E Eau de Javelle, 3, 47 Electrical conductivity of treated water, 70 Electrolysed sea water, 5 Electrolytic hypochlorite, 2, 104 Bradford, 5 Brest, 5 Brewster, 6, 105 cost of, 113 Electrolytic hydrochlorite, Crossness, 5 discovery of, 3 diaphragm cells, 110 early use of, 5 efficiency of, 109 Havre, 5 non-diaphragm cells, 106 Electrozone, Brewster, 6 Maidenhead, 6 Tonetta Creek, 6 F Filter effluents, chlorination of, 34 Filters, effect on beds, 60 effect on runs, 132 Fish, effect on, 8, 67, 68 G Germicidal velocity, effect of acids, 21 alkalies, 20 ammonia, 21 chlorides, 20 Guildford, chlorination at, 9 H Haas and Oettel cell, 108 Halazone, 128 Hardness, effect of chlorine on, 132 Havre experiments, 5 Hermite fluid, 5 Hexamethyl-_p_-aminotriphenylmethane, 83 Historical, 1 Hooghly River, 7 Hydrazine, 126 Hydrogen peroxide, 24 Hydrolysis of hypochlorites, effect of, acids, 19 alkalies, 19 chlorides, 20 Hygienic results, 134 Hypochlorous acid, 17 decomposition of, 24, 25, 26 hydrolytic constant, 18 I Initial contamination, effect on dosage, 32 Intestinal organisms, viability of, 52 Iodoform taste, 65 Iron salts, effect on dosage, 33 J Jersey City, court case, 11, 16 K Kellner cell, 108 L Labarraque solution, 105 Leavitt-Jackson machine, 91 Leblanc process, 2 Light, effect on dosage, 45 Lincoln, chlorination at, 8, 59 Liquid chlorine, advantages of, 97 and tastes, 65 effect of temperature on, 95 machines, 89 dry feed, 94 E. B. G. Co., 91 Leavitt-Jackson, 91 operation of, 95 Wallace and Tiernan, 92 L'Orient, experiments at, 5 M M. agilis, 53 Maidstone, use of bleach at, 8 Margin of safety for taste and odour, 64 Material for bleach plants, 74 Military work, bleach method for, 78 chlorine water, 103 dosage for, 47, 48, 78 early European, 10 liquid chlorine, 102 typhoid reduction, 143 use of chlorine in, 8 Mixing tank for bleach, 73 Moisture, effect on chlorine gas, 16 Montreal, dosage at, 34 electrolytic cells, 112 N Nascent oxygen hypothesis, 17 Nelson cell, 111 Neva River, 36 New Orleans, typhoid rates, 137 New York, bacteria surviving treatment, 53 bleach efficiency, 100 liquid chlorine plant, 97 Nitrites, effect on dosage, 33 Nitrogen trichloride, 24, 128 O Odours, effect of contact period on, 43 nature of, 63 Ottawa, aftergrowths at, 57 bleach plant efficiency, 100 chloramine plant, 120 chloramine results, 121 sludge trouble, 65 typhoid rates, 140 Oxidisable matter, effect on dosage, 32, 36 Oxychloride, Guildford, 9 Middlekerke, 9 Ostend, 9 Ozone, 24