By Gary Schwartz In 1942, in fulfillment of an essay competition announced in 1936, the Teyler’s Second Society in Haarlem published the winning study on the spread of Dutch painting throughout the world: Horst Gerson, “Ausbreitung und Nachwirkung der holländischen Malerei des 17. Jahrhunderts” (The diffusion and after-effect of Dutch 17th-century painting). Written in German-occupied…