Speaking of Humboldt - in our upcoming book, "Entangled Life," at the very end of Chapter 2,  (Loc 1173) the author,  Merlin Sheldrake says: 
"In 1845, Alexander von Humboldt observed that “Each step that we make in the more intimate knowledge of nature leads us to the entrance of new labyrinths.”  -
the paragraph ends with “oldest of life’s labyrinths" - which leads to the following note:

"oldest of life’s labyrinths:” Humboldt (1849), vol. 1, p. 20. -   and that’s Loc 4448 in the Notes. 

Then we go to the Bibliography and find the first entry under “Humboldt”: 

Humboldt A von. 1849. Cosmos: A Sketch of Physical Description of the Universe. London, UK: Henry G. Bohn.

There are 4 Notes from either the English “Cosmos" or the German “Kosmos" both of which are available at Amazon.  - In fact, you can get “Works of Alexander von Humboldt” which contains 4 works - Cosmos and Personal Narrative volumes 1, 2 and 3 - on Kindle for $2.99.   

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Yep -  sometimes I wonder if the universe isn’t expanding because we know more and more and so more and more is created.  Labyrinths indeed - we are creating the big one.   

Becky