Mijcellanea Curtofa. 1 1 5 



in the other two, and therefore may well be de- 

 fined Homogeneal ; .efpecially fmce Men ufually 

 call thole things Homogeneal, which are fo in all 

 Qualities that come under their Knowledge, tho* 

 in other Qualities, that their Knowledge extends 

 not to, there may poffibly be fome Heteroge- 

 neity. 



3, Thofe Colours I call Simple or Homoge- 

 neal , which are exhibited by Homogeneal 

 Light, 



4. And thofe Compound or Heterogeneal, 

 which are exhibited by Heterogeneal Light. 



jT. Different Colours, I call, not only the 

 more eminent Species, Red, Yellow, Green, Blue, 

 Purple, but all other the minuteft Gradations ; 

 much after the fame manner, that not only the 

 more eminent Degrees in Mufick, but all the lead 

 Gradations, are efteem'd different Sounds. 



PROPOSITIONS. 



1. The Sun's Light confifts of Rays differing 

 by indefinite Degrees of Refrangibility. 



x. Rays vhich differ in Refrangibility, when 

 parted from one another, do proportionally dif- 

 fer in the Colours which they exhibit. Thefe 

 Two Propofitions are Matter of Fact. 



g . There are as many Simple or Homogeneal 

 Colours, as Degrees of Refrangibility. For to 

 every Degree of Refrangibility belongs a different 

 Colour, by Prop. x. and that Colour is Simple, 

 by Def. 1, and 3. 



4. Whitenefs, in all re(pe6b like that of the 

 Sun s immediate Light, and of all the ufaal Ob- 

 jects of our Senfes, cannot be compounded of two 

 Simple Colours alone. For fuch a Composition 

 I % tnuil 



