PART III. 



PATHOGENIC BACTERIA. 



CHAPTER I. 



SUPPURATION PUS COCCI. 



Suppuration, or the formation of pus, is not necessarily the 

 result of bacterial activity. It may represent tissue-reaction 

 to irritants other than bacteria, or to both combined. When 

 suppuration is due to micro-organisms, it is called a specific 

 process ; when due to other agents, it is called a non-specific 

 process. Turpentine, croton oil, carbolic acid, ammonia, and 

 very strong solutions of mercuric chloride cause pus-formation. 

 Identical results can also be produced by injecting cultures 

 of the pus-forming bacteria that have been sterilized for two 

 hours or more ; by injecting sterilized products of bacterial 

 activity, such as the albumoses, enzymes, etc. Some of 

 the vegetable alkaloids, and any chemical substance which 

 exerts a chemotactic action on the leucocytes or which induces 

 necrosis of tissue, will cause a typical suppuration. No 

 matter whether the pus is the result of the action of bacteria 

 or chemicals, the composition of the pus is the same, except 

 that non-specific pus does not contain bacteria and is not 

 infectious. 



Before the nature of bacteria and their part in the produc- 

 tion of disease were thoroughly understood, pus-formation 

 was looked upon as a necessary step in the healing of wounds 

 and in the resolution of the infectious diseases. The physi- 

 cian did all in his power to facilitate the occurrence of sup- 

 puration, and to have as much pus as possible, so as to hasten 



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