But, first, what can we learn of the beliefs as to the origin of disease? Concerning this the great bulk of the folk lore in these manuscripts is apparently of native Teutonic origin, or rather it would be more correct to speak of its origin as Indo-Germanic; for the same doctrines are to be found among all Indo-Germanic peoples, and even in the Vedas, notably the Atharva Veda. Of these beliefs, the doctrine of the "elf-shot" occupies a large space, the longest chapter in the third book of the _Leech Book of Bald_ being entirely "against elf-disease." We know from their literature that to our Saxon ancestors waste places of moor and forest and marshes were the resort of a host of supernatural creatures at enmity with mankind. In the _Leech Book of Bald_ disease is largely ascribed to these elves, whose shafts produced illness in their victims. We read of beorg-ælfen, dun-ælfen, muntælfen. But our modern word "elf" feebly represents these creatures, who were more akin to the "mark-stalkers," to the creatures of darkness with loathsome eyes, rather than to the fairies with whom we now associate the name. For the most part these elves of ancient times were joyless impersonations and creatures not of sun but of darkness and winter. In the gloom and solitude of the forest, "where the bitter wormwood stood pale grey" and where "the hoar stones lay thick," the black, giant elves had their dwelling. They claimed the forest for their own and hated man because bit by bit he was wresting the forest from them. Yet they made for man those mystic swords of superhuman workmanship engraved with magic runes and dipped when red hot in blood or in a broth of poisonous herbs and twigs. We do not understand, we can only ask, why did they make them? What is the meaning of the myth? The water elves recall the sea monsters who attended Grendel's dam, impersonations of the fury of the waves, akin to Hnikarr, and again other water elves of the cavernous bed of ocean, primeval deadly creatures, inhabiting alike the sea and the desolate fens, "where the elk-sedge waxed in the water." If some were akin to the Formori of the baleful fogs in Irish mythic history and the Mallt-y-nos, those she-demons of marshy lands immortalised by the Welsh bards, creatures huge and uncouth "with grey and glaring eyes," there were others who exceeded in beauty anything human. When Cædmon wrote of the beauty of Sarah, he described her as "sheen as an elf." With the passing of the centuries we have well-nigh forgotten the black elves, though they are still realities to the Highlander and too real for him to speak of them. But have we not the descendants of the sheen bright elves in the works of Shakespeare, Milton and Shelley? One feels very sure that our Saxon ancestors would have understood that glittering elf Ariel as few of us are capable of understanding him. He is the old English bright elf. Did not Prospero subdue him with magic, as our ancestors used magic songs in administering herbs