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.

This is a small but diverse collection documenting Wheatley's interests in mines and mining technology, paleontology, mineralogy, and shells. There are sketches of Wheatley's mine near Phoenixville, Pennsylvania; estimates of costs of machinery, and a list of furnace products sent to the Centennial Exposition.

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.

This microfilm contains letters and drafts of replies, memoranda, lists of plants and shrubs, observations on natural history, diary notes, extracts from reading, and recipes. There is a "Catalogue of Books given to [Friends] Publick School of Philadelphia" by Collinson dated 1749. There is a copy by Collinson of a May 16, 1560 note by Elizabeth I of a gift of old clothes to her maids of honor. A 1811 letter is from C. S. Collinson to Aylmer Bourke Lambert.

From negative microfilm held by Dr. Leonard G. Wilson, the collection consists mostly of incoming correspondence from English and American scientists, with a small section of correspondence from Lyell.

This collection contains professional and personal correspondece, as well as some personal business accounts. The topics mentioned range from general ornithology to specific birds, particularly of the West Indies and South America; bird illustrations and various publications; paleontology, and zoology.

The Peale family is best known as a family of artists; however, family interests and activities were much more wide-ranging. The best known Peale is Charles Willson Peale (1741-1827, APS 1786), who produced more than one thousand paintings, including hundreds of portraits of leading Americans during the colonial and early national periods. Peale was married three times, to Rachel Brewster (1744-1790), Elizabeth de Peyster (1765-1804), and Hannah More (1755-1821). He had eighteen children, eleven of whom reached adulthood. Three of Charles Willson Peale's sons became artists: Raphaelle Peale (1774-1825), Rembrandt Peale (1778-1860), and Rubens Peale (1784-1865). A fourth son, Titian Ramsay Peale (1799-1885, APS 1833), was a naturalist (who made drawings on the exploring expeditions he accompanied) and pioneer in photography, and another son, Benjamin Franklin Peale (1795-1870), became a naturalist and paleontologist. Peale's daughter Sophonisba Angusciola was married to Coleman Sellers (1781-1834), an inventor and manufacturer of machinery, including locomotives. Two of their sons, George Escol Sellers (1808-1899) and Coleman Sellers (1827-1907, APS 1872), were inventors and engineers. The latter served as director of the construction of the hydro-electric power development at Niagara Falls. He was married to Cornelia Wells Sellers (1831-1909). One of their grandsons was Charles Coleman Sellers (1903-1980, APS 1979), a librarian and historian and the author of several studies of the Peale family, including a Charles Willson Peale biography.

Letters and papers to or from American scientists or about America, selected from the Linnean Society's collections. Includes letters to William Swainson from John Abbott, John J. Audubon, Constantine S. Rafinesque, Isaac Lea, and John E. LeConte; letters to Sir James Edward Smith from Jacob Bigelow, DeWitt Clinton, J.F. Correia da Serra, David Hosack, Theodore Lyman, William Dandridge Peck, Rafinesque, and Gotthilf H.E. Muhlenberg; letters to William Darlington; letters to Asa Gray; letters of John Bartram; letters of Peter Collinson to J.F. Gronovius; letters and papers of John Ellis, including letters from Alexander Garden, Samuel Martin, and Bernard Romans; letters to Carl Linnaeus from John Bartram, John Clayton, Cadwallader Colden, Correia da Serra, Peter Kalm, Adam Kuhn, James Logan, John Mitchell, and Charles Wrangel.

This collection includes letters from, and drafts of letters to, scientists, artists, musicians, soldiers, political figures, and court personages throughout Europe, especially Italy and France. Topics covered range from personal and social affairs to agriculture, botany, geology, natural history, coinage, museum management, politics, weights and measures, current affairs. The collection also includes four diaries, housed separately with manuscript volumes.

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.

The papers include miscellaneous letters, letterbooks, books, certificates, and diplomas of various members of the Muhlenberg family. Among them are photostats of letters and papers of General John Peter Gabriel Muhlenberg and officers of the Continental Army on military affairs in the Southern Department during the American Revolution (1772-1804); photostats of letters to Albert Gallatin, Nathanael Greene, Edward Hand, Winthrop Sargent, Baron von Steuben, William Alexander, and George Washington; photostat of General Muhlenberg's journal of trips to the Ohio (1784, 1797); photostats of letters and notes of Gotthilf H. E. Muhlenberg, including a diary kept at Halle (1771) and extracts of thirty letters to Stephen Elliott of Beaufort and Charleston, South Carolina (1808-1815); photostats of letters of Henry A. Muhlenberg about his biography of General Muhlenberg (1848-1849); and photostats of letters of Henry Melchior Muhlenberg (1711-1787). Also included is an original letterbook of Peter Muhlenberg, paymaster of the United States Army, kept at Augusta and Savannah, Georgia (1836-1842). Henry Muhlenberg's notebooks (1784-1813), written in Latin or German script, in a small hand, includes a wealth of botanical observations, with a focus on Lancaster, Pennsylvania. The Henry Muhlenberg journals are a record of daily occurrences, with many features of a commonplace book, containing prescriptions, notes of questions asked candidates for the Lutheran ministry, and the plan of a barn. There is also a biographical account of Rev. Henry Melchior Muhlenberg (1711-1787).

These papers reflect Isaac Hays' interests and activities in the medical profession and as an editor. His interest in paleontology, especially in the controversy with G. W. Featherstonhaugh, is also represented. There is one separate volume (77 letters) containing correspondence about natural history and naturalists, written to Hays by C. L. Bonaparte, George Ord, Thomas Say, and Charles A. Lesueur. The correspondence in the larger collection, however, contains much material on the American Journal of the Medical Sciences, particularly illuminated in the correspondence with John D. Godman. The I. Minis Hays material consists of letters from doctors, relating to medicine and medical publications and editing, as well as medical organizations. Most significant of the correspondence is that with John Shaw Billings (ca. 60 letters).