Page:Landscape Painting by Birge Harrison.djvu/77

 IV REFRACTION is refraction—refraction as applied to art? When I first had to speak to my own students of this most elusive but most important quality, I found myself curiously handicapped by the fact that there was no word in the English language to describe it. A careful search of the dictionaries revealed nothing that met the need. The French word envelope and our own "lost-edge" were descriptive of the result only and not of the cause. Neither radiation, nor reaction, nor reflection, nor ambience fully defined the thing which it was desired to describe. [47]