in Thoreau’s Journal:
To Walden, P.M.
A thick fog. The trees and woods look well through it. You are inclined to walk in the woods for objects. They are draped with mist, and you hear the sound of it dripping from them. It is a lichen day. Not a bit of rotten wood lies on the dead leaves, but it is covered with fresh, green cup lichens, etc., etc. All the world seems a great lichen and to grow like one to-day,—a sudden humid growth.
I remember now that the mist was much thicker over the pond than elsewhere. I could not distinguish a man there more than ten rods off, and the woods, seen dimly across a bay, were mistaken for the opposite side of the pond. I could almost fancy a bay of an acre in extent the whole pond. Elsewhere, methinks, I could see twice as far. I felt the greater coolness of the air over the pond, which it was, I suppose, that condensed the vapor more there.