394 DISEASES Class IV. 1. 3.3* 



the thread by a {ticking platter to a diftant part. An iflue be- 

 hind the ear. To pradlife daily by a iooking-glafs to flop the 

 motions with the hand. See the cure of a cafe of the leaping of 

 a mufcle of the arm, Seel:. XVII. 1. 8. See Convulfio debi- 

 lis, Ciafs III. 1. 1. 5. Frequent electric fparks, or very flight 

 fhocks. 



3. Rifus invitus. Involuntary laughter. When the pleafure 

 arifing from new combinations of words and ideas, as in puns ; 

 or of other circumftances, which are fo trivial, as to induce no 

 voluntary exertion to compare or confider their prefent impor- 

 tance or their future confequence •, the pleafure is liable to rife 

 into pain ; that is, the ideas or fenfual motions become exerted 

 too violently for want of fome antithefiftic ideas ; in the fame 

 manner as thofe mufcles, which have weak antagonists, as thofe of 

 the calf of the leg, are liable to fall into cramp of painful contrac- 

 tion. In this fituation a fcream is begun to relieve this pain of 

 ideas too violently exerted, which is Hopped again foon, as ex- 

 plained in Seel:. XXXIV. 1. 4. and Clafs III. 1. 1. 4. and IV. 



2 ' 3- 3- 



The pain, into which this pleafure rifes, which would excite 



the fcream of laughter, has been felt forcibly by every one 5 

 when they have been under fuch circumftances, as have induc- 

 ed them to reftrain it by a counter-volition 5 till at length the 

 increafed aflbciate motions produce fo much pain as to over- 

 come the counter-volition, and the patient burfts out into inde- 

 cent laughter, contrary to his will in the common acceptation of 

 that word. 



4. Lufus digitorum invitus. An awkward playing with the 

 fingers in fpeaking in public. Thefe habits are begun through 

 bafhfulnefs, and feem rather at firft defigned to engage the at- 

 tention in part, and thus prevent the difagreeable ideas of mau- 

 vaife honte j as timorous boys whittle, when they are obliged to 

 walk in the dark ; and as it is fometimes neceflary to employ 

 raw foldiers in perpetual manoeuvres, as they advance to the 

 firft charge. 



5. Unguium morfiuncida invita. Biting the nails is a de- 

 praved habit arifmg from fimilar caufes as thofe of the laft arti- 

 cle. 



M. M. Dip the fingers in folution of aloes. 



6. Vigdia invita. Watchfulnefs, where the perfon wifhes 

 and endeavours to fall afleep, properly belongs to this place, as 

 the with or volition to fleep prevents the defired effect ; be- 

 caufe fleep confifts in an abolition of volition. See Clafs III. 



1. 2-3- 



ORDO 



