668 



COLLECTED STUDIES IN IMMUNITY. 



TABLE III. 



The table needs no further explanation. It completely confirms 

 the results obtained by Madsen, and exhibits the paradoxical phe- 

 nomenon in the clearest manner. It should be noted that it makes 

 very little difference whether the dilutions of the original mixture 

 and the injections are made immediately after preparing the mixture 

 or after the latter has stood for three hours, though the phenomenon 

 is perhaps somewhat more striking if the injections are made at 

 once. 



A deeper insight was afforded when we used rabbits for the 

 inoculations, for then we were able to apply the toxin-antitoxin 

 mixtures by means of intravenous injections. A comparison of the 

 L 1 " values in rabbits, both with subcutaneous and intravenous 

 injections, at once showed marked differences. Thus when we 

 injected toxin-antitoxin mixtures which had stood three hours, we 

 found the intravenous injections to be considerably more toxic than 

 the subcutaneous. If, however, we waited 24 hours after preparing 

 the mixtures, and then injected, we found that this difference 

 was practically wiped out. Such an experiment is reproduced in 

 Table IV. 



From the table we see that the toxicity of the mixtures by sub- 

 cutaneous injection has been but slightly altered by the 24 hours' 

 standing; there is perhaps a little impairment, but it is inconsider- 

 able. When intravenous injections are employed, however, a marked 

 loss of toxicity is caused by the twenty-four hours' standing. In the 

 case of this botulism toxin we are apparently dealing with the same 

 conditions which Morgenroth has described in the case of diphtheria 



