of the French by the French Senate. May 21 – Père Lachaise Cemetery a cemetery in Paris, France is opened. June 9 – Beethoven's Symphony No. 3 in E–flat premiered in Vienna. June 15 – The Twelfth Amendment to the U.S. Constitution is ratified by New Hampshire, and arguably becomes effective (subsequently vetoed by the Governor of New Hampshire). June 21 – Smithson Tennant announces the discovery of the elements iridium and osmium; three days later, William Hyde Wollaston reveals to the Royal Society that he is the formerly anonymous discoverer of palladium. July–September July 11 – Aaron Burr, Vice President of the United States, shoots former U.S. Secretary of the Treasury Alexander Hamilton during a duel; Hamilton dies the next day. July 27 – The Twelfth Amendment to the U.S. Constitution, which reformed the way that candidates for President and Vice President are chosen, is ratified by Tennessee, removing doubt surrounding adoption. August 11 – In reaction to Napoleon being proclaimed emperor of France, Francis II assumes the title of a hereditary emperor of Austria (as Francis I) in addition to his title as emperor of the Holy Roman Empire. This latter title will become obsolete two years later when the formation of the Confederation of the Rhine instigated by Napoleon signals the end of the Holy Roman Empire. August 20 – Lewis and Clark Expedition: The Corps of Discovery, whose purpose is to explore the Louisiana Purchase, suffers its only death when Sergeant Charles Floyd dies, apparently from acute appendicitis. September 1 – German astronomer K. L. Harding discovers the asteroid Juno. October–December October 5 – Action of 5 October 1804: War between Spain and the United Kingdom is triggered by the battle between four British warships (Indefatigable, Medusa, Amphion and Lively) and four Spanish frigates (Medee, Fama, Clara and Mercedes), all carrying treasure and merchandise. Captain Graham Moore of Indefatigable informs Spanish Admiral Jose Bustamante of his orders to detain the treasure-laden ships and, "not receiving a satisfactory answer, an Action commenced"; La Mercedes is sunk and the other three ships surrender. October 8 – Jean-Jacques Dessalines holds his coronation as Jean-Jacques I, Emperor of Haiti. November 3 – The Treaty of St. Louis is signed by Quashquame and William Henry Harrison; controversy surrounding the treaty eventually causes the Sauk people to ally with the British during the War of 1812, and is the main cause of