SECT. XX. 8. OF VERTIGO. 187 



fecretions of the various glands, are other circles of irritative 

 motions, fome of them more or lefs complete, according to our 

 abftinence or fatiety. 



So that the irritative ideas of the apparent motions of obje 61 s, 

 the irritative battements of founds, and the movements of our 

 bowels and glands, compofe a great circle of irritative tribes of 

 motion : and when one confiderable part of this circle of mo- 

 tions becomes interrupted, the whole proceeds in confufion, a$ 

 defcribed in Sedlion XVII. i. 7. on Catenation of Motions. 



8. Hence a violent vertigo, from whatever caufe it happens, 

 is generally attended with undulating noife in the head, perver- 

 lions of the motions of the ftomach and duodenum, unufual ex- 

 cretion of bile and gaftric juice, with much pale urine, fome- 

 times with yellownefs of the ildn, and a difordered fecretion of 

 almoft every gland of the body, till at length the arterial fyftem 

 is affefted, and fever fucceeds. 



Thus bilious vomitings accompany the vertigo ocafioned by 

 the motion of a (hip ; and when the brain is rendered vertigin- 

 ous by a paralytic affection of any part of the body, a vomiting 

 generally enfues, and a great difcharge of bile : and hence great 

 injuries of the head from external violence are fucceeded by bil- 

 ious vomitings, and fometimes by abfcefles of the liver. And 

 hence, when a patient is inclined to vomit from other caufes, as 

 in fome fevers, any motions of the attendants in his room, or of 

 himfelf when he is raifed or turned in his bed, prefently induces 

 the vomiting by fuperadding a degree of vertigo. 



9. And converfely it is very ufual with thofe, whofe ftomachs 

 are affected from internal caufes, to be afflicted with vertigo, 

 and noife in the head ; fuch is the vertigo of drunken people, 

 which continues, when their eyes are clofed, and themfelves in a 

 recumbent pofture, as well as when they are in an erect pofture, 

 and have their eyes open. And thus the irritation of a ftone in 

 the bile-dudl, or in the ureter, or an inflammation of any of the 

 inteftines, are accompanied with vomitings and vertigo. 



In theie cafes the irritative motions of the ftomach, which are 

 in general not attended to, become fo changed by fome unnat- 

 ural ftimulus, as to become uneafy, and excite our fenfation or 

 attention. And thus the other irritative trains of motions, 

 which are affociated with it, become difordered by their fympa- 

 thy. The fame happens, when a piece of gravel flicks in the 

 ureter, or when fome part of the inteftinal canal becomes infla- 

 med. In thefe cafes the irritative mufcular motions are firft dif- 

 turbed by unufual ftimulus, and a difordered action of the fen- 

 fual motions, or dizzinefs enfues. While in fea-ficknefs the dif- 

 turbance of the irritative fenfual motions, as vertigo, precedes ; 



