Grinnell College has preliminarily agreed to acquire the Des Moines Salisbury House’s library collection of rare books, including first editions and historic documents. The parties are working toward a definitive purchase agreement and anticipate completing the acquisition by midsummer, the college said in a release. The Salisbury House library collection contains approximately 2,500 books and 2,000 documents. Among the collection’s treasures are William Shakespeare’s Second Folio, a 1632 collection of his plays; a 1492 letter from King Ferdinand II of Aragon, calling for the raising of an armada to fight the Barbary pirates; and a leaf from the original printing of the Gutenberg Bible in 1455. There are also signed books and documents from Abraham Lincoln, Charles Dickens, Mark Twain, John Singer Sargent, Walt Whitman and many other renowned individuals. “This is an extraordinary collection that would allow our faculty to incorporate new and exciting resources into their teaching and their support of student research,” said Michael Latham, vice president of academic affairs and dean of the college.