136 LECTURES ON IMMUNITY 



The nitrogen (calc.) is calculated according to the equa- 

 tion for a bimolecular process, and, as will be seen, the 

 agreement is very satisfying. The relation which, after 

 Bayliss's experiment, is very unexpected, may be regarded 

 as a purely empirical one. The reaction-constant is o. 173. 

 It increases with temperature, as might be expected. At 

 37 C. it reaches the value 0.194, corresponding to an in- 

 crease in the proportion 1.485 : i in an interval of 10 C. 

 O =7400). 



Many of the most important processes of normal life 

 occur in heterogeneous systems. As is seen from the fol- 

 lowing examples, they behave as regards the velocity of 

 reaction quite like enzymic processes. All of them pos- 

 sess an optimum at about 4O-5o C., and in the vicinity of 

 o C. the velocity of reaction sinks rapidly with tempera- 

 ture. 



The most important of these processes are the phenom- 

 ena of assimilation and of respiration of carbonic acid by 

 plants. As van't Hoff 1 remarks, the observations of 

 Clausen 2 seem to indicate that in the interval of tempera- 

 ture o-25 C. the quantity of carbonic gas given off by 

 seedlings of wheat, lupins, and flowers of syringa increases 

 with temperature in the proportion 1 12.5 for an increase 

 of 10 degrees (/i= 14,800). The three processes show an 

 optimum at 41,38 and 42 C. respectively. 



Godlewski 3 showed that the assimilation of a leaf of 

 four different plants the most regular results were those 



1 Van't Hoff: Vorlesungen uber theoretischc und physikalische Chemie, 2d 

 ed., 1. 224 (1901); E. Cohen: Vortrage f. Arzte, p. 43 (1901). 



2 Claussen: Landwirtsch. Jahrb., 19. 892 (1890). 



8 Godlewski : Arbeiten des botanischen Instituts in Wurzburg, 1. 243 

 (1872), 



