E-text prepared by Peter Yearsley, Josephine Paolucci,
and the Project Gutenberg Online Distributed Proofreading Team
(http://www.pgdp.net/)
Transcriber's Note:
Parentheses have been added to clarify fractions. Letters in brackets with a = sign before it means that the letters have a macron over them, e.g. H[=A=c] signifies that the Ac has a macron over it.
Minor typographical errors have been corrected. Footnotes have been moved to the end of the chapter, and all advertisements have been moved to the end of the book.