136 THE MORE CHRONIC INFECTIOUS DISEASES 



inflammation in the neighborhood of tubercles. The endo- 

 toxins, on the other hand, produce the peculiar local inflam- 

 mation called the tubercle, and cause its degeneration into 

 caseous material. During an infection with tuberculosis 

 there will be developed in the body fluids a very slight 

 amount of substances as antibody to these endo- and extra- 

 cellular poisons. It is of little importance in the diagnosis, 



FIG. 42. Tuberculosis of the lung. (Stengel.) 



treatment, or protection of the individual, and a specific 

 resistance to tuberculosis is not acquired by passing through 

 an attack. Recovery ensues when the health of the individual 

 and his tissues is strong enough to inhibit the multiplication 

 of bacilli. A lighting up of the disease may occur when the 

 resistance weakens by reason of some acute disease, bad 

 habits and the like. 



