180 



atic lobes of the lung's contained three tuberculous abscesses, one 

 of which was double the size of the closed hand. All contained 

 the characteristic gritty pus. 



No. 3. Swelling at point of inoculation still present. Disease 

 present in the left retro-pharyngeal gland, which was greatly en- 

 larged, measuring 5" long and 3" wide and filled with tubercii- 

 lous pus. All other organs in the body clean. 



In all of the above animals the disease was of a localized nature 

 and the carcasses in fine condition, and the meat was therefore 

 passed for food. As has been noticed before, the size of the 

 local swelling constituting a reaction has no definite relation to 

 the amount of disease in the animal body, as sometimes a very 

 pronounced reaction will be observed when the lesions are small 

 and few in number. There is no doubt that there is nothing con- 

 stant in the size of swelling, and that an animal may at one time 

 give a pronounced reaction and at another time a swelling half 

 the size. The degree of reaction varies as the anaphylaxis of 

 the animal tissues is of a high or low degree, and this degree 

 cannot at all times express correctly the amount or stage of the 

 disease, as it is conceivable that when first infected and when the 

 disease is becoming established the tissues of the body would be 

 in a highly sensitive state, and the injection of the toxins in the 

 tuberculin cause a violent reaction and the following post-mortem 

 examination would have to be careful indeed to discover the 

 seat of the lesions. 



The anaphylaxis brought about by the presence of the disease 

 in the various organs of the body will vary as the vitality of the 

 system varies and whether the disease is in a quiescent or active 

 stage. It is ])robable that when the disease is extensive in the 

 body the anaphylactic properties of the disease, the skin in par- 

 ticular, are much lowered, and as the disease progresses become 

 less and less until at times it is entirely nil, and this condition 

 may last for greater or lesser periods of time. Thus it is con- 

 ceivable that such an animal would not give a reaction to the 

 toxins injected and so pass the tuberculin test when extensively 

 affected with the disease. 



The post-mortem examinations I have been fortunate enough 

 to make since the intradermal method was inaugurated have 

 been positive; that is. the disease has been ]iresent in every case. 

 On the other hand, I have learned of examinations being made 

 on condemned animals where no lesions have been found. In 

 establishing a method of testing, negative findings are as valu- 

 able as those cases which are of a positive nature. hVom the 

 results thus far experienced in the use of this method, we are still 

 firmly convinced of the great value of the intradermal method 

 and of its C(|ual reliability to the subcutaneous test, which has 

 been demonstrated tcj be reliable in 98.36 per cent, of cases. 



