The Blairs and Fothringhams were connected by marriage, and the Earl of Perth had dealings with the Blairs. Many of the letters are addressed to David Drummond, Advocate and Treasurer of the Bank of Scotland, who looked after the Earl of Perth's affairs and may be the David Drummond as whose servant the Earl disguised himself when trying to escape in 1688.

The contents are as follows.

(i) Letters written by Sir Alexander Fothringham of Powrie to his mother, Lady Blair of Balthayock, from prison in the Tower of London, 1651, with a bond, 1657, and household accounts, 1679, of the Blairs of Balthayock. They are accompanied by transcripts by John W M Loney, C.A. (Folio 1.)

(ii) Letters written by James, 4th Earl of Perth, to David Drummond, Advocate and Treasurer of the Bank of Scotland, from the time when Perth was sentenced to imprisonment, 11 May 1688 or 1689, to 1696. They are mostly written from the Continent and relate to personal and family business and to the conduct of the Earl's son James. At the end are two unsigned letters, 1700, 1714, written from London, dealing with politics and current topics, at least one of which is addressed to David Drummond, Advocate. Every letter is accompanied by a modern transcript. (Folio 8.)

(iii) Letters and papers, 1632-1786, undated, chiefly of the Blairs of Balthayock. They include letters, 1723, of David Drummond, the Treasurer's son, about his marriage to the heiress of Balthayock, which seems to have presented difficulties, letters, 1783, advising Patricia Blair of Balthayock on the purchase of the lands of Balthayock for her son David, and a letter, 1786, from Edinburgh, describing new buildings in Perth and Edinburgh and censuring female fashions and the conduct of the Duchess of Gordon. (Folio 31.)