Sect. XXI. 2. REPETITION AND IMITATION. 29- 



II. The repetitions of motions may be at firft 

 produced either by volition, or by fenfation, or by 

 irritation, but they foon become eafier to perform 

 than any other kinds of action, becaufe they foon 

 become afibciated together, according to Law the 

 feventh, Section IV. on Animal Caufation. And 

 becaufe their frequency of repetition, if as much 

 fenforial power be produced during every reitera- 

 tion as is expended, adds to the facility of th^ir pro- 

 duction. 



If a (Umulus be repeated at uniform intervals of 

 time, as defcribed in Section XII. 3. 3. the action, 

 whether of our mufcles or organs of fenfe, is pro- 

 duced with ftill greater facility or energy ; becaufe 

 the fenforial power of aflbciation mentioned above, 

 is combined with the fenforial power of irritation ; 

 that is, in common language, the acquired habit af~ 

 fifts the power of the ftimulus. 



This not only obtains in the annual, lunar, and 

 diurnal catenations of animal motions, as explained 

 in Section XXXVI. which are thus performed with 

 great facility and energy; but in every lefs circle of 

 actions or ideas, as in the burthen of a fong, or the 

 reiterations of a dance. To the facility and diftinct- 

 nefs, with which we hear founds at repeated inter- 

 vals, we owe the pleafure, which we receive from, 

 mufical time, and from poetic time ; as defcribed 

 in Botanic Garden, P. 2. Interlude 3. And to this 

 the pleafure we receive from the rhimes and allite- 

 rations of modern verification ; the fource of which 

 without this key would be difficult to difcover. 

 And to this likewife fliould be afcribed the beauty of 

 the duplicature in the perfect tenfe of the Greek 

 verbs, and of fame Latin ones, as tango tetigi, mor- 

 deo momordi. 



There is no vaiiety of notes referable to the 

 gamut in the beating of the drum, yet if it be per- 

 formed in mufical time, it is agreeable to our ears ; 



and 



