ambroise vollard art institute of chicago art nouveau barnes foundation charles blanc charles henry chemistry chromoluminarism cloisonnism color cubism der blaue reiter dye emotion ernst ludwig kirchner expressionism fauvism france franz marc french people georges braque henri matisse henri rousseau henri de toulouse-lautrec hermann von helmholtz history of painting impressionism isaac newton karl schmidt-rottluff le barc de boutteville left bank les nabis les xx london maximilien luce mcgill university modern art modernism neo-impressionism odilon redon ogden rood optics pablo picasso painting paris parisian paul gauguin paul signac perception philadelphia museum of art pointillism post-impressionism scientist sunday in the park with george synthetism tapestry university of chicago press university of paris vincent van gogh wassily kandinsky western painting wikimedia commons wikiquote wool