The volume consists of an alphabetical index to Owen correspondence and brief abstracts. Includes 1981 letter (3 p.) from Gruber to British Museum regarding Owen calendar, key to locations of Owen correspondence, and an introductory essay (29 p.) by Gruber.

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.

These are primarily scientific letters from Buckland. The subjects mentioned include Milne-Home's seismological investigations, Wheatstone's self-registering instruments, geology (glacial phenomena in Scotland, mineralogy, etc.), numerous references to fossils, and mentions of Mastodon bones and sloths.

Series I is a miscellaneous collection of letters concerning geology, geological exploration of Russia, entomology, glaciers, appointments in the British Museum, Geological Society of London business, Royal Geographical Society, references to David Livingstone, and zoology. Series II consists of letters written from America, to Murchison, discussing geology, natural history, and contemporary topics.

This collection contains correspondence on natural history, expecially mollusks, fishes, and birds, and on medicine and social affairs, with references to the British Museum of Natural History. Also included are a paper by Owen on dinosaurs and a synopsis of a course of lectures, 1857.

The collection is a miscellaneous group of letters of mainly British scientists and physicians, purchased as an existing autograph collection. There are a few American signatures. The letters are primarily from the nineteenth century and focus on medical and geological topics, but also there are some earlier and later dates. In addition to the letters are anatomical drawings of surgery, sketches of bones, and one geological notebook.

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.

After a brief career in the Congregational church, J. Peter Lesley (1819-1903) left the ministry in 1852 to work full-time as a geologist. Having gained experience in structural geology and stratigraphy with the First Pennsylvania Geological Survey (1836-1842), Lesley became an expert in the geology of coal, working for the Pennsylvania Railroad and other corporations and conducting some of the first systematic studies of the state's hydrocarbon resources. A long-time professor at the University of Pennsylvania, he was elected to the APS in 1856, serving variously as its librarian, secretary, and vice president, and he was selected as Director of the Second Pennsylvania Geological Survey (1875-1889). The Lesley Papers include letters to and from Peter Lesley and his wife, Susan on geology, coal and iron mining, abolition, educational reform, organized charity, and Unitarianism. The collection offers important insight into academic and applied geology in late 19th century Pennsylvania, the development of the coal and iron industries, as well as into the Lesleys' progressive social and intellectual milieu. It is divided into three series: Lesley's general correspondence, his correspondence with his brother Joseph, and microfilms of Lesley's research notes.

There is correspondence concerning geology, botany, natural history, natural selection, evolution, British science and scientists, and other scientific topics. Most of the letters are written by Lyell, with a very few items by others.