Mangan’s prose comes in a variety of forms: Essays, stories, apologies, biographical sketches, comic articles, introductions to his poems and translations, a handful of surviving letters, an unfinished auto-biography. These prose publications appeared in a wide range of contemporary journals and newspapers demanding from the editors a great deal of scholarly detective work, especially when it came to Mangan’s chameleon way with pseudonyms. Many of his most famous pieces, like ‘The Thirty Flasks’, ‘A Sixty-Drop Dose Of Laudanum’, ‘The Three Rings’, Extraordinary Adventure In The Shades’; a translation from the Irish like ‘The Clown With The Grey Coat’, or from the German, like ‘The Story Of The Old Wolf, have appeared in the editions by Meehan and O'Donoghue. It was always necessary to check these against the earliest published versions, which sometimes exposed serious errors in the later text. With those prose pieces which presented otherwise insoluble problems of attribution, contiguous letter pair analysis has been employed to determine authorship. A particular difficulty arose with the extended introductions and linking commentaries to the poet’s verse translations from the German, Irish, oriental and Spanish sequences in the Dublin University Magazine. Wherever the piece can stand independently it is appropriated for the prose; where it is wedded to the verse it has been subsumed into the editorial commentary in the Collected Poems.