Ill 



errors of experiment, that the ciphers in the case n = 

 0,2 increase so much with the time after 10 min.) The ob- 

 servation after 24 hours (t==1440) shows that after the 

 decrease just mentioned a continual decrease takes place, 

 caused by the transformation of the lysin. It is there- 

 fore necessary not to use too long times of observation 

 if the process here examined is not to be interfered 

 with through a deterioration of the toxin itself. The ex- 

 periments with n -- f 0.1 and 0.2 show that this does 

 not take place, if the time be limited to 120 minutes. 

 The greater the addition of antitoxin, the greater is the 

 relative increase for the toxic quantity necessary within 

 the specified space of time. 



A new series of experiments was undertaken at con- 

 stant temperatures (6 C and 24.5 C) and the time for 

 the experiments was limited to 125 minutes at the low 

 temperature and 50 minutes at the high. The amount 

 of antitoxin added was taken from the interval 1. 2. , 

 which had shown the smallest variations. 



According to the above equation of equilibrium be- 

 tween toxin, antitoxin and toxin combined it seemed 

 probable, that the velocity of reaction could be expres- 

 sed by the following formula. 



= K! (A - x) (B - x) - K 2 x* 



where A and B stand for the amounts of toxin and an- 

 titoxin added in the beginning, and x signifies the amounts 

 of these bodies, which are combined together. Kj : K 2 

 should then be of equal value to the dissociation con- 

 stant K, calculated from the above experiments. But it 

 appeared to be quite impossible to include the experi- 

 ments in this formula, and the problem was therefore 

 treated quite empirically. A practical limit (I) for the reac- 



82 



