And in this connection I will deal, once for all, with the gifts to me from this wild nature to which I abandoned myself with all the ardor of a quest.  The tendency of the imagination, even healthy, acting in a vacancy, is to create illusions, or, if there be a certain occult mental activity, such as that I have alluded to in my Pittsfield experience, to intensify its action to such a degree that it finally usurps the function of the senses.  In the solitude of the great Wilderness, where I have passed months at a time, generally alone, or with only my dog to keep me company, airy nothings became sensible; and, in the silence of those nights in the forest, the whisperings of the night wind through the trees forced meanings on the expecting ear.  I came to hear voices in the air, words so clearly spoken that even an incredulous mind could not ignore them.  I sat in my boat one evening, out on the lake, watching the effects of the sky between the gaunt pines which, under the prevalence of the west winds, grew up with an easterly inclination of their tops, like that of a man walking, and thus seemed to be marching eastward into the gathering darkness.  They gave a sudden impression of a procession, and I heard as distinctly as I ever heard human speech, a voice in the air which said “the procession of the Anakim.”  Over and over again, as I sat alone by my camp-fire at night, dreaming awake, I have heard a voice from across the lake calling me to come over and fetch it, and one night I rowed my boat in the darkness more than a mile, to find no one.  Watching for deer from a treetop one day, in broad sunlight, and looking over a mountain range, along the crest of which were pointed firs and long level ridges of rock in irregular alternation, the eerie feeling suddenly came over me, and the mountain-top seemed a city with spires and walls, and I heard bands of music, and then hunting-horns coming down with the wind, and there was a perfect illusion of the sound of a hunting party hurrying down into the valley, which gave me a positive panic, as if I were being pursued and must run.  I remember also on another occasion a transformation—­transfiguration rather—­of the entire landscape in colors, such as neither Titian nor Turner ever has shown me.  It was a glorification of nature such as I had never conceived and cannot now comprehend.

The fascination of indulgence in this illusory life became such that I lingered every summer longer, and finally until November, when, in that high and northerly locality, the snow had fallen and the lake began to freeze, living only under a bark roof, open to the air and to the snow, which fell on my bed during the night.  I can easily imagine the life leading to insanity.  Probably my interest in nature and my painting kept me measurably free from this danger, but not from illusions as unaccountable as spiritism, and sometimes more real than the physical facts.  I had one evening, when I was lying awake in a troubled