Hints from the Health Department. Leaflet from the archive of the Society of Medical Officers of Health. Credit: Wellcome Collection, London
[Report of the Medical Officer of Health for London, City of ]
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Milligrammes per litre (unless otherwise stated)
Description of the Samples | Number of Samples | Ammoniacal Nitrogen | Albuminoid Nitrogen | Nitrate Nitrogen | Oxygen abs. from KMn04 4 hrs. at 27ºC. | B.O.D. 5 days at 20°C. | Hardness (total) CaC03 | Hardness (non-carbonate) CaC03 | Magnesium as Mg | Sodiurr as Na | Potassium as K | Chloride as CI | Phosphate as P04 | Silicate as Si02 | Sulphate as S04 | Natural Fluoride as F | Surface-active material as ManoxoI OT | Turbidity units | Colour (Burgess units) | PH value | Electrical Conductivity (micromhos) | |
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
(1) | (2) | (3) | (4) | (5) | (6) | (7) | (8) | (9) | (10) | (11) | (12) | (13) | (14) | (15) | (16) | (17) | (18) | (19) | (20) | (21) | (22) | (23) |
Stoke Newing-ton | 52 | 0.020 | 0.055 | 7.8 | 0.70 | - | 308 | 78 | 5.5 | 28.8 | 5.1 | 41 | 2.2 | 10 | 52 | 0.15 | 0.002 | 0.1 | 9 | 7.9 | 650 | |
River Thames derived | 364 | 0.031 | 0.069 | 6.9 | 1.06 | - | 274 | 82 | 5 | 24.5 | 5.5 | 35 | 2.8 | 10 | 58 | 0.15 | 0.02 | 0.1 | 13 | 7.9 | 570 |
Sources of Supply | BEFORE TREATMENT | AFTER TREATMENT | ||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
Agar plate count per ml. | Coliform count | Escherichia coli count | Agar plate count per ml. | Coliform | E.coli count | |||||||
Number of Samples | 20-24 hours at 37°C. | 3 days at 22°C. | Per cent samples negative in 100 ml. | Count per 100 ml. | Per cent samples negative In 100 ml. | Count per 100 ml. | Number of Samples | 20-24 hours at 37°C. | 3 days at 22°C. | Per cent samples negative in 100 ml. | Per cent samples negative in 100 ml. | |
Stoke Newington | 753 | 47.5 | 67.07 | 2.6 | 81.81 | 0.5 | 255 | 28.1 | 100.0 | 100.0 | ||
River Thames— derived | 8,087 | 42.3 | 41.94 | 10.2 | 56.76 | 4.0 | 3,891 | 10.0 | 99.85 | 99.97 |