How Light is propagated.
Detailed Remarks on the propagation of Light.
Why Rays are propagated only in straight lines.
How Light coming in different directions can cross itself.
CHAPTER II.
On Reflexion.
Demonstration of equality of angles of incidence and reflexion.
Why the incident and reflected rays are in the same plane
perpendicular to the reflecting surface.
That it is not needful for the reflecting surface to be perfectly
flat to attain equality of the angles of incidence and reflexion.
CHAPTER III.
On Refraction.
That bodies may be transparent without any substance passing through
them.
Proof that the ethereal matter passes through transparent bodies.
How this matter passing through can render them transparent.
That the most solid bodies in appearance are of a very loose texture.
That Light spreads more slowly in water and in glass than in air.
Third hypothesis to explain transparency, and the retardation which
Light suffers.
On that which makes bodies opaque.
Demonstration why Refraction obeys the known proportion of Sines.
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