editions Absurdities of Immaterialism (1849) Project Gutenberg Kindle, epub, html, and text editions Cubic and Biquadratic Equations (1866) Key to the Universe (1866) The Bible and Polygamy (1870) Death At age 70, Pratt died of complications from diabetes in Salt Lake City. He was buried in the Salt Lake City Cemetery. He continued to be a leading Mormon theologian and writer until his death. When he died, he was the last member of the LDS Church's Quorum of the Twelve who had been an original member of the 1835 Quorum. See also List of people with the most children Quorum of the Twelve References Sources . External links Grampa Bill's G.A. Pages: Orson Pratt Pratt Family Association Documents about Orson Pratt Minutes from Orson Pratt Jr. Excommunication, MSS6954, Digital Collections, Harold B. Lee Library, Brigham Young University Transcription of above minutes Blog entry explaining the context ] 1811 births 1881 deaths 19th-century American mathematicians 19th-century American politicians 19th-century American writers 19th-century Mormon missionaries American Christian theologians American Mormon missionaries in Austria American Mormon missionaries in England American Mormon missionaries in Scotland American Mormon missionaries in the United States American general authorities (LDS Church) American people of English descent Apostles (LDS Church) Apostles of the Church of Christ (Latter Day Saints) Burials at Salt Lake City Cemetery Converts to Mormonism Deaths from diabetes Doctrine and Covenants people Editors of Latter Day Saint publications Latter Day Saints from Illinois Latter Day Saints from New York (state) Latter Day Saints from Utah Mathematicians from New York (state) Members of the Utah Territorial Legislature Mission presidents (LDS Church) Mormon pioneers Mormon theologians Official historians of the Church of Jesus Christ of Latter-day Saints People excommunicated by the Church of Christ (Latter Day Saints) Pratt family (Latter-day Saints) Religious leaders from New York (state) Harold B. Lee Library-related 19th century articles