32 



METHOD OF DESTROYING ALG^E IN WATER SUPPLIES. 



Effect of copper sulphate upon Bacillus typhi at low temperature. 

 [Determination made in Petri dishes.] 



a Experiment conducted in test tubes each containing 5 cc. of sterilized water, part of which had 

 been previously treated with the desired amount of copper sulphate. All tubes inoculated with a 

 3 mm. loop of a culture of B. typhi of the proper age. 



Effect of copper sulphate upon Bacillus coli cultures of various ages. a 



[Determination made in tubes of bouillon. + indicates growth after 48 hours' incubation; indi- 

 cates no growth.] 



a Experiment conducted in test tubes each containing 5 cc. of sterilized water, part of which had 

 been previously treated with the desired amount of copper sulphate. All tubes inoculated with a 

 3 mm. loop of a culture of B. coli of the proper age. 



Effect of copper sulphate upon Bacillus coli at different temperatures. a 



[Determination made in tubes of bouillon. + indicates growth after 48 hours' incubation; indi- 

 cates no growth.] 



a Experiment conducted in test tubes each containing 5 cc. sterilized water, portions of which had 

 been previously treated with the desired amounts of copper sulphate. All tubes inoculated with a 

 3-mm. loop of a 24-hour culture of B. coli. 



