B. I'. I.— L'JS. 



\'11.-THE EFFF.CT OP COPPER UPON WATER 



BACTERIA." 



By Kaul ¥. Kellerman, Physiologist in Charge of Soil Bacteriology and ]Vatrr 

 Purification Investigations, 2Ln6. T. D. Bkckwitii, Scientific Assistant. 



INTRODUCTION. 



Of the many methods of chemical treatment for water purification, 

 the copper method has recently received the most attention. The use 

 of this metal, or its salts, was urged primarily^ for the eradication or 

 control of pollutino- algaj, though popular attention has been directed 

 more particularly- to the various results obtained in destroying the 

 typhoid bacillus. 



The discrepancies between laborator}- results of some of the investi- 

 gators of this phase of the subject have deterred man}" engineers and 

 sanitarians from conducting important tests of the value of copper 

 under emergency or epidemic conditions. These discrepancies are 

 perhaps in some cases due to reasons which are taken up later in this 

 bulletin, and in some cases to the lack of comprehensi6n of the essen- 

 tial difference between treatment of drinking water which contains 

 relatively little albuminoid matter'' and treatment of bouillons or 

 emulsions/' 



« The copper method for controlling algal pollution can no longer be considered 

 in an experimental stage. The accumulation of results of treatments constantly made 

 under the direct i^upervision of officials of the Department of Agriculture and the 

 numerous results reported to this Department by independent experimenters render 

 further discussion of this question superfluous. The caution should be reiterated, 

 however, that no rule for determining the amount of copper sulfate to be added can 

 be given, and each body of water must be treated in the light of its special condi- 

 tions. This caution is eminently applicable to copper treatment of a water sujiply 

 for bactericidal purposes, and, as Mr. Kellerman and Mr. Beckwith have shown in 

 their recent work, the problem of using dilute solutions of copper for destroying 

 Bacillus coli and Bacilhii^ typhi in water is a rather complicated one. Pertinent con- 

 ditions must be understood thoroughly before an application of copper can be safely 

 advised, and whether au emergency treatment of an untiltered and contaminated 

 water, or a continuous treatment of a filtered water supply, or a treatment of a sewage 

 effluent is contemplated the work should be supervised by an expert. — A. F. Woods, 

 Pathologist and Physiologist, Acting Chief of Bureau. 



b Buls. 64 and 76, Bureau of Plant Industry, U. S. Dept. of Agriculture. 



f'See also Buls. 64 and 76, Bureau of Plant Industry, U. S. Dept. of Agriculture. 



d A case in point is a paper by Dr. J. B. Thomas, Peport on the Action of \"arious 

 Substances on Pure Cultures of the Amoeba Dysenteripe. (Amer. Jour. Med. 

 Sci., vol. 131, No. 1, Jan., 1906, p. 116.) "Uniform suspensions of the amoeba were 

 made by pouring 4 cc. of distilled sterile water over the surface of a 48-hour slant 

 agar culture of the amteba and cholera spirillum, scraping off the surface growth 

 and mixing with the matter by means of a platinum wire, and pouring the resultant 

 emulsion into a sterile test tube; 4 cc. of the antiseptic solution (in double strength) 

 100— VII . 57 



