IMMUNIZATION 149 



The observation at the time o was made immedi- 

 ately before the injection. It indicates that the 

 ass possessed no natural immunity against diphtheric 

 poison. Half an hour later about 10 per cent of 

 the antitoxin had spread to the veins. After the 

 first day the rapid elimination took place. During 

 the three following days the content sank from 16 

 to 1 1 units, for which decrease at a later stage 20 

 days would have been needed. 



BEHRING has also observed that antitoxins remain 

 longer in the blood of animals of the same kind as 

 that from which the antitoxic serum is taken. 

 MADSENand JORGENSEN found that typhoid agglutinin 

 from a rabbit disappeared 2-5 times more slowly 

 from the veins of a rabbit than from those of a 

 goat. 



As the observations referred to above all con- 

 cern the fate of antidiphtheric serum it may be of 

 interest to reproduce the figures of MADSEN and 

 JORGENSEN regarding the fate of typhoid agglutinin 

 in the veins of a goat. 



[TABLE 



