Chap. CCV.—Of Outlines of Objects on the Side towards the Light.
The extremities of any object on the side which receives the light, will appear darker if upon a lighter ground, and lighter if seen upon a darker ground. But if such body be flat, and seen upon a ground equal in point of light with itself, and of the same colour, such boundaries, or outlines, will be entirely lost to the sight[1].
- ↑ See chap. cclxv.