This volume records the proceedings, from 18 June 1859 to 7 June 1862, of this York County (Pa.) Society. There are minutes of the meetings of the organization, formed to promote clear thinking and intelligent discussion on a wide range of topics which are noted for each session, with affirmative and negative arguments. There are lists of members and officers, and the constitution is set forth.

Correspondence with Philadelphia institutions, from Accademia delle Scienze. Letters, principally of a formal character, from the APS, Academy of Natural Sciences, Wistar Institute, Wagner Free Institute of Science, and other learned societies and institutions; also a letter from John Vaughan to Prospero Balbo, 1832; with drafts of some replies.

It is suggested that this manuscript draft "was written for the court of Charles III of Spain and for the plan of a Madrid academy of sciences. In his text, Condorcet tries to sell the idea of a scientific academy and all its advantages, and he treats questions of academic structure and organization at length. Also, what is most important, Condorcet makes the argument for the academy as an independent center of a professional scientific career" (McClellan 1977:241). Contains also an extract from the [minutes?] of the academie des sciences, May 12, 1785, consisting of a report of committee on this article.

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.

Minutes of meetings, mainly dealing with astronomy; added papers by Jean Paul Grandjean de Fochy and Jean-Jacques Dortous de Mairan.

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.

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.