Microbic Diseases Individually Considered. 301 



bit, guinea pig, dog, ape, rat, and birds. The last 

 named species almost invariably recover spontane- 

 ously (Gibier). The virulent material is taken from 

 the nervous substance (brain, medulla, cord and 

 nerves), from the salivary glands, the saliva, bron- 

 chial mucus, and from the pancreas. The milk occa- 

 sionally shows itself virulent, but the blood is not ; 

 complete transfusion of blood from a rabid dog to a 

 healthy subject did not produce the disease (Bert.) 

 In practice we resort more especially to the nerve 

 centers, which furnish a pure virus; for use, a parti- 

 cle is reduced to pulp and the latter diluted in steril- 

 ized water or bouillon ; in this way a white milky 

 fluid is obtained, a veritable emulsion of the nervous 

 substance. 



The inoculation maybe performed in various ways; 

 it may be subcutaneous, intra-muscular, intra-venous, 

 iutra-ocular, intra- cranial, intra-nervous, etc., the re- 

 sult varying according to the method employed. 



In the dog, subcutaneous and intra-venous inocula- 

 tions are usually followed by dumb rabies, without 

 barking or fury. Furious rabies can be obtained by 

 the same methods, but with small doses of virus. 

 The smaller the amount of the virus employed the 

 more readily is the furious form of the disease ob- 

 tained, the period of incubation being at the same time 

 prolonged. The injection of very small doses maybe 

 ineffective in the dog without conferring immunity, 

 whilst inoculation of large quantities of virus may 

 give immunity without the manifestation of any 

 symptoms of rabies. 



Intra-muscular inoculation is followed by rabies 

 with more certaiutv than subcutaneous inoculation. 



