116 PHYSIOLOGY AND HEALTH. 



suffer from disease of heart cannot make great exertions, be- 

 cause the heart cannot carry the blood needed to supply the 

 greater waste. 



253. The waste of the old atoms of flesh, and the demand 

 for new, being increased by exercise, of course more blood 

 is then consumed to supply the want which is thus created ; 

 and, consequently, more food must be eaten and digested, to 

 supply the blood with the new chyle sufficient to repair 

 this loss. ( 127, p. 61.) The laborer must therefore eat 

 more than the indolent, and individuals in active youth need 

 more food than in quiet old age. But, in inactive life, the 

 absorption is comparatively little, and the nutrition and the 

 consumption of blood are equally small ; there is less de- 

 mand for food, and a corresponding diminution of appetite. 

 If the idle disregards this law of his nature, and eats as much 

 as the laborious, the stomach is troubled with the burden; 

 and, if it digests and converts the food into chyle, the blood- 

 vessels are overfilled with the amount of blood which they 

 cannot use, and the whole frame is heavy and sluggish. The 

 apostle's command that; " if any would not work, neither 

 should he eat," which was given as a moral law, is equally 

 binding as a physical law, and cannot be disobeyed without 

 suffering. 



254. The processes of destruction and creation have usu- 

 ally the same comparative activity in all parts of the body, so 

 that no part grows fat or lean more than another. But this 

 is not always the case. If one organ or part is more active 

 than the others, it grows more than they. Thus the arms of 

 some laborers, and the legs of others, grow disproportion- 

 ately large, because they are more used than their other 

 limbs. But parts that are not used at all waste away, and 

 are often withered. The arm of one of my neighbors was 

 palsied about twenty years ago, and it is now shrunken to 

 the size of a child's arm; the unused muscles are nearly 

 absorbed. 



255. Wens, and other fleshy tumors, are the effect of the 

 unnatural activity of the nutrient vessels, which deposit 



