in Thoreau’s Journal:
The trunks & branches of the trees are of different colors at dif. times & in dif. lights & weathers. In sun, rain, & in the night. The oaks bare of leaves on Hubbards hill side are now a light grey in the sun and their boughs seen against the pines behind are a very agreeable maze. The stems of the white pines also are quite grey at this distance with their lichens. I am detained to contemplate the boughs—feathery boughs of the white pines, tier above tier, reflecting a silvery light—with intervals (between them) though which you look, if you so intend your eye, into the darkness of the grove. That is you can see both the silvery lighted & greenish bough—& the shadowy intervals as belonging to one tree—or more truly refer the latter to the shade behind.