(Koblenz/Ehrenbreitstein 1778–1860 Vienna)
A portrait of Nikolaus Joseph von Jacquin (1717–1817)
standing in a peacock aviary, signed, dated and inscribed J. Mähler pinx. 1806,
oil on canvas, 69.7 x 55 cm, framed, (W)

Although Joseph Willibrord Mähler had studied with Anton Graff (1736–1813) in Dresden and had taken lessons at the Academy in Vienna, he was not a full time artist but worked as a public official. He was first employed in the Geheime Kabinettskanzlei, a government agency in charge of controlling postal correspondence, before being in charge of protocol at court. Mähler is known to have painted several portraits of Ludwig von Beethoven, whom he had befriended.
Baron Nikolaus Joseph von Jacquin was a Netherlandish botanist. He studied in Leiden and Paris before moving to Vienna, where he was at the service of the Empress Maria-Theresa and later Emperor Franz I. Between 1755 and 1759 he travelled to the West Indies and Central America in order to collect plant and animal specimens as well as minerals for the royal collection in Schönbrunn. Von Jacquin, a member of the Royal Society, was professor at the University of Chemnitz and director of the Botanical Gardens of the University in Vienna. The plant species Jacquinia is named after him.