The shadows of plants are never black, for where the atmosphere penetrates there can never be utter darkness.
 Leonardo da Vinci, The Notebooks of Leonardo Da Vinci (1478 – 1519). copy citation

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Author Leonardo da Vinci
Source The Notebooks of Leonardo Da Vinci
Topic darkness shadow
Date 1478 – 1519
Language English
Reference
Note Translated by Jean Paul Richter in 1888
Weblink http://www.gutenberg.org/cache/epub/5000/pg5000-images.html

Context

“and consequently such an arrangement is very confused and the imitation of it should be avoided. The light shines least through a leaf when it falls upon it at an acute angle. The gradations of shade and colour in leaves (430-434) . 430. The shadows of plants are never black, for where the atmosphere penetrates there can never be utter darkness. 431. If the light comes from m and the eye is at n the eye will see the colour of the leaves a b all affected by the colour of m —that is of the atmosphere; and b c will be seen from the under side as transparent, with a beautiful green colour verging on yellow.” source