DISEASES OP SHEEP. 23 



part lias been of an important nature, the death of the 

 animal. Whenever exterior or less important parts (for 

 instance, the skin to a great extent) are affected- with 

 gangrene, there is no danger, but gangrene of the entrails 

 always results in death. The degree of importance of the 

 affected part, therefore, always increases the danger to be 

 feared from gangrene. Gangrene generally arises from ex- 

 tremely violent inflammations, which continue for a longer 

 period ; also from mechanical causes, such as continual 

 pressure or forcible contusions, from frost or burns (in frost- 

 bitten or scorched limbs), from the effect of animal, vege- 

 table and mineral poisons ; and wherever the circulation 

 of the blood is entirely checked, either by accident or by 

 design (for instance, when a wort or a scrotum is tied off, 

 such parts always become affected with gangrene). Two 

 kinds of gangrene exist — namely, the so-called hot gan- 

 grene (mortification), and cold gangrene (sphacelus), the 

 former being the last degree of inflammation, and con- 

 stituting the intermediate degree or transition from in- 

 flammation to the latter (sphacelus). Parts affected with 

 mortification can never be reanimated. A gangrenous 

 part ceases by degrees to be subject to pains, the swelling 

 and the former hardness and tension caused by inflamma- 

 tion partly disappears, and the impression made by the 

 touch of the finger upon such a part remains for a con- 

 siderable time. A gangrened spot is a dark red, bluish- 

 black, pallid or pale gray color. The skin of such a part 

 separates in different places of the ulcer and rises in the 

 form of bladders, from which a thin, acrid and bad-smell- 

 ing fluid issues, or sometimes in the form of air-bubbles 

 of larger or smaller dimensions. A gangrenous part con- 

 tains no warmth at all ; it is cold and painless, begin- 

 ning to rot, and therefore entirely void of life. The de- 

 tection of gangrene in interior or such parts as cannot be 



