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197but the cleaned glasses were deleterious on foam retention of beer.New work on hand soaps containing hexachlorophene antiseptics confirmed their effectiveness for maintaining a low count of resident bacteria on the skin (Browers--Proc. Chem. Specialties Mfrs. Assoc. J~ne 1950, 90; Code--Ibid. 92; Blank & Coolidge--J. Invest. Dvrmatol. 15, 257), and demonstrated that these antiseptics did not delay wound healing 895). Quaternary ammonium compounds as skin cleansers and antiseptics formed a film over the skin under which bacteria were retained (Blank & C'oolidge--J. Ineest. Dermatol. 15, 249).Sewage processing engineers were concerned with the increased use of synthetic detergents because it may affect conventional methods of treating sewage. Sperry (Sewage ~ Ind. Waste 23, 1469) observed that the following effects were produced by the synthetics: they reduced the amount of suspended solids deposited, thus diminishing removal from tanks; gas to be expected was diminished; grease tended to emulsify; and excessive frothing that occurred might be an annoying nuisance, Degens et al. (Inst. Sewage Purif. J: and Proe. 1950, 63) found that concentrations of five parts per million of four common synthetic detergents were lethal to tadpoles, sticklebacks, and Daphnia, whereas several other fauna and aquatic plants were unaffected. Some of the detergents decomposed under the conditions of the "biological oxygen demand '~ test. Waddams' (Ibid. 32) work on the problem included laboratory bactericidal tests and the reconciliation of results of these with washing practices and~ sewage treatments. He summarized the work as follows: The presence of 100 ppm. of synthetic detergents in sewage would be most unlikely; at 200 ppm. it did not affect settling of sewage; up to 500 ppm. it did not have bactericidal nor bacteriostatic action on bacteria common to crude sewage; it affected protozoan, Euplotus patella, at 100 ppm. only after 60 hours; it had no effect on sludge digestion below 750 ppm.; and floeeulation of sewage by alum was not affected.

Dean of Sradtutte College loim State ColXege X948 Signature was redacted for privacy. Signature was redacted for privacy. Signature was redacted for privacy. UMI Number: DP12937 INFORMATION TO USERS The quality of this reproduction is dependent upon the quality of the copy submitted. Broken or indistinct print, colored or poor quality illustrations and photographs, print bleed-through, substandard margins, and improper alignment can adversely affect reproduction. In the unlikely event that the author did not send a complete manuscript and there are missing pages, these will be noted. Also, if unauthorized copyright material had to be removed, a note will indicate the deletion.

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