ONYCOMANCY, or, as some persons write it, OXYMANCY, a kind of divination by means of the nails of the fingers. The word is formed from the Greek bin, a nail, and manua, divination. The ancient practice was to rub the nails of a youth with oil and soot, or wax, and to hold up the nails thus smeared against the sun, when certain figures or characters, showing the thing required, were supposed to appear upon them.