KOCH'S TUBERCULIN. 231 



latter is injected into a tubercular patient, the proportion of 

 necrosis-producing substance round a tubercular focus being 

 suddenly increased, necrosis of the spreading margin occurs 

 very rapidly, inflammatory reaction takes place around, and 

 the material containing the living or dead bacilli is thrown 

 off en masse instead of being disintegrated piecemeal. 



The publication of these results in the end of 1890 and 

 the beginning of 1891 raised great hopes that a means of 

 combating tuberculosis had been at last discovered, and 

 the earlier results of the treatment of lupus especially 

 appeared to be attended with success. Such hopes were, 

 however, soon seen not to be justified. Koch had stated 

 that the cases of tuberculosis likely to be most benefited 

 were those of early phthisis without cavities and of lupus. 

 Undoubtedly, in the early days of the treatment many cases 

 were treated which did not belong to those classes, but, 

 even in apparently suitable cases, it was very difficult to see 

 how the necrosed material containing the still living bacilli 

 could be got rid of either naturally, as would be necessary 

 in the case of a small tubercular deposit in a lung or a 

 lymphatic gland, or artificially, as in a complicated joint- 

 cavity where surgical interference could, as Koch had him- 

 self recommended, be undertaken. Not only so, but the 

 ulceration which might be the sequel of the necrosis 

 appeared to open a path for fresh infection. Again, it is 

 well known that isolated bacilli may occur in the normal 

 tissue at some distance from a tubercular nodule. Now, 

 while these would probably not be cast off in the necrosed 

 tissue the cells around them might be so depressed by the 

 tuberculin as to make them an easier prey to the bacilli. 

 Soon facts were reported which bore out these theoretical 

 considerations. Virchow threw the weight of his authority 

 against the treatment by adducing cases where rapid acute 

 tubercular conditions ensued on the use of tuberculin. 

 His views were confirmed by many other observers, and in 

 a few months the treatment was practically abandoned. The 

 conditions in guinea-pigs on which the discovery was based 

 have since been found not to be of universal occurrence. 



