the least; since solid and very dense
substances interposed, even squared blocks of marble, do not obstruct this
power, though they can separate atoms from atoms; and the stone and the
iron would be speedily dissipated into such profuse and perpetual streams
of atoms. In the case of amber, since there is another different method of
attracting, the Epicurean atoms cannot fit one another in shape. Thales, as
Aristotle writes, _De Anima_, Bk. I., deemed the loadstone to be endowed
with a soul of some sort, because it had the power of moving and drawing
iron towards it. Anaxagoras also held the same view. In the _Timaeus_ of
Plato there is an idle fancy[148] about the efficacy of the stone of
Hercules. For he says that "all flowings of water, likewise the fallings of
thunderbolts, and the things which are held wonderful in the attraction of
Amber, and of the Herculean stone, are such that in all these there is
never any attraction; but since there is no vacuum, the particles drive one
another mutually around, and when they are dispersed and congregated
together, they all pass, each to its proper seat, but with changed places;
and it is forsooth, on account of these intercomplicated affections that
the effects seem to arouse the wonder in him who has rightly investigated
them." Galen does not know why Plato should have seen fit to select the
theory of circumpulsion rather than that of attraction (differing almost on
this point alone from Hippocrates), though indeed it does not agree in
reality with either reason or experiment. Nor indeed is either the air or
anything else circumpelled; and the bodies themselves which are attracted
are carried towards the attracting substance not confusedly, or in an orbe.
Lucretius, the poet of the Epicurean sect, sang his opinion of it thus:

[149]_First, then, know,_
_Ceaseless effluvia from the magnet flow,--_
_Effluvia, whose superior powers expel_
_The air that lies between the stone and steel._
_A vacuum formed, the steely atoms fly_
_In a link'd train, and all the void supply;_
_While the whole ring to which the train is join'd_
_The influence owns, and follows close behind. &c._

{62} Such a reason Plutarch also alleges in the _Quaestiones Platonicae_:
That that stone gives off heavy exhalations, whereby the adjacent air,
being impelled along, condenses that which is in front of it; and that air,
being driven round in an orbe and reverting to the