Lyell's notes on the envelopes:
1. 'Delesse on Ch[apter] 28 Manual. June 30 1854'
2. 'Delesse Jan 1. 1855' [no corresponding letter]
3. 'Delesse on advance of [...] Feb 22 1860'.
5. 'Delesse Dec 1865. Metamorphism [wash] anticipated'.
6. 'Delesse May 16 1861. sending papers on [agate] in rocks and [...]. Asking for abstract of it for G.S. when presented. [...] and igneous in origins'.
7. 'Delesse, Société Philomathique'
8. 'Delesse, January 3 1866'
9. 'Delesse March 21st 1869'
Lyell also makes notes on the letters:
Folio 990- ‘Delesse, July 1854. Palagonite’.
Folio 997- ‘Delesse, August 1860, Human remains in Brazilian Diamond gravel’