SECT. XXXIV. i. DISEASES OF VOLITION. 479 



fmall noifes in the night. As explained in Section 

 XIX. 6. Hence by. our attention to the fauces from 

 our defire not to fwallow our laliva ; the fauces be- 

 come more ferifible ; and the flimulus of the faliva 

 is followed by greater fenfation, and confequent de- 

 fire of fwallowing it. So that the defire or volition 

 in confequence of the increafed fenfation of the fa- 

 liva is more powerful, than the previous defire not 

 to fwallow it. See Vol. II. Deglutitio invita. In 

 the fame manner if a modeft man wifhes not to 

 want to make water, when he is coiifined with 

 ladies in a coach or an aiTembly-room ; that very 

 act of volition induces the circumflance, which he 

 wifhes to avoid, as above explained ; infomuch that 

 I once faw a partial infanity, which might be called 

 a voluntary diabetes, which was occafioned by the 

 fear (and confequent averfion) of not being able to 

 make water at all. 



It is further neceiTary to obferve here, to prevent 

 any confufion of voluntary, with fenlitive, or affo- 

 ciate motions, that in all the inflances of violent 

 efforts to relieve pain, thofe efforts are at firft vo- 

 luntary exertions ; but after they have been fre- 

 quently repeated for the purpofe of relieving certain 

 pains, they become affociated with thofe pains, and 

 ceafe at thofe times to be fubfervient to the will ; as 

 in coughing, fneezing, and flrangury. Of thefe mo- 

 tions thofe which contribute to remove of diflodge 

 the offending caufe, as the actions of the abdominal 

 mufcles in parturition or in vomiting, though they 

 were originally excited by volition, are in this work 

 termed fenfuive motions ; but thofe actions of the 

 mufcles or organs of fcnfe, which do not contri- 

 bute to remove the offending caufe, as in general 

 convulfions or in madnefs are in this work termed 

 voluntary motions, or motions in confequence of 

 averfion, though in common language they are call- 

 ed involuntary ones. Thofe fenfitive unreftraiuable 



actions, 



