The Fairy belief, we have said, is a composite thing. On the materials given by tradition, such as the memory, perhaps, of a pre-historic race, and by old religion, as in the thoughts about the pre-Christian Hades, poetry and fancy have been at work. Consumption, lingering disease, unexplained disappearances, sudden deaths, have been accounted for by the agency of the Fairies, or People of Peace. If the superstition included no more than this, we might regard it as a natural result of imagination, dealing with facts quite natural in the ordinary course of things. But there are elements in the belief which cannot be so easily dismissed. We must ask whether the abnormal phenomena which have been so frequently discussed, fought over, forgotten, and revived, do not enter into the general mass of folk-lore. They appear most notably in the two branches of Browniedom—of “Pixies,” as they say in Devonshire, who haunt the house, and in the alleged examples of the second sight. The former topic is the more obscure, if not the more curious. Let us examine the occurrences, then, which may have begotten the belief in Brownies, and in house-haunting Pixies or Fairies. These appearances may be alleged, on one hand, to be actual facts in Nature, the workings of some yet unexplained forces; or they may merely be the consequences of some very old traditional method of imposture, vulgar in itself, but still historical. That form of imposture, again, may be wrought either by conscious agents, or unconsciously and automatically by persons under the influence of somnambulism; or, finally, the phenomena may in various cases be due to any one of these three agencies, all of which may possibly be _veræ causæ_, as conscious imposture and trickery is certainly one _vera causa_.