INTEBACTIONS BETWEEN VENOM AND ANTIVENIN 



257 



much more marked than the combining property of the venom, although 

 both undergo certain inactive modifications. 



In 1903-04 Madsen and Noguchi carried out a large series of experiments 

 on the partial-neutralization phenomenon of different venoms and their 

 specific antivenins, with specific reference to the haemolysis and toxicity. 



CROTALUS-VENOM ANTIVENIN. 



Guinea-pigs were used as test animals; the mixtures were injected intra- 

 peritoneally. The venom had the toxicity of 0.0005 gm. = 1 minimal 

 lethal dose for guinea-pigs (weight 300 grams) given intraperitoneally. 

 0.006 gm. was the amount of venom used for the experiment; 2.25 c.c. of the 

 antivenin (specific) made this amount non-lethal. Two hours' standing at 

 37 C. was always allowed to the mixtures before injection into the animals. 

 The results are given in table 34. Under n are indicated the quantities 



Table 35. 



[5 per cent suspension of dog's blood; i cc.of 0.05 percent 

 crotalus venom solution + n c.c. of crotalusa antivenin 

 4- 1- «c.c. 0.9 per cent NaCl solution.] 



Fig. 



0.2 0.3 0.4 0.5 0.6 



- Crotalolysin antilysin. Dog's blood. 



of antivenin added to a constant dose of venom, 0.006 gm., and under 

 "q observed," the observed toxicity. These observed values, after allowing 

 for errors in experiment, can be expressed by the same formula which repre- 

 sents the combinations of toxins and antitoxins of other substances. 



Free toxin Free antitoxin 



volume 



volume 



= K- Toxin-antitoxin 



In this case: 



- represents the quantity of antitoxin equivalent to an amount of toxin used, 

 and K the constant of dissociation. 



