As you can tell from the title, this book delves into the mysteries behind 2107 common phrases in order to explain to readers exactly why the phrases mean what they mean. Sometimes the meanings of these idioms have been pretty well preserved from the original; but quite often, you'll see that the current meanings are far different than what they were a few decades ago.
2107 Curious Word Origins, Sayings & Expressions is a massive volume that covers 954 pages (not including the index). Unfortunately, there doesn't seem to be any rhyme or reason to the arrangement of the phrases contained inside. They don't appear to be in chronological order, and they certainly aren't in alphabetical order, either. So you'll definitely have to make use of the index if you want to find something in particular.
Speaking of the index, it's arranged so that you can look up phrases in two different ways. First, if you know the exact phrase, you can look it up in the traditional way (i.e. alphabetically). But if you don't know the exact phrase you can still look it up by focusing on the keywords. Let's use the phrase "[to] cry over spilt milk" as an example. If I know the whole phrase, I can find it under the "C" section (for "cry"). If, on the other hand, I didn't know the whole phrase, I could look up the keyword "milk" and find reference to the entire phrase that way as well.
That being said, the book is quite a lot of fun to browse through. I frequently discover that once I start reading a few of the entries, I simply can't stop and I end up reading for an hour or more. As a result, I now can explain the origins of such phrases as "to have an ax to grind," "keeping up with the Joneses," "ride the gravy train," "walk the plank," "tooth and nail," and 2102 others.
You might recognize the last name of the author, as he is the Funk of Funk & Wagnalls dictionary and encyclopedia fame. There is both a positive and a negative aspect to this connection. On the positive side, at least you can be confident that Funk knows how to research words and word origins, and you can be relatively certain that what he says is pretty much the accepted view. On the negative side, however, the scholar in him shines through way too often. This makes some of the entries extremely tedious to read and comprehend. There are many long, drawn out sentences broken up by numerous commas throughout the book. The writing style seems pretentious these days, but I guess that was pretty much par for the course in his time.
Overall, I think 2107 Curious Word Origins, Sayings & Expressions can be a useful book for a variety of purposes. For example, it will certainly help you brush up on your knowledge of trivia and will help you review some words that you probably don't use all that often anymore, which can come in handy if you like to play Scrabble or do crossword puzzles. This book can also assist people who are trying to learn English as a Second Language. One of the stumbling blocks to learning any foreign language is getting a handle on idiomatic expressions. If someone made a concerted effort to study this book, then he or she would probably end up knowing more about the language than many native speakers!
In short, this is one of the more interesting reference books out there. You'll definitely get your money's worth, so buy a copy today and keep it in your office for the next time you need to satisfy your curiosity about the origins of a certain word or phrase.