(S(S LOCAL ILSSUE REACITIVITY 



Data oil tlic c'Hc'c I ol tlic Indro^cii ion (oiuentialioii upon 

 the atlixc j)iin(ij)lcs are still nica^ic. 



Dctoxiiuation of actixc j)iincij)Ic's ol B. coli and B. lyjjiiosii.s 

 cultures may result Iroin ultra\i()let radiation and also Ironi \)\o- 

 lon^ed e\j)osure to tornialin. l\\c inactivation by means ol 

 lormalin is acconijxinied by jjieservation of antigenieity. 



The active principles of the phenomenon are extracellular and 

 soluble substances. Bacterial autolysis is not necessary for their 

 j)reparation although they may also be ol)tained in autcjlyzed cid- 

 tures. The best preparations are obtained imder conditions of 

 iirsignificant cell autolysis, namely, in filtrates of washings of 

 growth on solid media incubated for only twenty-four hours. The 

 concentration of active principles in the first washing of a given 

 niiml)er of meningoccjccus cells is approximately looo times 

 stronger than in the disintegrate of the same number cjf cells chs- 

 solved in the same volume of NaCl solution. With B. typJiosns 

 the first washing is about ^^o times stronger than the respective 

 cell disintegrate. 



There are fluctuations in potency of filtrates observed on steer- 

 age. The filtrates may become inactive after several months of 

 standing" in the refrigerator, and the potency of the filtrates may 

 also substantially increase ^vithin one or t\vo months following" 

 their preparation. 



Quantitative studies demonstrate that the active principles of 

 the phenomenon are consistently retained inside of dialyzing 

 bags. An opportiniity is thus aflforded to obtain considerable 

 purification of the filtrates by means of dialysis. The pinification 

 may amount to about a three-fold increase in reacting potency per 

 milligram of dry ^veight and nitrogen. The active principles may 

 be retained by Seitz filtering membranes. 



Ecker and Welch obtained concentration of the active princi- 

 ples by the use of the method of Ecker and Rimington. 



The active principles may be precipitated by fidl saturation 

 with anmioniinn sidphate and also by addition of acid alcohol. 

 The precipitated and dried materials retain their potency for a 

 considerable length of time. 



Various investigations c:)n concentration, jjurificaticen and frac- 

 tionation of filtrates containing the active principles thus far car- 

 ried out suggest that these principles are either protein in natine 

 or perhaps associated with proteins and that they are closely re- 

 lated to important antigenic ccjmponents of the preparations. 



