Question V.
WHY THOSE THAT SAIL UPON THE NILE TAKE UP THE WATER THEY ARE TO USE BEFORE DAY.
ONE demanded a reason why the sailors take up the water for their occasions out of the river Nile by night, and not by day. Some thought they feared the sun, which heating the water would make it more liable to putrefaction. For every thing that is heated or warmed becomes more easy to be changed, having already suffered when its proper quality was remitted. And cold constipating the parts seems to preserve every thing in its natural state, and water especially. For that the cold of water is naturally constringent is evident from snow, which keeps flesh from corrupting a long time. And heat, as it destroys the proper quality of other things, so of honey, for it being boiled is itself corrupted, though when raw it preserves other bodies from corruption. And that this is the cause, I have a very considerable evidence from standing pools; for in winter they are as wholesome as other water, but in summer they grow bad and noxious. Therefore the night seeming in some measure to resemble the winter, and the day the summer, they think the water that is taken up at night is less subject to be vitiated and changed. To these seemingly probable reasons another was added, which confirmed the ingenuity of the sailors by a very natural proof. For some said that they took up their water by night because then it was clear and undisturbed; but at daytime, when a great many fetched water together, and many boats were sailing and many beasts swimming upon the Nile, it grew thick and muddy, and in that condition it was more subject to corruption. For mixed bodies are more easily corrupted than simple and unmixed; for from mixture proceeds disagreement of the [p. 416] parts, from that disagreement a change, and corruption is nothing else but a certain change; and therefore painters call the mixing of their colors φθοράς, corrupting; and Homer expresseth dyeing by μιῆναι (to stain or contaminate). Commonly we call any thing that is simple and unmixed incorruptible and immortal. Now earth being mixed with water soonest corrupts its proper qualities, and makes it unfit for drinking; and therefore standing water stinks soonest, being continually filled with particles of earth, whilst running waters preserve themselves by either leaving behind or throwing off the earth that falls into them. And Hesiod justly commends
The water of a pure and constant spring.1For that water is wholesome which is not corrupted, and that is not corrupted which is pure and unmixed. And this opinion is very much confirmed from the difference of earths; for those springs that run through a mountainous, rocky ground are stronger than those which are cut through plains or marshes, because they do not take off much earth. Now the Nile running through a soft country, like the blood mingled with the flesh, is filled with sweet juices that are strong and very nourishing; yet it is thick and muddy, and becomes more so if disturbed. For motion mixeth the earthly particles with the liquid, which, because they are heavier, fall to the bottom as soon as the water is still and undisturbed. Therefore the sailors take up the water they are to use at night, by that means likewise preventing the sun, which always exhales and consumes the subtler and lighter particles of the liquid. [p. 417]
