GERMICIDES, ANTISEPTICS, AND ANTISEPSIS 267 



dilution (1:80), thus -^ = 4.69, and the same is done for 

 the strength that kills in fifteen minutes, namely: 



~ = 5-9 1 

 no 



The average of these, - ^-7^ = 5.30, is called the co- 

 efficient. In other words, disinfectant A has a value of 

 5.30 times that of phenol. A disinfectant with a phenol 

 coefficient less than i is of very low germicidal value. 



