This catalog was compiled by James R. Friday, Roy M. MacLeod, and Philippa Shepherd, and includes guides to published works, diaries, notebooks, journals, correspondence, and newspaper clippings.

The collection is primarily professional letters written to Russell, but there are also a few letters from his wife and a few by him. There is also an autobiographical letter written by Russell. Most of the correspondence pertains to the Royal Meteorological Society, snow crystals, dew, frost, hail, fog, etc. Russell had wide-ranging interests, however, and some of his non-scientific concerns appear in the letters.

A miscellaneous collection of letters, mainly of English scientists, written to various people. There are mostly one or two letters, except for those of John Peter Gassiot, William Huggins, Edwin R. Lankester, James Mackintosh, David Prain, and William Whewell.

Correspondence of Charles Darwin with his family, Sir William J. Hooker, Sir John W. Lubbock, William Ogle, Daniel Oliver, John Tyndall, and Sir William Ramsay, 1836-1882. (1 reel). Letters to J. Brodie-Innes, W. H. Bates, Lady Dorothy Nevill, and others (1846-1882); also letters to his wife and son and letters and papers about him (1 reel). Letters from Darwin to G. H. K. Thwaites, William B. Tegetmeier, Albany Hancock, Richard Owen, Bernhard Studer, Auguste H. Forel, J. Moulinie, A. Bohrn, Karl Christoph Vogt, François Joseph Pictet de la Rive, and others.