SECT. XXXIV. i. 4- OF VOLITION. 33 x 



ground. Thus alfc in the bellon, or colica faturnina, the pa- 

 tients are faid to bite their own fle(h,and dogs in this difeafe to 

 bite up the ground they lie upon. It is probable that the great 

 endeavours to bite in mad dogs, and the violence of other mad 

 animals, are owing to the fame caufe. 



4. If the efforts of our voluntary motions are exerted with 

 ftill greater energy for the relief of fofne difagreeable fenfation, 

 convulfions are produced ; as the various kinds of epilepfy, and 

 in fome hyfleric paroxyfms. In all thefe difeafes a pain or difa- 

 greeable fenfation is produced, frequently by worms, or acidity 

 in the bowels, or by a difeafed nerve in the fide, or head, or by 

 the pain of a difeafed liver. 



In fome conftitutions a more intolerable degree of pain is 

 produced in fome part at a diftance from the caufe by fenfitive 

 affociation, as before explained ; thefe pains in fuch conititutions 

 arife to fo great a degree, that I verily believe no artificial tor- 

 tures could equal fome, which I have witnefled ; and am confi- 

 dent life would not have long been preferved, unlefs they had 

 been foon diminifhed or removed by the univerfal convulfion of 

 the voluntary motions, or by temporary madnefs. 



In fome of the unfortunate patients I have obferved, the pain 

 has rifen to an inexpreiTible degree, as above defcribed, before 

 the convulfions have fupervened ; and which were preceded by 

 fcreaming, and grinning ; in others, as in the common epilepfy, 

 the convulfion has immediately fucceeded the commencement of 

 the difagreeable fenfations ; and as a ftupor frequently fucceeds 

 the convulfions, they only feemed to remember that a pain at the 

 ftomach preceded the fit, or fome other uneafy feel ; or more 

 frequently retained no memory at all of the immediate caufe of 

 the paroxyfm. But even in this kind of epilepfy, where the pa- 

 tient does not recolleft any preceding pain, the paroxyfms gen- 

 erally are preceded by a quivering motion of the under jaw, 

 with a biting of the tongue ; the teeth afterwards become preff- 

 ed together with vehemence, and the eyes are then convulfed, 

 before the commencement of the univerfal convulfion ; which 

 are all efforts to relieve pain. 



Thereafon why thefe convulfive motions are alternately exerted 

 and remitted was mentioned above, and in Set. XII. i. 3. 

 *when the exertions are fuch as give a temporary relief to the 

 pain, which excites them, they ceafe for a time, till the pain is 

 again perceived ; and then new exertions are produced for its 

 relief. We fee daily examples of this in the loud reiterated 

 laughter of fome people ; the pleafurable fenfation, which ex- 

 cites this laughter, arifes for a time fo high as to change its name 

 and become painful : the convulfirs motions of the refpiratory 



mufcles 



