30 THE HUMAN BODY. 



in the arterial walls, which thus lose their elasticity; the 

 refracting media of the eye become more or less opaque; 

 the physiological irritability of the sense-organs in general 

 diminishes; and fatty degeneration, diminishing their work- 

 ing power, occurs in many tissues. In the brain we find 

 signs of less plasticity; the youth in whom few lines of 

 least resistance have been firmly established is ready to 

 accept novelties and form new associations of ideas; but 

 the longer he lives, the more difficult does this become to 

 him. A man past middle life may do good, or even his 

 best work, but almost invariably in some line of thought 

 which he has already accepted: it is extremely rare for an 

 old man to take up a new study or change his views, 

 philosophical, scientific, or other. Hence, as we live, we 

 all tend to lag behind the rising generation. 



Death. After the prime of life the tissues dwindle (or 

 at least the most important ones) as they increased in child- 

 hood; it is conceivable that, without death, this process 

 might occur until the Body was reduced to its original 

 microscopic dimensions. 



Before any great diminution takes place, however, a 

 breakdown occurs somewhere, the enfeebled community of 

 organs and tissues forming the man is unable to meet the 

 contingencies of life, and death supervenes. "It is as 

 natural to die as to be born," Bacon wrote long since; 

 but though we all know it, few realize the fact until the sum- 

 mons comes. To the popular imagination the prospect of 

 dying is often associated with thoughts of extreme suffering; 

 personifying life, men picture a forcible and agonizing 

 rending of it, as an entity, from the bodily frame with 

 which it is associated. As a matter of fact, death is prob- 

 ably rarely associated with any immediate suffering. The 

 sensibilities are gradually dulled as the end approaches; the 

 nervous tissues, with the rest, lose their functional capacity, 

 and, before the heart ceases to beat, the individual has 

 commonly lost consciousness. 



The actual moment of death is hard to define: that of the 

 Body generally, of the mass as a whole, may be taken to be 

 the moment when the heart makes its last beat; arterial 



