The writing of a preface is perhaps superfluous for a book which has had a
large and steady sale for nearly twenty years, and which has evidently met with
the approval of a large constituency. A few words of introduction appear,
however, desirable in view of the facts that the present edition has been almost
entirely re-written; that a large amount of new matter has been introduced; and
that, so far as is known, the comments on each subject represent the most recent
...