I presume it is the experience of every author, after his first book is published upon an important subject, to be almost overwhelmed with a wealth = of ideas and illustrations which could readily have been included in his book, and which to his own mind, at least, seem to make a second edition inevitable. Such certainly was the case with me, and when the first edition had reached its sixth impression in five months, I rejoiced to learn that it seemed to my publishers that the book had met with a sufficiently favorable reception to justify a second and considerably enlarged edition. The book has practically been rewritten, so important are the additions, although the first few chapters have been left very much as they were. The chapter on the " Cross-examination of Experts " has been rearranged, many new examples added, and the discussion much extended.