SECT. XIX. 5. OF REVERIE. 173 



5. The ideas and motions dependent on irritation during the 

 firft weeks of her difeafe, whilft the reverie was corriplete, were 

 never fucceeded by the fenfation of pleafure or pain j as (he 

 neither faw, heard, not felt any of the furrounding objects. 

 Nor was it certain that any irritative motions fucceeded the ititn- 

 ulus of external objects, till the reverie became lefs complete, 

 and then (he could walk about the room without running againft 

 the furniture of it. Afterwards, when the reverie became ftili 

 lefs complete from the ufe of opium, fome few irritations were at 

 times fucceeded by her attention to them. As when (he fmelt 

 at a tuberofe, and drank a diih of tea, but this only when (lie 

 feemed voluntarily to attend to them. 



6. In common life when we liflen to diftant founds, or wifh 

 to diftinguifh objects in the night, we are obliged (Irongly to 

 exert our volition to difpofe the organs of fenfe to perceive them, 

 and to fupprefs the other trains of ideas, which might interrupt 

 thefe feeble fenfations. Hence in the prefent hiftory the ftrong- 

 eft ftimuli were not perceived, except when the faculty of voli- 

 tion was exerted on the organ of ienfe ; and then even com- 

 mon ftimuli were fometimes perceived : for her mind was fo 

 ftrenuoufly employed in purfuing its own trains of voluntary or 

 fenfitive ideas, that no common ftimuli could fo far excite her 

 attention as to difunite them ; that is, the quanity of volition or 

 of fenfation already exifting was greater than any, which could 

 be produced in confequence of common degrees of ftimulation. 

 But the few ftimuli of the tuberofe, and of the tea, which ihe 

 did perceive, were fuch, as accidentally coincided with the trains 

 of thought, which were pairing in her mind ; and hence did not 

 difunite thofe trains, and create furprife. And their being per- 

 ceived at all was owing to the power of volition preceding or 

 coinciding with that of irritation. 



This explication is countenanced by a facl: mentioned con- 

 cerning a fomnambulift in the Laufanne Trattfeclibns, who 

 fometimes opened his eyes for a fliort time to examine, where 

 he was, or where his ink-pot flood, and then fhut them again, 

 dipping his pen into the pot every now and then* and writing 

 on, but never opening his eyes Afterwards, although he wrote 

 on from line to line regularly, and corrected fome errors of the 

 pen, or in fpelling : fo much eafier was it to him to refer to his 

 ideas of the pofitions of things, than to his perception? of them. 



7. The aflbciated motions perilled in their ufual channel, as 

 appeared by the combinations of her ideas, and the ufe of her 

 frmfcles, and the equality of her pulfe ; for the natural motions 

 of the arterial fyftem, though originally excited like other mo- 

 tions by ftimulus, feem in part to continue by their aflbciation 



M'ith 



