--Retained publisher information from the printed copy (the electronic
edition is in the public domain in the country of publication).
--Corrected some palpable typos, including several botanical names.
--Moved all promotional material to the end of the book.
--In the text versions only, represented text font and size variations
(the HTML version preserves the presentation of the original):
--Text in italics is delimited by _underscores_.
--Subscripted numbers are preceded by an underscore, as in the formula
for water “H_2O”.
--Superscripted numbers are preceded by a caret, as in “45^o”.