IMMUNIZATION 145 



three observations, as against the results of single 

 observations. 



During the first day after the injection the 

 decrease goes on abnormally rapidly. Therefore 

 the calculated values for the first dav, which fit in 

 with the regularity found for the decrease during the 

 later period, are written in brackets. Evidently 

 during the time immediately after the injection 

 another process is going on simultaneously with the 

 process which is typical for the following regular de- 

 crease. This goes on as a monomolecular process, 

 and the simplest hypothesis would be to suppose a 

 spontaneous destruction, if it was not known that 

 the antitoxins are rather stable at the temperature of 

 the animals investigated. But the formula for mono- 

 molecular reactions would also give good results if 

 the antitoxin reacted with some substance present in 

 great excess or which was secreted by the animal's 

 body as soon as it was consumed. In the time just 

 after the injection there must also be some other 

 action of great effectivity. 



It is highly probable that the foreign substances 

 introduced are eliminated by some substance pro- 

 duced by the animal in which they have been 

 injected. This is indicated by some interesting 

 experiments of Baron von Dungern. He injected 

 blood-serum of the sea spider (Maja squinado, a 

 Crustacean) into the veins of a rabbit. After three 

 hours it had disappeared (in this case sunk below 

 25 per cent). Then he introduced the same quantity 

 of Maja serum into the rabbit s blood, and found that 



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