308 PHYSIOLOGY AND HEALTH. 



fied, or else the brain will not cooperate with its full energy, 

 and give the muscles full power. When the farmer fears 

 that the cultivation of his fields will produce no crop, when 

 the laborer believes the wages are inadequate to his services, 

 and the mechanic thinks his wares will return him no profit, 

 they cannot make their greatest exertions, or, if they do, it is 

 at a cost of the permanent power. But the laborer who is 

 well paid generally feels a motive that stimulates the brain, 

 and strengthens the muscles, and enables him to work vigor- 

 ously and successfully. 



711. Hope and confidence give almost unmeasured strength ; 

 but despair weakens, almost paralyzes. When a man 

 falls overboard at sea, he swims for his life as long as 

 he has hope of rescue or can move his limbs, until, fatigued 

 with his labor, and in despair of obtaining relief, he seems 

 unable to swim any farther, and suspends all exertion, and 

 gives himself up to death. But if, at this moment, a boat 

 comes in sight, or land appears to him, a new hope is ex- 

 cited, new strength is given, and he swims again with a 

 power which was impossible a few minutes before. 



712. The same effect of confidence that strengthens the 

 muscular system, and of doubt that weakens and sometimes 

 paralyzes exertion, may be seen in any of the labors of com- 

 mon life. If the student walks grudgingly, with doubt as to 

 the efficacy of the exercise, and fear that he is misappropri- 

 ating his time ; if the over-cautious girl walks with fear lest 

 the exercise flush her cheek too much, or the perspiration 

 soil her garments, or the exercise derange her dress ; if she 

 moves with timid anxiety lest she assume ungraceful atti- 

 tudes, or in any way transcend the becoming delicacy of a 

 lady, the brain will not cooperate earnestly .with the work, 

 nor send full stimulus to the muscles ; the limbs then labor 

 languidly, and the exercise fails to invigorate the system. 



713. Cheerfulness and melancholy have the same op- 

 posing effects on muscular power as hope and despair, 

 Whatever depresses the spirits, depresses the energies of the 

 brain, and consequently the energies of the locomotive ap 



