SPECTRAL ILLUSIONS. 347 



in the room, but also when directing my eyes 

 to the bed-cloathes, to the white sheet, which 

 almost enveloped my face, there it was ; but 

 closing my eyes again, all was darkness. My 

 belief then was, and still is, and I trust you 

 will agree with me, that the luminous appear- 

 ance on waking was merely a continuance of 

 the idea or impression in sleep. And this 

 granted, may we not reasonably infer that in 

 the same manner ideas, impressions of forms 

 and persons experienced in sleep, renewed 

 cerebral actions, on waking may be preserved 

 for a few seconds, and be considered as spectral 

 illusions, or by the vulgar as spectres or appa- 

 ritions. ^ 



PISCATOR. I see no objection to your infer- 

 ence. Even when waking, the impression is 

 not lost the instant it is produced ; it has more 

 or less of duration; thus, on extinguishing a 

 candle, where there is no other, a light seems 

 to hover around it for a perceptible moment 

 of time, when we know no new rays of light 

 are emitted, and all that were produced have 

 passed away. Had the whole occurrence you 

 describe in its several parts taken place in 

 your bedroom, and had you, on suddenly waking, 



