Slime3017 is one great impurity of water: still, however, if a river of this description is full of eels, it is generally looked upon as a proof3018 of the salubrity of its water; just as it is regarded as a sign of its freshness when long worms3019 breed in the water of a spring. But it is bitter water, more particularly, that is held in disesteem, as also the water which swells the stomach the moment it is drunk, a property which belongs to the water at Trœzen. As to the nitrous3020 and salso-acid3021 waters which are found in the deserts, persons travelling across towards the Red Sea render them potable in a couple of hours by the addition of polenta, which they use also as food. Those springs are more particularly condemned which secrete mud,3022 or which give a bad complexion to persons who drink thereof. It is a good plan, too, to observe if water leaves stains upon copper vessels; if leguminous vegetables boil with difficulty in it; if, when gently decanted, it leaves an earthy deposit; or if, when boiled, it covers the vessel with a thick crust.3023

It is a fault also in water,3024 not only to have a bad smell,3025 but to have any flavour3026 at all, even though it be a flavour pleasant and agreeable in itself, or closely approaching, as we often find the case, the taste of milk. Water, to be truly wholesome, ought to resemble air3027 as much as possible. There is only one3028 spring of water in the whole universe, it is said, that has an agreeable smell, that of Chabura, namely, in Mesopotamia: the people give a fabulous reason for it, and say that it is because Juno3029 bathed there. Speaking in general terms, water, to be wholesome, should have neither taste nor smell.