TUBERCULIX. ITS HISTORY. PREPARATION AND 



USE. 



By C. J. POUND, F.R.M.S., 



Director, Queensland Stock Institute. 



[/?('//(/ hi'fon' the Ivnjal Socit'ti/ of Qiwennldntl, 17th IW., 1898.] 



Every day brings forth evidence of the prevalence of 

 .tuberculosis among cattle, in every country throughout the 

 , civilised world, but it is particularly interesting to note that by 

 far the greater number of cases have only been detected by means 

 -of that most invaluable agent, Tuberculin. 



HISTORY. 



In 1882, Robert Koch, the eminent German Bacteriologist, 

 announced that he had discovered a special bacillus in tubercular 

 tissues, which he isolated and cultivated artificially in or on 

 .specially prepared nutrient media outside the animal body ; also, 

 that he could reproduce the disease by means of inoculation with 

 the cultivated bacillus. Subsequent investigation proved that 

 the bacillus of human consumption was identical with that which 

 caused Tuberculosis in cattle. 



In 1890, Koch made another interesting discovery, viz., 

 ^that the isolated poisonous products of the tubercle bacillus were 

 (1) capable of preventing the effects of the inoculation of tuber- 

 culous material, (2) of healing in certain manifestations of tuber- 

 culosis HI the early stage, and (3) of indicating the presence of 

 tiiberculous lesions, when all other methods of diagnosis entirely 

 failed. 



Tuberculin is the name given by Koch to the glycerine 

 -extract of the poisonous products of the tvtbercle bacillus. 



