Manuscript titled 'The way of making that sort of potash wch is Commonly called pearl ash in England'., 1749., MS.17568. Papers of the family of Fletcher of Saltoun (previously of Innerpeffer), with some of Abernethy, Lords Saltoun., MSS.16501-17880. National Library of Scotland Archives and Manuscripts Division. https://nlssb.as.atlas-sys.com/repositories/2/archival_objects/40447 Accessed September 25, 2024.