266 CLINICAL BACTERIOLOGY. 



stain taken up. Smegma-bacilli are, however, readily to be 

 distinguished from tubercle-bacilli in that they are decolor- 

 ized within a minute in absolute alcohol, whereas the 

 tubercle-bacilli retain their stain under like conditions. 



Prophylaxis. The principal source of tuberculous in- 

 fection is the sputum of tuberculous patients. If it were 

 possible to render all sputum containing tubercle-bacilli in- 

 nocuous, complete suppression of tuberculosis might be 

 conceivable. The too zealous pursuit of this ideal aim would, 

 however, lead to hardship on the part of tuberculous 

 patients, so that in application the principle must be modi- 

 fied in accordance with humane considerations. Besides, a 

 certain degree of moderation is permissible in this connec- 

 tion, as the liability to the disease may be diminished in not 

 less degree by increasing the individual resistance that is, 

 by improving the general conditions of life than by 



Fig- 59- Pasteboard spit-cup for receiving infectious sputum. After being used, the 

 pasteboard can be removed from the steel frame and burned. 



destruction of the bacilli. In any event, however, the fol- 

 lowing principles should be enforced, or at least impressed 

 upon the general public : The tuberculous patient should 

 expectorate only into a spit-cup of glass or porcelain, filled 

 with water, in order that there may be no opportunity for 

 the sputum to dry and to be converted into dust. In this 

 conversion into dust resides the greatest danger, and for 

 this reason the addition to the cup of all substances capa- 

 ble of generating dust, such as sand, ashes, etc., should be 

 avoided. Disinfection of the sputum can not be accom- 

 plished by means of antiseptic agents, as most of these sub- 

 stances cause coagulation of the albuminous constituents 

 of the sputum and thus give rise to a dense membrane 

 that surrounds the mass and shields the tubercle-bacilli in 

 the interior from contact with the disinfectant. In general, 



