MSS.9250-9251 consist chiefly of letters to Principal William Dunlop (died 1700) and his son Alexander, with a few concerning members of the Carstares family. From 1685 to 1689 William Dunlop was in South Carolina, and in 1688 led an embassy to the Spanish governor of Florida. His later correspondence concerns political affairs, including the Skelmorlie Plot and the Darien Scheme, and ecclesiastical and university matters.

MSS.9252-9254 are chiefly family correspondence, but MS.9252 also contains letters on the affairs of Glasgow University, and on the Earl of Bute's estates, for which John Dunlop was factor.