(b Elberfeld, nr Wuppertal, 1780; d Italy, before July 10, 1846).
German merchant and collector. He played a key role in the introduction of early Netherlandish art to British writers and artists during the reign of George IV. In 1806, Aders and an Englishman, William Jameson, co-founded a counting house—sources suggest it was an accounting firm serving the shipping industry—in Elberfeld, Germany. Business often called him to the commercial centres of Europe, and in the 1810s he began to frequent art dealers and to make purchases. His only adviser in this appears to have been his fiancée (later his wife), Elizabeth Smith, whom he met c. 1816. She was the daughter of the mezzotint engraver John Raphael Smith and was herself an amateur artist.
Aders bought prints and paintings of the Italian and Dutch schools, but the core of his collection was early Netherlandish painting. Few northern artists were known at the time, and little attempt had been made by scholars to sort out and identify various oeuvres. Art dealers attached a few recognizable names, such as Dürer, van Eyck and Memling, to almost any work that came into their possession, and many of Aders’s paintings were falsely attributed to these artists. His collection, mainly purchased by the mid-1820s, was divided between his London house in Euston Square and a summer retreat in Godesberg, Germany. Alexander Gilchrist described the London establishment: ‘The walls of drawing-room, bedroom, and even staircase, were all closely covered; with gallery railings in front to protect the pictures from injury.’...