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CHAPTER I. 



DISCOVERY OF THE ORGANS OF VOLUNTARY 

 MOTION. 



Sect. 1. Knowledge of Galen and his Predecessors. 



IN the earliest conceptions which men entertained 

 of their power of moving their own members, 

 they probably had no thought of any mechanism or 

 organization by which this was effected. The foot 

 and the hand, no less than the head, were seen 

 to be endowed with life ; and this pervading life 

 seemed sufficiently to explain the power of motion 

 in each part of the frame, without its being held 

 necessary to seek out a special seat of the will, or 

 instruments by which its impules were made effec- 

 tive. But the slightest inspection of dissected ani- 

 mals showed that their limbs were formed of a 

 curious and complex collection of cordage, and 

 communications of various kinds, running along 

 and connecting the bones of the skeleton. These 

 cords and communications we now distinguish as 

 muscles, nerves, veins, arteries, &c. ; and among 

 these, we assign to the muscles the office of moving 

 the parts to which they are attached, as cords move 

 the parts of a machine. Though this action of the 

 muscles on the bones may now appear very obvious, 



