CHAPTER V.OF THE RAINBOW.
Those things which affect the air in the superior places of it are of two sorts.

Some have a real subsistence, such are rain and hail; others not.

Those which enjoy not a proper subsistence are only in appearance; of this sort is the rainbow.

Thus the continent to us that sail seems to be in motion.
Plato says, that men admiring it feigned that it took origination from one Thaumas, which word signifies admiration.

Homer sings:-- Jove paints the rainbow with a purple dye, Alluring man to cast his wandering eye.
(Iliad, xvii.