These letters are to William Hepworth Dixon, who was editor of the "Athenaeum," a journal of literature, science, the fine arts, music, and drama, from 1871 to 1900. They concern current publications and publishing expenses, Michael Faraday, astronomy, perspective, M. F. Maury, P. B. Du Chaillu, all in relation to the "Athenaeum" or letters to the editor thereof.

Adam Sedgwick (1785-1873, APS 1860), geologist, was an important figure in the development of the modern discipline of geology. He was educated at Cambridge, being ordained in 1817. An excellent field geologist, he did significant work interpreting complex old rock in such places as Devonshire (naming the Devonian Period after that location), Cornwall, and the Lake District, correlating his findings with strata in places such as Germany. Sedgwick first interpreted strata from the period he named Cambrian. He served in many professional organizations and was honored for his work with the Wollaston and Copley medals. Sedgwick, a Liberal in politics, served on committees that reformed the administration of university education. Despite being a friend of Charles Darwin's, Sedgwick was critical of the materialist bent of Darwinian thought. The 37 letters in the collection were acquired at various times, mainly through purchase, and assembled for the collection. The letters span the dates 1825-1870. Individually most letters are not especially significant, but collectively they touch on most aspects of Sedgwick's life and career. There are letters about Sedgwick's work on university reform, the Geological Museum at Cambridge, lectures, colleagues, travel, health, and family. Only one letter in the collection delves into detail about Sedgwick's geologic work.

The collection is divided into two series. The first contains disparate letters from Airy relating to his publications and his position as Astronomer Royal of England, with mentions of topics such as: electrical experiments, magnets, Observatoire de Paris, stars, and telescopes. Correspondents in this series include: Edward Wedlake Brayley, James Challis, Alexander S. Herschel, Balfour Stewart, Septimus Tebay, John Washington. The second series features a group of documents put together by George May of the Harton Colliery at South Shields (1889) relating to Airy's pendulum experiments at Harton Pit in 1854 to measure the density of the earth.

The papers of the Italian natural philosopher and electrician, Giambatista Beccaria (1716-1781) contain letters to Benjamin Franklin, Joseph Banks, Laura Bassi, Gian Francesco Cigna, and others on a variety of scientific topics, including atmospheric and terrestrial electricity, the aurora borealis, earthquakes, meteorology, and phosphorescence. In addition to Beccaria's epistolary essays, the collection includes several journals of meteorological observations and notes for Giovanni Eandi's biography of Beccaria.

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.

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.

Though the Miscellaneous Manuscripts collection is composed of items that do not fall readily into any other existing collection, the two dominant intellectual areas represented in the collection are Early American History and History of Science.