SUBTERRANEAN THINGS BOOK I

its own weight does not allow it to be carried on high. If it were above the springs, then it could emit water from itself like a fortress, but miners who have dug up certain mountains entirely would have discovered it by now. However, none has been discovered; therefore, either it does not exist, or if any such thing exists, it cannot be the cause of any spring. It follows, therefore, that not all spring and well water is collected from rain.

Conversely, those who maintain that it is all born of the earth affirm this to us by two arguments, which they snatch from Seneca’s Natural Questions. One is this: no rain is so great that it can flow and penetrate into the earth beyond ten feet and soak it; rather, the very "skin" of the earth either absorbs and consumes all moisture if it is dry, or, once sated, accepts none, but rather, excluded by itself, spreads it through torrents into brooks and rivers. The other argument is this: certain mountains, covered by no crust of earth and clothed with no grasses, but having bare rocks, emit a great force of waters from themselves, which cannot have been collected from rain because solid rocks do not drink it up. Therefore, they say, all spring and well water is generated within the earth.

"Every earthly thing has its veins, but some have more than others." Truly, however, rains do not descend into the bowels of the earth through inter-spaces cracks or fissures as they do through non-solid veins. But these men, because they look only at the inter-spaces and do not notice the veins, veinlets, and joinings of the rocks, deny that the earth is soaked by rainwater beyond ten feet in height. Yet that rainwater slips down into the depth of the earth through rare veins from the upper part is sufficiently indicated by excavated mountains, when tunnels have been driven into them or cellars have been cut in which wines or other liquids can be stored. And for this very reason, in regions situated in the northern and southern parts, there are more and larger springs than in those that are perpetually hot, and among us, we see that in great and lasting heat some springs fail entirely and others become smaller.

Now, although rainwater is carried away over bare rocks, nevertheless, a part of it is absorbed by the joinings, and not far from these same rocks, veins and veinlets can conceive them. These waters afterwards erupt from the rocks together with water of another kind. Therefore, from these things, we understand on the contrary that not all spring and well water is generated i.e., not all is purely internal. Relying, therefore, on experience, we say more correctly that the water which flows from springs or emerges from the sides or bottoms of wells is twofold: one, which is born generated within; the other, which the earth, soaked by rains, conceives and pours out again. Miners call this "celestial" water, because it has flowed into the earth from the air; that other they call "fountain" water, because the earth itself supplies it perennially. But again, it is asked whether the water that is not collected from rain was all generated once and now merely remains, or if it is generated daily, or if it partly remains and partly is generated. There are two opinions about water of this kind, because it has no origin. The former is very old, and belongs to those who placed all their concern in the knowledge of God—the Greeks call them theologians.