INFECTION AND IMMUNITY. 477 



former case the actual protecting body had first to be 

 manufactured by the tissues; whereas, in the second it 

 is already prepared, and is introduced as such into the 

 second animal. 



They found the serum of artificially immune animals 

 to be not only capable of rendering other animals im- 

 mune, but that it possessed curative powers when the 

 disease is already in progress. The serum of immu- 

 nized animals when injected into the circulation of ani- 

 mals in which there was a body-temperature of from 

 40.4° to 41° C. reduced this temperature to normal 

 (37.5° C.) in twelve consecutive experiments during 

 the first twenty-four hours following its employment. 



In their opinion, the crisis seen in pneumonia in 

 human beings indicates the moment at which the pois- 

 onous products, manufactured by the bacteria located in 

 the lungs, are present in the circulation in amounts suffi- 

 cient to stimulate the tissues to the reaction that results 

 in the production of the antidotal substance that has 

 the power of rendering the poisons inert. 



At the time of the crisis in pneumonia the bacteria 

 themselves are in no way affected. They remain in the 

 lungs, and can be detected, in full vigor and virulence, 

 in the sputum of patients a long time after the disease 

 is cured. They have lost none of their power of pro- 

 ducing poisonous products, and still possess their orig- 

 inal pathogenic relations toward susceptible animals. 

 It is only after the crisis that their poisons are neutral- 

 ized by this antidotal proteid that has been produced 

 by the cells of the tissues, and as this occurs the systemic 

 manifestations gradually disappear. The Klemperers 

 claim to have isolated from cultures of micrococcus 

 lanceolatus a proteid body that is the agent concerned in 



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