LECTURES ON IMMUNITY 



coagulates casein, just as rennet in neutral, or even in acid 

 solution. The two coagulating enzymes are therefore not 

 identical. 



The influence of rennet on the coagulation of milk has 

 been investigated in a manner analogous to that used in 

 the study of pepsin. Thus, for instance, Madsen adds dif- 

 ferent quantities, q, of rennet to a given quantity of milk. 

 Then he places the mixtures in test-tubes and places these 

 during a time, /, in a thermostat at given temperature. 

 After this the tubes are rapidly cooled, and it is deter- 

 mined which is the least quantity, q, sufficing for coagula- 

 tion. The results are quite concordant with those for 

 pepsin, as indicated by the following table : 



COAGULATING POWER OF DIFFERENT CONCENTRATIONS OF RENNET IN 

 MILK AT 36.55 C. 



The mean value of qt is 0.28 (or if the two last ob- 

 servations are excluded 0.267). The last values display 

 a notable increase of qt, that is, a decrease in the velocity 

 of reaction with increasing time. This agrees well with 

 the other series of observations from Copenhagen, as well 



