8
Waters from snow and ice are all bad. For, once frozen, water never recovers its original nature, but the clear, light, sweet part is separated out and disappears, while the muddiest and heaviest part remains. The following experiment will prove it. Pour by measure, in winter, water into a vessel and set it in the open, where it will freeze best; then on the next day bring it under cover, where the ice will melt best; if, when it is dissolved, you measure it again you will find it much diminished. This shows that freezing dries up and causes to disappear the lightest and finest part, not the heaviest and coarsest, to do which it has no power. In this way, therefore, I am of opinion that such waters, derived from snow or ice, and waters similar to these, are the worst for all purposes.
9
Such are the properties of rain waters, and of those from snow and ice. Stone, kidney disease, strangury and sciatica are very apt to attack people, and ruptures occur, when they drink water of very many different kinds, or from large rivers, into which other rivers flow, or from a lake fed by many streams of various sorts, and whenever they use foreign waters coming from a great, not a short, distance. For one water cannot be like another; some are sweet, others are impregnated with salt and alum, others flow from hot springs. These when mixed up together disagree, and the strongest always prevails. But the strongest is not always the same; sometimes it is one, sometimes another, according to the winds. One has its strength from a north wind, another from the south wind, and similarly with the others. Such waters then must leave a sediment of mud and sand in the vessels, and drinking them causes the diseases mentioned before. That there are exceptions I will proceed to set forth.
