Michael, why, oh why, are you still sprouting that Reeves rubbish about the symbolism of dew? Read Bob Thomson's article "The Frightful Foggy Dew" in Folk Music Journal IV:1 1980 pp. 35-61 and you will see what the song is all about. Namely a young lad scaring a girl into his bed by getting a friend to dress up as a ghost, or "bugaboo". Thomson prints the early broadsides to prove his point. There is now no need for speculation.