226 ON THE COMMUNICATION OF RABIES 
How few are the persons exposed to danger from herbivorous 
animals ! The sheep and the ox do not bite, and the horse has 
rarely the opportunity of biting, except when the attempt is 
made to force medicine upon him. Many thousand persons will 
be bitten by rabid dogs to one bitten by an herbivorous animal: 
therefore, the non-occurrence of the disease may be fairly at¬ 
tributed to the few cases of inoculation, without jumping at the 
conclusion, that the virus is absolutely inert. 
But let us see how the fact actually stands. M. Dupuy made 
several experiments to ascertain this point. He took a sponge, 
and tied it to the end of a stick, and then presented it in a 
threatening manner to a rabid cow : she bit it, and the sponge 
became impregnated with her saliva. He then rubbed this 
sponge on wounds he had made on other oxen, and on some 
sheep, but rabies was not produced. He offered a sponge in 
the same manner to a rabid dog, and he rubbed that sponge, 
wetted with the saliva, on wounds on other cows, and sheep, 
and dogs, and he was enabled to produce the disease. 
There are two or three thing’s, however, to be taken into con¬ 
sideration, before we draw any determinate conclusion from the 
result of these experiments. There is a circumstance attending 
ail inoculation, except by the tooth of the living animal, by 
which they who have engaged in extensive experiments of this 
nature have often been annoyed. If we were to expose three 
dogs to the bite of a rabid dog, one of them would certainly be¬ 
come rabid, and probably all three ; but if we were to take the 
saliva from the animal while living, and inoculate three other 
dogs, probably not more than one of them would become rabid, 
and, possibly, not one. It would seem, that the living principle 
of the virus, if we can suppose it to be endued with life, is, in 
a manner, extinct as soon as it is separated from the animal by 
which it was produced. 
There is likewise a most perplexing degree of caprice attend¬ 
ing these inoculations. We have sometimes succeeded in infect¬ 
ing the majority of, or almost all the dogs we have inoculated. 
In other cases, although the disease was undeniably present in 
the dog from whom the virus was taken, we could produce no 
