Georges Seurat entered the École Municipale de Sculpture et de Dessin in Paris at the age of fifteen, where he studied with the sculptor Justin Lequien (1826-1882) and met Aman-Jean (q.v.). At the École des Beaux-Arts three years later he was taught by Henri Lehmann (1814-1882), a former pupil of Ingres (q.v.). He developed an interest in the color theory of Michel-Eugène Chevreul, who had postulated how the isolation and juxtaposition of colors can affect their perception. In the Louvre he studied the works of two master colorists, Rubens (1577-1640) and Delacroix (q.v.). Seurat attended the Fourth Impressionist Exhibit in 1879, and he later confessed to be particularly shocked by the works of Monet (q.v.) and Pissarro (q.v.). After spending a year in military service on the Breton coast, Seurat started experimenting with drawing, using conté crayon and heavily textured "Ingres" paper to build up his figures through a wide range of tones, avoiding contour outlines. He also probably read Ogden Rood's Théorie Scientifique des Couleurs, which further investigated the perception of color and advocated the use of pure color in painting. Seurat additionally undertook to analyze the optical and emotional effects of various color combinations in his paintings, initiating studies for the Bathers at Asnières (1883, National Gallery, London). This painting appeared at the 1884 Salon des Indépendants, where he met Paul Signac (1863-1935), who became an important spokesman for neo-impressionism. Seurat's next major painting, Sunday Afternoon on the Island of La Grande Jatte (1884-86, Art Institute of Chicago), established him as the leader of the neo-impressionists. He began spending his summers on the Normandy coast, where he often started his large canvases that he would finish in his Paris studio during the winter. He was protective of his position as leader of the neo-impressionists, causing arguments with Pissarro and Signac in the late 1880s. His interest in using pure color influenced the symbolists as well as later "hard edge" painters of the modern era.