First, then, of the ballads that are steeped in the element of the supernatural, let it be remembered that it is well-nigh impossible for us in these days, when we have cleared about us a little island of light in the darkness, to understand the atmosphere of mystery that pressed close around the life of man in the age when the ballad had its birth. The Unknown and the Unseen surrounded him on every side. He could scarcely put forth a hand without touching things that were not of this world; and in proportion to the ignorance was the fear. Through the long twilight in which the primaeval beliefs and superstitions grew up and became embodied in legend and custom, in _maerchen_ and ballad, and all through the Middle Ages, man's pilgrimage on earth was indeed through a Valley of the Shadow. It was a narrow way, between 'the Ditch and the Quag, and past the very mouth of the Pit,' full of frightful sights and dreadful noises, of hobgoblins, and dragons, and chimeras dire. Tales that have ceased to frighten the nursery, that we listen to with a smile or at most with a pleasant stirring of the blood and titillation of the nerves, once on a time were the terror of grown men. The ogres and dragons of old are dead, and the Folklorist and the Comparative Mythologist make free of their caves, and are busy setting up, comparing, classifying, and labelling their skeletons for the instruction of an age of science. But there was a time when the wisest believed in their existence as an article of faith, and when the boldest shuddered to hear them named. What are now idle fancies were once the most portentous of realities; and in this lies the secret of the almost universal diffusion of certain typical tales, beliefs, and observances, and of the fascination which they have not ceased to exercise over the imagination of mankind. Into the subject of the origins, the relationships, and the signification of these venerable traditions and superstitions of the race and of all races, there is neither time nor occasion for entering. This oldest and yet last found of the realms of science is as yet only in course of being surveyed, and from day to day fresh discoveries are announced by the eager explorers of the darkling provinces of myth and folktale. But this at least may be said, that not in the wide domain of popular saga and poetry can there be reaped a richer or more varied harvest of weird and wild and beautiful fancies, touched by the light that 'never was on sea or land,' than is to be found in the Scottish ballads.