506 
tuberculin test, tubercle bacilli were found in over 41 per cent of the i 
cases, both by microscopic examination and animal inoculations. The 
danger from this method of infecting milk is impressed upon us as 
consumers when we consider the prevalence of tuberculosis in dairy 
herds as disclosed by numerous tests. 
PREVALENCE OF TL'BERCULOSIS AMONG COWS SL^PPLYING MILK TO THE DISTRICT 
OF COLUMBIA. 
Judging from the results of recent tuberculin tests, it is believed 
that on an average between 15 and 25 per cent of all the cows which 
supply milk to the District of Columbia are tuberculous. During 
1907 and the first half of 1908 the Bureau of Animal Industry I 
supervised the testing of 2,468 cattle in 128 herds supplying milk 
to the District, with the result that 387, or 15.68 per cent, were found 
tuberculous. Many other* tests have been made by local veterina- 
rians of which the Bureau has no records. The percentage given 
is scarcely a fair estimate of the extent of tuberculosis in the dairy 
herds of this vicinity, since our tests include many herds which have i 
either been cleaned previously by private tests or which have such a j 
healthy' appearance as to remove all suspicions of tuberculosis on a j 
physical examination. Thus far these tests have all been voluntary j 
on the part of the dairymen, and it is pleasing to note the large num- 
lier who have had their herds cleaned of tuberculosis and the prem- ( 
ises disinfected. 
DANGER FROM TOXIN IN MILK OF TUBERCULOUS COWS. 
Aside from the danger of tubercle bacilli in milk, some investiga- 
tors (Le Blanc, Kipper, Jemma, and De Michele) consider the milk i| 
of tuberculous cows dangerous even when bacilli are not present, on 
account of the toxin it contains. Michellazzi has injected such milk 
into tuberculous animals and obtained a reaction. 
ELIMINATE TUBERCULOUS CATTLE OR PASTEURIZE MILK. [ 
To eliminate all tuberculous cattle from the herd or to pasteurize 
all milk coming from untested cattle should therefore be the object 
of all producers of milk, and sanitarians will be remiss in their whole 
duty should the}" neglect to guard against the products of tuberculous 
animals in their attempts to eradicate tuberculosis from man. This 
view was crystallized in a resolution adopted by the International ' 
Congress of Tuberculosis recently held in Washington, D. C., as 
follows : ' 
Resolved, That preventive measures be continued against bovine tuberculosis, 
and that the possibility of the propagation of this infection to man be recognized. 
