The volume, almost entirely in the hand of Mylne, begins (folio i verso) with an index (extra entries have been added later; those for the letters B, C, D, K and M continue on folio v verso, those for P on folio vi verso); there follows (page 1) a transcript of Stewart`s historical collections as in Stewart`s own manuscript (Adv.MS.22.1.14) with most of the additions found also in the transcript Adv.MS.34.3.11, and further additions, some not by Mylne; finally (page 352) come the transcripts from Hay`s collections and elsewhere.
The transcripts from Steuart correspond to his manuscript as follows:
Adv.MS.34.3.12, folio vi and pages 1-6 = Adv.MS.22.1.14, folios 159-162 (but the list of events, here on pages 3-4, is there at the beginning of the section);
pages 18-71 = folios 162 verso-179 verso;
pages 77-157 = folios 180-202;
pages 161-236 = folios 204 verso-232;
pages 316-330 = folios 233-238.
The additions also in the other transcript are:
pages 7-17 = Adv.MS.34.3.11, folios 4 verso-8 verso;
pages 72-76 = folios 27-29;
pages 237-315 = folios 95-132;
pages 331-352 = folios 138-144 verso.
Mylne has himself added at a later date on page 184 a charter of Edward III concerning Coldingham (from Hay`s). An unidentified contemporary hand has added on pages left blank `A short discourse concerning the originall of Lay patronages` with regard to a dispute in Haddington in 1681 (page 48), the foundation charter of the collegiate church of Crichton, 1449 (page 157) (printed in ‘Collegiate Churches in Midlothian’, page 306), and the seal of cause of the Incorporation of Tailors of Edinburgh, 1500 (page 159).
The transcripts from Hay consist of charters and papers on ecclesiastical matters, from Adv.MSS.34.1.10(i) and 32.6.2. Despite the title there is almost as much material from other sources, mostly indicated by Mylne himself; two are printed (the Chronicle of Melrose and ‘Scotorum Historiae’ by Boetius), the rest manuscript - the public records, a copy of Hope and Durie`s alphabetic practicks similar to Adv.MS.24.2.3, and another volume of practicks belonging to Robert Govan, writer in Glasgow. A fuller list of these additions is available.