A TREATISE 



account ; and what difcreet yertue , it will give the fame things 

 to produce different colours , and to make ditferent appearan- 

 ces , meerely byfuch nice changes of fituation, I do not well 

 underftand : but peradventure the Patrones of it, may fay that 

 every fuch circumtfance-rs a fondiiiofint qtm nan: and therewith 

 (noioubt) their Auditors will be much the wifer in compre- 

 hending the particular nature or" light , and of the colours that 

 have their origine from it. 



3- . The Rainebow, for whofe fake moft men handle this matter 



'anyhow ^ ummous colours , is generated in the firft of the two wates 

 byThecolour we have delivered for the production of fuch colours : and hath 

 of any body its origine from refraction, when the eye being at a convenient 

 we may know diftance from the refracting body , looketh upon it to di.-cerne 

 thcconopofiti- ^^ appear^ ' m ' ltt The ipeculation of which may be found 

 Ufdfe. C ^ in that exceilenc diicourfe of Mounfeurdes Cartes which is the 

 /txt of IHS Meteors ; where he hath with great accuratenefie de- 

 livered a mofl ingenious doctrine of this myftery : had not his 

 bad chance of milling in a former principle(as I conceive) fbme- 

 what obfcured it. For he there gi veth the caufe fo neat , and ib 

 juftly calculated to the appearances, as no man can doubt but 

 that he hath found out the true reafon of this wonder of nature, 

 whiQh hath perplexed Ib many great wks : asmayalmoft be 

 feen with our very eyes ; when looking npon the frefli deaw in 

 a Sunfliiny morning,we. may in due portions perceive the rain- 

 bow colours, not three yards diftant from us : in which we may 

 diftingwifli even iingle drops with their effects. Jut he having 

 determined the nature of light to confift in motion , and pro- 

 ceeding consequently, he concludeth colours to be but cerraine 

 kinds of motion; by which I fearc it is impo/Tible that any good 

 icceunt mould be given of the experiences we fee. 



But what we have already iaid in that point,! conceive is (uf- 

 ficicnt to give the Reader fatisfe&ion therein : and to iecure 

 him, that the generation of the colours in the rain-bow, as well 

 as all other colours, is likewife reduced to the mingling of light 

 and darknefle : which is our princijwll intent to prove : adding 

 thereunto byway of advertisement, for others whofe lei/ure 

 ipay permit them to make uCe thereof, that who mail Hal lance 

 i^e proportions of luminous colours, may peradventure make 

 afteptp iu<%c of the natures ofthoitbocfics, which 



really' 



