32 LECTURES ON IMMUNITY 



ments that gave different results for rabbits and guinea- 

 pigs were carried out with nearly fresh mixtures of poison 

 and antibody. If such a mixture be injected subcutaneously, 

 it diffuses into the blood very slowly during several hours, 

 and in the meantime the antitoxin binds the toxin. It is not 

 necessary, with Morgenroth, to introduce a new hypoth- 

 esis; namely, that the tissues of the guinea-pig contain 

 some catalytic agent reacting on the poison. The relatively 

 high temperature (37 C.) of the animal explains the rela- 

 tively great velocity of the reaction. If, on the other hand, 

 the mixture is injected into the veins, the poison is bound 

 by the tissues of the animal before it has time to react 

 with the antitoxin. 



There are some other processes common in sero-therapy 

 which are distinguished by a very high velocity of reaction. 

 Thus, for instance, the agglutinins react with bacteria in 

 less than five minutes even at o C., according to the experi- 

 ments of Eisenberg and Volk. 1 (Shorter times of reac- 

 tion were not examined.) Here again we observe a 

 reversible process, since the agglutinin absorbed by the 

 bacteria (or erythrocytes) may be washed out from them 

 with the aid of a physiological salt-solution, as Landsteiner 

 and Eisenberg and Volk showed. It had been supposed 

 by Bordet that this reaction was of the same nature as the 

 adsorption of a dye by a fibre. But the adsorption phe- 

 nomenon is one of slow velocity ; the dyeing of fibres requires 

 some thirty minutes at iooC. and demands more than two 

 days at common room's temperature (i7C). Therefore 

 this theory of Bordet is quite improbable. I have come 

 to the conclusion that the process in question is an absorp- 



1 Eisenberg and Volk: Ztschr. f. Hygiene, 40. 155 (1902). 



