This is not so bad as Bashige said, but you won't need it to read MYSTÈRES DE PARIS, because the ten free Kindle volumes have internal links to translations of the slang words used in the story.
This is a non-alphabetical dictionary proceeding according to an order I don't quite understand, probably more or less glossing words and phrases as they come along in the book. The entries are unpunctuated and as simple as they could possibly be. They're all in French, but formatted something like this:
knock off kill
As you can see, this could be useful if the books didn't define their own slang terms, but since they do, the whole thing ends up being too much work. If you wanted to look up a slang term at random, you'd have to use Kindle's word-finding feature -- and why not, if you had to? But you don't have to.