Hardly any of the lectures are dated, but they were presumably delivered between 1845 and 1865, while he held the Chair of Rhetoric and Belles Lettres in the University of Edinburgh.

Apart from the introductory lectures in MS.4897 and a few miscellaneous lectures in MS.4912, they have been broadly grouped according to the threefold classification used by W E Aytoun himself; lectures on literature; lectures on language, style, and versification; and lectures on the principles of oratory.

Many of the lectures are considerably altered and corrected. Apparently some of the earlier lectures became drafts of the later ones, while others were revised and delivered on more than one occasion.

Some bear pencilled notes by Sir Theodore Martin, who read them with a view to publication.

Where the lecture was given a title this has been recorded. For untitled lectures the subject matter is indicated briefly.