456 THEORY OF FEVER. Sup. 1. 6. 2. 



proceeding in our waking hours, and are catenated by their firft 

 link, or in fome fubfequent parts of the chain, with the ftimuli 

 or the influence of external things ; which we fhall here enu- 

 merate, as they contribute to the knowledge of fever. Of thefe 

 are the irritative ideas, or fenfual motions of the organs of fenfe, 

 and the mufcular motions afibciatcd with them ; which, when 

 the chain is disturbed or interrupted, excite the fenforial power 

 of fenfation, and proceed in confufion. Thus if the irritative 

 ideas of fight are difturbed, the parabiotic motions of objects, 

 which in general are unperceived, becomes fenfible to us j and 

 the locomotive mufcles afibciatcd with them, which ought to 

 prefervc the body erect, ftagger from this decreafe or interrup- 

 tion of the fenforial power of aflbciation ; and vertigo is pro- 

 duced. 



When the irritative fenfual motions, or ideas, belonging to 

 one fenfc are increafed or diminifhed, the irritative fenfual mo- 

 tions, or ideas, of the other fenfes are liable to become difturbed 

 by their general catenations ; whence occur noifes in the ears, 

 bad taftes in the mouth, bad odours, and numbnefs or tingling 

 of the limbs, as a greater or lefs number of fenfes are affected. 

 Thefe conltitute concomitant circles of difturbed irritative ideas; 

 or make a part of the great circle of irritative ideas, or motions 

 of the organs of fenfe ; and whenthus difturbed occafion many 

 kinds of hallucination of our other fenfes, or attend on the ver- 

 tigo of vifion. 



2. Another great circle of irritative afterdated motions con- 

 fifts of thofe of the alimentary canal ; which are catenated with 

 ftimuli or with influences external to the fyftem, but continue 

 to be exerted in our fleeping as well as in our waking hours. 

 When thefe aflbciations of motion are difturbed by the too great 

 or too fmall ftimulus of the food taken into the ftomach, or by 

 the too great excefs or deprivation of heat, or by indigeftible 

 fubftances, or by torpor or orgafm occafioned by their aflbcia- 

 tion with other parts, various difeafes are induced under the 

 names of apepfta, hypochondriafis, hyfteria, diarrhoea, cholera, 

 ileus, nephritis, fever. 



3. A third circle of irritative aflbciate motions confiftsof thofe 

 of the abforbent fyftem ; which may be divided into two, the 

 lacteals, and the lymphatics. When the ftomach and inteftines 

 are recently filled with food and fluid, the lacteal fyftem is 

 ftimulated into great action ; at the fame time the cellular, cuta- 

 neous, and pulmonary lymphatics act with lefs energy ; becaufe 

 lefs fluid is then wanted from thofe branches, and becaufe- more 

 fenforial power is expended by the lacteal branch. On this ac- 

 count thefe two fyftems of abforbents are liable to act by re- 



verfe 



