The burned wick emits flashes of light just before it goes out for want of oil.
"Thus it is frequent for a single vowel to draw sighs from a multitude; and for a whole assembly of saints to sob to the music of one solitary liquid. . . . Hawking, spitting, and belching, the defects of other men's rhetoric, are the flowers, and figures, and ornaments of the enthusiastic preacher's (Jonathan Swift, Mechanical Operation of the Spirit [1704])..