512 
ON RABIES. 
The preceding table shews that, in following the march of the 
two maladies, it is possible to distinguish them from each other; 
but that, on an examination after death, there is not sufficient 
distinction between them to warrant us in affirming any thing 
decisive. 
B. Contagion. A great number of unfortunate cases have 
too well proved that rabies in the dog, the fox, the wolf, and the 
cat, are contagious as it regards man and our principal domes¬ 
ticated animals. The poisonous principle resides in the saliva, 
which, deposited in the wounds made by the teeth, and after¬ 
wards absorbed, occasions rabies, although the wounds are often 
rapidly healed. 
c. Incubation. The virus introduced into the system does 
not cause rabies until an uncertain period, both in the human 
being and in animals. The period of incubation in man is from 
thirty to forty days: it sometimes extends to two or three 
months, and, according to some authors, the disease has not 
appeared until two years after the bite. Among animals, Brendt 
says, that rabies never appears until after the cicatrization of 
the bite; and also, according to him, it sooner attacks the young 
subject than the adult. 
In calves the disease is usually developed between the third and 
the fourth week; in full grown cattle, not until the sixth or ninth 
week, or even later. Among horses, it generally appears a little 
after the ninth week; and, in pigs, towards the commencement 
of the fourth. According to Hertwig, rabies ordinarily declares 
itself within fifty days after the inoculation, accidental or artifi¬ 
cial. He has never seen it developed much later. It has been 
stated at the school at Alfort, that no danger exists after the 
fiftieth day. We think it impossible to fix any determinate time 
for the incubation of the disease. We have seen it manifested 
in dogs from the tenth day to the fourth month. Peyronnie has 
seen it declare itself on the seventy-second and on the ninety- 
second day; Vatel, after sixty-four days in the goat; Thorel, 
after forty-four days in the hog; and Gervi, after two years in 
the same animal. 
The precursor symptoms in rabies manifest themselves at the 
wound and through the whole system. Regarded as connected 
with the sanitary police, the observation of these symptoms is 
very important. An itching or pain manifests itself at the place 
that was bitten, and the animal licks or scratches the part. The 
cicatrix becomes red, and bleeds; the wound opens, and rabies 
appears. These premonitory symptoms, however, do not always 
develope themselves. Whatever else may be the case, the attack 
of rabies is announced in the dog by a hoarse baying and a dis¬ 
position to bite;—in the horse, to bite and to strike with the fore- 
