678 TEMPERATURE AND LATENT PERIOD 



The table contains not only, the values from the experimentally 

 determined latent periods, but above 21°, also those calculated 

 according to the Arrhenius equation (3) using ij. = 19,680. The 

 constants given in Table I are used in making the curves of Fig. 3. 



If the fundamental reaction of the latent period, as represented 

 by the isotherms, were allowed to form the thermolabile substance T 

 undisturbed, enough of this material to produce a response would 

 accumulate in the time indicated by the circles in Fig. 3. Below 21° 

 this is the time as actually found in the results of Fig. 2. Above 21° 

 the time is derived from the curve of Fig. 2 by extrapolation from the 

 Arrhenius equation. 



The action of the fundamental latent period reaction, however, 

 cannot result in the accumulation of this amount of T in the pre- 

 scribed time, because T is thermolabile, and above 21° is being 

 inactivated all the time it is being produced. The experimentally 

 determined data of Fig. 2 show for each temperature the time actu- 

 ally required for the accumulation of the necessary 0.10 mol of T. 

 The triangles represent these values in Fig. 3. The reaction iso- 

 therms extending to these triangles show the amount of T which 

 must be formed by the reaction L-^T before 0.10 mol of T can 

 accumulate. 



The difference between the amount of thermolabile substance T 

 formed, and the amount allowed to accumulate (0.10 mol) gives the 

 amount of thermolabile substance inactivated by the second reac- 

 tion, T -^ N, during the time of production. Graphically the quan- 

 tity of inactivated material (N) is given by the vertical distance 

 between the circles and the tri'angles in Fig. 3. 



The quantities thus represented are in part a measure of the 

 activity of the inactivating reaction T —^ N. By no means, however, 

 are they to be considered as the direct measure of this reaction, be- 

 cause the amount inactivated by the secondary reaction depends on 

 one other condition besides its own speed. This other condition is 

 the velocity of the fundamental reaction L -^ T which furnishes the 

 pabulum for the secondary reaction. It is precisely this error of as- 

 suming the difference to be the direct measure of the inactivation 

 factor, which vitiates the quantitative character of Putter's (1914) 

 explanation, as well as of the preliminary analysis given of the pres- 



