336 
ANIMAL PATHOLOGY. 
ception, universal law, that where there is a susceptibility of—a 
tendency to take on—a certain contagious disease, there is a 
power of communicating it. This is a perfect truism, a self-evident 
and undeniable proposition. I do again ask for a single case 
in which the susceptibility of receiving is given, and the power of 
communication denied. I see that in all these animals the malady 
assumes the same character—it runs the same course—it has the 
same inevitable termination ; and it is ridiculous to suppose that 
the power of communicating it should be wanting to complete 
and perfect the analogy. 
Different Susceptibility in different Animals. —The virus does 
not appear to have the same efiect on every animal. Of four dogs 
bitten by one that is rabid, three would display every symptom 
of the disease. Of four human beings, perhaps not more than 
one would become rabid : John Hunter said, not more than one 
in twenty. This, however, was carrying the matter too far. The 
majority of horses inoculated with the rabid virus, perish. Cattle 
appear to have a greater chance of escape, and a still fewer num¬ 
ber of sheep take on the disease. The hog stands next to the 
dog in the predisposition to become affected. Trolliet relates, 
in his valuable work on rabies, that twenty-three persons were 
bitten by a rabid wolf, no fewer than fourteen of whom died, in 
defiance of all preventive means. 
This immunity depends on various circumstances. In cattle 
the skin is looser than in either the dog or the horse, and less 
easily penetrated. As it respects the sheep, the tooth has pro¬ 
bably been cleaned in its passage through the wool. Circum¬ 
stances of a similar nature may have much influence in the 
human being. 
Causes of the apparent Immunity —In the too numerous cases 
of hydrophobia which medical journals and other publications 
contain, it is singular to observe that, with very few exceptions, 
almost any kind of clothing over the bitten part has prevented the 
development of the disease. In the long list just quoted from 
Trolliet, the far greater part of those who perished were bitten in 
the hand or the face. 
without assistance in the bounteous repast with which they are everywhere 
presented, have neither habits nor motives which febrile or nervous irritation 
might prompt into violent action : and into them the same great Author has 
instilled fear only as a motive of flight, seldom as a motive of aggression'or 
resistance. Hence probably the extreme paucity of their bites altogether, 
and the assertion that they never reproduce the disease; an assertion which we 
look upon as calculated to diminish circumspection, and to inspire more confi¬ 
dence than is warranted by the evidence upon which it is founded : we wish 
that in hydrojthobia no other conclusions had l)cen originally drawn from 
such blender premises, and afterwards expanded into general laws. 
