714 Tuberculosis 



absence of tubercle bacilli when examined by the usual 

 method, yet cause typical tuberculosis when implanted into 

 guinea-pigs, with typical bacilli, recoverable upon culture- 

 media, in the lesions. This is certainly due to the inability 

 of the bacilli in the bovine lesions mentioned to endure the 

 acids, for when the same tissues are stained by Gram's 

 method many organisms can be found. This shows that 

 Gram's method is really a more useful method for demon- 

 strating the bacillus than those in which acids are employed. 

 Naturally, Gram's method, not being differential, is inappro- 

 priate for sputum, cavity contents, and tissues in which many 

 other species of bacteria might be present. Much has found 

 two forms of the tubercle bacillus, one rod-like, the other 

 granular, that are not acid-proof, and has succeeded in 

 changing one into the other by experimental manipulation. 

 He believes that the acid-proof condition has some bearing 

 upon virulence, and speculates that the more acid-proof 

 the organisms are, the less virulent they will be found. 



In this connection the work of Maher,* who claims to be 

 able, by appropriate methods of cultivation, to make many 

 of the ordinary saprophytic bacteria (Bacillus coli, B. subtilis, 

 etc.) thoroughly acid-proof, must be mentioned. 



Staining the Bacillus in Sputum. As the purpose for 

 which the staining is most frequently performed is the 

 diagnosis of the disease through the demonstration of the 

 bacilli in sputum, the method by which this can be accom- 

 plished will be first described. 



When the sputum is mucopurulent and nummular, any 

 portion of it may suffice for examination, but if the patient 

 be in the early stages of tuberculosis, and the sputum is 

 chiefly thin, seromucus, and flocculent, care must be exercised 

 to see that such portion of it as is most likely to contain the 

 micro-organisms be examined. 



If one desires to make a very careful examination, it is 

 well to have the patient cleanse the mouth thoroughly upon 

 waking in the morning, and after the first fit of coughing 

 expectorate into a clean, wide-mouthed bottle, the object 

 being to avoid the presence of fragments of food in the 

 sputum. 



The best result will be secured if the examination be 

 made on the same day, for if the bacilli are few they occur 

 most plentifully in small flakes of caseous matter, which are 



* " International Conference on Tuberculosis," Philadelphia, 1907. 



