364 LOCAL ILSSUE REACTIVITY 



1. A stale ol lion s|)(( ilu lissiic rc';uti\it\ which is elicited by 

 iiuaiis ol the actixc pi iiu iples supplied I)n the iiilected loci. 



2. The reactions obtained in the leadixe tissues may be, A — 

 iionsJM'cific, i.e., produced by an antigen not related to the infec- 

 tion, (a) \vhen the injected antigen possesses acti\e j)rincij)les ol 

 its own {viz., B. coli cult me liltrate) , (b) when the injected anti- 

 "en enters into combination Avith antibodies not related to the dis- 

 ease but incidentally j)resent in the animal, and (c) xvhen certain 

 colloids possessing proxocative potency are injected (agar, starcli) . 

 The reactions may be, B — specific, i.e., produced by the antigen 

 related to the infection (a) when the antigen possesses active prin- 

 ciples of its oxvn and (1)) xvhen it enters into combination with 

 antibodies actively acc]uired in the coinse of the disease. The spe- 

 cificity of the bacterial allergy, therefore, in these terms is only 

 limited to the process of formation of reacting factcjrs thrc:)ugh the 

 antigen-|-antibody interaction. 



If the above explanations c^f bacterial allergy are granted, it is 

 readily tniderstocjd ^vhy the manifestations to bacterial allergy 

 are so closely contingent tipon the existence of the infection itself. 

 The infection plays, then, the role of the cultme mediiun into 

 which the bacteria secrete the active principles and from which 

 the latter are given off into the circulation and distant tissues of the 

 animal. As already mentioned, the possibility exists of eliciting a 

 state of l3acterial allergy by means of dead tufjercle bacilli. It xvas 

 shown in the work on the phenomenon to tuberculosis, that the 

 ttibercle bacilli produce /// vitro an insignificant amoinit of ac- 

 tixe ]nincij)les. It may be assumed that only xvith the help of the 

 inflammatory reaction of the tissues are the active ])rinciples re- 

 leased from tiie tubercle bacilli in sufficient concentration. With 

 the introduction of the notion that the active principles of the 

 phenomenon of local tissue reactivity are essential for the elicita- 

 tion of l)acterial allergy in its various forms, it is not surprising 

 to find that active and passive sensitization in bacterial allergy 

 has not yet been possible. In experiments recently described a 

 state of acti\e sensiti/atioir to tuberculin xvas elicited in the fol- 

 lowing manner: 



The animals were innnuni/ed xvith tul^erculin h)r a period of 

 several xveeks. Intradermal injections of bacterial active jMincijjles 

 of the phenomenon were then made and following this the tulier- 

 culin was injected intravenously. Severe hemorrhagic and necrotic 



