60 PHYSIOLOGY AND HEALTH. 



137. The wants of nutrition, even in men in good 

 health, depend upon so many circumstances, their exer- 

 cise, exposure, and their temperament, and the digestive 

 powers differ so widely in different people, that we could 

 scarcely find two who require exactly the same quantity of 

 food, nor would the same man require the same quantity at 

 all times. Therefore it is impossible to prescribe any exact 

 weight or measure, which all should eat. But every one 

 who learns the principles which have been stated here, who 

 examines the circumstances of his own life, and carefully 

 watches his own sensations, will be better able to determine 

 how much he shall eat. If then, he faithfully obeys the law 

 of nutrition, and applies it rigidly to his own self-management, 

 he will not err in his diet. 



138. When a man eats sufficiently, and no more, when 

 his stomach has received no more than it can easily digest, 

 he feels refreshed and easy ; he soon becomes light and buoy- 

 ant, and is then ready to recommence his active business. 

 But when the stomach has more than it can easily convert into 

 chyme, it is oppressed with labor, and feels a dead weight 

 bearing it down. All the energies of the body are then con- 

 centrated in the effort of the stomach to perform its extraor- 

 dinary labor, in the same manner as all the energies of the 

 system are concentrated in the extraordinary muscular exer- 

 tion, when we attempt to lift great weights, or to run a race. 

 While the digestive organs, or the muscles, are making these 

 great exertions, we can do nothing else ; we can neither use 

 the brain and think, or study, or calculate, nor can the 

 muscles perform any other labor. 



139. As much food, then, as the system needs and the 

 stomach can digest, gives a man comfort, strength, and ability 

 to apply his powers to business. It enables him to use his 

 brain, and his muscles, and his bones to work with his 

 hands, his feet, and his mind. But all excess of food beyond 

 this, every mouthful more than is needed or easily dissolved, 

 gives weakness, instead of strength, for business. It is a tax 

 upon the vital energies, and a clog upon the motions of the 



