OCCURRENCE OF CAUSATIVE AGENTS. 151 



which, next to the rheumatic, is probably the most com- 

 mon variety. Its exciting agent, the tubercle-bacillus, 

 gains entrance into the pericardium through direct exten- 

 sion of the tuberculous process from the adjacent lung, or 

 by way of the blood or the lymph. 



The bacteriologic diagnosis is possible during life only 

 on puncture or operation for the relief of the pericardial 

 effusion. 



MYOCARDITIS. 



Suppurative Myocarditis. A greater or smaller number 

 of purulent foci of varying size may be present in the heart- 

 muscle in association with pyemic processes of diverse 

 origin. They contain pyogenic microbes. 



Acute Diffuse Myocarditis. Acute inflammation of the 

 myocardium may complicate all infectious diseases of rapid 

 course. Its bacteriologic relations are as yet but little 

 known. The bacillus of GafTky-Eberth has been repeat- 

 edly found in the myocardium in cases of typhoid fever. 

 Frequently, however, the infection appears to be secondary 

 and dependent upon the common exciting agents of inflam- 

 mation. The metabolic products of microorganisms may 

 likewise give rise to similar myocarditic alterations as, for 

 instance, the toxin of the diphtheria-bacillus, which is the 

 cause of diphtheric myocarditis. 



PERITONITIS. 



The inflammatory processes involving the peritoneum 

 may be induced through chemic influences exerted by the 

 metabolic products of bacteria aseptic peritonitis, for in- 

 stance, in consequence of absorption of decomposition- 

 products from the intestine in cases of ileus. In the 

 majority of cases, however, such processes result directly 

 from the activity of bacteria (bacterial or septic peritonitis). 

 In accordance with the source of the exciting agents, peri- 

 tonitis is conveniently divided into several varieties : (i) 

 That which arises from the digestive tract from the 

 stomach, the duodenum, and the small intestine, as well as 

 from the cecum, the vermiform appendix, the colon, and the 

 rectum ; (2) that which arises from the gall-bladder and 

 the liver ; (3) that which arises from the kidneys and the 

 urinary bladder ; (4) that which arises from the female 



