10 LOCAI, TISSUE REACTIVITY 



ol all the iioinial animals tested showed a j)ositive erythematous 

 reaction to the injedions ol these filtrates. The reactions differed 

 considerably in intensity. Only a small percentage of the posi- 

 tively reacting animals gave stiong erythematous reactions (12 

 per cent) , the majority of positive rabbits, ho^vever, reacting 

 weakly. Different areas of the skin of the abdomen also presented 

 considerable \ariations in jjrimary reactions to B. typJiosiis toxic 

 filtrates. These residts ^vere substantiated l)y protocols of several 

 hundred rabbits. A report on these animals woidd unnecessarily 

 lengthen this monograph. 



"Agar washings" hltrates of the typhoid-paratyphoid-dysentery 

 groups of bacteria give still less significant primary reactions, as 

 illustrated l)y the following typical experiment: 



Protocol 7 : Forty rabbits each received six simultaneous injections of 

 B. lypliosus "agar washings" filtrate in dilutions of 1:2, 1:8, 1:16, 1:24, 1:36, 

 and 1:48. The readings of the primary effect of these injections were made 

 twenty-three to twenty-four hours later. The dilution 1:2 produced well- 

 marked erythema (4-(-) in one rabbit, moderate erythema (2-f-) hi 3 rab- 

 bits, slight reddening (i-|-) in 7 rabbits, and doubtful reddening or no 

 erythema in the remaining 29 rabbits. With the dilution 1:8, only one rab- 

 bit showed a moderate erythema (2-)-) , and the remaining rabbits developed 

 very slight erythema, or no reactions whatsoever. None of the higher dilu- 

 tions had any visible primary effect upon the skin. 



A single intradermal injection of the undihited B. typhosus 

 "agar washings" filtrate gives primary reactions of similar mild- 

 ness and variability. Although the reactions in thotisands of rab- 

 bits Asere recorded, it appears to be sufficient to report the restilts 

 in r,'^7 animals, as follo^vs: 



Fotu" htmdred and seven rabjjits sh(^Aved no detectable reac- 

 tions; 22 rabbits had a doubtftil erythema; 73 erythemas were 

 recorded as 2-|-. and 12 labbits developed marked erythema clas- 

 sified as 4-j-i 19 rabbits showed a distinct swelling at the pre- 

 pared skin sites. There appeared to be no relationshi}) betAveen 

 the intensity of the erythema and swelling. Four rabbits showed 

 small hemorrhagic lesions which could be confused with the reac- 

 tions of the phenomenon. 



The primary effect of meningococcus "agar washings" filtrates 

 upon the skin of normal rabbits was similarly sttidied. 



Protocol 8: Thirty-six rabbits received each five simultaneous intra- 

 cutaneous injections of 0.25 c.c. of undiluted meningococcus "agar washings" 

 filtrates and of the same filtrate diluted with 0.9 per cent NaCl 1:10, 1:20, 



