300 
FRANK S. BILLINGS. 
eral conflagration, but rather by bivouaeks of destruction here 
and there, which become more and more frequent and near to¬ 
gether the longer mankind neglects making proper endeavors to 
check its course. 
It can thus be seen that the regulative and hygienic prevent¬ 
ive of specific infectious diseases is, in many cases, much more 
difficult than the contagious variety. Every spot is a seat of dan¬ 
ger, and one that may continue so for months or years where an 
animal has been that is affected with such an infectious disease as 
anthrax or swine-plague. Not only that, but, under favorable 
telluric and atmospheric conditions, the specific cause, the germs, 
gain access to the air by transportation from the ground, or be¬ 
come attached to the vegetation, and thus the disease may spread 
in ways mysterious and strange to the farmer and stock owner. 
It is sometimes very difficult indeed to decide whether a given 
disease is contagious or infectious. The opinion of the general 
practitioner is not worth a fig upon such a subject. 
It often happens that a disease extends rapidly over a country 
among a given species of animals. In this regard I have only to 
call attention to the horse epizootic of 1872. The world said it 
was “ contagious.” It was not! It was infectious. Horses un¬ 
doubtedly aided in spreading the infecting element, but at that 
time there must have existed peculiar climatic and telluric condi¬ 
tions, which have not since occurred. There was a common in¬ 
fecting cause to which the equine organism was alone susceptible, 
that extended from North to South, East to West. 
Had it been a contagious disease, it would never have worn 
its energies out as it did. 
Again, in infectious diseases it so happens that under peculiar 
circumstances there is no doubt that the disease becomes trans¬ 
mitted from one animal to another in the same stable. This fact 
has led many reputable men to speak of such cases as “ conta¬ 
gious,” but they are not. The transmission in such cases is not 
due to the cohabitation in the same building or house, but to some 
accidental circumstance ; some intermediate factor comes into ac¬ 
tion ; accidental inoculation occurs, not transmission per conta¬ 
gion. The sick individual does not convey the disease ; some- 
