DR. LEG EAR'S STOCK BOOK. 319 



ment all over the world, and consumptives undertook journeys 

 of hundreds of miles for the sake of being treated with the new 

 cure for consumption. It was noticed by several observers that 

 when a person suffering from consumption received an injec- 

 tion of the lymph, it invariably caused a rise in temperature; 

 and in 1891 Gutman, a Bussian, took advantage of this fact and 

 began to make experiments with it as a diagnostic agent in cattle; 

 and as a result of which, we are able to detect the slightest 

 forms of the disease. 



On account of the deep-seated tubercles usually existing with 

 superficial ones, they render tuberculin almost useless as a cura- 

 tive agent, since, to eradicate the disease, the deep-seated tuber- 

 cles must be afterwards removed by surgical means. 



But this action which renders tuberculin so objectionable as 

 a curative agent, makes it of the highest value as a test of tu- 

 berculosis in cattle. The minute (small) dose which has no 

 effect on a healthy cow, sheep or goat, when employed on the 

 slightly tuberculous one, produces an acceleration of the disease 

 process, and in eight to fifteen hours a material rise of tempera- 

 ture. 



This has been now employed on thosuands of cows, and those 

 who have used it most value it the most highly; whereas many 

 who at first reported reactions in non-tuberculous animals are 

 now acknowledging with Nocard, one of the best veterinarians in 

 K u rope, that the fault has been mainly their own, for the tuber- 

 cles were present, but were overlooked through careless and 

 faulty post mortems. 



The explanation of the reaction under tuberculin may be sim- 

 ply stated as follows: The dose is so small that it will not affect 

 a healthy cow under ordinary conditions. In the slightly dis- 

 eased cow the system contains a certain amount of tuberculin 

 produced by the bacillus (germ) in the tubercles, or nodules, 

 but to this the system has become accustomed and it causes no 

 appreciable fever. But when, in addition to this, we introduce 



