138 CLINICAL BACTERIOLOGY. 



coccus is frequently encountered, it is advisable to inoculate 

 a white mouse or a rabbit immediately with the pus. 



BRONCHITIS. 



Bronchitis, whatever its nature may be, is likewise de- 

 pendent upon the activity of the common exciting agents of 

 inflammation : pneumococci, streptococci, staphylococci, 

 pneumobacilli, bacterium coli. Through the action of 

 cold or of some other injurious agency that generally leads 

 to bronchitis, these normal inhabitants of the commence- 

 ment of the respiratory tract become lodged in the bronchi, 

 and there excite inflammation. Their demonstration in 

 sputum is easy. The patient is instructed to cleanse his 

 mouth thoroughly with a solution of boric acid or of potas- 

 sium chlorate, and then to expectorate in a sterilized glass 

 dish. The sputum thus obtained is rinsed carefully in sev- 

 eral vessels of sterile water, and then a flake from the center 

 of the mass is smeared successively upon each of several 

 agar-tubes or upon an agar-plate (Koch). In this way the 

 usual plate -procedure can be avoided, as only one of the 

 species of bacteria named is, as a rule, found in the bron- 

 chitic sputum in each case. The large number of bacteria 

 that are found on microscopic examination of the expectora- 

 tion are mostly derived from the mouth and the pharynx, and 

 are adherent, therefore, to the outer layers of the sputum. 

 In the majority of cases there develop from the expectora- 

 tion thus treated pure cultures of staphylococci, Frankel's 

 diplococci, or streptococci. If mixed infection is present, 

 the colonies develop separately in the tubes last inoculated, 

 and from these they can be readily isolated. 



Fetid bronchitis is associated with the presence of the 

 same bacteria, but, in addition, also with putrefactive 

 bacteria (proteus and others). 



The green color that is sometimes observed in bron- 

 chitic sputum is in some cases due to the bacillus pyocya- 

 neus, in others to the bacillus fluorescens, and to varieties 

 of sarcinae. 



PLEURITIS. 



Pleuritis has no uniform bacteriology. It may be pri- 

 mary or secondary ; in the latter event in association with 

 diseases of the lungs, diseases of adjacent organs, trauma- 



