The William Hutton Papers relate primarily to geology and botany, and there is also much on the Newcastle Natural History Society, of which Hutton was the secretary. There is much correspondence with Alexandre Brongniart, H. S. Davis, John S. Henslow, John Lindley, David Milne, Roderick I. Murchison, George Steuart MacKenzie, and John Phillips.

These notebooks contain lectures or reports on lectures, with corresponding watercolor and pen-and-ink drawings. There are volumes on geology (Great Britain and elsewhere), natural history, mechanics (sketches of levers, valves, and weighing machines), and steam engines (sketches of mechanics of boilers).

These are letters written from America, to Murchison, discussing geology, natural history, and contemporary topics.

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.

These are primarily letters to Gray on various aspects of natural history, with many references to collections at the British Museum of Natural History. There are numerous letters from British scientists and from European colleagues. There are letters from Americans too, such as those from Agassiz which relate to his Florida expeditions and the creation of natural history collections.

The Scientists Collection is comprised of individual letters and small groups of correspondence from American, British, French, and German scientists during the past three centuries. Although the content is highly varied, there is significant strength in astronomy, natural history, conchology, and geology. Among the scientists better represented in the collection are the astronomers William Radcliffe Birt, J.F.W. Herschel, and Franz Xaver von Zach; the conchologists A.D. Brown, Fred L. Button, Otto Mörch, Alfred Newton, Christian M. Poulsen, Temple Prime, Benjamin Lewis Vulliamy, and A. G. Wetherby; the physical scientists George Biddell Airy, Arnold Sommerfeld, Ferdinand R. Hassler, and Max Planck; the archaeologist Jean François Nadaillac; the philosopher William Whewell; and the naturalists Walter Henry Bates, Robert Chambers, Edme Dupuget, Robert Kaye Greville, Joseph Henry, John Stevens Henslow, John Lubbock, and Herbert Spencer.

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.