688 
REPORT ON THE CATTLE PLAGUE. 
Veterinary Institute, into Bohemia. He at once found that 
it was the rinderpest, and recommended the rigorous enforce- 
ment of the former measures, the result of which was that in 
six weeks or two months afterwards the malady had entirely 
disappeared in the kingdom of Bohemia.” 
Incubation . — Like small-pox, and many other affections 
common to man and animals, rinderpest lies dormant for a 
time after the infection has entered the organism. This 
period is found to vary in different diseases, and also in the 
same disease at different times, as well as with animals 
which belong to different zoological classes. It is influenced 
by many external circumstances, such as the manner in 
which the infection is received, the heat of the weather, 
temperament of the animal, freedom from other diseases, 
peculiarity of constitution, &c. None of these causes can 
be said, however, to prevent the outbreak of the malady, 
although some of them may retard, and others facilitate, its 
appearance. During the incubative period, the animal gives 
no indication of ill-health, and only does so when the disease 
is about to declare itself. 
The time that the poison of the rinderpest lies dormant is 
also found to vary ; many animals sickening on the seventh 
day after exposure, and others not until thethirteenth or four- 
teenth. Some are said even to pass to the twentieth day before 
giving evidence of the malady. Such cases are few, and may 
possibly depend on secondary exposure to the infection rather 
than on so great a variation in the periods of incubation. 
These secondary exposures are not unfrequently entirely 
overlooked, and especially with such an affection as the 
rinderpest, the infecting materials of which can be con- 
veyed by indirect as well as by direct means. It must 
not be forgotten, also, that it is a rule or law belonging 
to this class of maladies, that if an animal passes over the 
usual period of incubation, it is secure against an attack, 
and in order to become the victim of an infection, 
it must be a second time exposed to the influence of 
the morbific matter. Direct and well-considered expe- 
riments are wanting with regard to the incubation of the 
pest, and these we had no opportunity of making while on 
our mission. No doubt, however, should be allowed to 
remain on a point like this, as on it depends the security 
to be afforded to every country which is contiguous to the 
steppes of Russia. Austria, which suffers almost annually 
from this disease in some parts of her dominions, has an 
especial interest in the question, and should lose no time 
in effecting its complete and satisfactory solution. In our 
