Derived its origin, and this the cause.
Through a dark cave a craggy passage lies
To ours ascending from the nether skies,
Through which, by strength of hand, Alcides drew
Chained Cerberus, who lagged and restive grew,
With his bleared eyes our brighter day to view.
Thrice he repeated his enormous yell,
With which he scares the ghosts, and startles hell;
At last outrageous (though compelled to yield),
He sheds his foam in fury on the field;