CHAPTEE IX. 



GANGRENE. 



GANGRENE, resulting from mycosis of the tissues, is caused by 

 oue of three well defined conditions : 



1. The microbes are so numerous in the capillary vessels that 

 their presence interferes mechanically with the blood supply, and 

 death of the part ensues in consequence of greatly diminished or 

 suspended nutrition. 



2. The microbes in the tissues produce ptomaines which destroy 

 the tissue by their direct destructive chemical action on the proto- 

 plasm of the cells. 



3. The specific inflammation caused by the microbic infection is so 

 intense that the inflammatory products in the paravascular tissues 

 accumulate so rapidly, and in such abundance, that nutrition is sus- 

 pended by impairment or suspension of the arterial blood supply or 

 mechanical interference with the venous return of the blood from 

 the part, or both of these conditions combined. 



For these reasons no one variety of microbes can be the sole cause 

 of gangrene. In its different forms, different microbes will be 

 found. In cases of inoculation anthrax, when at the point of in- 

 oculation an abundant growth of the bacillus takes place, the con- 

 nective-tissue spaces and bloodvessels become so blocked with the 

 bacilli that circulation is mechanically arrested, and a circumscribed 

 gangrene is the result. In the progressive gangrene which Koch 

 produced artificially in rabbits by subcutaneous inoculation of putrid 

 fluids, the gangrene always occurred in advance of the line of mi- 

 crobic invasion, and must, on that account, have been caused by 

 the local toxic effects of the ptomaines. In phlegmonous inflam- 

 mation, when the process is very acute and diffuse, gangrene fre- 

 quently follows as one of the consequences of the inflammation, and 

 the microbe which is found in the gangrenous part is the same as 

 that which caused the inflammauitiou. 



Tricomi (" II micro-parasitica della gangrena senile," Rivista 

 internazionale di Medicina e. CMrwgia, 1886) has found a slender, 

 long bacillus in the blood of patients suffering from senile gangrene. 

 The same bacillus was also found in the secretions of the gangrenous 

 part at the line of demarcation in the lymph spaces and in the sub- 

 cutaneous connective tissue beyond the seat of gangrene. He culti- 



