Apart from general bibliographical knowledge, Laing was best known as a student of the literary and artistic history of Scotland.
[5] Laing was struck with paralysis in October 1878 while in the Signet Library, and it is said that, on recovering consciousness, he looked about and asked if a proof of Wyntoun had been sent from the printers.
Of these, the major ones are: William Dunbar's Works (2 vols., 1834), with a supplement added in 1865; Robert Baillie's Letters and Journals (3 vols.
; 1846–64); Poems and Fables of Robert Henryson (1865); Andrew of Wyntoun's Orygynale Cronykil of Scotland (3 vols.
For over 50 years, Laing was a member of the Society of Antiquaries of Scotland, and contributed over 100 papers to its Proceedings.