8
Such are the facts about spring waters. I will now proceed to speak of rain water and snow water. Rain waters are the lightest, sweetest, finest and clearest. To begin with, the sun raises and draws up the finest and lightest part of water, as is proved by the formation of salt. The brine, owing to its coarseness and weight, is left behind and becomes salt; the finest part, owing to its lightness, is drawn up by the sun. Not only from pools does the sun raise this part, but also from the sea and from whatever has moisture in it—and there is moisture in everything. Even from men it raises the finest and lightest part of their juices. The plainest evidence thereof is that when a man walks or sits in the sun wearing a cloak, the parts of his skin reached by the sun will not sweat, for it draws up each layer of sweat as it appears. But those parts sweat which are covered by his cloak or by anything else. For the sweat drawn forcibly out by the sun is prevented by the covering from disappearing through the sun’s power. But when the man has come into a shady place, his whole body sweats alike, as the sun no longer shines upon it. For this reason too rain-water grows foul quicker than any other, and has a bad smell; being a mixture gathered from very many sources it grows foul very quickly. Furthermore, when it has been carried away aloft, and has combined with the atmosphere as it circles round, the turbid, dark part of it separates out, changes and becomes mist and fog, while the clearest and lightest part of it remains, and is sweetened as the heat of the sun produces coction, just as all other things always become sweeter through coction. Now as long as it is scattered and uncondensed, it travels about aloft, but as soon as it collects anywhere and is compressed into one place owing to sudden, contrary winds, then it bursts wherever the most compression happens to take place. For this is more likely to occur when the clouds, set in motion and carried along by a wind that allows them no rest, are suddenly encountered by a contrary blast and by other clouds.The reading of Kéhlewein means, condensed, set in motion and carried along by a wind, are suddenly, etc. In such cases the front is compressed, the rear comes on and is thus thickened, darkened and compressed into one place, so that the weight bursts it and causes rain. Such waters are naturally the best. But they need to be boiled and purifiedOr, with the reading of Coray, filtered. from foulness if they are not to have a bad smell, and give sore throat, coughs and hoarseness to those who drink them.
