24 THE PRINCIPLES OF MYODYNAMICS. 



1 6. In a human body, whose entire weight is 

 1434 pounds, the recent bones weigh 2 1 4 pounds, 

 and the recent muscles weigh 77^ pounds : and 

 the weight of the bones is to the weight of the 

 muscles as, 



43 : i55 ; 



and the weio^ht of the muscles is to the weigfht 

 of the body as, 



i55 : 287. 



It is easy to determine from the weights and 

 the specific gravities of bones and muscles, that, 

 in the human body, the bulk of the muscles is more 

 tha7i six times the bulk of the bo?ies. 



17. The force of a contracting muscle 

 acting on a bony lever of the first, second, 

 or third order is resolved into two rec- 

 tangular components. 



(a) One of these components tends to move 

 the movable bone, and may be called the moving 

 component : (b) The same component tends to 

 hold the movable bone and the fixed bone to- 

 gether, and may be called the reteiitive co?7i- 

 ponent. (c) The other of these components tends 

 to displace the movable bone from the fixed 



