in Thoreau’s Journal:

 Nature has looked uncommonly bare & dry to me for a day or two. With our senses applied to the surrounding world we are reading our own physical & corresponding moral revolutions. Nature was so shallow all at once I did not know what had attracted me all my life. I was therefore encouraged when going through a field this evening, I was unexpectedly struck with the beauty of an apple tree –– the perception of beauty is a moral test….

I see the tephrosia out through the dusk––a handsome flower. What rich crops this dry hill side has yielded. First I saw the v. pedata here––& then the Lupines & the Snap-Dragon covered it––& now the Lupines are done & their pods are left––the tephrosia has taken their place. This small dry hill side is thus a natural garden–– I omit the flowers which grow here & name only those which to some extent cover it or possess it. No eighth of an acre in a cultivated garden could be better clothed or with a more pleasing variety from month to month––& while one flower is in bloom you little suspect that which is to succeed & perchance eclipse it. It is a warmly placed dry hill side beneath a wall––very thinly clad with grass. Such spots there are in nature-natural flower gardens. –– Of this succession I hardly know which to admire the most. It would be pleasant to write the history of one hill side for one year. First and last you have the colors of the rain-bow & more––& the various fragrances which it has not. Blackberries––roses––& dogs bane also are now in bloom here–– I hear neither toads not bull frogs at present––they want a warmer night. I hear the sound of distant thunder though no cloud is obvious. muttering like the roar of artillery. This is a phenomena of this season––