<*6 IRRITATIVE SECT. VII. i. 4 v 



beginning of fome fevers this irritation of the mufcles produces 

 perpetual ftretching and yawning ; in other periods of fever an 

 univerfal reftlefTnefs arifes from the fame caufe, the patient 

 changing the attitude of his body every minute. The repeated 

 ftruggles of the foetus in the uterus mud be owing to this inter- 

 nal irritation : for the foetus can have no other inducement to 

 move its limbs but the tsedium or irkfomenefs of a continued 

 pofture. 



The following cafe evinces, that the motions of ftretching the 

 limbs after a continued attitude are not always owing to 

 the power of the will. Mr. Dean, a mafon, of Auftry, in 

 Leicefterfhire, had the fpine of the third vertebra of the back 

 enlarged ; in fome weeks his lower extremities became feeble, 

 and at length quite paralytic : neither the pain of blifters, the 

 heat of fomentations, nor the utmoft efforts of the will could 

 produce the leafl motion in thefe limbs ; yet twice or thrice a 

 day for many months his feet, legs, and thighs, were affe&ed 

 for many minutes with forcible ftretchings, attended with the 

 fenfation of fatigue , and he at length recovered the ufe of his 

 limbs, though the fpine continued protuberant. The fame cir- 

 cum Ranee is frequently feen in a lefs degree in the common 

 hemiplegia ; and when this happens, I have believed repeated 

 and ftroflg (Locks of electricity to have been of great advantage. 



4. In like manner the various organs of fenfe are originally 

 excited into motion by various external ftimuli adapted to this 

 purpofe, which motions are termed perceptions or ideas ; and 

 many of thefe motions during our waking hours are excited by 

 perpetual irritation, as thoie of the organs of hearing and of 

 touch. The former by the con Rant low indiftincl: noifes that 

 murmur around us, and the latter by the weight of our bodies 

 on the parts which fupport them j and by the unceating varia- 

 tions of the heat, moifture, and preflure of the atmofphere ; 

 and thefe fenfual motions, precifely as the mufcular one above 

 mentioned, obey their correfpondent irritations without our at- 

 tention or confcioufnefs. 



5. Other claifes of our ideas are more frequently excited by 

 our fenfations of pleafure or pain, and others by volition : but 

 that thefe have all been originally excited by Rimuli from exter- 

 nal objects, and only vary in their combinations or feparations, 

 ]>as been fully evinced by Mr. Locke : and are by him termed 

 the ideas of perception in contradiilinction to thofe, which he 

 calls the ideas of reflection. 



II. i. Thefe mufcular motions, that are excited by perpetual 

 irritation, are neverthelefs occafionally excitable by the fenfations 

 of pleafure or pain, or by volition ; as appears by the palpita- 

 tion 



