TOXICOLOGY AND PHARMACOLOGY 401 



weak destructive action. According to K. SPIBO and J. BRUNS,* as 

 well as PAUL and KRONIG, the figures show that mercuric cyanid is 

 far inferior to sublimate as a disinfectant. 



We see from the table, moreover, in the case of mercuric acetate, 

 which is more strongly fixed and more strongly adsorbed than HgCl 2 , 

 that fixation and adsorption are not in themselves alone sufficient for 

 strong disinfection; the disinfectant must be offered in a suitable 

 form. Mercuric actetate is less ionized than HgCl 2 , and since, 

 according to PAUL and KRONIG, as well as SCHEURLEN and SPIRO, the 

 Hg ion is responsible for the disinfectant action, mercuric acetate is 

 weaker than sublimate. 



An especially convincing proof of the specific chemical action of the 

 disinfectant on the living substance seems to me to be that there is a 

 difference in the resistance of various groups of bacteria to disinfect- 

 ants. Whereas anthrax spores, tubercle bacilli, etc., show an enor- 

 mous resistance, cholera vibrios, gonococci and streptococci succumb 

 to even slight chemical attacks. The other groups of bacteria are 

 ranged between these two extremes typhoid, B. coli, staphylo- 

 cocci, diptheria bacilli, etc. 



Were merely the strength of adsorption responsible for the disin- 

 fectant action, we could readily understand that substances of differ- 

 ent disinfectant power would exist; we would understand for instance 

 that cresol has a stronger action than naphthol, but in that case cresol 

 would always possess a stronger action than naphthol, both on B. coli 

 and on typhoid bacilli, as well as on streptococci. If we found, how- 

 ever, that lysol was more active against one microorganism and that 

 /3-naphthol was more active against others, we could attribute the 

 action to general physical properties among which we might include 

 adsorption, but we would then have to ascribe it to the difference in 

 behavior caused by specific inherent chemical differences in the bac- 

 teria affected. This might be either a variation in the solubility 

 of the bacterial pellicle or a variation in the grouping of the atoms 

 in the body of the bacteria so as to manifest a greater or less 

 affinity to the disinfectant; in either case the important factor is 

 the chemical difference in the microorganism. Such cases actually 

 exist as has been demonstrated by H. BECHHOLD.* 9 He showed 

 that the minimal lethal dose in 24 hours is: 



