ROLE OF INFLAMMATION I51 



The primary skin reactions following injections of the active 

 principles into the skin of these animals yield erythema and swell- 

 ing ^vhich is frequently quite pronoiniced. Here again, no corre- 

 lation may be borne out loetween the primary reaction and the 

 susceptibility or resistance to the phenomenon. 



Repeated intradermal injections of B. typJwsus active filtrates 

 frequently elicit an active acquired immunity to the phenomenon 

 of local skin reactivity to B. typhosus, ^vhile some of the animals 

 thus immimized may retain their susceptibility to the actixe prin- 

 ciples of other microorganisms. Following two or three repeated 

 intradermal injections of the innnunizing material, the primary 

 reactions become distinctly intensified as compared to the effect 

 of the first injection. This is expressed in an indinated swelling 

 of the site reinjected. In spite of this intensihcation of the ery- 

 thema and swelling, the provocative intravenous injection of the 

 homologous filtrate frequently fails to elicit a reaction at the in- 

 flamed site. The microscopic observations on the lack of any re- 

 lationship between the primary effects of the filtrates and the 

 state of reactivity following their use, as reported by Kielanowski 

 (1935) and Kielanowski and Selzer (1934/;) , Apitz (1935^/) , and 

 Gerber (1936^) will loe discussed in a later part of this chapter. 



SKIN-PREPARATORV EFFECT OF NON-BACTERIAL SUBSTANCES 



In 1928, the basic experiments on the phenomenon xvere ac- 

 companied by control studies in Avhich there xvas determined the 

 skin-preparatory effect of the sterile iniinocidated medium, serv- 

 ing for preparation of bacterial active principles and the skin- 

 preparatory effect of ttupentine, as illustrated by the following" 

 protocols: 



Skin-preparatory potency of sterile tryptic digest broth: 



Protocol 15: Five rabbits were used for this experiment. The tipper and 

 lower right and upper left areas of the skin of the abdomen were injected 

 with 0.5 c.c. of sterile tryptic digest broth. The lower left areas were injected 

 with 0.5 c.c. of B. typhosus cidtiue filtrate. Twenty-four hours later, these 

 rabbits were each injected intravenously with B. typhosus culture filtrate. 

 The dose was 3 c.c. per kilo of body Aveight. One and one-half hours after 

 the intravenous injections, 1 rabbit died. No readings were made. Five hours 

 after the intravenous injections the remaining rabbits showed no reactions 

 in the upper and lower right and upper left areas. The lower left areas of 

 the skin of these rabbits showed severe hemorrhagic necrosis. The size of 

 the reactions varied from 2.5 x 2.5 cm. to 3.5 x 4 cm. 



