Then the Empress enquired of them the reason, why springs were not as salt as the sea is? also, why some did ebb and flow? To which it was answered, that the ebbing and flowing of some springs, was caused by hollow caverns within the earth, where the seawater crowding through, did thrust forward, and drew backward the spring-water, according to its own way of ebbing and flowing; but others said, that it proceeded from a small proportion of saline and acid particles, which the spring-water imbibed from the earth; and although it was not so much as to be perceived by the sense of taste; yet it was enough to cause an ebbing and flowing-motion. And as for the spring-water being fresh, they gave, according to their observation, this following reason: There is, said they, a certain heat within the bowels of the earth, proceeding from its swift circular motion, upon its own axe, which heat distills the rarest parts of the earth into a fresh and insipid water, which water being through the pores of the earth, conveyed into a place where it may break forth without resistance or obstruction, causes springs and fountains; and these distilled waters within the earth, do nourish and refresh the grosser and drier parts thereof.