Some researchers hold that certain ghosts are sensed only as ‘phantom scents’, i.e. they often appear in the form of a phantom scent in the air.
There have been numerous reports of people who have suddenly become conscious of a smell they can instantly identify with people who have died. Perhaps the most famous historical instance of a ghostly scent was given by John Aubrey, in his Miscellanies (1696): ‘Anno 1670, not far from Cirencester, was an apparition.
Being demanded whether a good spirit or bad, it returned no answer, but disappeared with a curious Perfume and most melodious Twang.’