it is a cloudy circle, which continually appears in the air, and by reason of the whiteness of its colors is called the galaxy, or the milky way. some of the pythagoreans say that, when phaeton set the world on fire, a star falling from its own place in its circular passage through the region caused an inflammation. others say that originally it was the first course of the sun; others, that it is an image as in a looking-glass, occasioned by the sun’s reflecting its beams towards the heavens, and this appears in the clouds and in the rainbow. metrodorus, that it is merely the solar course, or the motion of the sun in its own circle. parmenides, that the mixture of a thick and thin substance gives it a color which resembles milk. anaxagoras, that the sun moving under the earth and not being able to enlighten every place, the shadow of the earth, being cast upon the part of the heavens, makes the galaxy. democritus, that it is the splendor which ariseth from the coalition of many small bodies, which, being firmly united amongst themselves, do mutually enlighten one another. aristotle, that it is the inflammation of dry, copious, and coherent vapor, by which the fiery mane, whose seat is beneath the aether and the planets, is produced. posidonius, that it is a combination of fire, of finer substance than the stars, but denser than light.