This addition—hence the title Mantissa—to the rich vein of information about Constantine Samuel Rafinesque is in fact a supplement to Charles Boewe's own revised and enlarged edition of Thomas J. Fitzpatrick's book Rafinesque .The details of the peripatetic life of Rafinesque, one of America's most original yet undisciplined naturalists, are too well known to bear repeating here. Suffice it to say that because of the vicissitudes of his life—his perpetual wandering between and within Europe and frontier America, his impecunious circumstances (...) that forced him to find different ways of making a living—finding and identifying his publications is a bibliographer's nightmare. Even now, more than 160 years after his death and with the benefit of serious studies by Fitzpatrick and Boewe, as well as by Richard E. Call and Elmer D. Merrill, among others, we can only approximate the number of his publications, including both original titles and republications. Probably we will never have a complete list of Rafinesque's publications because he published regularly in newspapers, broadsides, sales catalogues, privately printed journals, and other ephemera that are infrequently archived. Even his own references to “published” works cannot be trusted as, to him, this term included papers that he sent to journals but were never published. On the other hand, Rafinesque complained to one correspondent that he never knew whether some of these manuscripts were ever published or he learned only years later that they had been. The total number has been estimated at about a thousand, but, as Boewe points out, this number is based on Fitzpatrick's faulty numbering system in which each version of a paper or volume of a multivolume work was given a number. Thus Fitzpatrick's system, continued by Boewe, represents serial numbers, not individual titles. Rafinesque's own estimate was 220, a number Boewe now thinks is a reasonable guess.The Mantissa is an important addition to Rafinesquiana. It lists twenty hitherto‐unrecorded publications by Rafinesque, thirty‐three new translations or reprints, and more than two hundred newly listed secondary references. For the first time we have a list of every manuscript letter written by Rafinesque that is known to exist, and Boewe provides a documented discussion of Rafinesque publications still remaining to be discovered. Several titles known to me, however, are missing from Mantissa, but Boewe's book represents a learned guide for the next scholar willing to take up the challenge and carry on the search. The newly listed manuscript letters will doubtless be particularly helpful in providing leads to undiscovered publications and other facets of Rafinesque's still not completely understood life. Among his correspondents were fellow naturalists such as John James Audubon, Joseph Banks, Benjamin Barton, Charles Bonaparte, Alexandre Brongniart, Augustin de Candolle, Georges Cuvier, Amos Eaton, Asa Gray, William Jackson Hooker, Muhlenberg, Ord, Paolo Savi, James Edward Smith, William Swainson, and John Torrey, as well as prominent leaders of the day, including John Adams, De Witt Clinton, Eleuthère Irénée du Pont, George IV, Thomas Jefferson, and Joel Roberts Poinsett. A total of 346 letters are listed.More important, Boewe has given us the benefit of his many years of scholarly searching and thinking about Rafinesque in his discussions entitled “Hints about Unlisted Titles,” “Letters as a Source of Leads,” and “Hints in Publications.” We learn, for example, that Rafinesque signed some of his papers simply as “Constantine” or “Linneus.” The Mantissa makes it abundantly clear why arriving at a complete account of Rafinesque's writings is an elusive goal, but Boewe shows us that the attempt still offers an exciting trail to follow. (shrink)