TUBERCULOSIS IN CATTLE. 47 
from its use in the hands of ignorant or unscrupulous individ- 
uals than in tts use in the hands of officials. It has been shown 
that an animal once inoculated and showing the characteristic 
reaction of the disease is then, to a certain extent, protected 
from a second inoculation. If this animal be now re-inoculated 
it will frequently, though not always, fail to show a second 
reaction until after a number of weeks or a number of months 
have passed. This fact has led in some countries to a fraudu- 
lent use of the tuberculin, as follows: An owner of a large 
herd will have all his animals privately inoculated with tuber- 
culin. He will then select all the animals that do not react 
to keep, while all the reacting animals will be at once rushed 
to the border of the country for exportation. When they are 
to be imported into another country, according to the laws in 
most European states, they must be inoculated and only the 
non-reacting animals imported. But most of these animals 
having recently been inoculated are protected from the second 
inoculation, and the official test at the boundary fails to show 
the presence of the disease. They are, therefore, accepted as 
free from tuberculosis, and thus by this fraudulent means 
tuberculous animals are to a certain extent freely sold. Of 
course the remedy for this is not difficult to find. In Belgium 
there is a law forbidding the use of tuberculin by the private 
individual, and making it only possible to use it under official 
inspection. After such official inoculation the animals that 
react are marked by a notch in the ear, and from that time on 
anyone who sees them knows perfectly well that the animal 
has had tuberculosis, whatever be the result of the tuberculin 
test atthe moment. It is not possible to emphasize too greatly 
the importance of this marking of animals. Every ani- 
mal that has once reacted should be marked in such a way that 
the mark cannot be obliterated. Apparently, then, the only 
proper use of tuberculin must be in the hands of officers who 
understand its use and who will honestly use the test and prop- 
erly mark all reacting animals. In this way only can the pur- 
chaser of cattle be properly protected. 
INCREASE IN USE OF TUBERCULIN. 
The use of tuberculin is certainly extending more and more 
widely every year in all European countries. There has been 
there the same objections to its use that there has among our 
own farmers. These objections have been partly well founded 
