44 STORRS AGRICULTURAL EXPERIMENT STATION. 
DETECTION OF TUBERCULOSIS BY CLINICAL SYMPTOMS. 
It is, of course, manifest that there is no possibility of deal- 
ing with tuberculosis until we have some satisfactory means of 
determining the presence of the disease. There are two 
methods which have been used for indicating its presence. 
The first is by means of clinical symptoms, and this, for pur- 
poses of controlling the disease, is almost useless. A skilled 
veterinarian is able, by means of clinical symptoms, to distin- 
guish many cases of tuberculosis. Most advanced cases of the 
disease he will discover, but all of the incipient cases will 
escape his observation entirely, and many of the cases that are 
really very far developed show no external signs which the 
veterinarian can detect. As a result, the method of detecting 
the disease by means of clinical symptoms is absolutely un- 
satisfactory, and if we had no other means than this it would 
certainly be hardly possible to cope with the disease at all. 
In spite of the most rigid inspection of this sort the disease may 
run through a herd, many animals will have the disease and 
distribute it from one to another, and yet the veterinarian be 
unable to detect it early enough to prevent the disease from 
being distributed from animal to animal. We must admit, 
with all veterinarians, all scientists, and all bacteriologists, 
that the clinical detection of the disease is so unsatisfactory as 
to be practically useless in giving us adequate means for 
battling with this widespread disease. 
DETECTION OF TUBERCULOSIS BY USE OF TUBERCULIN. 
The second method of detecting the disease is the use of 
tuberculin; and here we come to a problem over which there 
has been the greatest amount of contention. The opposition 
has arisen from many sources and for many causes. It is well 
for us, however, to consider the facts clearly and to notice the 
condition of things in regard to the use of this much-abused 
test. : 
Accuracy of Tuberculin Test.— The first question is in re- 
gard to the accuracy of the test. Over this, as over every other 
point, there has been much dispute, but at the present time 
there is an absolutely universal consensus of opinion. Tuber- 
culin, as a means of detecting this disease, is very accurate. 
By this statement it is not meant that it never makes a mistake, 
