﻿IMMUNITY RESEARCH. 351 



organ-antibodies obscure the phenomenon due to any existing infection- 

 antibodies. Of course any experimental evidence, either for or against, 

 must be rcenforccd with all of the numerous controls demanded, or must 

 prove the uselessness of these controls. 



It is quite possible that these studies will throw some light upon the 

 nature of complement. The use of the method outlined above for ordi- 

 nary clinical diagnosis is evidently out of the question at the present time 

 because of the special training required, but if the results above described 

 are confirmed, it may well furnish a means for aiding in the discovery 

 of yet unknown infectious agents, and in diagnosis, when employed by 

 suitably trained specialists. 



Finally, we may refer once more to the interesting results obtained by 

 applying this method to the study of the pathologic physiology of tuber- 

 culosis and of syphilis. 



That the technique is a difficult and complicated one has been pointed 

 out with sufficient emphasis. It remains to investigate critically the 

 constancy and accuracy of the method and to remove or mitigate sources 

 of error. 



In concluding I wish to refer to one other suggestion made by Was- 

 sermann and Bruck(35) to the effect that the softening occurring in a 

 tuberculous focus is brought about by the enzyme-like action of comple- 

 ment which is bound in the diseased tissues by the recurring union of 

 tuberculin and anti-tuberculin. They think that the complement comes 

 from both the broken down leucocytes and from the infiltrating small 

 round cells. They attribute the fever partly to a nonspecific effect such 

 as follows the injection of any bacterial preparation and partly. to the 

 specific action upon the tuberculous tissue of material derived from the 

 bacilli. However, another possibility suggests itself. We know that 

 complement is blocked in the union of tuberculin and anti-tuberculin, 

 and on the other hand we must suppose that complement has some 

 definite function to perform in the healthy body, probably some function 

 having to do with metabolism. Now it seems reasonable to suppose that 

 the removal of complement in normal function must upset the physio- 

 logical processes occurring in the body. This may well be true even 

 when the binding of complement occurs locally as in an isolated tuber- 

 culous focus, but in the reaction to a general infection, when bacterial 

 substance and anti-substance are being bound in widely scattered parts 

 of the body, or in the circulation, an enormous amount of complement 

 may be blocked. It will be important to determine how much com- 

 plement is so blocked during infections, whether definite complements 

 are blocked by certain bacteria and whether there is any relation between 

 the symptoms and the loss of complement. 



It was recently found by Pfeiffer(30), that the loss of available com- 

 plement in the living body interferes with bacteriolysis. 



