390 
DAVID S. WHITE. 
diagnosis was confirmed in 489 instances, while in 74 cases the 
lesions of the disease were not found. In Denmark 515 post 
mortems showed 50 false diagnoses. My own experience has 
been that, whenever tuberculin caused a rise in temperature in 
an animal to exceed 2° F., tuberculosis was present, but at 
times notoriously tubercular cattle do not react to the test. At 
the present time, however, tuberculin must be considered as the 
most valuable diagnostic agent that we possess, and by its use 
alone are we placed in position to discover and control con¬ 
sumption in cattle. 
Tuberculosis in onr bovine herds is the most generally 
prevalent and widely distributed of plagues. No country 
where cattle raising and dairying are the source of wealth is 
free from its ravages. Especiall)^ in lands and districts where 
cattle cohabit together through a long period of time does it 
seem to flourish. In localities where cows are kept for dairy 
purposes, to supply food for human food, the germ of consump¬ 
tion- finds a fertile soil upon which to grow and perpetuate 
itself. While the young beef cattle of onr plains and pasture 
lands are comparatively immune, in the more densely popu¬ 
lated milk-producing sections of a country a large percentage of 
the older milch cows are affected. To give exact statistics as to 
tuberculosis’ prevalency among cattle in onr own land would 
be at this time impossible. 
From Dr. Ostertag’s observations at the Berlin slaughter- 
houses it would seem that few old milch cows were free from 
the disease. He found 75 per cent, of those old dairy veterans 
harboring tuberculosis. In Denmark the production of milk, 
butter, and beef is the chief source of wealth and pro.sperity, 
and in this country nearly 40 per cent, of the cattle have been 
found to be tuberculous. The larger the herd the more ex¬ 
tended has been the disease. The longer the disease exists in a 
herd the wider will be its distribution. Of one herd of 208 
animals, 80 per cent, of the milch cows reacted to a tuberculin 
test. One dairy herd in Ohio tested by myself showed 32 per 
cent, to be affected. The germ of consumption does not seem 
