It affected me like looking into an impassable swamp

From Henry David Thoreau's Journal.

The Library a wilderness of books. The volumes of the Fifteenth, Sixteenth, and Seventeenth Centuries, which lie so near on the shelf, are rarely opened, are effectually forgotten and not implied by our literature and newspapers. When I looked into Purchas’s Pilgrims, it affected me like looking into an impassable swamp, ten feet deep with sphagnum, where the monarchs of the forest, covered with mosses and stretched along the ground, were making haste to become peat. Those old books suggested a certain fertility, an Ohio soil, as if they were making a humus for new literatures to spring in. I heard the bellowing of bullfrogs and the hum of mosquitoes reverberating through the thick embossed covers when I had closed the book. Decayed literature makes the richest of all soils.