3Iicrohic Diseases Indiindually Considered. 199 



cliarbon is pathogenic only for ruminants and the 

 guinea pig. 



Dermic inoculation with the lancet or by superficial 

 scarifications is nearly always unsuccessful, whilst the 

 introduction of the virus into the subcutaneous cellu- 

 lar tissue or into the muscular tissue gives positive re- 

 sults. However, it is necessary to take into account 

 the dose injected and the place in which the injection 

 is made. Very small doses do not produce the dis- 

 ease but confer immunity; similarly, a dose which 

 would be fatal if injected in a favorable place is inof- 

 fensive when inoculated in the cellular tissue of the 

 tail and of the extremity of the limbs. The experi- 

 ments of M. Arloing have shown that this local im- 

 munity, w^hich had been established by clinical obser- 

 vation, depends upon the greater density of the con- 

 nective tissue and on the lower temperature of these 

 regions. He succeeded in overcoming this immunity 

 by heating the region or by lacerating its cellular 

 tissue. 



After the insertion of the virus in the subdermic tis- 

 sue there results a painful and progressive inflamma- 

 tory engorgement wiiich extends to neighboring re- 

 gions and in the guinea pig leads to death in twenty- 

 four to forty-eight hours. 



The intra-venous inoculation of small doses, but 

 doses which would be fatal by the subcutaneous 

 method (three to five drops of juice in young bovines, 

 three-tenths of a drop in sheep), excites a rather in- 

 tense febrile reaction ; tumors are not produced unless 

 some of the virus has been deposited in the cellular 

 tissue surrounding the bloodvessel. The subject thus 

 inoculated is vaccinated against the temporary reac- 



