NA TURE OF SUPPURA TION. 145 



cells of the part, those most highly organised being affecte'd 

 first ; and (c] a liquefaction or digestion of the supporting 

 elements of the tissue. Any previously- formed fibrin is 

 also softened and disappears. The result is that the solid 

 tissue becomes replaced by the cream-like fluid called pus, 

 a fluid which does not coagulate, and in which the chief 

 cellular elements are multinucleated leucocytes, along with 

 the degenerated cells of the part. Suppuration is therefore 

 to be distinguished, on the one hand, from a severe inflam- 

 mation, in which, however, the tissue is not destroyed, and 

 on the other hand, from necrosis or death of the tissue en 

 masse. When, however, suppuration is taking place in a 

 very dense fibrous tissue, liquefaction may be incomplete, 

 and a portion of dead tissue or slough may remain in the 

 centre, as is the case in boils. In the case of suppuration 

 in a serous cavity the two chief factors are the progressive 

 leucocytic accumulation and the disappearance of any fibrin 

 which may be present. 



The liquefaction of the formed tissue elements in sup- 

 puration is believed to depend upon a peptonising action of 

 the organisms or of ferments produced by them, and the 

 progressive leucocytic aggregation is explained by many as 

 also being the effect of microbic products which attract the 

 leucocytes, or in other words exert a positive chemiotaxis. 

 We might expect that any organisms which could flourish 

 in the tissues and exert these actions would produce sup- 

 puration, and as a matter of fact a considerable number 

 have been found to possess pyogenic properties. 



The terms septicizmia sm&pycemia may be first explained, 

 as these will be frequently used. Septicaemia is applied 

 to conditions in which the organisms multiply within the 

 blood and give rise to symptoms of general poisoning, 

 without, however, producing abscesses in the organs. It is to 

 be distinguished from conditions in which there is a merely 

 local growth of bacteria, the symptoms being produced by 

 absorption of their toxines. In all cases of septicaemia the 

 organisms are more numerous in the capillaries of certain 

 organs than in the peripheral circulation, and, in the case 

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