736 SMALLPOX AMONG SHEEP IN WILTSHIRE. 
It follows, therefore, that while giving just attention to 
measures of sanitary restriction, our chief hope in the restraint 
of any contagious epidemic or epizootic must rest in ascer¬ 
taining and controlling the conditions which are requisite for 
the development of its contagious properties. In several of 
the most fatal epidemics and epizootics, as, for example, in 
the typhus or typhoid of man, and the so-called “ contagious 
typhus” and “pleuro-pneumonia” of beasts, we know that 
the conditions for their extension by contagion depend upon 
certain well-known deficiencies in the sanitary circumstances 
under which the individual is placed, and which being re¬ 
moved, the influence of contagion or infection, or both, is ren¬ 
dered nugatory. It does not follow that these deficiencies are 
at all times capable of being readily removed, as in the case of 
an old-built, imperfectly drained town, and ill-ventilated, 
badly sewered houses, fostering typhoid fever; or in the con¬ 
ditions of the vast herds of Western Europe or of Australia— 
the former liable to frightful murrains of contagious typhus, 
the latter recently decimated by epizootic pleuro-pneumonia. 
The proposition is that these conditions are much more cer¬ 
tainly under our control than the contagious germs of 
diseases, as shown by experience. On the other hand, we 
know that the conditions of development of other contagious 
diseases, as smallpox and scarlatina, are less dependent upon 
local circumstances than upon the state of the individual at 
the time. What that state may be we are as yet entirely 
ignorant of in both cases named, and in the latter case we are 
unhappily compelled to depend for protection upon isolation 
of the disease alone ; and how sadly inefficient this protection 
is, and almost necessarily so, we need not say. In the former 
case w r e should be in a like unfortunate position, were it not 
that science had discovered that the disease may be induced 
in a modified form, and the predisposition to it, that is, condi¬ 
tion of development, thus exhausted. 
What, then, should be the course of action to be adopted in 
the present outbreak in Wiltshire for the prevention, as far as 
practicable, or restraint, of the further spread of the disease, 
or obviation of its chief evils ? Of the police measures pro¬ 
hibiting the sale of sheep within the infected districts, unless 
under the permission of a competent judge, the disinfection 
and purification of places occupied, temporarily or not, by 
affected animals, and also of the sale of diseased meat, as a 
safeguard to the public, there can be no question; and an 
Order in Council (somewhat late in the day, it must be con¬ 
fessed) has authorised the local authorities to take all needful 
steps in carrying out such measures. Of the means to be 
adopted for the more immediate treatment of the diseased 
