THE FOCAL REACTION 71 



immunologists have elaborated theories to picture the processes go- 

 ing on at the site of the reaction. According to Wassermann and 

 Bruck the reaction takes place when the injected tuberculin joins 

 with an "antituberculin" at the focus and the complement is bound 

 by these two reacting bodies. The fixed complement is then able 

 to "digest" the focal material and so cause the well-known lytic 

 phenomena that we associate with focal activation. Wolff-Eisner 

 and others have expressed the idea that all the tuberculin manifesta- 

 tions are due to preformed specific "lysins." These break up the 

 nontoxic tuberculin; only the tuberculin so altered can initiate the 

 various reactions. The entire mechanism, according to the humoral 

 views, depends on the presence of lysins i.e., "much lysin much 

 reaction." 



As a matter of fact little or no evidence has been put forward 

 to support this humoral theory, but, on the contrary, much convincing 

 evidence discrediting it. No antibodies of the kind hypothecated 

 have been demonstrated. Nor does a parallelism exist between the 

 local, focal and general reactions, such as would be predicated if 

 the reaction were a humoral one. On the contrary, while a general 

 reaction follows in the wake of a focal reaction, the local reaction 

 is under these circumstances suppressed. But practically every 

 clinical phenomenon has, nevertheless, been interpreted according to 

 these theories with resulting confusion. One illustration will suffice. 

 Menzer noted that tuberculous foci would respond with a typical 

 "Herd Reaktion" after the injection of a streptococcus vaccine and that 

 tuberculous patients would very frequently have a general reaction. 

 From this he drew the conclusion that such reactions merely indicated 

 that a secondary infection with streptococci had been imposed on the 

 focus and that the evidences of reaction which he observed merely 

 confirmed the specific concept. 



As a matter of fact it was through the demonstration of the focal 

 or "Herd Reaktion" that the theory of specificity for the tuberculins 

 gained wide credence. We fitted a theory to the observation and 

 then proceeded to interpret every clinical observation in this or the 

 related fields to conform to our theory. Reasoning in a vicious circle 

 retarded the study of actual clinical conditions and particularly held 

 back the proper recognition of certain factors in cellular resistance 

 which are of great importance not only in tuberculosis but in in- 

 flammation in general. 



Inasmuch as experience with tuberculosis is common to every 

 physician, the consideration of the focal reaction in the tuberculous 

 is perhaps of greatest interest and importance, but the problem is so 

 closely bound up with inflammatory reactions in general that it may 

 be permissible to include certain references to conditions of non- 

 tuberculous origin in this discussion. 



