Miscellanea Curiosa, Vol. 1 / Containing a collection of some of the principal phaenomena in nature, accounted for by the greatest philosophers of this age

by Unknown

PROPOSITIONS.

1. The Sun's Light consists of Rays differing by indefinite Degrees of Refrangibility.

2. 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 Fact.

3. 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.

4. 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.

5. 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 indefinite Degrees of Refrangibility, by Prop. 1. And those infer as many Simple Colours, by Def. 1 and 3. and Prop. 2 and 3.

To make these a little plainer, I have added also the Propositions that follow.

6. The Rays of Light do not act on one another, in passing through the same Medium.

7. The Rays of Light suffer not any change of their Qualities from Refraction.

8. Nor afterwards from the adjacent quiet Medium: These two Propositions are manifest de Facto in Homogeneal Light, whose Colour and Refrangibility is not at all changeable, either by Refraction, or by the Contermination of a quiet Medium. And as for Heterogeneal Light, it is but an Aggregate of several sorts of Homogeneal Light, no one sort of which suffers any more alteration than if it were alone; because the Rays act not on one another, by Prop. 6. and therefore the Aggregate can suffer none. These two Propositions also might be further proved apart, by Experiments too long to be here described.