TO BE DUE TO SPECIFIC MICROORGANISMS. 527 



guinea-pigs by injecting into the cavity of the abdomen various 

 chemical substances, such as concentrated mineral acids, acetic acid, 

 phenol, nitrate of silver, etc. It is also demonstrated by numerous 

 experiments that pure cultures of various bacteria injected into the 

 cavity of the abdomen of the animals mentioned may produce a 

 fibrinous or a purulent peritonitis. Among these is the Bacillus coli 

 communis, which is constantly present in the intestine of healthy 

 persons ; and in peritonitis following perforation of the bowel it is 

 probable that this bacillus is responsible, in part at least, for the in- 

 tense peritoneal inflammation which so quickly occurs. In puerperal 

 peritonitis the pus cocci, and especially Streptococcus pyogenes, 

 appear to be the usual cause of the inflammatory process. 



Weichselbaum has observed two cases of primary peritonitis and 

 pleuritis apparently induced by Micrococcus pneumonise crouposse, 

 as this microorganism was found in the exudate into the peritoneal 

 cavity. The same author, in a case of peritonitis resulting from 

 rupture of the spleen in the course of typhoid fever, obtained a pure 

 culture of the typhoid bacillus from the peritoneal cavity. 



The recently published (1891) results of A. Frankel's researches 

 are as follows : In thirty-one cases examined pure cultures were 

 obtained in twenty, viz. : Bacillus coli communis, nine times ; strep- 

 tococci, seven times ; Bacillus lactis aerogenes, twice ; Micrococcus 

 pneumonise crouposae, once ; Staphylococcus pyogenes aureus, once. 

 In three cases Bacillus coli communis was present in association with 

 other bacilli, and in four cases the bacteriological examination gave 

 a negative result. 



PLEURITIS. 



See Empyema, page 520. 



PLEURO-PNEUMONIA OF CATTLE. 



This is an infectious disease, the etiology of which is still undetermined, 

 notwithstanding the researches of numerous bacteriologists. Various bac- 

 teria have been isolated from the exudate into the pulmonary alveoli, but 

 there is no satisfactory proof that any one of these is the specific cause of the 

 disease. 



PURPURA H^EMORRHAGICA. 



See account of bacilli found in purpura hsemorrhagica by Babes 

 (No. 146), Kolb (No. 147), and Tizzoni and Giovannini (No. 145). 



RHINOSCLEROMA. 



See Bacillus of rhinoscleroma (No. 58). 



SCARLET FEVER. 



The specific infectious agent in scarlet fever has not been demonstrated. 

 In the diphtheritic exudate frequently seen in the angina of scarlet fever a 



