Water-supply: (Considered Principally from a Sanitary Standpoint.)

acid Albuminoid ammonia algæ Altona amount analysis average bacteria bacteria per cubic Board of Health boiler calcium carbonate carbonic acid cause cent Chem chemical chlorine cholera cleaning color cubic centimetre death-rate deaths deep depth dilute disease dissolved distilled drinking-water Engineering epidemic evaporation experiments feet filter-bed filtered water filtration flow forest free ammonia germs grammes ground-water hard water impure inches increase instance intake iron Lake layer litre material miles million morocco Nessler Nitrogen Nitrogen as nitrates number of bacteria observed organic matter oxidation oxygen peaty pipe polluted ponds potable precipitate present pumped purification quantity rain rainfall removed reservoir residue River river-water salt samples sand sea-water sedimentation sewage sewers snow sodium sodium carbonate sodium chloride soil solution spirilla spirillum spring sterilized stream sulphuric acid supply surface surface-waters temperature tion town trace typhoid fever U. S. gallons water-supply well-water