There has lately been set before us, in exhibitions and critical essays, a twofold proposition: that there is such a thing as a specifically North American light, with physical and moral properties not quite to be paralleled elsewhere, and that that light, and those properties, were captured once and for all in the third quarter of the nineteenth century by a group of painters who now bear the name of 'luminist.'.    From Wordnik.com.  [Light and Lively] Reference