is another person's gold. I enjoyed this brief essay: Does Guano Drive History?
Bat and bird droppings contain high concentrations of nitrates and phosphates that have been mined for centuries. One of the more interesting guano mines (now defunct) in the US is in the Grand Canyon.
Who would have known that excrement has such value that wars have been fought over it? No blood for dung!
Monday, June 1, 2009
Subscribe to:
Post Comments (Atom)
No comments:
Post a Comment