Technically, much of the Victorian slang you can find on the Internet was used mainly by lower classes. Since Book 2 doesn't feature characters from the lower classes, I probably don't have much good reason to go down this particular rabbit hole today, but it's still fun and fascinating stuff.
It's particularly easy to get sucked into an amazing full-text resource like this one:
There's also a hard copy version, as well as an $.99 e-book version available at Amazon--which I bought for ease of use.
While it generally covers later in the Victorian period than I'm writing now, it's impressive and engrossing for itself. And some of the phrases are particularly revealing about the period--the entry for "Angel-Makers," for instance, gave me a chill.
In case you're interested, here are some other handy-dandy sites on Victorian slang:
What I find particularly noteworthy is that so many of the phrases (1) have much older origins, including Shakespeare AND (2) that some of them persist even today.
I hope you enjoy these little procrastination-friendly jaunts as much as I do!