Contains correspondence and papers of John Mackenzie, Advocate and a Principal Clerk of Session, of Cramond and later of Delvine (died 1731), his sons Alexander, Writer to the Signet and a Principal Clerk of Session (died 1737), and John, Writer to the Signet, Deputy-Keeper of the Signet (died 1778), and Alexander's grandson Sir Alexander Muir Mackenzie, 1st Baronet, Writer to the Signet (died 1835); formed a distinguished line of lawyers who were active in the affairs of their day and included among their family connexions and clients a great number of Highland and Lowland families. The chief interest of the papers is the light which they throw on family history, for they give much information about some less-known Highland families and supply corrections to existing histories of those more famous. Public events are also mentioned. There is a considerable amount of correspondence about the Rising of 1715 and its consequences, but remarkably little about that of 1745.