These are copies of letters, chiefly relating to the American Philosophical Society, from Peter S. Du Ponceau, John Vaughan, and James Mease. There are a few original letters, one to Benjamin Franklin Peale.

Circa 160 transcripts prepared for publication in Alan Armstrong, ed. Selected correspondence.

Written by William Alexander at Basking Ridge, New Jersey, March 27, 1773, this essay appeals to the American Philosophical Society to collect and publish astronomical observations. It was sent to the American Philosophical Society, where it was duly read in May 1773.

These manuscripts are in the hand of various unknown authors, and concern research and observations on the torpedo fish, which was of much interest to those studying electricity at the time. Included are copies of letters from John Walsh to Benjamin Franklin, and a copy of a Walsh and Thomas Pennant letter, read before the Royal Society (1774), concerning a torpedo fish found off the coast of England.

This volume contains extracts, chiefly in an unknown hand (probably Charles Waterton), from Ord's letters, 1831-1835, criticizing Audubon as a man and as a naturalist. Ord wrote the last part of the volume (signed and dated June 29, 1838), and there are manuscript comments by Charles Waterton.

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.

All but one of these letters are to Charles Alston, the professor of botany at Edinburgh University, and concern medicine, botany, and science in general. They are dated between 1737 and 1750. One letter is to George Whately, dated 1778.

This is a small group of letters written to Johann Ambrosius Beurer, J. von Sprehelson, and Christoph Jacob Trew.

Miscellaneous letters from and to Benjamin Smith Barton, Nicholas Collin, Henry Muhlenberg, Jeremy Belknap, Monsieur Le Roi, and a broadside by Robert Aitken. These letters concern botany and zoology in the U.S., England, and on the Continent, and mention contemporary figures as well as the American Philosophical Society.

These letters concern various scientific subjects, such as fishes, insects, snakes, mice, fossils, and mosses. Other subjects include learned institutions, notably the Smithsonian Institution and the Academy of Natural Sciences of Philadelphia, and men of science. Correspondents include S. S. Haldeman, Walter J. Hoffman, Spencer F. Baird, Edward D. Cope, and Leo Lesquereux.

This material relates to Alexander B. Grosart's biography of Wilson. There are notes and copies of letters and documents, including a copy of Wilson's will. There is one poem by Wilson, "The Last Wish," and an 1806 letter to William Bartram.

Correspondence compiled by Edward E. Wildman and Francis D. West, chiefly from original letters in the Historical Society of Pennsylvania and other depositories, 1956.

The primary correspondence (ca. 65 letters) is with William Cooper (1798-1864) on Bonaparte's publications, especially "American Ornithology" and "Observations on the Nomenclature of Wilson's Ornithology," but also included are many references to American and European men of science and learned societies. There are also letters to Isidore Geoffroy Saint-Hilaire, George Robert Gray, Titian Ramsay Peale, and Wilhelm P. S. Rüppell.

Nine of these letters are addressed to Sir Alexander Dick of Edinburgh (1763-1768), and relate to Morgan's medical studies, his travels on the Continent, and the founding of the medical department of the College of Physicians. These are copies of originals in possession of Mrs. Dick Cunyngham, Prestonfield House, Edinburgh. In addition there are letters from Morgan to: Petrus Camper, William Smith, Samuel Vaughan, Jr.; and from Peter Collinson to Camper; Camper to Morgan; S. Vaughan Jr. to Camper; and an exchange between Christian F. Michaelis and Camper. These concern Morgan, with mentions of fossils (mastodon bones in America), natural history, comments on Franklin, Jefferson, and Angelica Kauffmann. These are from originals in the Petrus Camper Papers, on deposit (1976) at the University of Amsterdam Library.

Benjamin Silliman (1779-1864, APS 1805) was a scientist and educator. As a professor of chemistry at Yale University from 1802 to 1853, and pioneering teacher of chemistry, mineralogy and geology, Silliman was largely responsible for the conversion of Yale College to Yale University, with strong medical and scientific departments.

These papers include letters on natural history, metals and mineralogy, botany, insects, the geological survey of New York, and analyses of distilled liquors in the cause of temperance.

This is primarily a collection of letters and manuscripts sent to Wistar by prominent men who were among his many correspondents. These documents reflect his broad interests, including botany, paleontology, medicine, the American Philosophical Society, and André Michaux's plans for exploring the Missouri.

A key spokesman for the medical establishment against the antivivisection movement, Walter B. Cannon was head of the Council for the Defence of Medical Research of the American Medical Association from 1908 to 1936. He and his colleague William W. Keen monitored antivivisectionist activity, mobilized the medical profession, lobbied politicians, testified in public hearings, and wrote tirelessly in defense of animal experimentation. Cannon was George Higginson Professor of Physiology at Harvard Medical School and head of its physiology department. Keen was a prominent surgeon and neurologist from Philadelphia. The Cannon Papers consist of over 1.5 linear feet of correspondence, 1905-1928, primarily between Cannon (1871-1945) and Keen (1837-1932) regarding their mutual opposition to the antivivisection movement.

The largest portion of correspondence is with Charles Edwin Bessy on botanical matters, including botanical publications in the United States and Europe, and plants and shell specimens.

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.