That lucid whitish zone in the firmament among the fixed stars, which we
call the “Milky Way,” was supposed by the Pythagoreans to have once been
the sun’s path, wherein he had left that trace of white, which we now
observe there. The Peripatetics asserted, after Aristotle, that it was
formed of exhalations, suspended high in air. These were gross mistakes;
but all the ancients were not mistaken. Democritus, without the aid of a
telescope, preceded Galileo in remarking, that “what we call the milky
way, contained in it an innumerable quantity of fixed stars, the mixture
of whose distant rays occasioned the whiteness which we thus
denominate;” or, to express it in Plutarch’s words, it was “the united
brightness of an immense number of stars.”