Mrs. John Dart, Henrietta Isabella Sommers (1750–1783). 1772 Jeremiah Theus (American, Chur, 1716–1774 Charleston, South Carolina) The Metropolitan Museum of Art tells us that Henrietta Isabella Sommers (1750–1783) was the daughter of Humphrey Sommers, a successful building contractor in Charleston, South Carolina. She was married to John Dart. The costume in this portrait was probably based on a print, since it is unlikely that Mrs. Dart possessed an ermine-trimmed robe. Theus probably painted her face from life and the clothing in his studio, with a mezzotint before him.