But it is in the doctrine of the worm as the ultimate source of disease that we are carried back to the most ancient of sagas. The dragon and the worm, the supreme enemy of man, which play so dominating a part in Saxon literature, are here set down as the source of all ill. In the alliterative lay in the _Lacnunga_ the opening lines describe the war between Woden and the Serpent. Disease arose from the nine fragments into which he smote the serpent, and these diseases, blown by the wind, are counteracted by the nine magic twigs and salt water and herbs with which the disease is again blown away from the victim by the power of the magician's song. This is the atmosphere of the great earth-worm Fafnir in the Volsunga Saga and the dragon in all folk tales, the great beast with whom the heroes of all nations have contended. Further, it is noteworthy that not only in Anglo-Saxon medicine, but for many centuries afterwards, even minor ailments were ascribed to the presence of a worm--notably toothache. In the _Leech Book_ we find toothache ascribed to a worm in the tooth (see _Leech Book_, II. 121). It is impossible in a book of this size to deal with the comparative folk lore of this subject, but in passing it is interesting to recall an incantation for toothache from the Babylonian cuneiform texts[21] in which we find perhaps the oldest example of this belief. "The Marshes created the Worm, Came the Worm and wept before Shamash, What wilt thou give me for my food? What wilt thou give me to devour? . . . . . . . Let me drink among the teeth And set me on the gums, That I may devour the blood of the teeth And of the gums destroy their strength. Then shall I hold the bolt of the door. . . . . . . . So must thou say this, O Worm, May Ea smite thee with the might of his fist." Closely interwoven with these elements of Indo-Germanic origin we find the ancient Eastern doctrine which ascribes disease to demoniac possession. The exorcisms were originally heathen charms, and even in the _Leech Book_ there are many interesting survivals of these, although Christian rites have to a large extent been substituted for them. Both mandrake and periwinkle were supposed to be endowed with mysterious powers against demoniacal possession. At the end of the description of the mandrake in the _Herbarium of Apuleius_ there is this prescription:-- "For witlessness, that is devil sickness or demoniacal possession, take from the body of this same wort mandrake by the weight of three pennies, administer to drink in warm water as he may find most convenient--soon he will be healed."--_Herb. Ap._, 32. Of periwinkle we read:--