RETROGRADE ABSORBENTS. SECT. XXIX. n. 



fociated in trains, which have been accuftomed to 

 fucceflive afrions : hence when one ring of, fiich a 

 mufcle is fatigued from its too great debility, and is 

 brought into retrograde adion, the next ring from 

 its affociation falls fucceflively into retrograde action, 

 and fo on throughout the whole canal. See Sect. 

 XXV. 6. 



6. But as the retrograde motions of the ftomach, 

 cefophagus, and fauces in vomiting are, as it were, 

 apparent to the eye ; we mail coniider this opera- 

 tion more minutely, that the fimilar operations in 

 the more recondite parts of our fyftem may be eafier 

 underftood 



From certain naufeous ideas of the mind, from 

 an ungrateful tafle in the mouth, or from foetid 

 fmells, vomiting is fometimes inflantly excited ; or 

 even from a ftroke on the head, or from the vibrato* 

 ry motions of a fhip ; all which originate from afib- 

 ciation, or. fympathy. See Seel. XX. on Vertigo. 



But when the ftomach is fubjected to a lefs ftimu- 

 lus than is natural, according to the firft law of 

 irritation mentioned above, its motions become clif- 

 turbed, as in hunger ; firft pain is produced, then 

 fickoefs, and at length vain efforts to vomit, as many 

 authors inform us. 



But when, a great quantity of wine, or of opium, 

 is fw allowed, the retrograde motions of the ftomach 

 do not occur till after federal minutes, or even 

 hours ; for when the power of fo ftrong a ftimulus 

 ceafes, according to the fecond law of irritation, 

 mentioned above, the periftahic motions become tre- 

 mulous, and at length retrograde ; as is well known 

 to the drunkard, who. on the next morning has fick- 

 nefs and vomitings. 



When a ftill greater quantity of wine, or o r opium, 

 or when naufeous vegetables, or ftrong bitters, or 

 metallic falts, are taken into the ftomach, they 

 qaickly induce vomiting ; though all thefe in lefs 



dofes 



