River or Running WATER, is next in purity to snow or distilled water; and for domestic purposes superior to both, in having less putrescent matter, and more fixed air. Such water, however, is to be chosen as runs in a clear stream through a rocky or stony channel; such as passes over mud, clay, or mossy ground, being impregnated with some part of these substances. The water of large rivers which run slowly is apt to be putrescent.