250 TUBERCULOSIS. 



and in addition there occurs around any tubercular focus 

 great inflammatory reaction, resulting in necrosis and a 

 casting off of the tubercular mass, when this is possible. 

 These appearances can be well seen in such a superficial 

 tuberculosis as lupus. The bacilli are, it was shown, not 

 killed in the process. Koch's theory of the action of the 

 substance was that the tubercle bacillus ordinarily secretes 

 a body having a necrotic action on the tissues. When 

 this is injected into a tubercular patient, the proportion 

 present round a tubercular focus is suddenly increased, 

 inflammatory reaction takes place around, and necrosis of 

 the spreading margin occurs very rapidly, the material con- 

 taining the living or dead bacilli being thrown off en masse 

 instead of being disintegrated piecemeal. 



The hopes which the introduction of tuberculin raised 

 that a curative agent against tuberculosis had been dis- 

 covered were soon seen not to be justified. It was very 

 difficult to see how the necrosed material which it produced 

 and which contained 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 be undertaken. Not only so, but the 

 ulceration which might be the sequel of the necrosis 

 appeared to open a path for fresh infection. Soon facts 

 were reported which justified these criticisms. Cases where 

 rapid acute tubercular conditions ensued on the use of 

 tuberculin were reported, and in a few months the treat- 

 ment was practically abandoned. The conditions in 

 guinea-pigs on which the discovery was based have since 

 been found not to be of universal occurrence. 



Recent results appear to show that the tuberculin reaction (i.e., 

 fever, and local necrosis round tubercular deposits, following injection 

 of tuberculin) is not yet fully understood ; for, on the one hand, 

 other substances besides products of the tubercle bacillus may give 

 rise to similar effects in tubercular animals, and, on the other, a 

 similar reaction can take place in other diseases where there is 

 locally in the body a deposit of new tissue. Matthes has, for instance, 

 found that albumoses and peptones isolated from the ordinary peptic 



