218 BAENETT COHEN 



infection curve there are deviations from the monomolecular 

 rate. This is emphasized as evidence that the monomolecular 

 rate at the middle portion of the curve is more apparent than 

 real. However, with cultures having presumably the same 

 distribution of resistances we have found that the shape of the 

 beginning and end of the curve may be modified at will by chang- 

 ing the exterior conditions. 



Consequently, what force do these objections to Chick's theory 

 possess? The chance distribution of variable resistances assumed 

 for bacteria is paralleled by the chance distribution of variable 

 energy quotas in the molecules of a substance. Furthermore, 

 the logarithmic rate observed, whether in chemical phenomena 

 or in disinfection, is actually a statistical resultant of like signifi- 

 cance in both.* From such considerations we must conclude 

 that the criticisms of the monomolecular theory of the disinfec- 

 tion process are of no fundamental force for they reduce to a 

 matter of definitions only. 



It appears that Chick's contribution has a larger significance 

 than merely the application to a special phase of bacterial exist- 

 ence. Yule's statistical deduction, the experimental findings of 

 Loeb and Northrop regarding the viability of Drosophila, those 

 of Brooks regarding hemolysis of red blood cells and a number of 

 others of like import, all indicate the operation of a general 

 principle. 



CONCLUSIONS 



1. The mortality at constant temperature of bacteria in un- 

 buffered media like distilled or tap water is variable and coinci- 

 dent with apparently insignificant pH variations. Controlling 

 the pH by means of M/500 buffer solutions stabifizes this 

 variability. 



2. Subjecting organisms of the colon-typhoid group to mild 

 lethal conditions under moderate temperatures and hydrogen 

 ion concentrations tends to magnify the induction period prior 



• It must be remembered that the logarithmic curve merely integrates the 

 results of all factors. It is a statistical summation and gives no information 

 regarding the forces at play. 



