SERUM CHEMISTRY 47 



Bacteria -f immune body + complement solution (Pfeiffer's re- 

 action). 



Bacteria -f immune body + complement (heated) = no solution. 

 Bacteria -f immune body (heated) + complement = solution. 



[The same phenomena in the blood of animals immunized against 

 the red blood corpuscles of another animal of foreign species have 

 been observedTj 



lf a rabbit is immunized with the blood of a dog by repeated and 

 increasing doses, the serum of that rabbit will become h&molytic to 

 the corpuscles of the dog's blood if they are mixed, provided some 

 normal rabbit's blood complement is added to the mixture? 



Dog's erythrocytes + immune rabbit serum=no solution. 



Dog's erythrocytes + immune rabbit serum + complement = solu- 

 tion. 



Dog's erythrocytes -f immune rabbit serum + complement, heated 

 = no solution. 



immune body acts as a preparer of the corpuscles, or bac- 

 teria, so that the complement can act upon the cells. The reaction 

 is very like the action of pepsin on fibrin. Hydrochloric acid must 

 be present^ 



(1) Pepsin + fib rin = no solution or lysis. 



(2) HC1 + fibrin = no solution or lysis. 



(3) Pepsin + HC1 + fibrin = solution or lysis. 

 The HC1 corresponds to the immune body. 



In the case of haemolysis, or bacteriolysis the action of the immune 

 body is specific. The immune body of cholera spirilla will not 

 prepare, or fix typhoid bacilli, so that they can be acted upon 

 by the complement. Nor will the immune body of dog's ery- 

 throcytes prepare these of a pigj so that the complement may 

 act on it. 



