Sentence:  The most fetid and poisonous smells everywhere prevailed; and by the aid of that ghastly light which, even at midnight, never fails to emanate from a <WSD>vapory</WSD> and pestilential atmosphere, might be discerned lying in the by-paths and alleys, or rotting in the windowless habitations, the carcass of many a nocturnal plunderer arrested by the hand of the plague in the very perpetration of his robbery. 
Meaning of the word marked with <WSD> tags:  Characterized by the presence of vapor; full of, or obscured by, vapor.