BiblioVault may have an electronic file which would meet your requirements for this title:
Essay on the Geography of Plants
Alexander von Humboldt, Aimé Bonpland, Stephen T. Jackson, Sylvie Romanowski and Stephen T. Jackson
Paper: 978-0-226-05473-5
Cloth: 978-0-226-36066-9
Electronic: 978-0-226-36068-3