NEUTRALISATION OF H^MOLYSINS 1/9 



The values calculated are derived with the aid of the same 

 equation as given above for ammonia, with the constant 

 o. 1 1 5. The experiments were so executed that the mixture 

 of toxin and antitoxin were left at 20 C. for two hours ; 

 thereupon they were mixed with the suspension of erythro- 

 cytes (2.5 per cent horse blood) and for one hour held in 

 a thermostat at 37. The degree of haemolysis was deter- 

 mined as described above (cf. p. 15). The constant 

 0.115 is therefore valid at 20 C. In these and similar 

 experiments it is assumed that the absorption of the poison 

 in the erythrocytes may be neglected. 



The antitoxin used was a solution containing 0.0025 per 

 cent (per c.c.) of the content of antitoxin in a standard 

 solution. This fact indicates that the original blood-serum 

 containing the antitoxin derived from a horse injected 

 with tetanus poison contained in one c.c. nearly 5800 times 

 as much antitoxin as that which was equivalent to the 

 quantity of poison contained in one gram of the dried teta- 

 nus preparation prepared by precipitation from a strong 

 tetanus bouillon with ammonium sulphate. From this 

 figure it is easy to see that the injected horse held in its 

 blood (about 50 1.) many (about 1 5) million times the equiva- 

 lent quantity of the injected poison (about 20 g. ; some- 

 times this quantity may be still less). This circumstance 

 deters us from accepting an idea which seemed at first 

 rather probable it was suggested by Behring that 

 the antitoxin is a derivative of the injected toxin. To sim- 

 ilar results have led the experiments on the production of 

 diptheria-antitoxin. If the antitoxin produced did not ex- 

 ceed many times the poison used for its production, the prep- 

 aration of antitoxin would evidently have no practical value. 



