SANITARY POLICE AND THE CATTLE PLAGUE. 939 
Western Europe, nor as to the mode in which it is propa¬ 
gated. We are now thoroughly convinced that outside the 
Russian empire it is never developed spontaneously, no matter 
what may be the breed of cattle, not excepting even that of 
the Steppes. Consequently, whenever cattle plague appears 
elsewhere, it is because it has been imported by some means 
or another. We also know equally well that, when it remains 
for a longer or shorter time in a country that it has invaded, 
it is kept up solely by means of contagion, that it cannot be 
perpetuated otherwise, and that it becomes extinct when it 
can no longer be communicated to other animals. It is, 
therefore, necessary to repeat, contrary to the opinion of some 
physicians, that the cattle plague cannot become an indi¬ 
genous malady in our country, under the influence of what 
is somewhat obscurely termed an epidemic nature. A hun¬ 
dred and twenty years ago it persisted in England for thirteen 
years consecutively, because it was not known how to get rid 
of it; but the phantom of epidemicity is not slow to vanish 
when it is decided to attack the contagion and to annul its 
effects. 
The same fact was reproduced in the same country in the 
year 1866, and in a manner still more flagrant. When, in 
that year, the cattle plague w r as imported through the channels 
of commerce, people persisted in ignoring its origin, and in 
considering it an indigenous disease developed by the excep¬ 
tional heat of the season. Under the impression of this false 
idea they refused, for three long months, to apply the sani¬ 
tary measures, the certain efficacy of which had been attested 
by the experience of the Continent. Thus England and 
Scotland suffered immense losses. But when, finally, the 
error was recognised, and Parliament had passed a Bill 
which empowered the English authorities to slaughter, in 
the cause of the public interest, animals which could convey 
the contagion, or enlarge the focus of the disease, then—and 
this is a thing apparently very remarkable, and by no means 
common in the annals of medical science—the epizootic 
disease, which was in its full destructive activity, was not 
slow in disappearing, as if it were at the express command of 
the Government. 
Contagion is thus the exclusive cause of the importation, 
the propagation, and the greater or less permanence of the 
cattle plague in Western and Central Europe. 
From this conclusion, so certain and so incontestable, pro¬ 
ceeded all the sanitary measures which the International Con¬ 
ference decided upon, and the adoption of which they pro¬ 
posed to the governments of all the countries that are 
