The Riddle of the Three Vials
Empiric, while exploring an ancient apothecary, discovers a locked chest containing three vials. Each vial is filled with a different liquid: one with a potion to cure any ailment, another with a deadly poison, and the third with a harmless water. Accompanying the chest is a note with three statements:
The red vial is not the potion.
The blue vial is either the potion or the poison.
The green vial is not the poison.
Empiric knows that only one of these statements is true. He must determine the contents of each vial without tasting any of them.
The Riddle:
What is in each of the three vials?