The idea of a “Professor of Books” originated from Ralph Waldo Emerson, who wrote in his essay on books in 1856: “Meantime the colleges, while they furnish us with libraries, furnish no Professor of Books, and I think no chair is so much wanted.” Quoted from a book that has over fifty quotes by Emerson: A Dictionary of Library and Information Science Quotations. Edited by Mohamed Taher & L S Ramaiah. ISBN: 8185689423 (New Delhi , Aditya, 1994) p. 126
Emerson's legacy in practice: "Upon becoming the President of Rollins College, Holt saw the cultural possibilities in Emerson’s suggestion, and believed it suited his hope of making Rollins an ideal small liberal college. He made Grover his first faculty appointee as America’s first “Professor of Books.” Some years later Grover recalled “the thrill which I experienced when I came upon Emerson’s suggestion which was to change my life work and make my new vocation also an avocation. My imagination immediately took wings and I began to mull over the possibilities dormant in Emerson’s idea.” Edwin O. Grover (1870-1965): Professor of Books and Citizen of the Community.
A new book that finds a model for library education is here: The Politics of Professionalism: A Retro-Progressive Proposal for Librarianship ~ Juris Dilevko
Extract from the book: "Instead, building on Ralph Waldo Emerson’s “professor of books” model, Dilevko suggests that anyone wishing to work in an academic, research, or public library must independently pass a series of essay-type subject-specific examinations in about ten to fifteen fields or areas of the arts, social sciences, and sciences. In addition, he or she must be able to read and speak at least one non-English language fluently, as well as attend courses about various aspects of the operation of libraries at regional summer institutes."
Interesting is another dig. John Mark Tucker's essay Emerson's Library Legacy: Concepts of Bibliographic Instruction (1984): "Ralph Waldo Emerson's criticism that libraries lack the profession of "professor of books" represents the central problem of bibliographic instruction: an inadequately formed theoretical or conceptual framework. A history of the ideas, notions, terms, and phrases about bibliographic instruction illustrates this."
Bottomline: The notion of 'A professor of books' (not just caretaker or possessor of books), is not new with Emerson. Libraries in the middle ages were managed by a scholar of repute, who had subject-specific knowledge. Period. These caretakers of libraries (the equivalent of modern librarians) were not trained in library schools, but they knew their art and craft of managing the books, providing service to their users, as per the best practices of the time. Examples of such scholarly librarians (with a transition from old-fashioned librarians to the modern librarian), are many. For instance, Ibn al-Nadim (died 995 C.E), and among others the caretakers at the Alexandrian Library, Bodlean Library, Cambridge and Oxford University libraries (details are here: Encyclopedia of Library History ~ Wayne Wiegand ), and much about them here: Some Old-Time Old-World Librarians. Scholar librarians are in the modern era replaced by bibliographers or subject librarians.
Questions for Further Study includes:
"Finally, what difference does the scholarship of librarians make to library users? Are scholarly librarians, and libraries that support and encourage scholarship, more innovative? Is there a measurable relationship between the degree of scholarship undertaken at certain libraries and the quality of library service delivered?" [source: The Scholarship of Canadian Research University Librarians, David Fox, Partnership: the Canadian Journal of Library and Information Practice and Research, Vol 2, No 2 (2007)]