366 EDEMA 



of suuli gaseous accumulations; it is questionable if the ordinary path- 

 ogenic organisms can cause a pneumothorax, since they are for the 

 most part not capable of producing gas. The colon bacillus produces 

 gas in sugar-containing media, but the amount of sugar in the patho- 

 logical exudates is too small to yield any considerable amount of gas; 

 an exception is the pleural eflfusion in diabetes, and pneumothorax 

 from infection of the pleural effusion in a diabetic by B. coli has 

 been reported. Complete quantitative analyses of the gas in this form 

 of pneumothorax seem not to have been made, but ^lay found about 

 20 per cent, of CO,. The combustibility of the gas has frequently 

 been noted, and is probably due to hydrogen and methane. 



