ANTIBIOTIC SUBSTANCES AND DISINFECTANTS 



191 



gram-positive and the second active against members of both groups. 

 These four compounds show various other differences in the nature of 

 their antibacterial action. Differences in the bactericidal properties of 

 other antibiotic substances are brought out in Tables ^6 and 37. 



Various attempts have been made to compare the antibacterial action 

 of antibiotic substances with that of organic antiseptics. According to 

 Suter (866), the bactericidal action of a compound depends upon cer- 

 tain physical and chemical characters j a property that determines the 

 bactericidal action of the compound upon E. typhosa may be relatively 

 unimportant in the case of another organism such as S. aureus. A sub- 

 stance may have the same activity, as expressed by the phenol coeffi- 

 cient, against two organisms and still differ markedly in its relative 



TABLE 35. BACTERIOSTATIC SPECTRA OF FOUR ANTIBIOTIC SUBSTANCES 



Note. Activity is indicated in thousands of dilution units per gram. 



* Our own data, based on a sample having 470 Oxford units. 



t Data reported by Abraham et al. (i), based on a less active preparation. 



