Papers concerning Morrison's research into the diary of the Rev. Murdo MacDonald, minister of Durness (1696-1763). The whereabouts of this diary, which covered the years 1737-1763 in eight octavo volumes, are not currently known, although a number of extracts were copied from it. MacDonald's position as minister of Rob Donn's parish during the poet's lifetime makes his diary a valuable document that links to many references in Rob Donn's poetry.

According to Morrison's account (see Acc.14317/22), the diary passed to MacDonald's son Patrick MacDonald, minister of Kilmore and Kilninian in Lorn, and then to Patrick's son Donald, minister of Kilchenzie in Kintyre. Donald MacDonald gave it to Patrick MacDonald, "Paruig Mòr", who gave it to Morrison in 1882. Morrison gave it to James Macalister Hall, in whose library at Tangy the manuscript volumes had been kept before they had been lent to him. The diary was subsequently lost sight of.