The Collection of publishers’ prospectuses, catalogs, and other materials at the Newberry Library contains, not unsurprisingly, a large number of book prospectuses. A book prospectus is a description or advertisement with which a bookseller or publisher hopes to generate interest in a book that he or she proposes to publish.
The Newberry’s collection is comprised mostly of 18th-century French prospectuses, published during a time in which many booksellers and publishers offered books via subscription. In some cases, the proposed work was never published, whether because of lack of interest or insufficient funds, or simply because it was never written.
Jean Bouillet’s Histoire generale des maladies, described in a 1737 prospectus entitled Plan d’une Histoire generale des maladies (Case Wing Z 45 .18 ser. 1a no. 6), is one such example of a work never completed by its author. (Cf. Michaud, J.F. Biographie universelle ancienne et moderne (Nouv. éd), V, p. 216.)
Some prospectuses have become complete works in themselves. French geologist, diplomat, and historian Jean-Louis Soulavie published his Histoire philosophique du progrès des sciences en France (Case Wing Z 45 .18 ser. 1c no. 69) in 1783.
Intended to be a somewhat lengthy (37 p.) prospectus for a work that was eventually never published, it contains an introduction and summaries of the three parts of the proposed work. A cursory Google search reveals that this prospectus has been cited many times, both in bibliographies on the Enlightenment and in scholarly works on the history or science in 18th-century France.