82 



LECTURES ON IMMUNITY 



stant quantity of trypsins. The results are given below 

 together with some calculated figures : 



The calculated values a*re obtained on the basis of the 

 assumption that the digested quantities for the gelatin 

 are proportional to 3.05^- A and for the casein to 

 5.2 V^A where c is the concentration of per cent and t the 

 time in minutes. (In the table above G represents gelatin 

 and C represents casein.) The agreement seems to be 

 within the errors of observation, so that we may well con- 

 clude that the mass digested is, for short times, propor- 

 tional to the square root of the concentration as well as of 

 the time. The calculated values for the mixtures are 

 made under the assumption that I per cent of casein 

 is, so to speak, equivalent to 2.9 per cent of gelatin 



2.9 



Therefore 3.5 per cent gelatin + 2.5 per 



cent casein are equivalent to 3.5 -f 7.3 = 10.8 per cent 

 gelatin. The observed effect is in most cases greater 

 than the calculated one for the mixtures ; only for a brief 

 period do they correspond closely. It therefore seems 



