This is probably one of the most amusing Boswell related books.
The book basically consists of two parts. The first part is a biography written by Charles Rogers. The biography is very well written, not particularly abusive (compared to many other early Boswell biographies) and very informative, despite all the errors which were bound to be there, due to the lack of sources at the time. In this edition, for example, Alexander Boswell actually accompanied James Boswell to London in 1760. There are some quotes from Boswell's early writings, including the Cub at Newmarket and Ode to Tragedy.
The most interesting part of the book is the second one, which is an edited version of Boswell's own Commonplace Book. It is a collection of short amusing 3-10 line anecdotes, quotes, etc. experienced by Boswell himself througout his life.
"Boswell was one day complaining that he was sometimes dull. 'Yes, yes,' cried Lord Kames, 'aliquando dormitat Homerus' (Homer sometimes nods.) Boswell being too much elated with this, my lord added, 'Indeed, sir, it is the only chance you had of resembling Homer.'"
"The Honourable Mrs. Stuart was one day talking to me with just severity against dunkenness (the sin which doth most easily beset me). I attempted to apologise, and said that intoxication might happen at a time to any man. 'Yes,' said she, 'to any man but a Scotsman, for what with another man is an accident is in him a habit.'"
Some of his own one-liners found their way into his Commonplace book as well:
"Captain Erskine complained that Boswell's hand was so large, that his letters contained very little. My lines (said Boswell) are, like my ideas, very irregular, and at a great distance from each other."
All in all, Boswelliana is a brilliant work, and highly amusing. It is very well annotated, even if some of the annotations are known today to be faulty. One last quote, from the foreword by The Rt. Hounourable Lord Houghton:
"Boswell's commonplace-book exhibits some of the author's weaknesses, but is on the whole a valuable repertory. The social talk of leading persons during the latter part of the century is graphically depicted. Considerable light is thrown on the character of individuals respecting whom every fragment of authentic informations is treasured with interest."
The book was originally printed in 1874 for The Grampian Club. Original copies can sometimes be found on AbeBooks, but from 2007 it is also available as Print-On-Demand (also via Abebooks) from Kessinger Publishing and others. Keep an eye on which copy you order, as it is not always clear from the listings - if it is marketed as "New" it is almost certainly Printed-on-Demand, even if the publication date is listed as 1874.