72 MECHANISM OF DISINFECTION AND HEMOLYSIS 



Madsen and Nyman,'* who were the first to notice the analogy, 

 recognized the fact that variability among the cells was a factor to 

 be reckoned with, but appear nevertheless to have regarded their 

 curves as expressions of the average rate of change in the individual 

 cells. We have seen that it is impossible, without special assumptions, 

 to account for the phenomenon on this basis. Miss Chick,^ working 

 independently, secured data like those of Madsen and Nyman, but 

 states exphcitly that the monomolecular reaction formula is 

 applicable to the process, "one reagent being represented by the dis- 

 infectant" which being present in excess may be regarded as having 

 a constant concentration, "and the second by the protoplasm of the 

 bacterium;" she amphfies this statement by making the supposition 

 that the bacteria undergo rapid cyclic variations in their ability to 

 react with the disinfectant. Phelps^ in developing Miss Chick's 

 method for standardizing disinfectants, adopts the same explanation. 

 Arrhenius^*^ says, "there is no doubt that the different cells in a sample 

 of bacteria or red blood-corpuscles possess a different power of resist- 

 ance to deleterious substances," but that "the different lifetime of the 

 different bacteria does not, therefore, depend in a sensible degree on 

 their different ability to resist the destructive action of the poison," 

 and accepts Chick's explanation, as does Eijkman,* at least in the 

 case of certain bacteria. 



The acceptance of such an explanation makes it necessary to 

 assume that loss of viability, like the breaking up of a single molecule 

 of saccharose during inversion, takes place in a single step; in other 

 words, that the disinfectant cannot have any cumulative effect on 

 the viabihty of individual cells. If the loss of viability occurred in 

 two or more steps, some or all of the cells surviving at any time during 

 the process would be "partially dead," and a greater proportion of 

 them would succumb in any given interval of time than would have 

 done so during the same interval at the beginning orthe process when 

 all of the cells were entirely unaffected. In other words the per cent 

 death would increase during the process instead of remaining con- 

 stant as demanded by the law of monomolecular reactions. 



This assumption that death occurs at a bound, as it were, is surpris- 

 ingly at variance with the usual conception of vital processes. It 

 seems to necessitate that we regard a living cell as being dynamically 



