METEOROLOGY WATER. 1 L37 



Gage {Jour. Tnfect. Diseases, 1906, Feb., Sup. ?, pp. /; / t74)> [nvestiigations are 

 briefly reported which indicate thai the use of copper sulphate as ;i preliminary 

 treatment in the purification of sewage results in a lowering of the efficiency of sub- 

 sequent filtration and bacterial purification <>!' the filter bed. 



On the bactericidal action of copper, H. W. Glare and S. DeM. Gagi {Jour, 

 Tnfect. Diseases, 1906, Feb., Sup. ?, pp. 175 .'"/). A.n account is here given of a series 

 of experiments in which waters were treated with definite amounts of copper or 

 copper sulphate or placed in contact with metallic copper and allowed to absorb an 

 unknown amount of copper. The efficiency of the treatment was measured by its 

 effect on the total number of bacteria and on the numbers of Bacillus coli and /»'. typho- 

 sus in the water. 



The conclusion is reached that the treatment of water with copper sulphate or by 

 Btoring in copper vessels has little practical value because it is nol absolutely effective 

 and is therefore dangerous in the hands of the general user. It was found in some 

 cases that in order to insure the complete destruction of /.'. coli and /;. typhosus it 



was necessary to use copper sulphate at the rate of 1 part to 1,000 of water, in 



which case the water was of a strongly astringent taste and would be repugnant to 

 the user. Allowing water to stand in copper vessels for short period- was occasion- 

 ally effective in removing />'. coli and /»'. typhosus. In other cases, however, the very 

 dilute solutions of copper sulphate or colloidal copper absorbed from contact with 

 clean metallic copper appeared to have a decidedly invigorating effect on bacterial 

 activity. 



The resistance to decomposition of certain organic matters in sewage, 

 II. W. Clare [Jour. Tnfect. Diseases, 1906, Feb., Sup. 2, pp. 186-138). — It is shown in 

 this article that a certain small percentage of exceedingly stable carbonaceous and 

 nitrogenous matter accumulates year after year in filters used for ordinary domestic 

 sewage and seriously impairs their efficiency. This material was found to resist 

 nitrification and is believed to be of a carbonaceous rather than nitrogenous nature. 



Biological purification of sewage waters, Riche (.1////. Chim. AnalyL, 11 

 {1906), Nos. /, pp. 16-19; 2, pp. 64-69). — The importance of biological proa Bses as 

 compared with chemical methods is discussed and various methods in which bio- 

 logical processes play a prominent part are considered, especially from the stand- 

 point of disposal of Paris sewage. These include irrigation, and filter bed, septic 

 tank, the Candy (intermittent sprinkling and carboferrite) method of treatment. 

 ami others. 



A consideration of the difficulties in the way of disposing of the Paris sewage by 

 means of irrigation leads to the conclusion that the only solution of the problem 

 appears to be a combination of bacterial purification and irrigation. 



Recent views of the sewage disposal problem {Engin. Rec, 58 {1906 . No. 

 pp. 87, 86'). — This is a brief editorial review of the recent rapid progress in this field, 

 which is ascribed largely to progress in adopting better method- ol sewage analysis, 

 which yield fairly comparable results. 



it is stated that "the old idea that sewage tanning is the best method oi disposal 

 was exploded long ago, and the sewage farms still in service are not kept in operation 



because they afford the most economical method of treatment, as a rule. The rise 

 of intermittent filtration has similarly reached its culmination. It is acknowledged 

 to he the most perfect method of treatment when all conditions are favorable, but it 

 is now known that it is much more expensive than was formerly anticipated, and 

 the character of the effluent which it furnishes is often unnecessarily good mi dis- 

 charge into the body of water receiving the purified sewage. . . . 



" ruder these circumstance- specialists in sewage treatment have hern working to 

 ascertain just what methods are best for securing different degrees of purification 

 from the partial clarification resulting from simple sedimentation to the extreme 

 4 1 13— No. 12—06 2 



