DISINFECTANTS 



71 



10 20 30 40 50 MINUTES 80 90 00 



©V 



LOG. DEATH TIME VS. LOG. CONCENTRATION 



2 3 5 MIN. 10 



Fig. 16. Two methods of representing the relation between concen- 

 tration of disinfectant and death time. The different curves illustrate 

 how the "concentration exponents" n affect the results. 



ber of reacting molecules becomes definitely untenable 

 if the observation by Tilley (1939) can be confirmed, 

 that the exponent decreases when the temperature in- 

 creases. Though Tilley 's data show a good deal of 

 fluctuation, they clearly indicate this influence of tem- 

 perature (see, in particular, the figures for the concen- 

 tration exponents of phenol and ethyl alcohol in Table 15). 



