272 CLINICAL BACTERIOLOGY. 



arise through them. In the case of tuberculosis, however, 

 only those individuals are dangerous who present actual 

 symptoms of disease that is, those who throw off tubercle- 

 bacilli with the sputum or other excretions. In the case of 

 tuberculosis thus the diagnostic requirements on the part 

 of both physician and sanitarian are identical ; whereas in 

 the case of cholera and of diphtheria these diverge. From 

 the foregoing considerations the employment of injections 

 of tuberculin for diagnostic purposes should be restricted to 

 cases of actual disease of obscure etiology. Frequently, how- 

 ever, under such conditions also this test has been abstained 

 from because experience in some cases has demonstrated 

 the possibility of the bacilli being disseminated from a pre- 

 viously circumscribed focus throughout the entire body as 

 the result of an injection of tuberculin. 



The therapeutic employment of tuberculin in tuberculous 

 individuals has yielded the following results : Lupus is at 

 times favorably influenced by tuberculin. Extensive areas 

 of lupus undergo necrosis and are exfoliated, so that com- 

 plete recovery may take place ; but no case is yet known 

 in which recurrence has not taken place. Ulcers of the 

 larynx clear in a most remarkable manner after injections 

 of tuberculin, and undergo healing ; but in these cases also 

 recurrence generally takes place. Intestinal and peritoneal 

 tuberculosis appears to pursue a relatively favorable course 

 when treated with injections of tuberculin. Under all of 

 these conditions, however, the fact stands out that the 

 results are not final, because tuberculin lacks immunizing 

 properties. Tuberculous disease of bones and joints is not 

 at all influenced by the treatment. With relation to pul- 

 monary tuberculosis, it may be stated with certainty that in 

 the presence of advanced infiltration, of cavity-formation, 

 and of mixed infection success can not be attained with 

 tuberculin-treatment ; and it is questionable, further, whether 

 even incipient tuberculosis can be cured by the original 

 method of Koch. A large number of unfavorable results 

 are opposed to a small number of undoubted cases of in- 

 cipient tuberculosis treated with favorable results. The 

 objection may be raised that the results obtained in these 

 cases are not attributable to the specific agent, but to the 

 nutritive and general therapeutic measures employed simul- 

 taneously. Tuberculin has been almost entirely abandoned 

 by physicians. In veterinary medicine, especially in France, 



