The stele of Félix Boisselier is set in the wall of the counterfaçade. The French historical painter was a pensionary of the French Academy in Rome and died at the age of 34 years in 1811. The monument was erected by "his comrades whose hearts were filled with pain at his premature death", according to the French inscription. The stone slab is decorated with Boisselier's classicising portrait in relief.