FIRST CENTURY OF DAIRYING IN NEW SOUTH WALES. 



literature reports of cases treated with tuberculin as originally pre- 

 pared by Koch, and in many instances improvement has been recorded, 

 its use as a therapeutic agent has, except in special cases, been dis- 

 carded. Its value, on the other hand, for the early diagnosis of tuber- 

 culosis in animals is generally recognised. Fo lowing the careiul 

 methods proposed by Dr. Trudeau, tuberculin offers also a means of 

 positive diagnosis in man, and of indicating whether the disease, after 

 treatment, has been arrested or cured. 



" When tuberculin failed to give satisfactory results as a curative 

 agent, attention was quickly directed to the preparation of a serum on 

 the same principle as the diphtheria anti-toxic serum. Maragliano, 

 Babes, Behring, and others prepared such material for the treatment 

 of tuberculosis by infecting horses with tuberculin alone, or a com- 

 bination of tuberculin and virulent cultures. After a long-continued 

 infection of the animals, the serum obtained was claimed to have anti- 

 toxic properties, and when this scrum was injected subcutaneously 

 into tuberculous animals, together with a dose of tuberculin, the fatal 

 effects or characteristic rise of temperature from the latter was 

 counteracted. The strength o*f the serum was based upon the quantity 

 necessary to prevent a tuberculous reaction. This method, however, 

 did not fulfil all the conditions. In the first place, as tuberculin is 

 prepared from the cultures of the germ, it is submitted to such a 

 temperature that some of the products of the germ 1 ife ar: changed 

 or decomposed, and hence tuberculin as used does not represent the 

 poisons of the tubercle germ as they are actually found in the animals 

 suffering from this disease. Consequently, a serum which counteracts 

 the fever-producing properties of tuberculin does not necessarily exert 

 a beneficial influence upon all the phases of the disease." 



Dr. Schweinitz further states : " Assuming that while it may not be 

 possible to establish a perfect artificial immunity in animals, but that 

 the disease may be checked by reinforcing the natural resistance which 

 is always present, we have endeavoured to secure, in a slightly dif- 

 ferent way from the one above described, a serum useful for treat- 

 ing tuberculosis. In the first place, as reported to the Medical Society 

 some time ago, we had 'found that if an originally virulent tubercle 

 bacillus was cultivated for many generations upon artificial media, 

 while it did not lose the property of producing active poisons when 

 so cultivated, it did lose the property of p.odu.iig tuberculosis in 

 animals when the latter was injected. Furthermore, sucli animals as 

 guinea pigs after a time possessed a very marked resistance to tuber- 

 culosis when they were subjected to an inoculation with virulent 

 tubercle bacilli that would cause disease in six months." 



Whether further application of the serum treatment in its present 

 form will continue to prove beneficial and give better results ; whether 

 this must be materially modified, cannot be stated positively. The 

 results obtained certainly show that the efforts are properly directed. 

 True, many individuals hold that on account of the slight evidence 

 that can be found in the clinical history of tuberculosis, there is little 

 to lead us to believe that immunity ever occurs in the natural course 

 of this disease. Vet the experiments of Dr. Trudeau and Schweinitz 

 certainly show that artificial immunity is possib e. In th: meantime 

 it behoves every dairyman to keep a strict watch on his stock, and 

 note every symptom that may indicate the presence of th~ disease. 

 Immediate destruction is the safest plan. 



The condition which favours tuberculosis is first and forem.t ex 

 cessive milk production, and this is often rendered hereditary by close 

 in-breeding and breeding in line from predisposed animals. Again, 

 whatever undermines the health or stamina, such as breeding and 

 heavy milking before maturity, breeding from old and debilitated ani- 

 mals, insufficient rations, and ill-balanced ration, such as brewers' 

 grains or similar foods, possessed of but one or two constituents 

 which stimulate the milk production only ; ill-health, local inflamma- 



268. 



