"Tales of Wonder", published in 1801, is a collection with contributions from Matthew Gregory Lewis, Sir Walter Scott, Robert Southey, and John Leyden. It contains a work titled "Saint Patrick's Purgatory". The intro, and a small portion of that ballad, are below.
"In the Reliques of Ancient Poetry, is the following—," Owaine Myles it a Ballad, giving an account of the wonders of St. Patrick's Purgatory. This is a translation into verse, ofthestory related in Mat. Paries Hist, sub Ann. 1152."— The version which is here offered to the Public is evidently modern: I am ignorant of the Author. I think the 19th stanza, in particular, has a great degree of merit."
" Now enter in ! "—the Prior cried,
—" And God, Sir Ouvain, be your guide !
" Your name shall live in story :
" Many there are who reach this shore,
" But few who venture to explore
" St. Patrick's Purgatory."—
" St. Patrick's Purgatory;
" For after death these seats divine,
" Reward eternal shall be thine,
** And thine eternal glory."—
Inebriate with the deep delight,
Dim grew Sir Ouvain's swimming sight,
His senses died away ;
To life again revived, before
The entrance of the cave once more
He saw the light of day."