De generatione coloris. chap. 3.
THen in the matter of cléere coulour, drinesse hath the masterie, or moy∣sture hath the masterie, or the matter is meanly drye and moyst: and if drinesse hath masterie in the matter, then ye wor∣king of heate hath the mastrie, then is white colour gendered, for heate maketh the matter thin, and spredeth and depar∣teth the parts thereof, and maketh them subtill, and gendreth cléernesse & bright∣nesse. And in this wise Arist. speaketh in li. de Animalibus 19. and saith, That white coulour is gendred of scarsitie of humour in drie matter by mastrie of heat that worketh and maketh the mat∣ter subtill or small, as it fareth in mem∣bers & in bones burnt; and in other such. And if colde hath masterie, & worketh in dry matter, then is blacke colour gende∣red, for cold gathereth & constraineth the parts of dry matter and fasteneth them togethers, & maketh them sad & dimme. And dimnesse is not onely priuation of Page [unnumbered] light, but also of colour: for cléernesse is diuersitie both of light and of colour: for cléerenesse, is a certaine condition of things that are séene, and then the mat∣ter is determined drye, that néedeth to the generation of white colour, & right so blacke colour is gendred. Then if the matter be moyst, then the heate which hath mastrie gendreth blacke coulour: for heate burneth and also wasteth the moyst partes, and altereth and tourneth the moysture, which passeth out, into blacke smoke, as it fareth in wood, which is gréene and moyst: for out of the ends thereof, commeth blacke humour when it is burned. Héerof Aristo. speaketh in libro. Meth. and saith, that in poores of things that burneth, is féeble humour that may not withstand the heate of the fire, nor is sodainly stuffed, but it rather nourisheth and féedeth the fire: and so it is sooth, that fire worketh principally in moyst things, & that moyst things is cause of black coulour. By working of heate, it maketh subtil humour, and moi∣sture of water and of aire passe out of the matter, and then thus leaueth earthy matter and thicke, therefore it néedeth that blacke colour be gendered. Quarto li. Metheo. Arist. saith, that subtill kinde of earth and cléernesse of water, & kinde of aire maketh whitenesse in quicke sil∣uer, the contrary héereof gendreth black∣nesse in the drye matter that leaueth by working of heate in moist matter. And so lib. 19. Arist. saith, that blacknes gen∣dreth in the eye because of multitude of moysture, for heate worketh kindlye in moyst matter, and maketh therein dige∣stion, and fastneth and drieth it, and le∣ueth there blacke at last.