By a "drink of oblivion" Druids and other persons could make one forget even the most dearly beloved. Thus Cúchulainn was made to forget Fand, and his wife Emer to forget her jealousy.[1115] This is a reminiscence of potent drinks brewed from herbs which caused hallucinations, e.g. that of the change of shape. In other cases they were of a narcotic nature and caused a deep sleep, an instance being the draught given by Grainne to Fionn and his men.[1116] Again, the "Druidic sleep" is suggestive of hypnotism, practised in distant ages and also by present-day savages. When Bodb suspected his daughter of lying he cast her into a "Druidic sleep," in which she revealed her wickedness.[1117] In other cases spells are cast upon persons so that they are hallucinated, or are rendered motionless, or, "by the sleight of hand of soothsayers," maidens lose their chastity without knowing it.[1118] These point to knowledge of hypnotic methods of suggestion. Or, again, a spectral army is opposed to an enemy's force to whom it is an hallucinatory appearance--perhaps an exaggeration of natural hypnotic powers.[1119] Druids also made a "hedge," the _airbe druad_, round an army, perhaps circumambulating it and saying spells so that the attacking force might not break through. If any one could leap this "hedge," the spell was broken, but he lost his life. This was done at the battle of Cul Dremne, at which S. Columba was present and aided the heroic leaper with his prayers.[1120] A primitive piece of sympathetic magic used still by savages is recorded in the _Rennes Dindsenchas_. In this story one man says spells over his spear and hurls it into his opponent's shadow, so that he falls dead.[1121] Equally primitive is the Druidic "sending" a wisp of straw over which the Druid sang spells and flung it into his victim's face, so that he became mad. A similar method is used by the Eskimo _angekok_. All madness was generally ascribed to such a "sending."