200 PATHOGENIC BACTERIA. 



are easily prepared, as the thermal death-point deter- 

 mined by Sternberg is 56 C. 



The bacillus appears to be rather common as a sapro- 

 phyte, and, as it has been found in the perspiration, 

 probably is not uncommon upon the skin. 



Before leaving the subject of suppuration attention 

 must be called to several rather common bacteria which 

 may at times be the cause of troublesome suppuration. 

 Among these are the pneumococcus of Frankel and 

 Weichselbaum, the typhoid bacillus, and the Bacillus 

 coli communis (q. v.). 



The pneumococcus has not infrequently been discov- 

 ered most unexpectedly in abscesses of the brain and 

 other deep-seated organs, and seems to have powerful 

 chemotactic powers. For a careful consideration of it 

 the reader must be referred to the chapter upon Pneumo- 

 nia, where it is considered in full. 



The Bacillus coli communis, which is always present in 

 the intestine, seems at times to enter the blood- or lymph- 

 channels and stimulate suppuration, and numerous cases 

 are on record showing this. The points most frequently 

 attacked seem to be the bile-ducts and the vermiform ap- 

 pendix, though the significance of the organism in appen- 

 dicitis has no doubt been overrated. It has also been found 

 in the kidney in scarlatinal nephritis, and is thought to 

 be the exciting cause of some cases. It was originally 

 described by Passet as the Bacillus pyogenes fcetidiis. 

 For a more particular study of this organism the reader 

 is referred to the chapter devoted to its consideration. 



The Bacillus typhosus is probably less frequently a cause 

 of suppuration than either of the others, yet it seems to 

 be the occasional cause of the purulent sequelae of typhoid 

 fever. A case has recently been reported by Flexner in 

 which metastatic abscesses were found to be caused by it. 



The Micrococcus tetragcnus has also been found in the 

 pus of acute abscesses: it is quite common in the cavities 

 of pulmonary tuberculosis, and may aid in the destructive 

 processes involved in the general phthisical infection. 



