612 OF NUTRITION. 



the Cells (and of the tissues produced by their transformation) diminishes in 

 proportion to the prolongation of the general life of the system ; and this law 

 exactly corresponds with what has just been observed, as to the comparison 

 of the tissues of different kinds, which are present in the same body. 



5. Of Death, or Cessation of Nutrition. 



813. It is a necessary consequence of that intimate mutual dependence of 

 the several operations, which is characteristic of the higher organisms, that 

 the interruption of the function of any one important part is followed by the 

 Death of the whole structure; because it interferes with the elaboration, cir- 

 culation, or depuration of that nutritive fluid, which supplies the pabulum for 

 the growth and reproduction of each portion of the system. Cut the lives 

 of individual parts may be prolonged for a greater or less duration, after the 

 suspension of the regular series of their combined operations ; hence it is 

 that Molecular Death is not always an immediate result of Somatic Death. 

 But, on the other hand, if the function of the part have no immediate relation 

 to the indispensable actions just alluded to, it may cease without affecting 

 them ; so that Molecular death may take place to a considerable extent (as in 

 entire limbs, or in the muscles and integuments of the head and trunk) with- 

 out Somatic death necessarily resulting. 



814. The permanent and complete cessation of the Circulating current, is 

 that which essentially constitutes Somatic Death; and this may be traced to 

 several distinct causes. In the first place, it may be due to failure in the pro- 

 pulsive power of the Heart, which constitutes Syncope; and this may result 

 from a variety of causes, which cannot be here particularized. Secondly, it 

 may be occasioned by an obstruction to the flow of blood through the capil- 

 laries of the lungs, constituting Asphyxia; and this, as we have seen, may 

 be consequent upon disordered states of the lungs themselves, or upon sus- 

 pension of the respiratory movements, through afl'ections of the Nervous 

 centres. It is in this mode that most fatal disorders of the Nervous System 

 produce death ; except when a sudden and violent impression (as from con- 

 cussion of the brain, or a blow on the epigastrium) occasions a cessation of 

 the heart's power. Thus in Apoplexy, Narcotic Poisoning, &c., death results 

 from the paralyzed condition of the Medulla Oblongata ; whilst in the con- 

 vulsive diseases, the fatal result ensues upon a spasmodic fixation of the 

 respiratory muscles. Thirdly, Somatic death may be occasioned by a dis- 

 ordered condition of the Blood itself, which at the same time weakens the 

 power of the Heart, impairs the activity of the Nervous system, and prevents 

 the performance of those changes in the systemic capillaries, which afford a 

 powerful auxiliary to the circulation. This is Death by Necrsemia. Fourthly, 

 Somatic death may result directly from the agency of Cold, which stagnates 

 all the vital operations of the system. Where the cooling is due to the agency 

 of an extremely low external temperature, which acts rirst upon the super- 

 ficial parts, there is reason to think that the congestion of the internal vessels 

 thereby induced, occasions a torpid condition of the nervous centres, and that 

 the cessation of the Circulation is immediately due to Asphyxia. But when 

 the cooling is gradual, and the loss of heat is nearly equally rapid throughout, 

 it is obvious that the stagnation will be universal, and that no cessation of 

 activity in any one part is the occasion of the stagnation in the functions of 

 the remainder. It is in this manner that death results from Starvation; and 

 not by the weakening of the heart's action, as commonly supposed. The 

 proofs of this will be stated hereafter ( 896). 



815. That Molecular death should speedily follow Somatic death, is not 

 surprising; when it is borne in mind how constant is the dependence of all 



