48 TUBERCULIN, ITS HISTORY, I'liEPAHATION AND USE. 



At the present time there are many different brands of 

 tuberculin (each of which possesses its own particular proper- 

 ties) obtainable from various commercial agents in each of the 

 colonies ; but it is specially recommended that in order to obtain 

 uniform results, only that tuberculin should be used which is 

 prepared and supplied by the Stock Institute : precisely on the 

 same lines that in Germany only Koch's tuberculin is used ; 

 while in Denmark the Government will only allow that to be 

 used which is prepared under the direction of Professor Bang, at 

 Copenhagen ; and in the United States the Government specially 

 recommend that prepared in the Laboratory of the Agricultural 

 Department. 



The overwhelming evidence collected in different countries 

 throughout the world have shown that the use of tuberculin as 

 an aid to the diagnosis of tuberculosis in cattle is one of the 

 most brilliant discoveries of the nineteenth century, and as time 

 passes, its real value and significance will be more and more 

 appreciated by the masses of mankind. 



Now that this test has proved itself to be almost infallible, 

 it should be the desire of every person interested in cattle to 

 commence at once in a judicious and systematic manner and 

 eliminate from his herd, with the least possible loss, every tuber- 

 culosis animal, not forgetting the obligations to the public both 

 in the exchange and sale of live stock and products, both of 

 which should be guaranteed free from tubercular taint. At the 

 same time special attention should be directed to the preserva- 

 tion of certain strains of well known and productive blood, 

 which have taken many years of intelligent thought and careful 

 study by the most observant minds to bring certain well known 

 breeds of cattle up to their present high standard of perfection. 



HOW TO ELIMINATE TUBERCOLOSIS FROM A HERD. 



The following is the method, based on the practical ex- 

 pei'ience of such keen observers and eminent scientists as Pro- 

 fessor Bang, of Copenhagen, Professor McFadyean, of London, 

 and Dr. Salmon, of Washington, I have adopted for the eradica- 

 tion by tuberculosis from the dairy herd at the island of St. 

 Helena : — 



