FRANK H. JOHNSON 277 



temperature. Thus, with alcohol, for example, the inhibition caused by 

 a given drug concentration increases with rise in temperature (Fig. 

 8). Stimulatory' efiFects of low concentrations of the drug at low tem- 

 peratures, as seen in Fig. 8 or encountered under other conditions, 

 must involve other reactions. 



Two interesting results of the denaturation-promoting mechanism 

 of action are that, in the presence of alcohol, ( 1 ) the measured activa- 

 tion energy for luminescence decreases, and (2) the temperature of 



0.0033 0.0034 0.0035 



Reciprocal of the absolute temperature 



0.0036 



Fig. 8. The influence of temperature on the inhibition of luminescence in P. 

 phosphoreum by different concentrations of ethyl alcohol at neutral pH. 

 Alcohol concentrations from uppermost to lowermost curve: 0, 0.4, 0.5, 0.6, 

 0.8 M. (From Johnson, Eyring, and Polissar, 1954, courtesy of John Wiley & 

 Sons; data of Johnson et al., 1945.) 



