CLASS IV. 1. 1. OF ASSOCIATION. Z 6t 



D. AJJbctations affefted by other Senforial Motions, 



Circles and trains of affociate motions are alfo liable to be af- 

 fected by their catenations with other fenforial powers, as of ir- 

 ritation, or fenfation,or volition , which other fenforial powers ei- 

 ther thus fimply form fome of the links of the catenation, or add 

 to the energy of the aflbciated motions. Thus when vomiting 

 is caufed by the ftimulus of a ftone in the ureter, the fenfation of 

 pain feems to be a link of the catenation rather than an efficient 

 caufe of the vomiting. But when the capillary veffels of the 

 fldn increafe their action from the influence of external heat, 

 they are excited both by the ftimulus of unufual heat, as well 

 as by the ftimulus of the blood, and by their accuftomed affoci- 

 ation with the actions of the heart and arteries. And laftly, in 

 the blufh of anger the fenforial power of volition is added to 

 that of affociation, and irritation, to excite the capillaries of the 

 face with increafed action. See Clafs IV. 2. 3. 5. 



E. djjociations catenated 'with Senfation* 



Pain frequently accompanies affociate trains or circles of mo- 

 tion without its being a caufe, or a link, of them, but fimply an 

 attendant fymptom , though it frequently gives name to the 

 difeafe, as head-ach. Thus in the cramp of the calves of the 

 legs in diarrhoea, the increafed fenforial power of aflbciation is 

 the proximate caufe ; the preceding increafed action of the bow- 

 els is the remote caufe ; and the proximate effect is the violent 

 contractions of the mufculi gaftrocnemii ; but the pain of 

 thefe mufcles is only an attendant fymptom, or a remote effect. 

 See Sect. XVIII. 15. Other fenfitive aflbciat ions are mention- 

 ed in Clafs IV. I. 2. and IV. i. 2. 15. 



Thus, if the flufhing of the face above mentioned after dinner 

 be called a difeafe, the immediate or proximate caufe is the in- 

 creafed power of aflbciation, the remote caufe is the increaf- 

 ed irritative motions of the ftomach in confequence of the ftim- 

 ulus of food and wine. The difeafe or proximate effect confifts 

 in the increafed actions of the cutaneous veffels of the face ; and 

 the fenfation of heat, the exiftence of heat, and the red colour, 

 are attendants or fymptoms, or remote effects, of the increafed 

 actions of thefe cutaneous veffels. 



F. Direfl andreverfe Sympathy* 



The increafed actions of the primary part of the trains of af- 



fociated motions are fomctimes fucceeded by increafed actions 



VOL. IL Y Y of 



