ECT. XVIL i. CATENATION OF MOTIONS. 223 



Other catenations of motions are gradually ac- 

 quired by frequent voluntary repetitions ; as when 

 \ve deliberately learn to march, read, fence, or any 

 mechanic art, the motions of many of our mufcles 

 become gradually linked together in trains, tribes, 

 or circles of aclion. Thus when any one at firft 

 begins to ufe the tools in turning wood or metals 

 ia a lathe, he wills the motions of his hand or fin- 

 gers, till at length thefe actions become fo connected 

 with the effect, that he feems only to will the point 

 of the chifiel. Thefe are caufed by volition, con- 

 nected by aflbciation like thofe above defcribed, and 

 afterwards become parts of our diurnal trains or 

 circles of action. 



3. All thefe catenations of animal motions are li- 

 able to proceed fome time after they are excited, un- 

 lefs they are diflurbed or impeded by other irrita- 

 tions, fenfations, or volitions ; and in many in- 

 flances in fpite of our endeavours to flop them ; 

 and this property of animal motions is probably the 

 caufe of their catenation. Thus when a child re- 

 volves fome minutes on one foot, the fpeclra of 

 the ambient objects appear to circulate round him 

 fome time after he falls upon the ground. Thus 

 rhe palpitation of the heart continues fome time 

 after the object of fear, which occafioned it, is re- 

 moved. The blufh of fhame, which is an excefs 

 of fenfation, and the glow of anger, which is an 

 excefs of volition, continue fome time, though the 

 affected perfon finds, that thofe emotions were 

 caufed by miftaken facts, and endeavours to ex- 

 tinguifh their appearance. See Sect. XII. i. 5. 



4. When a circle of motions becomes connected 

 by frequent repetitions as above, we can exert our 

 attention ftrongly on other objects, and the conca- 

 tenated circle of motions will nevertheless 'proceed 

 in due order ; as whilfl you are thinking on this 



fubjects, 



