A Witch can designate her familiar as the "toucher" for touch spells and hexes. The spell fizzles if you cast another spell before the touch spell finds a target.
If the familiar had yet to use the touch spell and the witch is knocked unconscious, does the spell fail or can it still be used? If I hex a cure light wounds with the familiar as the "toucher" and then I take all the weapons to the face, can the familiar come over and heal me?