. Preventive medicine and hygiene. ALGAE: I, Clathrocystis- x500/ 2, Anabaena-x 500- 3 OSCILLATORIA-X 500: 4 , ASTER ION E LLA-X 500 ; S Navigula showing structure ok diatom -X 500. Fig 104.—Algae Commonly Found in Watkr. |Yeae Booi, V-. S. Dept. of Agr., 1902.] 825. 826 SANITARY ANALYSIS OF WATER On the whole, the waters of natural lakes and ponds are less subjectto objectionable odors and tastes than are the waters of artificial reser-voirs, and putrefaction is less troublesome, but the difference is one ofdegree, not of kind. The power of water to dissolve or absorb gases and odors is an im
. Preventive medicine and hygiene. ALGAE: I, Clathrocystis- x500/ 2, Anabaena-x 500- 3 OSCILLATORIA-X 500: 4 , ASTER ION E LLA-X 500 ; S Navigula showing structure ok diatom -X 500. Fig 104.—Algae Commonly Found in Watkr. |Yeae Booi, V-. S. Dept. of Agr., 1902.] 825. 826 SANITARY ANALYSIS OF WATER On the whole, the waters of natural lakes and ponds are less subjectto objectionable odors and tastes than are the waters of artificial reser-voirs, and putrefaction is less troublesome, but the difference is one ofdegree, not of kind. The power of water to dissolve or absorb gases and odors is an im-portant one, and explains how water may become contaminated^ bymere exposure to an impure atmosphere, as when an uncovered cisternis placed in a water-closet or when an overflow pipe is directly connectedwith a drain. Method of Determining Odor.—The odor of the water should beobserved both at room temperature and just below the boiling may be detected at room temperature (20° C.) by shaking asample violently in a gallon collecting bottle when it is half or two-thirds full; or by heating about 150 c. c. in a tall beaker without a lip and covered with a well-fittingwatch glass. In either case careshould be taken to observe the char-acter of the
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Keywords: ., bookauthorwh, bookcentury1900, bookdecade1910, booksubjecthygiene
