Onychomancy

Onychomancy or variously onuchomancy, onychomantia, onycomancy, onymancy (from Greek "onychos", 'fingernail', and "manteia", 'fortune-telling') is an ancient form of divination using fingernails. It consists of watching the reflection of sunlight on the oiled fingernails of an unpolluted boy, then interpreting the symbols that appear. 
The fingers where symbols appear allegedly indicate the nature of the coming events, while the location of the symbols on the nail allow to date them. The higher the symbol is situated on the nail, the nearer the events are in the future.
The term is also used for a method of chiromancy, consisting of reading health & character from fingernails.