REACTING POTENCY 267 



The fact that the autigen+antibody mixtures (i.e., inactive 

 bacterial and non-bacterial antigens with homologous antisera) 

 consistently failed to induce the state of reactivity, ^vhilst they 

 possessed a strong reacting potency, is to be borne in mind inas- 

 much as it offeis the opportunity of a clear differentiation 

 between the actixity of antigen-j-antibody complexes and bacte- 

 rial filtrates. For these reasons, ^vhen some biological fluid pos- 

 sesses both skin-j)reparat()ry and reacting potencies, it may be 

 assumed ^vith a considerable degree of certainty that there are 

 jjresent acti\e princij)les of bacterial origin in the material tested. 

 Materials sho^ving reacting potency alone may he assiuned to be 

 free of active bacterial principles (Shwartzman, 1931^, 1932/7). 



REACTING PC^TEXCV OF NON-BACTERIAL SUBSTANCES 



The folkj^ving inert colloidal suspensions and sera tested t^vo, 

 six, and twenty-four hours following the preparatory injectic:)!! in 

 doses per kilo of body ^veight indicated belo^v, were found totally 

 devoid of reacting potency: 



(1) Foiu- per cent charcoal, 1 c.c; (2) 2 per cent infusorial 

 earth, 1 c.c; (3) 4 per cent Witte's peptone, 1 c.c; (4) 4 per cent 

 silicic acid, 1 c.c; (5) 10 per cent gelatine, 1 c.c; (6) heparin 

 diluted 1:100, 1 c.c; (7) histamine diluted 1:3000, 1 c.c; (8) 

 20 per cent NaCl soltition, 1.5 c.c; (9) rabbit, guinea pig, liver, 

 adrenal, kidney, and brain saline extracts. 2 c.c; (10) allylamine 

 diluted 1:2000, 1 c.c; (11) pyridine, 0.06 gm.; (12) 10 per cent 

 inulin, 1 c.c; (13) acetylcholine, 500 mgm.; (14) 10 per cent 

 lecithin emulsified in saline, 2 c.c; (15) normal human sera, 

 3 c.c; (16) anti-meningococcus horse sera, 3 c.c; (17) anti- 

 meningococcus rabbit sera, 2 c.c; (18) normal rabbit sera, 2 c.c; 

 (19) normal guinea pig sera, 2 c.c; (20) normal rat sera, 0.25 

 c.c; (21) normal chicken sera, 1 c.c; (22) anti-typhoid immune 

 chicken serum, 1 c.c; (23) pooled sera of rabbits injected 

 intravencjusly ^vith 2.5 c.c. of B. typhosus culture filtrate per 

 kikj of body weight, three hours befc^re bleeding, 5 c.c; (24) 

 normal chicken plasma, 1 c.c; (25) plasma of chicken immunized 

 intravencjusly \vith Streptococcus viridans culture filtrates for fi\'e 

 weeks and obtained t^\enty-iour hcnirs after the last injection, 1 

 c.c; (26) plasma of chicken immunized intravenously Avith the 

 above filtrate for t^vc^ months and obtained four days after the 

 last injection, 1 c.c; (27) plasma of chicken immunized intra- 

 xenously witli large doses of B. typhosus "agar Avashings" filtrates 



