Rays which differ in Refrangibility, when parted from one another, do proportionally differ in the Colours which they exhibit. These Two Propositions are Matter of
- There are as many Simple or Homogeneal Colours, as Degrees of Refrangibility. For to every Degree of Refrangibility belongs a different Colour, by Prop. 2. and that Colour is Simple, by Def. 1, and 3.
- Whiteness, in all respects like that of the Sun's immediate Light, and of all the usual Objects of our Senses, cannot be compounded of two Simple Colours alone. For such a Composition
must be made by Rays that have only two Degrees of Refrangibility, by Def. 1 and 3. and therefore it cannot be like that of the Sun's Light. by Prop. 1. nor, for the same Reason, like that of ordinary white Objects.
- Whiteness, in all respects, like that of the Sun's immediate Light, cannot be compounded of Simple Colours without an indefinite Variety of them. For to such a Composition, there are requisite Rays endu'd with all the