EDITORIAL OBSERVATIONS. 
689 
we are constantly in the habit of advising the use of 
“ disinfectants ” with or without sufficient reason ; the 
chemicals which are employed are comparatively inex- 
pensive, the results of their application are, if not always 
beneficial, never injurious, and hence they are constantly 
prescribed. When an epizootic is known to be contagious in 
its nature, the first step in prevention is disinfection. 
When the disease is virulent, but sporadic and non-conta- 
gious, disinfectants are also enjoined as an essential part 
of prophylaxis. At this point the charge of inconsistency 
arises ; disinfection, if it means anything, means the neutral- 
izing or destroying of infectious material, and where no 
infection exists, disinfection is unnecessary. Such is the 
home thrust which the non-professional critic aims at the 
man of science ; and the attack is not easily met, because 
on the face of it the recommendation of disinfectants for 
what is not infectious seems absurd ; in a popular view of the 
matter, at least, although the chemist understands that a 
great deal more is implied in the term disinfectant, than 
the single property of disinfecting. Among the lower 
animals especially there are certain diseases prevalent only 
in certain localities or under special conditions. For want 
of a better name these affections are classed under the head 
of blood diseases, on the ground of an altered condition of 
the blood being an invariable element in the disease, what- 
ever form it may assume ; some of the affections are not in 
the ordinary sense of the word contagious, a healthy 
animal might be placed in contact with a diseased one 
without danger, and a diseased beast might be placed in the 
midst of a healthy herd in a healthy locality without any 
risk being incurred of spreading the disease ; but on the 
other hand, animals from a healthy district cannot with 
impunity be brought into the neighbourhood of the diseased 
and be placed under the influence of the conditions which 
favour the development of the malady. Peculiar atmo- 
spheric changes; excess of organic matter in the water, 
imperfect development of the herbage, may one and all be 
concerned in the production of the affection, and the 
majority of animals which are brought within the sphere of 
