Madam,
Your faithful Friend,
and Servant.
[1] Of Meteor., c. 2, 4, 5, 6.
[XL.]
MADAM,
I cannot perceive the Rational Truth of your Authors opinion, concerning Colours, made by the agitation of little spherical bodies of an Æthereal matter, transmitting the action of Light; for if colours were made after this manner, there would, in my opinion, not be any fixed or lasting colour, but one colour would be so various, and change faster then every minute; the truth is, there would be no certain or perfect colour at all: wherefore it seems altogether improbable, that such liquid, rare and disunited bodies should either keep or make inherent and fixed colours; for liquid and rare bodies, whose several parts are united into one considerable bulk of body, their colours are more apt to change then the colours of those bodies that are dry, solid and dense; the reason is, that rare and liquid bodies are more loose, slack, and agil, then solid and dry bodies, in so much, as in every alteration of motion their colours are apt to change: And if united rare and liquid bodies be so apt to alter and change, how is it probable, that those bodies, which are small and not united, should either keep or make inherent fixed colours? I will not say, but that such little bodies may range into such lines and figures, as make colours, but then they cannot last, being not united into a lasting body, that is, into a solid, substantial body, proper to make such figures as colours. But I desire you not to mistake me, Madam, for I do not mean, that the substance of colours is a gross thick substance, for the substance may be as thin and rare as flame or light, or in the next degree to it; for certainly the substance of light, and the substance of colours come in their degrees very neer each other; But according to the contraction of the figures, colours are paler or deeper, or more or less lasting. And as for the reason, why colours will change and rechange, it is according as the figures alter or recover their forms; for colours will be as animal Creatures, which sometimes are faint, pale, and sick, and yet recover; but when as a particular colour is, as I may say, quite dead, then there is no recovering of it. But colours may seem altered sometimes in our eyes, and yet not be altered in themselves; for our eyes, if perfect, see things as they are presented; and for proof, if any animal should be presented in an unusual posture or shape, we could not judg of it; also if a Picture, which must be viewed side-wards, should be looked upon forwards, we could not know what to make of it; so the figures of colours, if they be not placed rightly to the sight, but turned topsie-turvie as the Phrase is, or upside-down, or be moved too quick, and this quick motion do make a confusion with the lines of Light, we cannot possibly see the colour perfectly. Also several lights or shades may make colours appear otherwise then in themselves they are, for some sorts of lights and shades may fall upon the substantial figures of colours in solid bodies, in such lines and figures, as they may over-power the natural or artificial inherent colours in solid bodies, and for a time make other colours, and many times the lines of light or of shadows will meet and sympathize so with inherent colours, and place their lines so exactly, as they will make those inherent colours more splendorous then in their own nature they are, so that light and shadows will add or diminish or alter colours very much. Likewise some sorts of colours will be altered to our sight, not by all, but onely by some sorts of light, as for example, blew will seem green, and green blew by candle light, when as other colours will never appear changed, but shew constantly as they are; the reason is, because the lines of candle light fall in such figures upon the inherent colours, and so make them appear according to their own figures; Wherefore it is onely the alteration of the exterior figures of light and shadows, that make colours appear otherwise, and not a change of their own natures; And hence we may rationally conclude, that several lights and shadows by their spreading and dilating lines may alter the face or out-side of colours, but not suddenly change them, unless the power of heat, and continuance of time, or any other cause, do help and assist them in that work of metamorphosing or transforming of colours; but if the lines of light be onely, as the phrase is, Skin-deep; that is, but lightly spreading and not deeply penetrating, they may soon wear out or be rubbed off; for though they hurt, yet they do not kill the natural colour, but the colour may recover and reassume its former vigour and lustre: but time and other accidental causes will not onely alter, but destroy particular colours as well as other creatures, although not all after the same manner, for some will last longer then others. And thus, Madam, there are three sorts of Colours, Natural, Artificial, and Accidental; but I have discoursed of this subject more at large in my Philosophical Opinions, to which I refer you, and rest,
Madam,
Your faithful Friend