The letters are mostly to John Murray II, but included are letters to John Murray III. Also included is a letter of Lyell to John Gibson Lockhart.

The letters are arranged chronologically.

1826: folios 1-3;

1827: folios 4-21;

1829: folios 22-35;

1830: folios 36-47;

1831: folios 48-57;

1832: folios 58-92;

1833: folios 93-118;

1834: folios 119-141*.

* Folios 139-140: letter, 1 December 1834, of Lyell to John Gibson Lockhart informing him that the Royal Society has awarded “Principles

of Geology” the Royal Medal.