It is observable that the effect of small doses was comparatively small and transient; large doses of bleach reduced the bacteria very materially but the reduction was not maintained and the subsequent increase was abnormally rapid. BIBLIOGRAPHY [1] Wesbrook, Whittaker and Mohler. J. Amer. Pub. Health Assoc., 1911, 1, 123. [2] Thomas. Jour. Ind. and Eng. Chem., 1914, 6, 548. [3] Smeeton. Jour. of Bact., 1917, 2, 358. [4] Clark and De Gage. Rpt. Mass. B. of H., 1910, p. 319. [5] Thomas and Sandman. J. Ind. and Eng. Chem., 1914, 6, 638. [6] Jordan, H. E. Eng. Record, 1915, May 17. CHAPTER V COMPLAINTS The complaints that have been made against chlorinated water since the practice was commenced have been very diversified in character and can be numbered by the legion and although some have been justifiable, the great majority has been unsubstantiated and must be ascribed to auto-suggestion. Almost every one who has had charge of chlorination plants has noted the latter phenomenon, for in some instances complaints have been made following the publication of the information that chlorination was to be commenced but antecedent to its actual operation, and in others when for some reason or another, the chlorination plant has been temporarily stopped. Similar observations have been made in laboratory experiments when independent observers have been requested to detect the chlorinated waters from an equal number of treated and untreated waters. Such observers are wrong in the majority of the waters which they designate as treated ones if the dosage is not in excess of that required for satisfactory purification. One amusing example of auto-suggestion was experienced by the author some years ago. During a ceremonial visit to the waterworks, the Mayor and several civic representatives happened to visit a hypochlorite plant that was built on a pier over the river and which had no ostensible connection with the city mains. One of the party expressed a desire for a drink of good river water without any hypochlorite in it and was served with water from the plant supply by an assistant engineer of the waterworks department. The water was consumed by all with great relish and as it was being finished, the writer entered the plant and was invited to join them in the enjoyment of this "dopeless" water; on asking where it had been obtained he was astonished to hear that it was from a tap which was supplied with the ordinary chlorinated water of the city.