68 INJUEY, EECOVEEY, AND DEATH 



same factor is equivalent to dividing all the abscissae by 

 the same factor and that in the case of a curve which 

 rises and falls, this does not change the height of the 

 maximum. If, therefore, both reactions have the same 

 temperature coefficient, raising the temperature is equiv- 

 alent to multiplying both K^ and E^ by the same factor 

 and the maximum will not be changed. But if the reac- 

 tions have different temperature coefficients this will not 

 be true. 



Perhaps it may be desirable in this connection to add 

 a word regarding the measurement of life processes. The 

 development of quantitative methods in biology depends 

 largely on finding means of measuring the speed of life 

 processes. In most cases the absolute rate is of less 

 importance that the relative rate (e. g., the normal veloc- 

 ity compared with that observed under the influence of a 

 reagent). Examination of the literature shows that the 

 determination of relative rates is frequently made in a 

 faulty manner, which might easily be avoided by a slight 

 change of method. 



As an illustration of this we may consider the processes 

 shown in Fig. 30. In the case of Curve A the process is 

 twice as rapid as in the case of Curve B. This is shown by 

 the fact that the abscissae of A are everywhere one-half 

 those of B. This means that the velocity constants of A 

 are twice those of B.*^ In other words the velocity con- 

 stants are inversely proportional to the abscissae, or in- 

 versely proportional to the times required to bring 

 the reaction to the same stage*^ {e.g. one-half com- 

 pleted). This is true for chemical processes in general, 

 not only for reactions of the first order (where a 



"C/. Osterhout (1918, B). 

 "Cf. Osterhout (1918, B). 



