"La Marchande de Moutarde" is an etching by James McNeill Whistler from his series "Twelve Etchings from Nature," which documents everyday scenes from Venice and other locations observed during his travels. The work depicts a street vendor selling mustard, capturing a fleeting moment of urban life with Whistler's characteristically delicate line work and atmospheric effects. This piece exemplifies Whistler's mastery of the etching medium and his interest in recording informal subjects with artistic refinement.