No. 4.] TUBERCULIN. 345 



or two small inert tuberculous nodules no larger than a buck 

 shot as it is when there are extensive and active lesions. 

 Consequently, in order to prove the accuracy of the tuber- 

 culin test, it becomes necessary to make a thorough exami- 

 nation in all autopsies, to detect the minutest nodules that 

 may be present. In many cases this requires prolonged 

 search and a knowledge of the gross and microscopical 

 appearances of tuberculous tissue. 



Following there appear the conclusions drawn from a series 

 of experiments made with tuberculin at the Massachusetts 

 Agricultural College. These are taken from Bulletin No. 27 

 of the Hatch Experiment Station, a few copies of which are 

 still in the hands of the director for distribution. 



1 . That it is unsafe to purchase animals to add to a healthy 

 herd from a herd in which tuberculosis has existed. 



2. That poor sanitary surroundings, especially imperfect 

 ventilation and insufficient light, are favorable to the rapid 

 spread of tuberculosis among cattle. 



3. That it is much better to dispose of excrement outside 

 of stables than in cellars underneath them. 



4. That mangel's and other stable fixtures which increase 

 the amount of surface, cracks and corners that cannot be 

 easily cleaned are objectionable, from the fact that when the 

 germs of tuberculosis become scattered, under such conditions 

 they are not easily destroyed by the use of disinfecting fluids. 



5. That infected stables bear close relation to the propa- 

 gation of the disease. 



6. That even by the use of strong disinfecting fluids it is 

 very difficult if not impossible to rid an old stable of the 

 germs of tuberculosis. 



7. That the diagnosis in most cases of this disease by 

 physical examination is impossible. 



8. That in tuberculin we have an exceedingly delicate 

 and reliable test for tuberculosis. 



9. That tuberculin indicates the existence of tuberculosis 

 in the lungs and other parts of the body when objective 

 symptoms are absent, and when no germs can be discovered 

 by microscopical examination of the mucus from the nostrils. 



10. That its use is not followed by any ill effects of a 

 serious or permanent nature. 



