174 
to the tuberculin test. He stated that he did not consider this a fair 
estimate of the extent of tuberculosis in the dairy herds of this vicinity 
as the tests were onty being applied to those herds which had recently 
been cleansed by private tests or appear so healthy that their owners 
have no fear of having them tested. 
I am informed by the District health department that 1,059 cows, 
from 51 herds in Virginia, Maryland, and the District of Columbia, 
supplying milk to the city of Washington were tested for their reac- 
tion to tuberculin; of this number 160, or 15.1 per cent of the total 
number of cows tested, responded to the tuberculin test. 
Of course the above figures furnished by the department of Agri- 
culture and the District health department do not give a fair idea of 
the prevalence of tuberculosis in the herds supplying milk to Wash- 
ington, as only the owners of those herds who had reason to think 
that their cows were free from tuberculosis permitted the test to be 
made. If the test had been applied to all the cows supplying milk 
to the District I have no doubt that the percentage would be very 
much higher than the above figures would seem to indicate. 
RESULTS OF TUBERCULIN TESTS ELSEWHERE THAN IN HERDS 
SUPPLYING WASHINGTON. 
The following figures by Salmon ® show the number and percent- 
age of cattle carcasses condemned for tuberculosis during the years 
1901-1905 in the meat-inspection service of the Bureau of Animal 
Industry : 
Year. 
Number ex- 
amined. 
Per cent 
con- 
demned. 
1901 
5, 219, 149 
0. 10 
1902 
5, 559, 969 
.14 
1903 
6, 134, 410 
.14 
1904 
6, 350, 011 
.16 
1905 
6, 096, 597 
.18 
This does not show the total number of animals affected with tuber- 
culosis, for in many cases only a part of the carcass was condemned 
and probably many had the disease so slightly that the entire carcass 
was passed as fit for food. 
The following table, also taken from Salmon’s article, showing the 
results of the tuberculin test of cattle in some States, is of value as 
showing the wide distribution of bovine tuberculosis. It must be 
remembered that most of the herds tested were suspected herds, 
which may account for the very high percentages found : 
a Salmon, D. E. : Bull. No. 3Sr Bureau Animal Industry, 1906. 
