VELOCITY OF REACTION. HOMOGENEOUS SYSTEMS 73 



as with those of other observers, and may perhaps be 

 ascribed to an attenuation of the rennet with time. 



The influence of temperature on the coagulating power 

 of rennet was investigated by Fuld. 1 He found the fol- 

 lowing values of the time of coagulation, /, for the same 

 quantity of rennet : 



fi = 20,650 



The values of l oba , are 10,000 divided by t. They agree 

 quite well with the calculated values up to a temperature 

 of 40 C. ; above this the agreement fails. This evidently 

 depends on the fact that above 40 C. the destruction of 

 the rennet proceeds at such a speed that the observations 

 are disturbed thereby. This explains also the occurrence 

 of an optimum at about 44 C., which optimum therefore 

 must not be regarded as real. The observed effect de- 

 pends upon /z being many times greater (in this case 4.4 

 times) for the spontaneous destruction than for the pro- 

 cess of fermentation. The same observation may be 

 applied to the other cases in which such optima occur 

 (cf. p. 53). 



Reichel and Spiro 2 have contributed some interesting 



1 Fuld : Hofmeisters Beitr'dge, 2. 169 (1902). 



2 Reichel and Spiro : Hofmeisters Beitrage, 7. 478 (1905). 



