"Guillaume-Benjamin-Amant Duchenne (de Boulogne), Spasm of m. corrugator supercilii under very strong light (left); A relaxed face (photographed in full sunshine) (right) , 1854-1855, albumen print, printed 1862, image: 22.9 × 16.9 cm (9 × 6 5/8 in.) mount: 40.3 × 27.6 cm (15 7/8 × 10 7/8 in.), W. Bruce and Delaney H. Lundberg Fund, in Honor of the 25th Anniversary of Photography at the National Gallery of Art, 2015.52.6"
