The work was intended as a reply to the criticisms of Buchanan by Robert Freebairn in the preface and by Thomas Ruddiman in the life of Buchanan in Ruddiman`s edition of Buchanan`s ‘Opera Omnia’. The edition appears to have been proposed by the Lord Advocate, Sir David Dalrymple, 1st Baronet, of Hailes, and a society was formed under Anderson in 1719, but following the deaths shortly afterwards of some of Anderson`s principal collaborators, including Dalrymple, the project lapsed.
The materials consist of an apparently complete text in Latin, comprising replies to Freebairn (folio 1), and to Ruddiman (folio 113), with numerous amendments and additions, some quite lengthy, in the margins, followed by a number of Errata seu Corrigenda (folio 157) in another hand on somewhat smaller leaves bound in at the back, and additions formerly loosely enclosed at folio 60 (folio 165), before folio 5 (folio 169) and pinned to folio 85 verso (folio 170). These last are written in a small hand in which are written notes, including references to ‘Critical Essay on the ancient inhabitants of the Northern parts of Britain, or Scotland …’, inside the front cover, and which appears to be the same hand as that of Adv.MS.31.6.4.
Conflicting information about Ruddiman`s edition, the proposed edition and those taking part is contained at the beginning of the text and at Adv.MS.31.6.2, folio i, Adv.MS.31.6.4, folio i verso, and at Adv.MS.31.6.11, folio i.
Two leaves are cut out between folios 46 and 47.