132 



ANTISEPTICS 



should occur when antisepsis has reached a certain stage, 

 e.g., when 99% of certain molecules are inactivated. The 

 reaction could reach the same stage (death) at the same 

 time (10 minutes) only if Bacterium coli were exposed 

 to a concentration 40 times as high as that for Staphylo- 

 coccus. However, the experiment shows that the concen- 

 tration for death need be only 4 times as high for Bac- 

 terium coli. Therefore, disinfection has a different con- 

 centration coefificient than antisepsis, and that means a 

 ditferent reaction. 



The above-mentioned experiments by Jean Conn have 

 shown that the inhibiting concentration for yeast is 0.16% 

 with phenol and 0.008% with formaldehyde. The killing 

 concentrations are approximately 1.0% and 2.5% for 10 

 minute death times. The ratios of the killing to the in- 

 hibiting concentrations are thus: 1:0.16=6.25 and 



TABLE 26 



Inhibitory and lethal doses of mercury compounds. 

 (From Birkhaug, 1933.) 



