1^]S LOCAL riSSLE REACTIVITY 



imuii/at ion with l)()llir()j).s and ralllcsnakc xenoms. In contrast, 

 copj)eiheacl and moccasin venoms proved efficacious. Tlie mini- 

 mnm effective dose of moccasin venom (of the sample used) neces- 

 sary to produce tlie refractc^ry state was 0.04 mgms. intradermal ly. 

 Solutions of moccasin venom made from different samples of 

 pooled venom differed markedly, in their ability to produce a 

 refractory state to the phenomenon of local skin reactivity. The 

 ability of venom to induce the refractory state was titrated by this 

 author. Although various moccasin venoms showed very little 

 difference in their neinotoxic titer, there was a marked variation 

 in their content of refractivity-producing factors. There was, then, 

 no parallelism betAveen the content of hemorrhagins or neuro- 

 toxins and these factors. His experiments also showed that com- 

 plete inhibition of refractivity-inducing factors could be accom- 

 panied by the production of anti-venom and that complete or 

 partial inhii)ition could be brought about by various lots of nor- 

 mal horse serum. It seemed to the author that the above experi- 

 ments pointed very strongly against the assimiption that the re- 

 fractory state induced by previous injections of venom, is based 

 on a foreign protein reaction, in a broad sense of the term. II 

 the refractoriness to the phenomenon were based on such a 

 foreign protein reaction alone, there xvould not be any variation 

 in the potency of the refractivity-inducing factors in the \arious 

 venoms, and the addition of anti-venom and horse seriun xvould 

 tend to increase such a foreign protein effect. Since the ability 

 of the venoms to induce a refractory state to the phenomenon 

 apparently signifies their efficacy in the production of some re- 

 sistance of the capillary wall, i.e., decrease in its permeability and 

 increase in the resistance to toxic influences, Peck decided to deter- 

 mine clinically xvhether the venoms xvoidd be of value in treatment 

 of conditions of hemorrhagic diathesis. His clinical results xvill be 

 discussed in Chapter xni. 



PHENOMENON OF LOCAL SKIN REACTIVITY TO BACTERIAL FILTRATES 

 IN ANIMALS OTHER THAN THE RABBIT 



Gratia and Linz (i932r) Avere the first authors to report on the 

 phenomenon of local skin reactivity in guinea pigs. The abdomi- 

 nal skin xvas prepared by an injection of 0.5 c.c. of a six day old 

 Vibrio cholerae culture filtrate. Txventy-fotir hours later the 

 provocative injection was given either intracardially or into the 

 jugular vein. Some of the guinea pigs thus treated showed hemor- 



