Your constant Friend,
and faithful Servant.
[1] C. 25. a. 1.
[2] Art. 2.
[XIX.]
MADAM,
To discourse of the World and Stars, is more then I am able to do, wanting the art of Astronomy and Geometry; wherefore passing by that Chapter of your Author, I am come to that[1] wherein he treats of Light, Heat and Colours; and to give you my opinion of Light, I say, it is not the light of the Sun, that makes an Animal see, for we can see inwardly in Dreams without the Suns light, but it is the sensitive and rational Motions in the Eye and Brain that make such a figure as Light; For if Light did press upon the Eye, according to your Authors opinion, it might put the Eye into as much pain as Fire doth, when it sticks its points into our skin or flesh. The same may be said of Colours, for the sensitive motions make such a figure, which is such a Colour, and such a Figure, which is such a Colour; Wherefore Light, Heat and Colour, are not bare and bodiless qualities, but such figures made by corporeal self-motions, and are as well real and corporeal objects as other figures are; and when these figures change or alter, it is onely that their motions alter, which may alter and change heat into cold, and light into darkness, and black colour into white. But by reason the motions of the Sun are so constant, as the motions of any other kind of Creatures, it is no more subject to be altered then all the World, unless Nature did it by the command of God; for though the Parts of self-moving Matter be alterable, yet all are not altered; and this is the reason, that the figure of Light in our eye and brain is altered, as well as it is alterable, but not the real figure of the Sun, neither doth the Sun enter our eyes; and as the Light of the Sun is made or patterned in the eye, so is the light of Glow-worms-tails, and Cats-eyes, that shine in the dark, made not by the Sun's, but their own motions in their own parts; The like when we dream of Light, the sensitive corporeal motions working inwardly, make the figure of light on the inside of the eye, as they did pattern out the figure of light on the outside of the eye when awake, and the objects before them; for the sensitive motions of the eye pattern out the figure of the object in the eye, and the rational motions make the same figure in their own substance. But there is some difference between those figures that perceive light, and those that are light themselves; for when we sleep, there is made the figure of light, but not from a copy; but when the eye seeth light, that figure is made from a copy of the real figure of the Sun; but those lights which are inherent, as in Glow-worms-tails, are original lights, in which is as much difference as between a Man and his Picture; and as for the swiftness of the Motions of light, and the violence of the Motions of fire, it is very probable they are so, but they are a certain particular kind or sort of swift and violent motions; neither will all sorts of swift and violent motions make fire or light, as for example the swift and violent Circular motion of a Whirlewind neither makes light nor fire; Neither is all fire light, nor all light fire, for there is a sort of dead fire, as in Spices, Spirits, Oyles, and the like; and several sorts of lights, which are not hot, as the light which is made in Dreams, as also the inherent lights in Glow-worms, Cats-eyes, Fish-bones, and the like; all which several fires and lights are made by the self-moving matter and motions distinguishable by their figures, for those Motions make such a figure for the Suns light, such a figure for Glow-worms light, such a figure for Cats-eyes light, and so some alteration in every sort of light; The same for Fire, onely Fire-light is a mixt figure, as partly of the figure of Fire, and partly of the figure of Light: Also Colours are made after the like manner, viz. so many several Colours, so many several Figures; and as these Figures are less or more different, so are the Colours.
Thus, Madam, whosoever will study Nature, must consider the Figures of every Creature, as well as their Motions, and must not make abstractions of Motion and Figure from Matter, nor of Matter from Motion and Figure, for they are inseparable, as being but one thing, viz. Corporeal Figurative Motions; and whosoever conceives any of them as abstract, will, in my opinion, very much erre; but men are apt to make more difficulties and enforcements in nature then nature ever knew. But to return to Light: There is no better argument to prove that all objects of sight are figured in the Eye, by the sensitive, voluntary or self-motions, without the pressure of objects, but that not onely the pressure of light would hurt the tender Eye, but that the eye doth not see all objects according to their Magnitude, but sometimes bigger, sometimes less: as for example, when the eye looks through a small passage, as a Perspective-glass, by reason of the difficulty of seeing a body through a small hole, and the double figure of the glass being convex and concave, the corporeal motions use more force, by which the object is enlarged, like as a spark of fire by force is dilated into a great fire, and a drop of water by blowing into a bubble; so the corporeal motions do double and treble their strength, making the Image of the object exceeding large in the eye; for though the eye be contracted, yet the Image in the eye is enlarged to a great extension; for the sensitive and rational matter is extremely subtil, by reason it is extreamly pure, by which it hath more means and ways of magnifying then the Perspective-glass. But I intend to write more of this subject in my next, and so I break off here, resting,
Madam,