The Writings of Henry David Thoreau, Volume 5 - Journal, Volume 5: 1852-1853.

From 1837 to 1861 Thoreau kept a journal that began as a conventional record of ideas, grew into a writer's notebook, and eventually became the principal imaginative work of his career. This book finds Thoreau intensely concentrating on detailed observations of natural phenomena and on 'the mysterious relation between myself and these things.