266 Mr. A. W. Blyth. [Nov. 26, 



Chlorine, Bromine, Iodine. 



Days 



o 

 _ . 



Q 

 O. 





0. 





h 



4 . 



c 

 O. 



Q 



1U. 



1 1 



ii. 



1 9 

 LZ. 



1 Q 

 lo. 



niilnrinp A -001 -n n 



+ 

























n-nno 



U UU<5 . . 





+ 























U ULHfc . . 





















































loaine u uui . . 



























+ 

























002 „ .. 





+ 























„ 004 „ .. 





+ 























001 „ .. 



























Bromine 0"001 „ .. 



+ 

























002 „ .. 





+ 























0-004 „ .. 





+ 























001 „ .. 



























Control 



+ 

























2. Experiments on the Disinfection of Sewage. 



In the following series of experiments an entirely different method 

 of procedure was adopted. The number of colonies in a gram 

 of sewage or other suitable liquid was carefully determined by a 

 modification of known methods. 



The same sewage was then treated by substances the disinfectant 

 properties of which formed the subject of inquiry, and the number of 

 colonies capable of growing in a nutrient soil, representing the micro- 

 organisms which had escaped destruction, again enumerated. 



