The Gaelic text is in the hand of the Reverend Dr Thomas Ross of Lochbroom (1768-1843), then a tutor in Edinburgh. It is his adaptation (into the orthography of the Gaelic Bible) of the manuscripts left by James Macpherson in 1796 as the ‘originals’ of his ‘translations’ of Ossian’s poems. These were written partly by Macpherson, partly by another hand (Adv.MSS.72.3.11, folio 50 verso; 72.3.13, folio 80 recto). They are now lost. Sinclair describes the circumstances of the work in ‘Poems of Ossian in the original Gaelic’, volume 1, page xcii.

The Latin text is largely the work of Robert Macfarlan, A.M., schoolmaster at Walthamstow. Macfarlan was killed by a coach in August 1804 (Adv.MS.73.2.24, folio 90), so some extra sheets were added in another hand; one such includes an accompanying letter, Colin Macrae to William Bulmer, dated 30 October 1804 (Adv.MS.73.4.4, folio 19).

Folio 1 of each is a title-page added by Sinclair, notes in whose hand appear at Adv.MS.73.4.1, folios 2, 7; Adv.MS.73.4.2, folio 24; and Adv.MS.73.4.4, folio 44.