EASIEST POSITION. 533 



itself, as well as the muscles, passes into a state of rest. Some 

 of the hamboo easy chairs manufactured in India allow us to 

 obtain the advantages of both positions. These chairs are made 

 in the form of a somewhat irregular straggling W> and in them 

 one can lie on one's back with every part of tlie body thoroughly 

 supported, and the knees bent in the same way as they would 

 be if one lay upon one's side. 



Thus simple inaction, the relaxation of muscles, and the 

 laxity of joints, are some of the factors necessary for complete 

 rest, and an easy chair, to be perfect, must secure them all. 



But it is possible for an easy chair to secure all these and yet 

 be imperfect. We have just said that usually, as the fatigue 

 becomes greater and greater, the tendency is to assume the 

 position of the |\| with the limbs at a more or less obtuse 

 angle, but when sitting in an ordinary chair we find relief from- 

 raising the feet by means a foot-stool, although this tends to* 

 make the angles of the N more acute instead of more obtuse- 

 Still more relief, however, do we obtain when the legs are raised 

 up on a level with the body by being placed upon another- 

 chair, or by being rested on the Indian bamboo seat already 

 described. If, in addition to this, tlie logs are gently sham- 

 pooed upwards, the sensation is perfectly delightful, and the- 

 feelings of fatigue are greatly lessened. To understand how 

 this can be, it is necessary for us to have some idea as to the 

 cause of fatigue. Any muscular exertion can be performed for 

 a considerable time by a man in average health, without the- 

 least feeling of fatigue, but by and by the muscles become- 

 weary, and do not respond to the will of their owner so rapidly 

 as before ; and if the exertion be too great, or be continued for 

 too long a time, they will ultimately entirely refuse to perform 

 their functions. The muscle, like a stcaiu -engine, derives the 

 energy which it expends in mechanical work* from the combus- 

 tion going on within it, and this combustion, in both cases, 

 would come to a standstill if its waste products or ashes were 

 not removed. It is these waste products of the muscle which, 

 accumulating within it, cause fatigue, and ultimately paralyse 

 it. This has been very neatly shown by Kronccker, who caused 

 a frog's muscle, separaited from the body, to contract until it 



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