[47] This number was the result of numerous counts made from fæces from persons suffering with typhoid fever in the Lawrence City Hospital in 1891 and 1892. Mr. G. W. Fuller afterward made at the Lawrence Experiment Station some further investigation of fæces from healthy people in which the numbers were considerably lower, usually less than 200,000,000, per gram and sometimes as low as 10,000,000 per gram. [48] These experiments, so far as they have come to the notice of the author, have been made with water sterilized by heating, usually in small tubes stoppered with cotton-wool or other organic matter. In this case the water, no matter how carefully purified in the first place, becomes an infusion of organic matters capable of supporting bacterial growths, and not at all to be compared to natural waters. In experiments often repeated under my direction, carefully distilled water in bottles, _most scrupulously clean_, with glass stoppers, and protected from dust, but _not sterilized_, has uniformly refused to support bacterial growths even when cautiously seeded at the start, and the same is usually true of pure natural waters. Some further experiments showed hardly any bacterial growth even of the most hardy water bacteria in a solution 1 part of peptone in 1,000,000,000 parts of distilled water, and solutions ten times as strong only gave moderate growths. [49] The Water-supply of Chicago: Its Source and Sanitary Aspects. By Arthur R. Reynolds, M.D., Commissioner of Health of Chicago, and Allen Hazen. _American Public Health Association_, 1893. Page 146. [50] _Journal für Gas- u. Wasserversorgung_, 1893, 694. [51] _Journal für Gas- u. Wasserversorgung_, 1894, 185. [52] The method of making this determination was given in the _American Chemical Journal_, vol. 12, p. 427. [53] Some of the companies secure some ground water which they mix with the filtered water, and this is included in the quantities for the separate companies, but is excluded from the totals for all the companies by years. [54] Exclusive of gravity supplies. [55] Not in use. [56] Under construction. [57] Not in use. [58] Under construction. [59] Not in use. [60] Under construction. [61] Not in use. [62] Under construction.