true Argumentation can deduce from it, performed by the fame. Thus we see when it falls upon the Superficies of a Looking-Glass, that it paints the Object from whence it flows, as if it was behind the faid Looking-Glass, where the Image is reprefented erect equally large, and at the fame Distance as the Obje&:

Obje&: If it falls upon Spherical Convex-Glaffes, it likewife makes behind the fame a nearer and direct Image upon the Glafs; and upon Spherical Concave-Glaffes the Image will be fometimes erect, fometimes inverted, now greater, then fmaller; one while it will appear before, another while behind the Glafs, which may be fhewn almoft by Refraction in fo many Changes thro' Convex and Concave Glaffes.

SECT. XXXIX. A Dark Chamber, and Convictions from thence.

Now if any Body would with fmall Expence try an Experiment about the Operations of Light, let him make what they call a Dark Chamber, of which mention has been already made in Contempl. XII. by which means he will fee upon a white Paper, or a Piece of Linnen held in the Focus of the Glafs that is fix'd in the Window, the Pictures of every thing that is on the outside of the Chamber, which will produce a very pleafing Profpect, especially if the Chamber looks upon a Flower-Garden; for then one may fee the Flowers in all their Colours and Figures, painted upon the Paper, and their Motions occafion'd by the Wind; and if there be any Men or other Creatures in the Garden, it will be a natural Moving Picture.

Now fince every one can judge by a Picture, of the Art and Skill of the Painter, and can be affured by the exact Reprefentation of the Object after the Life, that the Man who drew it was a great Master of Painting; let a miferable Atheist but only contemplate with us thefe Pictures formed by the Light, and tho' he were himself a very skilful Limner, let him tell us whether he, or any Man befides in the whole World, could copy a

Ex Piece, not only fo very like, with fuch noble Colouring, fo nicely adapted to all the Rules of a Mathematical Perspective, but also with all its Motion, as he may obferve to be done in an Inftant by the Rays of Light: And in case he be obliged to own, as to be fure he muft, that it exceeds all human Power, what Reason can he give with the least Show of Truth, why he should not confess an understanding Artificer in a Work which exceeds the Skill and Power of all human Invention: Whereas in other Works of much lefs Excellence, a Man would be juftly esteem'd a Fool, if not mad, who should maintain, that it had acquir'd its Figure without any Knowledge. The rather fince we fee that the Rays which reprefent the Colours each of 'em fo diftin&tly in the Chamber, pafs all of 'em together thro' this little Hole and Glass; and altho' they be fo numerous, and coming from the Objects, yet are they not jumbled and confounded with each other in this little Defilee, thro' which they pafs together; a thing that is not eafily to be credited, if we had not occular Proof of it. And cannot then an unhappy Sceptic difcover yet an over-ruling Power and Wisdom in this Direction of Light? What can be further done to extricate him out of this miferable Blindness.

SECT. XL. The Properties of the Rays of Light, with refpect to Colours.

BUT before we take our leave of Light, we fhall add fomething which feems to surpass even Wonder itself. Could any Body believe it, when he looks upon the bright and untinged Light of the Sun, that the fame can be divided and diftinguished into fo many different forts of tinged or dyed Rays, as the Great Creator has been plea

fed

fed to communicate of primary Colours or fimple Tinctures, or as the Learned call them, Homogeneal Colours?

And yet Experience teaches the fame, as alfo that each of thefe coloured Rays fuffers a particular Quantity of Refraction, and that the white, or rather the clear Light, is thereby fplit into different Parts or Kinds of Rays, which appearing fingly, fhew a red, yellow, green, blew and purple Colour; on which account thefe Rays ar named by Sir Ifaac Newton, Red, Yellow, &c. each of 'em according to their particular Colours, forafmuch as they are natural to them, and cannot be altered by any fubfequent Refraction or Reflection.

Moreover, fince all unmix'd Rays of the Sun do represent a certain Colour, and the whole Subftance of Light confifts of the faid Rays, it feemed to be hardly poffible, but that all thefe Tin&tures jumbled together, muft occafion an Obfcurity to our Sight; forafmuch as Blue, Purple, Red, and other Rays, are far fhort of that Brightnefs which occurs to us in the pure Light of the Sun or Day; and yet we find that all these colour'd Rays that proceed from Light by Separation, being collected and mix'd with each other, do entirely lose their respective Tin&tures, and together produce a clear and transparent Light, entirely like that untinged Light that comes down to us from the Sun: Which new conftituted Light may be again, as before, divided into its colour'd Rays, which, if one will, being mix'd together again, fhall the fecond time represent an uncoloured Light clear and tranfparent; concerning all which, the firft Discoverer, Sir Ifaac Newton, has treated largely in his Opticks.

Now I ask an unhappy Atheift, whether he can believe that Light has acquired thefe Properties either by Chance or ignorant Causes? Or whether