TUBERCULIN AND MALLEIN 175 



has always been feared that tuberculin might cause a necrosis 

 of the tuberculous tissue without completely killing the bacilli, 

 and might thus set them free and inoculate them on a tissue 

 till then unaffected. 



When the tuberculin action does not quite reach the degree 

 of necrosis, it merely produces around the tuberculous focus 

 an active inflammatory reaction with an afflux of leucocytes, 

 which may build up a fibrous, cicatricial tissue in place of the 

 tuberculous ulceration. 



Tuberculin does not produce only local reactions; it pro- 

 vokes a general reaction of the body, the most obvious sign 

 of which is fever. In large doses the reaction occurs even in 

 a healthy individual according to R. Koch, who observed this 

 in himself ; but it is very probable that he had at that time 

 some tuberculosis, and it has been maintained that tuberculin 

 is entirely inactive in subjects who have never been attacked 

 by the bacillus. 



Three or four hours after the inoculation of ^ c.c., Koch 

 observed "twinges of pain in the limbs, a feeling of 

 fatigue, and a tendency to cough. The symptoms became 

 more pronounced, and about the fifth hour he had a violent 

 rigorwhich lasted awhole hour with general uneasiness, vomiting, 

 and fever (103 -3 F.). The symptoms began to settle about 

 the twelfth hour, and on the following day the temperature was 

 normal ; a heaviness of the limbs and stiffness were perceptible 

 for several days after. The point of inoculation remained red 

 and painful for a considerable time." 



In the treatment of a tuberculous patient with tuberculin, 

 doses are employed which do not produce these violent 

 symptoms. As far as possible no symptom, not even fever, 

 ought to occur. A well-conducted treatment produces an 

 improvement in many patients ; this fact is certain, but the 

 mechanism of these cures is not yet well understood. The 

 indications and contra-indications for treatment are complex, 

 and cannot be settled except by a physician with a large 

 experience of tuberculosis and tuberculin treatment. 



The febrile reaction which follows the inoculation of a dose 



