LECTURES ON IMMUNITY 



By means of the formula used for the calculation of 

 peptic digestion I have determined /&, which was found to 

 be 15,570, and from this value I have deduced the calcu- 

 lated values given above. The agreement is very satisfac- 

 tory, but additional investigations will be necessary to give 

 a definite value for p. According to Schiitz and Huppert 

 the process has an optimum at about 50 C. 



On analogous topics many interesting experiments have 

 been carried out in the Danish Serum Institute. Different 

 quantities (q c.c.) of pepsin were added to a solution of 

 2 c.c. of 7 per cent thymolgelatin, i c.c. 0.4 per cent solu- 

 tion of HC1, and i q c.c. of i per cent solution of NaCl. 

 The liquid was thereafter well mixed, and the whole was 

 put in a test-tube which was placed in a thermostat at 

 36.6 C, and held at this temperature during a certain time, 

 /. Then the test-tube was placed on ice until the next day. 

 In this manner different test-tubes with varying q were 

 prepared. The contents of tubes with high q were liquefied. 

 It was noted which value of q was just high enough to 

 produce liquefaction. In this way the following table was 

 found : 



DIGESTING INFLUENCE OF PEPSIN ON THYMOLGELATIN 



The mean value is q t = 0.96, and the observed values 



