GANGRENK 83 



Which parts resist gangrene considerably ? 

 Bones and cartilages. 



Describe the chemical causes of gangrene. 



To tMs class belong the escharotics. Caustic acids, as 

 nitric acid, destroy the cells by coagulating the albumen and 

 form' a scurf, or kill the cells, as sulphuric acid, for instance, 

 does by dehydration. Caustic alkalies change the tissue 

 albumen into a smeary, soapy mass, while metallic caustics, 

 as copper sulphate, chloride of zinc, corrosive sublimate, 

 kills the tissue cells by precipitation of a metallic albuminate 

 and the setting free of acids. Finally, snake poisons and 

 certain toxines produce gangrene by chemical processes. 



Describe the thermic causes of gangrene. 



Here excessive heat (combustion) and cold are to be 

 considered. 



Describe the infectious causes of gangrene. 



Certain strep tococcji and staphylococci, Bang's necrosis 

 bacillus, the bacilus of malignant oedema, anthrax, acute 

 glanders, etc., produce gangrene by their toxines, which pro- 

 duce death of the affected tissues either chemically or by 

 interfering with the circulation. Even certain fungi are also 

 credited with such actions, as the ustilago carbo, tilletia 

 caries, polydesmus exitosus. 



Describe the compound causation of gangrene. 



In all diseases where the circulatory apparatus of an 

 animal is seriously taxed, as heart disease, general debility, 

 fevers, cachexia, septicaemia, etc., extensive and serious 

 decubitus is seen to follow comparatively slight traumatisms, 

 .explained by the limited vitality of the tissues due to the 

 impaired nutrition of the body. 



