90 OF THE MUSCLES. 



ropes, and places the strand of one opposite and between th6 

 strand of" another, and so interlaces them. And this explains 

 wlty a hawser-rope, a sort of small cable, is spun of three 

 strands ; for as they are necessary for many operations in the 

 ringing of a ship, they must be formed in a way that admits 

 of being cut and spliced, for the separation of three strands, 

 at least, is necessary for knotting, splicing, whipping, mail- 

 ing, &c., which are a few of the many cm-ious contrivances 

 for joining the ends of ropes, and for strengthening them by 

 filling up the interstices to preserve them from being cut or 

 frayed. As these methods of splicing and plaiting in the 

 subdivisions of the rope make an intertexture stronger than 

 the original rope, it is an additional demonstration, if any 

 were wanted, to show the perfection of the cordage of an 

 animal machine, since the tendons are so interwoven; and 

 until the yarns of one strand be separated and interwoven with 

 the yarns of another strand, and this done with regular ex- 

 change, the most approved patent ropes must be inferior to 

 the corresponding part of the animal machinery. 



A piece of cord of a new patent has been shown to us, 

 which is said to be many times stronger than any other cord 

 of the same diameter. It is so far upon the principle here 

 stated, that the strands are plaited instead of being twisted ; 

 but the tendon has still its superiority, for the lesser yarns of 

 each strand in it are interwoven with those of other strands. 

 It however, gratifies us to see, that the principle we draw 

 from the animal body is here confirmed. It may be asked, 

 do not the tendons of the human body sometimes break ? 

 They do ; but in circumstances which only add to the interest 

 of the subject. By the exercise of the tendons, (and their 

 exercise is the act of being pulled upon by the muscles, or 

 having a strain made on them, they become tirmer and strong- 

 er ; but in the failure of muscular activity, they become less 

 capable of resisting the tug made upon tiiem, and if, after a 

 long confinement, a man has some powerful excitement to 

 muscular exertion, then the tendon breaks. An old gen- 

 tleman, whose habits have been long staid and sedentary, 

 and who is very guarded in his walk, is upon an annual festi- 

 val tempted to join the young people in a dance ; then he 

 breaks his tendo Achillis. Or a sick person, long confined 

 to bed, is, on rising, subject to a rupture or hernia, because 

 the tendinous expansions guarding against protrusion of the 

 internal parts, have become weak from disuse. 



Such circumstances remind us that we are speaking of a 

 living body, and that, in estimating the properties of the ma- 

 chinery, we ought not to forget the influence of life, and that 

 the natural exercise of the parts, whether they be active or 

 passive, is the stimulus to tlie circulation through them, and 

 to their growth and perfection. 



