DISINFECTANTS 



TABLE 20 (Continued) 

 Phenol coefficients 



107 



coefficients of 90 and 267 respectively, one value being 

 3 times as large as the other. The phenol coefficient of 

 chlorine was found by McCulloch (1936) to be 139, by 

 Rideal 218 and by Zoller 223, all data being obtained with 

 Bacterium typhosum. 



The above-mentioned deathrate constants observed by 

 Chick for the effect of phenol upon paratyphoid bac- 

 teria show a deviation of the extremes greater than 360%, 

 Of the 5 constants found on different days, 4 differ by 

 less than 360% but the highest value is 4.3 times as large 

 as the lowest while the F.D.A. method considers 3.6 times 

 the permissible limit. Obviously, the culture was unus- 



