Transcriber's note:
There are two levels of notes (footnotes) in this book: The first level is called Notes by the author and are referred from the main body of text as [C_n] where C is the Chapter number and n the number of the note related to this chapter. The second level conists of regular footnotes referred from the Notes of the author and are numbered the usual way.
In the HTML file Notes and footnotes are numbered without chapter numbers.