354 



PHYSIOLOGY OF BACTERIA 



The method originally suggested by Rideal and Walker (1903) was 

 to determine the minimum time required to kill a bacterial suspension 

 by a certain concentration of the disinfectant under test, then to 

 determine the phenol concentration required to kill the same organism 

 in the same time. Dividing the one concentration by the other, the 

 ''phenol coefficient" was obtained which stated how many times 



550 : 100 = 5 . 5 is the Phenol coefficient. 



Table 112. — Phenol Coefficients of HgCh and AgNOa 



