De Defectu Oraculorum

Those, however, who had reached the conclusion that the two are one and the same god very naturally dedicated the oracle to Apollo and Earth in common, thinking that the sun creates the disposition and temperament in the earth from which the prophet-inspiring

vapours are wafted forth. As Hesiod,[*](Theogony, 117.) then, with a better understanding than some philosophers, spoke of the Earth itself as

Of All the unshaken foundation,

so we believe it to be everlasting and imperishable. But in the case of the powers associated with the earth it is reasonable that there should come to pass disappearances in one place and generation in another place, and elsewrhere shifting of location and, from some other source, changes in current,[*](Cf. 432 e, supra.) and that such cycles should complete many revolutions within it in the whole course of time, as we may judge from what happens before our eyes. For in the case of lakes and rivers, and even more frequently in hot springs, there have occurred disappearances and complete extinction in some places, and in others a stealing away, as it were, and sinking under ground[*](A not uncommon phenomenon in Greece; cf. Moralia, 557 e.); later they came back, appearing after a time in the same places or flowing out from below somewhere near. We know also of the exhaustion of mines, some of which have given out recently, as for example the silver mines of Attica and the copper ore in Euboea from which the cold-forged sword-blades used to be wrought, as Aeschylus[*](Cf. Nauck, Trag. Graec. Frag. p. 107, Aeschylus, no. 356. The hardness and temper of cold-forged copper is well attested.) has said,

Euboean sword, self-sharpened, in his hand.

And it is no long time since the rock in Euboea ceased to yield, among its other products, soft petrous filaments like yarn.[*](An interesting early notice of the use of asbestos.) I think some of you have seen towels, nets, and women’s head-coverings from there, which cannot be burned by fire; but if any become soiled by use, their owners throw them into a blazing fire and take them out bright and clear. To-day all this has disappeared, and there are scarcely any attenuated fibres or hairs, as it were, running through the mines.