EFFECT OF CUrrFK Ul'ON PATHOGENIC H.KCTEKIA. 



33 



Effect of cujijnr Kulphate upon liiu-Ulu.'< co/i <it room liiiijxrninn: " 

 [Oetenuiuiitiuu iiiadu in I'ltrl dishes.] 



" Experiment conducted in test tuhcs, each cont^iining 5 cc. of sterilized water. i>ortions of which 

 had liecn i)reviously treated with the desired amountsof copper sulphate. All tubes inoculated with 

 a 3 mm. loop of an is-ho\ir culture of Ji. roli. 



Effect of copper snlpliulc upon JlacilluK <<>li at loir tcinpcndnrc'i 

 [Determination made in I'etri dishes.] 



Duration of exposure to action of cuiiinr sulpliate. 



3 hours . . 

 6 hours . . 

 9 hours . . 

 12 hours . 



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

 been previou.sly treated with the desired amount of copper sidphate. All tubes inoculated with a 

 3 mm. loop of a culture of B. cnli of the jiropcr af<e. 



Effect oj copper .nilpJiate upon paracolon cultures of rariotis ages. « 



[Determination made in tubes of bouillon. + indicates growth nfter 4s hours' incubation; —indi- 

 cates no growth.] 



"Experiment conducted in test tubes each containing 5 cc. of sterilized water, 7„it 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 paracolon of the jjroper age. 



These tables show that Bdcillus typhi is more sensitive to copper 

 sulphate than is coU, that the para group are about equally sensitive, 

 and that temperature has a veiy important bearing- on the toxicity of 



