. Not content
with explaining the winds, this prototype of Franklin turned his
attention even to the tipper atmosphere. "Thunder," he is reputed to
have said, "was produced by the collision of the clouds, and lightning
by the rubbing together of the clouds." We dare not go so far as to
suggest that this implies an association in the mind of Anaxagoras
between the friction of the clouds and the observed electrical effects
generated by the friction of such a substance as amber. To make such
a suggestion doubtless would be to fall victim to the old familiar
propensity to read into Homer things that Homer never knew. Yet the
significant fact remains that Anaxagoras ascribed to thunder and to
lightning their true position as strictly natural phenomena. For him it
was no god that menaced humanity with thundering voice and the flash of
his divine fires from the clouds. Little wonder that the thinker whose
science carried him to such scepticism as this should have felt the
wrath of the superstitious Athenians.

Biological Speculations

Passing from the phenomena of the air to those of the earth itself, we
learn that Anaxagoras explained an earthquake as being produced by
the returning of air into the earth. We cannot be sure as to the exact
meaning here, though the idea that gases are imprisoned in the substance
of the earth seems not far afield. But a far more remarkable insight
than this would imply was shown by Anaxagoras when he asserted that a
certain amount of air is contained in water, and that fishes breathe
this air. The passage of Aristotle in which this opinion is ascribed to
Anaxagoras is of sufficient interest to be quoted at length:

"Democritus, of Abdera," says Aristotle, "and some others, that have
spoken concerning respiration, have determined nothing concerning
other animals, but seem to have supposed that all animals respire.
But Anaxagoras and Diogenes (Apolloniates), who say that all animals
respire, have also endeavored to explain how fishes, and all those
animals that have a hard, rough shell, such as oysters, mussels, etc.,
respire. And Anaxagoras, indeed, says that fishes, when they emit water
through their gills, attract air from the mouth to the vacuum in the
viscera from the water which surrounds the mouth; as if air was inherent
in the water."(2)

It should be recalled that of the three philosophers thus mentioned
as contending that all animals respire, Anaxagoras was the elder;
he, therefor