CHAPTER XIII. 



suppuration, pyemia, septiggmia, erysipelas. 



Abscess. 



When inflammation is followed by an accumulation of leucocytes 

 and of plasma which does not coagulate, the result is a white or 

 creamy liquid called pus, and when the surrounding tissues are 

 involved so that a cavity develops containing pus, we have what 

 is termed an abscess. The almost constant association of bacteria 

 with the production of pus has created a behef that they are 

 the direct cause of suppuration. Ogston found micrococci present 

 in all acute abscesses, and concluded that acute inflammation was 

 invariably due to their presence. The fact that inflammation 

 occurs more frequently in the external tissues of the body is 

 accordingly explained by the ready entrance of bacteria which 

 are in the air ; and suppuration following pericarditis, pleurisy, 

 and other conditions in which air is excluded is attributed to the 

 presence of pyogenic cocci, which have gained access by the blood 

 stream. There is no pyogenic organism constantly present, but 

 several different species of bacteria have been isolated from pus 

 and carefully studied, and the antiseptic treatment is based upon the 

 principle of excluding bacteria in surgical operations, and destroying 

 any which may have previously obtained access to wounds and 

 broken surfaces. Inflamed tissue and pus form a most suitable 

 medium for the growth of bacteria, which in some cases are 

 unquestionably only accidental epiphytes. 



In tuberculosis, actinomycosis, and glanders, pus formation may 

 take place without the presence of pyogenic cocci ; and it is generally 

 believed that chemical irritants, such as croton oil, turpentine, iodine, 

 cadaverin, and tuberculin, will excite the formation of pus in the 

 absence of bacteria, although Klemperer, after a number of very 

 careful experiments, maintains that no genuine pus will be produced 

 if the chemical irritants are first carefully sterilised. 



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