Joseph Smith becomes violently ill at dinner and assumes that his wife Emma has poisoned him due to her opposition to polygamy. At the prayer circle meeting that evening Joseph Smith accuses her, and Brigham Young regards her shocked silence as proof of her guilt.
[Joseph Smith Diary] [Joseph] Was taken suddenly sick at the dinner table. Went to the door and vomited /all [his] dinner/. [His] jaws [were] dislocated and raised fresh blood. Every symptom of poison. [several lines left blank]
Prayer Meeting eve at the Hall over the store. <Joseph did not dress [in robes of the priesthood, as customary], nor Emma> [several lines left blank]
[Quinn, D. Michael, The Mormon Hierarchy: Origins of Power, Appendix 7: Selected Chronology of the Church of Jesus Christ of Latter-day Saints, 1830-47, http://amzn.to/origins-power;Faulring, Scott (ed.), An American Prophet's Record: The Diaries and Journals of Joseph Smith: Joseph Smith Diary, 1843-44, http://amzn.to/jsdiaries]