TUBERCULOSIS. 425 



using this test regularly for two 3'ears, Mr. Edwards wrote as fol- 

 lows: 



I have seen nothing to lead me to believe that the tuberculin test had any 

 injurious influence on the course of the disease. It is bj' no means our opinion 

 that the disease has been stimulated or aggravated by the application of the 

 tuberculin test. All animals that we liave tested two or three times continue 

 as hale and hearty as they were previously, and not one animal in our herds 

 has brolien down or failed in any way since we began testing. 



Mr. Edwards, in December, 1901, verbally stated that his views 

 as to the harmlessness of tuberculin remained unchanged, and that 

 he had not seen the least ill effect in an}^ of his cattle from its use. 



Those who have had most experience with tuberculin have failed 

 to observe any injurious effects following its use upon healthy cattle. 

 With tuberculous cattle it produces a fever of short duration, and in 

 the great majority of cases all derangement of the system which it 

 causes disappears within 48 hours after the tuberculin is adminis- 

 tered. There appear to have been a very few cases in which the dis- 

 ease was aggravated, and a greater number in which it was benefited 

 by the injection of tuberculin. The cases of abortion following the 

 tuberculin test have not been numerous, even when cows were tested 

 within a few weeks of the normal time of calving. The few cases of 

 this kind which have occurred may be explained by the fact that 

 abortion in cattle is a very common occurrence, and that it would 

 inevitably happen sometimes after the tuberculin test as a mere coin- 

 cidence and without any relation between the test and the loss of 

 the calf. The cases of abortion which have been cited appear to be 

 no more numerous than might be expected to have occurred among 

 the same number of cattle within the same period if the test had 

 not been applied. 



At the present time there is ample evicience 10 snow that tuberculin 

 is the most reliable means of detecting tuberculosis in the living 

 animal and that its use is not attended by any harmful aftereffects. 



An act of Congress was approved Jul}^ 24, 1919, for the purpose of 

 controlling and eradicating tuberculosis of animals. The official 

 means of detecting tuberculosis in the living animal is the tuberculin 

 test, which may be applied by three different methods — the subcu- 

 taneous, the intradermic, and the ophthalmic. It is not necessary 

 to discuss here the details of these three methods, which are made use 

 of in the work of eradication of tuberculosis. 



The plan adopted by the State and Federal authorities in eradica- 

 tion of the disease is known as '' The Accredited-Herd Plan." Under 

 this plan herds are tested under State and Federal supervision, the 

 diseased animals are appraised, removed, and slaughtered under 

 Federal inspection. Retests are then made after definite periods of 

 time until two successive tests show all the animals to be free from 

 the disease. At this time the herd owner is given a certificate of an 

 accredited herd. 



