I'm intrigued by the Prophet's polyglot New Testament consulted in the 7 April 1844 general conference address (King Follett Sermon) and in a 12 May 1844 sermon. "A Bible in various tongues" is how visitor Josiah Quincy described it. For some Saints the book became an iconic way of remembering Brother Joseph. A lithograph depicting the April 1844 general conference shows the Prophet with his Testament on the pulpit; the book even surfaces in Wilford Woodruff’s dreams: "I met with Br Joseph Smith in the Congregation of the Saints. He had his old Hebrew and Jerman Bible, and preached to the Saints." As the dream continues, Joseph, "thronged by people," lifts a curtain into "another room and there he was going to teach the people" (19 August 1844; 2: 449, in ed., S. Kinney; Josiah Quincy, Figures of the Past).
Note what Brother Woodruff calls the book: "his old Hebrew and Jerman Bible."
Thomas Bullock reports Joseph as saying: “I have an old book [Clayton: ‘N.T.’] in the Latin, Greek, Hebrew, and German” (7 April 1844). The book comprises “the old German [Luther’s original], Latin, Greek, and Hebrew translations” (Bullock Report, 8 April 1844). The Prophet further terms his Testament “the oldest book in the world” (Woodruff Journal and Clayton Report for 7 April), which matches Samuel W. Richards’s characterization of it as “an ancient German Bible” (12 May 1844). Only one polyglot Testament fits the description and that is Elias Hutter’s Novum Testamentum harmonicum (Nuremberg, 1602).
I’ve examined the polyglot and compared its readings against published transcriptions of the sermons to understand how Joseph used this unique Testament to rhetorical effect. After giving a new interpretation of the first verse of Genesis, the Prophet turns to his Testament for evidence that English translators often got it wrong. The example chosen is simple: “James the son of Zebedee” should be rendered “Jacob the son of Zebedee” (Matthew 4:21). And to clinch the case, after giving the German form, Joseph reads the name from the three preceding columns: Hebrew, Greek, Latin. Now the rendering of Jacob varies from language to language, and the Clayton Report, which alone shows all four forms, transcribes these phonetically, but the evidence is conclusive: the Prophet was reading from a 1602 Hutter.
There’s some humor. A lithograph of Joseph Smith addressing the April 1844 conference was “respectfully dedicated” to the Quorum of the Twelve Apostles by George Lloyd (Church History Library, catalog entry for Lloyd, George). The lithograph tells a story: Joseph, large Bible open before him, proclaims the pan-American Zion and the building of the temple. This story now becomes, as the dedication shows, the future story of the Twelve. But there’s something odd about the Clayton Report of 8 April 1844. Joseph, too weak in lungs to open the meeting, calls on Brigham Young to read 1 Corinthians 15. Brigham arises and announces: “[We] shall com[mence] by read[ing]  Cor.—from an old Bible—W. W. Phelps read[.] Prayer by E[lde]r B. Young.” What’s that all about? Brigham arose, took one look at the old Bible, remembered that Phelps was something of an adept—and voilà.
Update, 8 March 2010: Before publishing this post on the Prophet's polyglot Testament, I poked around BYU and the Joseph Smith Papers to see if others had already done research on the topic (I felt certain that such would indeed be the case), and even tried to search for posts about the polyglot on Google early last Fall. I also checked W.V. Smith's Book of Abraham Project Website, a fine resource for sermons of the Prophet Joseph and Book of Abraham studies. I was certain that if anyone had done research on the subject it would be he. I didn't find anything on the Web site but now see, on Google, under date of November 20, 2009, a note from Boap.org's Blog, entitled (just like my post!) "Joseph Smith's Polyglot New Testament," which states: "When Joseph Smith lived in Nauvoo, Ill., he had acquired a polyglot NT. One can narrow down which one it was by the languages it contained: Hebrew, Greek, German, Latin." Professor Smith further states that he has attempted to find the Prophet's own copy of the polyglot and asks: "Anyone out there know where this NT is?" I don't know where the Prophet's polyglot is but have confidence it will be located.
Many copies of the Hutter Polyglot can be found in America's libraries, so it's possible the copy owned by the Prophet may be found. Quincy, Illinois has a Hutter, but the likelihood of any connection to the Prophet is slim; I was intrigued by BYU's copy because the page next to Matthew 24, cited by the Prophet, had been torn and repaired, but BYU's copy (which merits study anyhow) was obtained fairly recently. As for Brother Smith's suggestion that Alexander Neibaur was the original owner of the polyglot, we can deduce from the Prophet's discourses that the polyglot was his lesson book for readings in German and Hebrew, and we know that Brother Neibaur was his teacher.
Notes: 1) The George Lloyd lithograph is featured on the dust jacket of Glen Leonard's Nauvoo (2002); see also pages 332-33. Because the lithograph is privately owned, the color image on Leonard's book is a rare view of a cultural treasure. Update: 5 April 2016: The lithograph is on display at the Church History Museum, Salt Lake City. The lender is Mr. Jim Ostvig.
2) Special Collections at the Harold B. Lee Library at BYU has a copy of the 1602 Hutter Polyglot.
3) The book I consulted and followed (with a few editorial additions for 8 April 1844) for the Nauvoo discourses was Lyndon Cook and Andrew Ehat, The Words of Joseph Smith. I also compared Cook and Ehat with W.V. Smith's transcriptions found on his Book of Abraham Project Website, a fine resource for students of The Book of Abraham.