Quaestiones Naturales

WHETHER is it because (as Laitus thinks) showers, parting the earth by the violence of their fall, make passages, whereby the water may more easily penetrate to the root? Or cannot this be true; and did Laitus never consider that marsh-plants (as cat’s-tail, pond-weeds, and rushes) neither thrive nor sprout when the rains fall not in their season; but it is true, as Aristotle said, rain-water is new and fresh, that of lakes old and stale? And what if this be rather probable than true? For the waters of fountains and rivers are ever fresh, new always arriving; therefore Heraclitus said well, that no man could go twice into the same river. And yet these very waters nourish worse than rain-water. But water from the heavens is light and aerial, and, being mixed with spirit, is the quicker passed and elevated into the plant, by reason of its tenuity. And for this very reason it makes bubbles when mixed with the air. Or does that nourish most which is soonest altered and overcome by the thing nourished?—for this very thing is concoction. On the contrary, inconcoction is when the aliment is too strong to be affected by the thing nourished. Now thin, simple, and insipid things are the most easily altered, of which number is rain-water, which is bred in the air and wind, and falls pure and sincere. But fountain-water, being assimilated to the earth and places through which it passes, is filled with many qualities which render it less nutritive and slower in alteration to the thing nourished. Moreover, that rain-water is easily alterable is an argument; because it sooner putrefies than either spring

or river-water. For concoction seems to be putrefaction, as Empedocles says,—

When in vine wood the water putrefies,

It turns to wine, while under bark it lies.

Or, which may most readily be assigned for a reason, is it because rain is sweet and mild, when it is presently sent by the wind? For this reason cattle drink it most greedily, and frogs in expectation of it raise their voice, as if they were calling for rain to sweeten the marsh and to be sauce to the water in the pools. For Aratus makes this a sign of approaching rain,

When father frogs, to watery snakes sweet food,

Do croak and sing in mud, a wretched brood.