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may be made a root of evil, yet as employed by the intelligent and careful expert it 
is not only perfectly safe, but it is the only known means of ascertaining approximately 
the actual number affected in a given herd. In most infected herds living under what 
are in other respects good hygienic conditions two-thirds or three-fourths are not to 
be detected without its aid, so that in clearing a herd from tuberculosis and placing 
both herd and products above suspicion the test becomes essential. * * * In 
skilled hands the tuberculin test will show at least nine-tenths of all cases of tuber- 
culosis when other methods of diagnosis will not detect one-tenth. 
It is perfectly natural that there should be objection to its use 
among those who are not acquainted with its method of preparation or 
its properties, but it is difficult to explain the antagonism of farmers 
who are familiar with the facts connected with the manufacture and 
use of tuberculin. Probably the most popular objection to tuberculin 
is that it is too searching, since it discovers cases in which the lesions 
are small and obscure. While this fact is admitted, it should also be 
borne in mind that such a small lesion to-day may break down and 
become widely disseminated in a relatively short period. Therefore 
any cow affected with tuberculosis even to a slight degree must be 
considered as dangerous not only to the other animals in the herd, 
but also to the consumer of her products. Furthermore, tuberculin 
must be considered as harmless for healthy animals in view of the 
results revealed by numerous tests covering vast numbers of animals. 
And it has also been clearty demonstrated that tuberculin interferes 
in no way with the milking function in healthy cattle ; neither in the 
quantity of milk nor in butter-fat value has any variation been 
detected. 
Nocard and Leclainche state: 
Direct experiments and observations collected by thousands show that the tuber- 
culin injections have no unfavorable effect. With healthy animals the system is 
indifferent to the inoculation ; with tuberculous animals it causes only slight changes 
which are not at all serious. 
Most of the objections to tuberculin would probably be removed 
if some method of compensation for the reacting animals could be 
devised. Thus, in Pennsylvania, where tuberculosis is being eradi- 
cated with more Success than in any other State, and where there are 
usually three times as many voluntary requests on file for the applica- 
tion of the test as can be made, all reacting animals are paid for by 
the State. As the suppression of tuberculosis is a public health 
measure it would appear perfectly logical for the State governments 
to appropriately reimburse cattle owners for the animals condemned 
and slaughtered. 
Provision could be made to pay 70 per cent of the appraised value 
of the condemned animals, not to exceed $30 per head for common 
stock or $60 for registered stock. Such legislation should also include 
a requirement for the testing of all cattle coming into the State. 
