Art. V. i. i, INVERTENTIA. 6$ 



Art. V. 

 INVERTENTIA. 



1. Those things, which invert the natural order of the fuc* 

 ceflive irritative motions, are termed invertentia. 



i. Emetics invert the motions of the ftomach, duodenum, 

 and cefophagus. 



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

 inteftinal lymphatics. 



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

 the frontal and maxillary finufes. 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 abforbents ; if 

 the dofe of alcohol is greater, it inverts the ftomach, producing 

 the drunken ficknefs. 



5. Medicines producing cold fweats, palpitation of the 

 heart, globus hyftericus j as violent evacuations, fome poifons, 

 fear, anxiety, act by inverting the natural order of the vafcular 

 motions. 



II. Observations on the Invertentia. 



I. 1. The action of vomiting feems originally to have been 

 occafioned by difagreeable fenfation from the detention 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- 

 jetted by the retrograde motions of the tongue and lips ; as 

 explained in Clafs IV. 1. 1. 2. and mentioned in Sect.. XXXV. 

 1.3. Or the difagreeable fenfation may thus excite the power 

 of volition, which may alfo contribute to the retrograde actions 

 of the ftomach and cefophagus, as when cows bring up the con- 

 tents of their firft ftomach to remafticate it. To either of thefe 

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

 to operate, and leave the ftomach ftronger, or more irritable, 

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

 rial power of irritation during its torpid or inverted action. 

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

 nium tartarizatum, in fmall dofes. 



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

 as digitalis, firft ftimulate the abforbent veflels of the ftomach 

 into greater action -, and that the inverted motions of thefe ab- 

 forbents next occur, pouring the lymph, lately taken up, or ob- 

 tained 



