STANDARDIZATION OP DISINFECTANTS 231 



ferent laboratories. A simplified method will no doubt be sub- 

 stituted for the Anderson-McClintic method. A method has 

 been proposed based on the percentage of bacteria killed within a 

 unit of time by a unit quantity of the disinfectant when added 

 to a unit quantity of a typhoid bacillus culture known to contain 

 a definite number of organisms. The Ohno-Hamilton method 

 is simpler than the Anderson-McClintic method and is included 

 for purposes of comparison. 



An efficient disinfectant for general purposes should comply 

 with certain requirements which may be stated as follows: 



1. Should be highly potent as destroyers of bacteria. 



2. Should be readily soluble in water and should readily permeate or penetrate 

 solutions of organic substances. 



3. Should be comparatively nontoxic to man, when applied externally or when 

 taken internally. 



4. Should have a minimum albumen coagulating power, and conversely should 

 be capable of penetrating organic substances readily. 



5. Should be comparatively cheap and should be readily usable by those of aver- 

 age ability and intelligence. 



The ideal disinfectant, that is, one which is highly potent, 

 readily soluble in all organic solutions and capable of penetrating 

 such substances readily, and at the same time nontoxic and 

 cheap, does not exist. There is no disinfectant which is highly 

 efficient as a destroyer of bacteria and at the same time non- 

 toxic, notwithstanding all claims to the contrary by manu- 

 facturers. It is true, however, that disinfectants vary greatly 

 regarding the essentials above stated. Our present means for 

 testing the efficiency of disinfectants may be summarized as 

 follows : 



i. John F. Anderson and Thomas B. McClintic 1 of the United 

 States Public Health Service have worked out a method for de- 

 termining the comparative germ-destroying power of disinfectants, 



1 John F. Anderson and Thomas B. McClintic. A Method for the Bacteriolog- 

 ical Standardization of Disinfectants. The Journal of Infectious Diseases, Vol. 

 VIII, No. i, Jan. 3, 1911. 



