New findings on Bach portraits
Three Bach portraits, one in the possession of a collector from Dortmund and two from the holdings of the Bachhaus Eisenach, have been dated more precisely using more recent methods. Questions have remained unanswered.
Physicist Alex von Bohlen, who works at the ISAS (Leibniz Institute for Analytical Sciences) in Dortmund, is known for analyzing works of art, for which he prefers to use X-ray spectroscopy. He has been called in as an expert to examine three portraits of Johann Sebastian Bach. One of them belongs to a collector from Dortmund, the other two were contributed by the Bachhaus Eisenach.
The owners wanted to know whether their paintings were genuine and whether the dating was correct. The portraits were therefore examined to determine whether the pigments in their dyes matched the respective eras. The result: the color composition of the two Eisenach paintings indicates that they were painted in the 18th and 19th centuries respectively. In the painting of the Dortmund collector, however, von Bohlen and his colleagues found larger proportions of pigments that do not really match 18th century colors.
However, the scientists warn against jumping to conclusions: The portrait could simply have been restored in some places. For this reason, it is now to be analyzed on a large scale. The pigment lithopone, a compound of barium sulphate and zinc sulphide, which was not yet used in the 18th century, plays a decisive role here. Further investigations should now provide more clarity.
