2 1(S LOCAL I LSSl L REACTIVITY 



guinea ])igs iiijcclc'd siniiiltancoiisK with a series ol three clifFcr- 

 eiit flilulioiis ol t iil)er( iiliii ) . A purple discoloration was not ob- 

 scr\e(l in (onlrol tubereulous guinea pigs Avhich receixed tuber- 

 culin alone. Ilie autlioi thought that the specific inllamniation 

 j)rodu(e(l bv tuberc nlin in the hypersensitive skin rather than the 

 products ol the tubercle bacilli jjer se, piepared the skin lor the 

 reaction to the intra\enous injection of typhoid lUtrate. This con- 

 clusion is not justified, ho\vever, since it was shown f)y me tiiat 

 tul:)er{idin j:)ossesses a skin-preparatory potency for normal ral)- 

 bits. The potency of tiie tufjerculin depends on the mode of 

 preparation and may l)e at)sent in l)atches sul^jected to higti tem- 

 peratine. Although Freund holds that the specific tuberctdin in- 

 flammation is responsible for the state of reactivity in tid)ercu- 

 loiis guinea pigs, he states in a fiuther communication that silver 

 nitiate is also likely to induce a state of reactivity in tidjercidous 

 animals. In such experiments the inflaimnatory reaction set up by 

 silver nitrate and tid)erciilin (if the latter possesses only a low 

 skin-preparatory potency, or is totally devoid of it) may be able 

 to localize live bacteria and bacterial sid^stances circidating in 

 the vascular system of the infected tuberculous animal. This pos- 

 sibility is clearly indicated by the Avork of Opie (1929) , Menkin 

 (h)'', 1), Cannon and Pacheco (1930). and others. Rettuning to 

 Freinid's observation, the localization from the blood stream of 

 certain factors secreted by the l^acteria dining the coinse of the 

 active infection may now induce a state of reactivity at the site 

 of fixation. Obviously, sul)secjuent provocative injection of bac- 

 terial nitrates may produce a reaction at the site of the tuber- 

 ctdin or silver nitrate injection. It shoidd be pointed out again, 

 that silver nitrate alone has no skin-preparatory potency. 



In Dienes' xvork (1929-^50), guinea pigs were injected intra- 

 perltoneally \vith 10 to 20 mgms. of slightly \ indent B. tubercu- 

 losis, strain R-i, or xvith killed B. tuberculusis. The infection Avas 

 followed three to eight days later by the intraperitoneal injection 

 of 0.1 to 1 mgm. egg Avhite (dry weight) . This treatment usually 

 lesidted in a strong skin sensitixeness to egg xvhite, often giving 

 large necrotic skin reactions \vith 0.01 mgms. of egg xvhite. 



Incidentally, there xvere also noted reactions typical of the 

 phenomenon of local skin reactivity at the sites of tid^ercidin tests, 

 as folloAvs: 



Eight guinea pigs Avere injected intraperitoncally with egg white twenty- 

 three clays alter sensitization. The guinea jjigs were infected with tubercle 



