JOHN A. KOLMER 1115 



Kriegler, and Walker with methyl violet, B. anthracis, and B, diphtheriae. Morgen- 

 roth and his colleagues have been especially interested in the chemical constitution 

 of the acridin dyes in relation to bactericidal activity for streptococci, and in tests 

 employing serum-broth dilutions of these dyes found that the structure of the whole 

 molecule may influence the function of the side-arms, but that in the acridins the 

 alkyl groups are the most active therapeutically and the isoamyl groups the least. 

 As a result of these investigations, "rivanol" (2-aethoxy-6, 9-diaminoacridin chlor- 

 hydrate) was evolved and found particularly effective in the treatment of mice 

 inoculated subcutaneously with virulent streptococci. 



Working with gentian violet and magenta as "normal" triphenylmethanes and 

 with acid fuchsin and the trisulphonic acid salt of rosanilin as representatives of "re- 

 verse selective activity," Churchman has shown that the selective activity of these 

 dyes is not to be ascribed to sodium. On the contrary, however, the presence of SO3 

 radicals appears to account for reverse selective activity. It would appear, therefore, 

 that with this group of dyes, at least, .the specific selective activity might depend not 

 so much on the presence of the sulphonic group as on the method of its bonding, 

 though it is exhibited by substances like chromotropic acid, in which the SO3 group 

 is firmly attached, as well as by substances like sulphonic acid, in which the bonding 

 is very weak. 



MECHANISM OF THE BACTERIOSTATIC AND BACTERICmAL ACTIVITY OF THE ANILIN DYES 



Just as we are lacking in sufl&cient information on the relation of chemical con- 

 stitution of the anilin dyes to bacteriostatic and bactericidal activities to enable one 

 to establish the highly desirable "laws" for aiding advances in our knowledge of the 

 chemotherapy of these substances by synthesizing new compounds in a more orderly 

 fashion, so are we likewise lacking in accurate information on the mechanism of their 

 bactericidal activities. We ordinarily state that phenol, mercuric chlorid, and other 

 disinfectants kill bacteria by coagulating the proteins of their protoplasm, but the 

 process is probably not so simple and certainly is not in relation to the anilin dyes. 



As stated by Churchman, there is a great deal of reason for supposing that bac- 

 teriostasis may act by paralyzing the reproductive mechanism of bacteria without 

 otherwise injuring the organisms, due to changes effected by the dye at the surface 

 of the organisms. In his opinion the simplest explanation for the behavior of gentian 

 violet and acid fuchsin toward bacteria is that the whole process is simply one of 

 selective penetration referring not merely to the arrival of the dye within the bacterial 

 membrane, but its arrival at some particular portion of the bacterial body concerned 

 with reproduction. 



Furthermore, the method of ionization of the two groups of dyes whose action has 

 been studied by him may explain their behavior. It is suggestive in his opinion that 

 one group is basic and the other acidic, and that if this kind of explanation is the cor- 

 rect one it must be that gram positive spore-bearers and gram negatives differ in their 

 H-ion concentration. He also mentions that since the basic dyes are electro-positive 

 while the acid dyes are electro-negative it is tempting to explain selective activity on 

 the basis of electrical adsorption — an interesting thought deserving of further in- 

 vestigation. 



