146 . « CATENATION Sect. XVII. i. 9. 



and another in her arm, which occurred four or five times every 

 minute ; the mufcles were feen to leap, but without bending the 

 arm. To counteract this new morbid habit, an iffue was placed 

 over the convulfed mufcle of her arm, and an adhefive plafter 

 wrapped tight like a bandage over the whole fore arm, by which 

 the new motions were immediately deitroyed, but the means 

 were continued fome weeks to prevent a return. 



9. If any circle of actions is diffevered, either by omiffion of 

 feme of the links, as in fleep, or by infertion of other links, as 

 iri furprife, new catenations take place in a greater or lefs degree. 

 The laft link of the broken chain of actions becomes connected 

 with the new motion which has broken it, or with that which 

 was neareft the link omitted ; and thefe new catenations pro- 

 ceed inftead of the old ones. Hence the periodic returns of 

 ague-fits, and the chimeras of our dreams. 



10. If a train of actions is diffevered, much effort of volition 

 or fenfaticn will prevent its being reftored. Thus in the com- 

 mon impediment of fpeech, when the affociation of the motions 

 of the mufcles of enunciation with the idea of the word to be 

 fpoken is difordered, the great voluntary efforts, which diltort 

 the countenance, prevent the rejoining of the broken affocia- 

 lions. See No. II. 10. of this Section. It is thus likevvife ob- j 

 fervable in fome inflammations of the bowels, the too flrong ef- 

 forts made by the mufcles to carry forwards the offending ma- 

 terial fixes it more firmly in its place, and prevents the cure. So . 

 in endeavouring to recal to our memory fome particular word 

 of a fentence, if we exert ourfelves too ftrongly about it, we are 

 lefs likely to regain it. 



1 1. Catenated trains or tribes of action are eafier diffevered 

 than catenated circles of action. Hence in epileptic fits the 

 fynchronous connected tribes of action, which keep the body 

 erect, are diffevered, but the circle of vital motions continues 

 undifturbed. 



12. Sleep deftroys the power of volition, and precludes the 

 ftimuli of external objects, and thence diffevers the trains, of 

 which thefe are a part ; which confirms the other catenations, 

 as thefe of the vital motions, fecretions, and abforptions ; and 

 produces the new trains of ideas, which conflitute our dreams. 



II. 1. All the preceding circumftances of the catenations of 

 animal motions will be more clearly understood by the follow- 

 ing example of a perfon learning mufic : and w r hen we recollect 

 the variety of mechanic arts, which are performed by affociated; 

 trains of mufcular actions catenated with the effects they pro-?' 

 d (ice, as in knitting, netting, weaving ; and the greater variety 

 :i trains of ideas eaufed or catenated by volitions or 



fenfations, 



