Two drawings by James McNeill Whistler, part of the Davison Art Center’s collection of more than 100 Whistler works, will be shown in a new documentary on the life of the painter. The sketches, one in pencil and one in pen and ink, will be seen in “James McNeill Whistler & The Case for Beauty,” premiering September 12 on PBS. They represent just a small part of Wesleyan’s extensive holdings of works on paper by Whistler, one of the most important American artists of the 19th century. “Whistler was crucial in making the connection between the Impressionists and British art,…