290 Veterinary Medicine. 



toxin, and it can only protect so long as it remains in the system. 

 Whenever it is eliminated or destroyed, the susceptibility to 

 rabies returns. Hence it is important to continue its administra- 

 tion as long as the microbe remains in the system. As in tetanus 

 and diphtheria antitoxin treatment, it is also important to de- 

 stroy the microbe and its toxins in the infection wound. 



The animal which is to furnish the antitoxin is immunized as 

 in the Pasteur method by a succession of graduated doses of rabic 

 virus. After a treatment of 20 days the rabbit or sheep furnishes 

 a serum which is protective when injected in the proportion of i 

 of serum to 25,000 of body weight, even though its use be delayed 

 until 24 hours after the introduction of the virus. The sheep can 

 be immunized in 12 days by doses of 0.25 gramme of emulsion of 

 the infected cord to every kilogramme of body weight. To main- 

 tain the serum at its highest standard the treatment must be 

 repeated at intervals of 2 to 5 months, as the animal may be able 

 to bear it without loss of condition. 



Treatmettt with Sterilized Brain Matter froTn a Rabid Animal. 

 In 1886 I sterilized with heat an emulsion of the spinal cord of a 

 man who died of hydrophobia and injected two rabbits with 3 one 

 drachm doses each, and a third with 4 one drachm doses on as 

 many successive days. These rabbits were afterwards inoculated 

 with virulent spinal cord and remained well for nine months, 

 while three control rabbits injected with virulent cord, but which 

 had received no previous treatment died rabid. 



Puscarin and Vesesco have shown that the virus is rapidly 

 weakened by heat up to 60° C. at which point the virulence is 

 destroyed. It becomes easy therefore to secure in this way a 

 toxin uncomplicated by any living microbe. 



Theoretically the sterilization and use of infecting nervous sub- 

 stance, should share with the Pasteur method the advantage of 

 the selective action of the medullary matter in uniting with the 

 toxins and robbing them to a greater or less extent of their 

 toxicity. It has the additional recommendation that it introduces 

 no living germ, and thus obviates any possible danger of the 

 propagation of disease through the animal operated ou. 



Fernandez claims an immunity from rabies for dogs that have 

 survived the bite of a viper. Many facts and experiments are 

 adduced in support of this. 



