are Further experiments necessary ? 
351 
lung plague, in three of the large herds the outbreak is still in 
progress. In by far the largest herd it has only just commenced, 
and in two others there will probably be additional cases. 
As a matter of fact, therefore, the test of communicability 
has already been made on a scale compared to which the little 
experiment proposed by the Live-Stock Exchange sinks into in¬ 
significance. After six hundred animals have been exposed and 
ninety have become affected, the infection in every instance being 
traceable to one original herd, it appears somewhat ridiculous to 
be asked to leave all of these cases out of consideration and to 
rely entirely upon the results which follow from the exposure of 
ten animals. Can there be any doubt that persons dissatisfied 
with a test on so grand a scale would he equally unwilling to ac¬ 
cept the results with an additional ten animals, even if all suc¬ 
cumbed ? 
An experiment of the kind you propose would require at least 
three months to produce definite results, and it might be four or 
five months before a sufficient proportion of the animals were at¬ 
tacked to furnish satisfactory proofs of contagion. By that time 
we hope to have the West freed from every vestige of the disease, 
and this will almost certainly he accomplished in - Illinois by the 
slaughter of all affected animals. It is difficult to see what bear¬ 
ing such an experiment would have, therefore, on our course 
with the present outbreak. Pleuro-pneumonia is a most danger¬ 
ous disease, which once distributed widely over the country 
would almost defy our most vigorous efforts to control it. It has 
already been considerably scattered, and but for the prompt ac¬ 
tion taken to suppress sales, it would probably be to-daj^ in double 
the present number of herds. To relax our grasp upon it now, 
and turn our attention to a course of experiments requiring 
months of valuable time, might be compared to firemen who 
could be persuaded to stop fighting the flames and apply the 
torch to other inflammable structures to learn by experiment 
whether or not they would burn. 
Pleuro-pneumonia is not an unknown disease or one of recent 
origin; on the other hand, it was studied and described by the 
earliest authors who wrote intelligently of animal diseases. Its 
