280 PHYSIOLOGY AND HEALTH. 



all this without any great fatigue. But let a student, whose 

 arms are unaccustomed to labor, and whose muscles are 

 therefore soft, small, and feeble, undertake to do either, and 

 he will, in a few minutes, be exhausted. 



647. The student is not necessarily weak in body. If he 

 is faithful to the laws of health, and takes daily exercise to 

 a suitable degree, his muscular system is sufficiently de- 

 veloped, and he is strong enough for the support of health, 

 though he may be much weaker than the farmer. He can 

 walk several miles. He can do the work of gardening, rake 

 hay, or perform the lighter labor of farming for an hour or 

 two, without much fatigue. The muscles of the inactive 

 and indulged girl, who has been taught that exercise how- 

 ever useful to the laborer, and proper for men and boys is 

 not requisite for her delicate frame, are soft, like those of a 

 babe, and not much stronger. If she attempts to walk a mile, 

 she will fail of accomplishing her purpose, or suffer from 

 fatigue, perhaps from exhaustion. 



648. Exercise develops the form and the strength of the 

 muscles which are called" into operation. In order that the 

 whole should be developed and strengthened, this exercise 

 should be so varied as to use every one of them. The 

 farmer is at one time cutting wood, and thereby using the 

 muscles of the arms and shoulders ; at another, laying stone 

 wall, wjth the muscles of his arms, shoulders, and back; at 

 another time, he is ploughing, and using the muscles of his 

 arms, back, and legs; sometimes pulling, sometimes push- 

 ing, lifting, striking, treading; and in all these ways calling 

 every muscle into action. His muscular energies are, con- 

 sequently, universally developed, and he is strong in all his 

 frame beyond other men. There are other occupations that 

 have nearly the same effect, but none that give the variety 

 of exercise and universality of muscular power that comes 

 from the cultivation of the earth. 



649. All employments that call for the use of only a part 

 of the muscles, but not the whole, develop the size and the 

 strength of those that are used more than the others. So 



