ART. V. i. i. INVERTENTIA 65 



ART. V. 

 INVERTENTIA. 



I. THOSE THINGS, which invert the natural order of the fuc 

 ceflive irritative motions, are termed invertentia. 



1. Emetics invert the motions of the flomach, duodenum, 

 and cefophagus. 



2. Violent cathartics invert the motions of the ladeals, and 

 mteftinal lymphatics. 



3. Violent errhines invert the nafal lymphatics, and thofe of 

 the^ frontal and maxillary fmufes. And medicines producing 

 naufea, invert the motions of the lymphatics about the fauces. 



4. Medicines producing much pale urine, as a certain quan- 

 tity of alcohol, invert the motions of the urinary ablbrbents ; if 

 the dofe of alcohol is greater, it inverts the ft omach, producing 

 the drunken ficknefs. 



5. Medicines producing cold fweats, palpitatron of the heart, 

 globushyflericus; as violent evacuations, fome poifons, fear, anx- 

 iety, act by inverting the natural order of the vafcular motions, 



II. OBSERVATIONS ON THE INVERTENTIA. 



1. i. The aclion of vomiting feems originally to have been 

 occafioned by difagreeable fen fation from the diflentkm or acri- 

 mony of the aliment -, in the fame manner as when any difguft- 

 ful material is taken into the mouth, as a bitter drug, and is re- 

 jected by the retrograde motions of the tongue and lips ; ar> 

 explained in Clafs IV. i. i. 2. and mentioned in Scft. XXXV 

 1.3. Or the difagreeabl-e fen fation may thus excite the powei 

 of volition, which may alfo contribute to the retrograde aHon" 

 of the flomach and cefophagus, us when cows bring up the con- 

 tents of their firfl ftomach to remafticate it. To either of thefr 

 is to be attributed the action of mild emetics, which foon ceafe 

 to operate, and leave the flomach Wronger, or more irritable> 

 after their operation ; owing to the accumulation of the fenfo- 

 rial power of irritation during its torpid or inverted adlion- 

 Such appears to be the operation of ipecacuanha, or of .antimo- 



"nium tartarizatum, in fmall dofes. 



2. But there is reaibn to believe, that the ftronger emetics, 

 as digitalis, firfl ilimulate the abforbent vefTels of the flomach 

 into greater aclion ; and that the inverted motions of thefe ab~ 

 forbems next occur, pouring the lymph, iately ta"ken up, or ob- 

 tained from other lymphatic branches, into the flomach ; the 

 quantity of whichsin fome difeafes, as in the cholera morbus,io 



inconceivable. 



