Sect. XVII. i; I. CATENATION, &c. j 4i 



SECT. XVII. 



THE CATENATION OF MOTIONS. 



I. I. Catenations of animal motion, 2. Are produced by irritations ± 

 byfenfations, by volitions. 3 . They continue fome time after they 

 have been excited. Caufe of catenation. 4. We can then exert 

 our attention on other objecls, 5. Many catenations of motions go 

 on together. 6. Some links of the catenations of motions may be 

 left without dij uniting the chain. 7. Interrupted circles of tno- 

 tion continue confufedly till they come to the part of the circle, 

 where they ivere diflurbed. 8. Weaker catenations are dijfever- 

 ed byjlronger. 9. Then new catenations take place. 10. Aluch 

 effort prevents their re-uniting. Impediment of fpeech. II. Trains 

 more eafly diffevered than circles. 12. Sleep deflroys volition and 

 external Jlimulus. II. In/lances of various catenations in a young 

 lady playing on the harpfichord, III. 1. What catenations are 

 the firongefl. 2. Irritations joined with afifociationsfromfirong~ 

 ejl connexions. Vital motions. 3. New links with increafed 

 force y cold fits of fever produced. 4. New links with decreafed 

 force. Cold bath. 5. Irritation joined with fenfation. inflam- 

 matory fever. Why children cannot tickle themfelves. 6. Voli- 

 tion joined with fen fatwi. Irritative ideas of found become Jcnfi- 

 ble. 7. Ideas of imagination diffevered by irritations y by volition, 

 production of furprife. 



I. 1. To inveftigate with precifion the catenations of animal 

 motions, it would be well to attend to the manner of their pro- 

 duction ; but we cannot begin this difquifition early enough for 

 this purpofe, as the catenations of motion feem to begin with 

 life, and are only extinguifhable with it. We have fpoken of 

 the power of irritation, of fenfation, of volition, and of afTocia- 

 tion, as preceding the fibrous motions ; we now ftep forwards, 

 and confider, that converfely they are in their turn preceded by 

 thofe motions ; and that all the fuccelfive trains or circles of our 

 actions are compofed of this twofold concatenation. Thofe we 

 (hall rail trains of action, which continue to proceed without 

 any dated repetitions ; and thofe circles of action, when the 

 parts of them return at certain periods, though the trains, of 

 which they confift, are not exactly fimilar. The reading an 

 epic poem is a train of actions •, the reading a fong with a cho- 

 rus at equal diftances in the meafure conftkutes fo many circles 

 of action. 



2. Some catenations of animal motion are produced by reiter- 

 ated 



