His last opera was a German language singspiel Die Neger, ( The Negroes ), a melodrama set in colonial Virginia with a text by Georg Friedrich Treitschke ( the author of the libretto for Beethoven's Fidelio ) performed in 1804 and was a complete failure.

* 1885 – Karl Theodor Ernst von Siebold, German physiologist ( b. 1804 )

* 1804 – Carl Freiherr von Rokitansky, German physician ( d. 1878 )

* 1804 – Karl Theodor Ernst von Siebold, German physiologist ( d. 1885 )

* 1804 – Ludwig Feuerbach, German philosopher ( d. 1872 )

* 1804 – Wilhelm Eduard Weber, German physicist ( d. 1891 )

* 1804 – Juno, one of the largest main belt asteroids, is discovered by German astronomer Karl Ludwig Harding.

* Karl Theodor Ernst von Siebold ( 1804 – 1885 ), German physiologist and zoologist

* 1804 – Eduard Mörike, German poet ( d. 1875 )

One very early experiment in electrical telegraphy was an electrochemical telegraph created by the German physician, anatomist and inventor Samuel Thomas von Sömmering in 1809, based on an earlier, less robust design of 1804 by Spanish-Catalan polymath and scientist Francisco Salva Campillo.

* Immanuel Kant ( 1724 – 1804 ) German.

* June 4 – Eduard Mörike, German poet ( b. 1804 )

* September 13 – Ludwig Feuerbach, German philosopher ( b. 1804 )

* February 18 – Carl Gustav Jakob Jacobi, German mathematician ( b. 1804 )

* August 8 – Johann Friedrich Gmelin, German naturalist ( d. 1804 )

* April 22 – Immanuel Kant, German philosopher ( d. 1804 )

The German libretto is by Joseph Sonnleithner from the French of Jean-Nicolas Bouilly which had been used for the 1798 opera Léonore, ou L ’ amour conjugal by Pierre Gaveaux, and for the 1804 opera Leonora by Ferdinando Paer ( a score of which was owned by Beethoven ).

Matthias Jakob Schleiden ( 5 April 1804 23 June 1881 ) was a German botanist and co-founder of the cell theory, along with Theodor Schwann and Rudolf Virchow.

From the Gramsci analysis derived the political science denotation of hegemony as leadership ; thus, the historical example of Prussia as the militarily and culturally predominant province of the German Empire ( Second Reich 1871 – 1918 ); and the personal and intellectual predominance of Napoleon Bonaparte upon the French Consulate ( 1799 – 1804 ).

* Hermann Schlegel ( 1804 – 1884 ), German ornithologist

* Wilhelm Eduard Weber ( 1804 – 1891 ), German physicist

After the Louisiana Purchase in 1804, Anglo-Americans as well as German immigrants migrated to the village.

His translations of the dramas of Sophocles were published in 1804 but were generally met with derision over their apparent artificiality and difficulty caused by transposing Greek idioms into German.

Claude Louis Berthollet ( 9 December 1748 – 6 November 1822 ) was a Savoyard-French chemist who became vice president of the French Senate in 1804.

This observation was first made by the French chemist Joseph Proust, based on several experiments conducted between 1798 and 1804.

English chemist and co-discoverer of oxygen Joseph Priestley lived in Northumberland for the last decade of his life, until his death in 1804.

* March 13-Joseph Priestley, English chemist ( died 1804 )

* Antoine Baumé, ( 1728 – 1804 ), French chemist

* Otto Linné Erdmann ( 1804 – 1869 ), a German chemist

Named after the French chemist Antoine Baumé ( 1728 – 1804 ).

Antoine Baumé ( 26 February 1728 – 15 October 1804 ) was a French chemist.

It was first isolated in 1804 by Friedrich Sertürner, first distributed by him in 1817, and first commercially sold by Merck in 1827, which at the time was a single small chemists ' shop.

In addition, by the time he submitted his dissertation in 1804 ( September ), he was in regular contact at Jena with Jakob Friedrich Fries and Karl David Ilgen, who perhaps led him to his contact with Johann Severin Vater, a scholar whose work he both admired and, in some respects, duplicated independently.

The expulsion in 1837 of the seven professors – Die Göttinger Sieben – the Germanist, Wilhelm Eduard Albrecht ( 1800 – 1876 ); the historian Friedrich Christoph Dahlmann ( 1785 – 1860 ); the orientalist Georg Heinrich August Ewald ( 1803 – 1875 ); the historian Georg Gottfried Gervinus ( 1805 – 1875 ); the physicist Wilhelm Eduard Weber ( 1804 – 1891 ); and the philologists, the brothers Jakob ( 1785 – 1863 ) and Wilhelm Grimm ( 1786 – 1859 ), for protesting against the revocation by King Ernest Augustus I of Hanover of the liberal constitution of 1833, further reduced the prosperity of the university.

Friedrich Schlegel's wife, Dorothea von Schlegel, a daughter of Moses Mendelssohn, was the author of an unfinished romance, Florentin ( 180 ,), a Sammlung romantischer Dichtungen des Mittelalters ( Collection of Romantic Poems of the Middle Ages ) ( 2 vols., 1804 ), a version of Lother und Maller ( 1805 ), and a translation of Madame de Staël's Corinne ( 1807 – 1808 )-all of which were issued under her husband's name.

Hänlein ( 1762 – 1829 ), Christoph Friedrich von Ammon and Heinrich Eberhard Gottlob Paulus, and afterwards as sole editor ; from 1801 to 1804 of the Journal für theologische Litteratur ; and from 1805 to 1811 of the Journal für auserlesene theologische Litteratur.

Karl Friedrich Hermann ( August 4, 1804 – December 31, 1855 ) was a German classical scholar and antiquary.

Erich's mother, Klara Jeanette Henriette von Tempelhoff ( 1840 – 1914 ), was the daughter of the noble but impoverished Friedrich August Napoleon von Tempelhoff ( 1804 – 1868 ), and his wife Jeannette Wilhelmine von Dziembowska ( 1816 – 1854 ) – she from a Germanised Polish landed family on her father's side, and through whom Erich was a remote descendant of the Dukes of Silesia and the Marquesses and Electors of Brandenburg.

A concert in Leipzig in December 1804 brought the influential music critic Friedrich Rochlitz " to his knees ," not only because of Spohr's playing but also because of his compositions.

* Palma, 1804 opera by Friedrich Witt

( 21 November 1804 – 17 or 30 January 1830 ) was a German romantic poet, mostly remembered today in connection with Friedrich Hölderlin.

Eduard Friedrich Mörike ( 8 September 1804 – 4 June 1875 ) was a German Romantic poet.

Composers who wrote a called " Missa Solemnis " have included France Ačko ( 1941 ), Hendrik Andriessen ( 1946 ), Marco Betta, František Brixi, Antonio Buonomo ( 1983 ), Alfredo Casella ( 1944 ), Paul Creston, Georg Druschetzky ( 1804 ), Bohumil Fidler ( 1901 ), Joseph-Hector Fiocco, Konstanty Gorski, Michael Haydn ( 1772 ), Václav Emanuel Horák, Sigurd Islandsmoen ( 1954 ), Friedrich Kiel, Karel Blažej Kopřiva, Josef Lammerz ( 1990 ), Boleslaw Ocias and Johann Nepomuk Schelble, Wolfgang Seifen, Johann Baptist Vanhal ( 1778 ), Bedřich Antonín Wiedermann ( 1848 ).

Friedrich Sertürner, discoverer of morphine ( 1804 ), opened his first pharmacy here.

Friedrich Schleiermacher was so much struck by their excellence that he endeavoured, unsuccessfully, to obtain for Steffens a chair in the new Berlin University in 1804, in order that his own ethical teachings should be supported in the scientific department.

* August 8-Johann Friedrich Gmelin, German naturalist ( died 1804 )

The business was carried on by his sons, Friedrich Brockhaus ( 1800 – 1865 ), who retired in 1850, and Heinrich Brockhaus ( 1804 – 1874 ), under whom it was considerably extended.

The introduction in France of the Napoleonic code in 1804 created in Germany a similar desire for obtaining a civil code ( despite the opposition of the Historical School of Law of Friedrich Carl von Savigny ), which would systematize and unify the various heterogeneous laws that were in effect in the country.

Heinrich Friedrich Emil Lenz () ( 12 February 1804 – 10 February 1865 ) was a Russian physicist of Baltic German ethnicity.

* Johann Friedrich Gmelin ( 1748 – 1804 ), a German naturalist ; publisher of the Systema Naturae of Carolus Linnaeus

Grand Duke Friedrich ( 1800 – 1842 ) decided to rebuild the castle, and ordered his architect Georg Adolph Demmler ( 1804 – 1886 ) to do so.

* Wilhelm Friedrich Waiblinger ( 1804 – 1830 ), German poet and biographer of Friedrich Hölderlin