310 EXPERIMENT STATION RECORD. 



results of examinations of 730 samples of well water collected chiefly within the 

 drainage area of the Ottawa Valley with a view to determining their normal 

 chlorin content and the possibility of using this determination as a means of 

 detecting contamination. 



More complete analyses, showing not only chlorin but also alkalinity and 

 total, permanent, and temporary hardness, are reported for 32 wells each in the 

 towns of Weston and Richmond Hill and 64 In Oakville, Ontario. 



The chlorin test is advocated because it is very simple and definite, but its 

 value depends upon the exact determination of tlie normal chlorin content of 

 ground waters. The results reported by the author show that this normal is 

 very difficult to determine with the present careless method of constructing 

 wells. He therefore believes that there should be some legal requirement pro- 

 viding that new wells shall be so constructed as to protect them from surface 

 drainage. 



Conference of municipal and private owned w^ater plants of Indiana with 

 the State board of health, 1908 {Indianapolis, Ind.: State Board of Health, 

 J908, pp. 111). — This is an account of a conference held at Indianapolis July S 

 and 9, 1908, to consider the source of water supplies in Indiana, their preserva- 

 tion and purification, and to establish standard and uniform methods of analysis. 

 Among the more important papers presented were : History of Indiana's Water 

 Supply, by J. X. Hurty; Undergroimd Water Supply of Indiana, by F. G. Clapp; 

 Transmission of Typhoid Fever, by H. E. Jordan ; and The Present Condition 

 of the Water Supply of Indiana, by H. E. Barnard. Smaller articles relating to 

 water pollution and its prevention and methods of examining waters are 

 included. 



Purification of water by freezing, F. T. Shutt (Canada Expt. Farms Rpts. 

 1907, pp. 176, 177). — Analyses are reported which show the elimination of a 

 laige amount of organic matter from highly colored river water on freezing. It 

 was also observed that a large proportion of the saline matter in lake water was 

 removed by freezing, a samjile of the water before freezing containing 1,525 

 parts per million of total solids yielding an ice containing only 00 parts per 

 million of solids. 



The disinfection of sewage and sewage filter effluents, E. B. Piifxps (TJ. 8. 

 Gcol. Surveif, Watpr-Siipplji Paper No. 229, pp. 91, pi. 1). — The results of 

 investigations on disinfection of sewage at Boston. Mass.. Red Bank, N. J., 

 and Baltimore. Md.. are reiiorted. An account is also given of investigations 

 at the sanitary research laboratory and sewage experiment station of the 

 Massachusetts Institute of Technology on the putrescibility and stability of 

 sewage effluents. 



It is pointed out " that purification of sewage has come to mean primarily 

 the I'emoval of its tendency to putrefy and not the total oxidation and removal 

 of all its organic matter," and that " chemical disinfection offers a means 

 whereby a reasonable bacterial purification may be accomplished without com- 

 plete purification of the organic matter." 



On a cost basis, chlorin in some form is considered the most efficient agent 

 for chemical disinfection. " The application of 3 parts per million of avail- 

 able chlorin in the form of bleaching powder to a trickllng-filter effluent similar 

 to those on which experiments were made effects satisfactory disinfec- 

 tion. . . . The cost of disinfection ranges from $1 to $1.50 per million gallons 

 of sewage, depending chiefly on the size of the plant. Effluents of higher 

 degrees of purity can be disinfected at still lower cost. Five parts per million 

 l)robably represents the maximum amount of chlorin required for the treat- 

 ment of tricklhig-filter effluents of poorer quality." 



