DEATH. 301 



the limit to the duration of vitality, which necessitates a system 

 of reproduction for the continuance of the species, is not con- 

 fined to the organism as a whole, but is found in the vital 

 elements of which it is composed. 



During health, we have seen that though the microscopic 

 constituents of the body are continually changing, and the 

 vital elements dying and replaced by others, yet so perfect 

 are the arrangements for the removal of debris, that no 

 accumulation of effete matter takes place. The baneful 

 effects of even minute quantities of putridity in contact with 

 living textures are now well known to surgeons, and the 

 knowledge furnishes the basis for the proper treatment of 

 sores. But sometimes it happens that in consequence of 

 irritation, either from without or within the body, the 

 nutritive actions in the textural elements are deranged, the 

 living particles attract different constituents from the blood 

 than they are wont to do, act differently on them, and 

 undergo rapid proliferation and disintegration. Examples 

 of such a process are found in ulceration and suppuration, 

 in which, although the pus thrown out consists of living 

 corpuscles, and is the result of vital action, yet there is 

 increased mortality of textural elements and disruption of 

 texture. Sometimes it happens that a whole mass of texture 

 is deprived of vitality by over-irritation, chemical alteration, 

 withdrawal of the supplies of nourishment, or other inter- 

 ference with its nutrition. Such a mass undergoes decom- 

 position all the more rapidly that it is in contact with the 

 warm body; it is called a slough or sphacelus, and when the 

 texture which has died is bone, the death is termed necrosis 

 and the dead part a sequestrum. 



221. As it is with portions of the body, so also with the 

 whole being; death, considered physiologically, is the perma- 

 nent cessation of nutrition. The cessation of consciousness 

 is not death; life may continue when consciousness is gone; 

 and the relation of consciousness to the body is that it is 

 dependent on the nutrition of the brain. 



Death is sometimes spoken of as beginning either at the 

 heart, the lungs, or the brain, which constitute the tripod of 

 life; but the cessation of circulation, leading to the with- 

 drawal of fit nutriment from all the textures, the nervous 



