The quintessence was a second element that Aristotle was an addition to the other four already known: earth, water, fire and air. According to the alchemists the quintessence would be the main compound of the philosopher's stone. Later medieval alchemists pointed to the ether or quintessence of the life force of bodies, a sort of elixir of life, that anything that changes metals into gold and possesses extraordinary virtues: how to preserve your health until death and integrates do not put the death until after several centuries. Indeed, for those who know it may be used as an immortal work of art.