518 DISINFECTION 
adapted to the various places and conditions requiring disinfection. 
The many chemicals possessed of germicidal powers and the numerous 
commercial disinfectants, recommended largely from the results of 
certain definite tests, which in point of fact may be of no value in 
determining their efficiency for the conditions in question, render 
further inquiry into the best methods for disinfecting after animal 
diseases a matter of much scientific interest and great practical value. 
Conditions to be taken into account in practical disinfection. In 
the effort to destroy the microérganisms in such places as yards, 
stables, cattle cars and the like, it is necessary to consider before 
applying a disinfectant the following conditions: 
a. The resistance of the particular organism to be destroyed. 
b. The medium or material in which it exists. 
c. The nature of the place containing the organism to be de- 
stroyed. 
d. The chemical action of the material surrounding the micro- 
organisms on the disinfectant itself. 
If the disinfection is for anthrax a more powerful disinfectant must 
be employed than would be required in disinfecting for the bacteria of 
septicemia hemorrhagica. If the infecting organisms are mixed with 
fecal matter, dirt or fodder, the problem is a different one than where 
they rest on a comparatively clean surface. It matters again whether 
the infecting organisms are in the soil (on surface), on a stable floor 
that is tight and hard or on one containing cracks of various sizes 
and made up of boards more or less shattered, thus forming deep 
crevices for the hiding away, as it were, of the specific organisms. 
In the disinfection of human dwellings the fumigation with formal- 
dehyde has proven to be one of the cheapest and ordinarily the most 
efficient procedures, but it requires a tightly closed room. It is 
evident that such a method cannot be trusted for the disinfection of 
most barns, stalls or stables which are usually large compared with 
dwelling rooms, and what is of far more importance, they are too open. 
In the disinfection for animal diseases the agents used must from the 
nature of the buildings in most cases be applied in the form of a 
solution. 
Jeger’s investigations brought out very clearly the necessity of 
adapting the disinfecting agent to the specific kind of organism to be 
destroyed. For instance, while brushing the surface with a 1-3 milk 
of chloride of lime destroyed anthrax spores, it was untrustworthy as 
a disinfectant for the bacteria of tuberculosis and of glanders. For 
