FCtAssII. 1. 1. 10. OF SENSATION. 159 



10. Oscitatio et pandiculatio. Yawning and stretching of the 

 limbs is produced either by a long inactivity of the muscles now 

 brought into action, as sometimes happens after sleep, or after 

 listening a long time to a dull narrative; or it is produced by a 

 too long continued action of the antagonist muscles. In the 

 former case there is an accumulation of sensorial power during 

 the quiescence of the muscles now brought into action; which 

 probably constitutes the pain or wearisomeness of a continued 

 attitude. In the latter case there is an exhaustion of sensorial 

 power in the muscles, which have lately been acting violently, 

 and a consequent accumulation in the muscles, which are antago- 

 nists to them, and which were at rest 



These involuntary motions are often seen in paralytic limbs, 

 which are at the same time completely disobedient to the will; 

 and are frequently observable in very young children; and from 

 thence we may conclude, that these motions are learnt before na- 

 tivity; as puppies are seen to open their mouths before the mem- 

 branes are broken. See Sect. XVI. 2. 



Where these motions are observed in limbs otherwise paraly- 

 tic, it is an indication that electric shocks may be employed with 

 advantage, as the excitability of the limb by irritation is not ex- 

 tinct, though it be disobedient both to volition and sensation. 



11. Tenesmus consists in violent and frequent ineffectual ef- 

 forts to discharge the contents of the rectum, owing to pain of the 

 sphincter. The pain is produced by indurated feces, c*r by some 

 acrid material, as the acidity of indigested aliment; and the ef- 

 forts are attended with mucus from the pained membrane. The 

 feces must sometimes be taken away by the end of a marrow- 

 spoon, as cathartics and even clysters will pass without removing 

 them. It is sometimes caused by sympathy with the urethra, 

 when there is a stone at the neck of the bladder. See Class II. 

 2. 2.1. and IV. 1. 2. 8, 



M. M. Fomentation, an enema with mucilage and laudanum* 

 The common exclusion of the feces from the rectum is a pro- 

 cess similar to this, except that the muscles of the sphincter ani, 

 and those of the abdomen, which act along with them by the 

 combined powers of sensation and association, are in tenesmus 

 excited by painful sensation, and in the latter by a sensation, 

 which may in some instances be almost called pleasurable, as re- 

 lieving us from a painful one in the exclusion of the feces. 



12. Stranguria. Strangury consists in painful efforts to dis- 

 charge the contents of the urinary bladder. It is generally ow- 

 ing to a stone in the sphincter of the bladder ; or to the inflam- 

 mation of the neck of it occasioned by cantharides. It is some- 

 times caused by sympathy with the piles; and then is liable in 



