One of his major works is Rives de l’Ain, a large decorative panel created for the staircase of the Rhône Prefecture in Lyon. Initially a musician, Appian decided to fully dedicate himself to the visual arts in 1852, a pivotal year marked by his encounter with Corot and Daubigny, who had a profound influence on his work. He also spent significant time in Fontainebleau, painting alongside artists of the Barbizon School.
Appian was a master of charcoal drawing, with a particular fondness for backlit scenes and the subtle interplay of light and shadow. Upon discovering the Mediterranean light, his palette brightened, his colors became fresher, and his technique evolved toward a more fluid touch, reflecting the influence of his friend Félix Ziem.