At the end of this choral song appears Io, performing her mystic pilgrimage [21]. The utter wo and despair of Io are finely contrasted with the stern spirit of Prometheus. Her introduction gives rise to those ancestral and traditionary allusions to which the Greeks were so attached. In prophesying her fate, Prometheus enters into much beautiful descriptive poetry, and commemorates the lineage of the Argive kings. After Io's departure, Prometheus renews his defiance to Jupiter, and his stern prophecies, that the son of Saturn shall be "hurled from his realm, a forgotten king." In the midst of these weird denunciations, Mercury arrives, charged by Jupiter to learn the nature of that danger which Prometheus predicts to him. The Titan bitterly and haughtily defies the threats and warnings of the herald, and exults, that whatever be his tortures, he is at least immortal,-- to be afflicted, but not to die. Mercury at length departs--the menace of Jupiter is fulfilled--the punishment is consummated--and, amid storm and earthquake, both rock and prisoner are struck by the lightnings of the god into the deep abyss. "The earth is made to reel, and rumbling by, Bellowing it rolls, the thunder's gathering wrath! And the fierce fires glare livid; and along The rocks the eddies of the sands whirl high, Borne by the hurricane, and all the blasts Of all the winds leap forth, each hurtling each Met in the wildness of a ghastly war, The dark floods blended with the swooping heaven. It comes--it comes! on me it speeds--the storm, The rushing onslaught of the thunder-god; Oh, majesty of earth, my solemn mother! And thou that through the universal void, Circlest sweet light, all blessing; EARTH AND ETHER, YE I invoke, to know the wrongs I suffer."