not naturally be moved, yet divers parts
and places of the earth may move one upon another. Parmenides and
Democritus, that the earth being so equally poised hath no sufficient
ground why it should incline more to one side than to the other; so that
it may be shaken, but cannot be removed. Anaximenes, that the earth by
reason of its latitude is borne upon by the air which presseth upon it.
Others opine that the earth swims upon the waters, as boards and broad
planks, and by that reason is moved. Plato, that motion is by six manner
of ways, upwards, downwards, on the right hand and on the left, behind
and before; therefore it is not possible that the earth should be moved
in any of these modes, for it is altogether seated in the lowest place;
it therefore cannot receive a motion, since there is nothing about it so
peculiar as to cause it to incline any way; but some parts of it are
so rare and thin that they are capable of motion. Epicurus, that the
possibility of the earth's motion ariseth from a thick and aqueous
air under the earth, that may, by moving or pushing it, be capable of
quaking; or that being so compassed, and having many passages, it is
shaken by the wind which is dispersed through the hollow dens of it.

CHAPTER XVI. OF THE SEA, AND HOW IT IS COMPOSED, AND HOW IT BECOMES TO
THE TASTE BITTER.

Anaximander affirms that the sea is the remainder of the primogenial
humidity, the greatest part of which being dried up by the fire, the
influence of the great heat altered its quality. Anaxagoras that in the
beginning water did not flow, but was as a standing pool; and that it
was burnt by the movement of the sun about it, by which the oily part of
the water being exhaled, the residue became salt. Empedocles, that the
sea is the sweat of the earth heated by the sun. Antiphon, that the
sweat of that which was hot was separated from the rest which were
moist; these by seething and boiling became bitter, as happens in all
sweats. Metrodorus, that the sea was strained through the earth, and
retained some part of its density; the same is observed in all those
things which are strained through ashes. The schools of Plato, that the
element of water being compacted by the rigor of the air became sweet,
but that part which was expired from the earth, being enfired, became of
a brackish taste.

CHAPTER XVII. OF TIDES, OR OF THE EBBING AND FLOWING OF THE SEA.

Aristotle and Heraclides say, they proceed from the sun