I found this book absolutely fascinating although it really is for people very interested in financial history. It's not a light read.
There were a lot of lessons but as I read the quotes from the bankers two centuries ago I thought nothing has changed. My favourite bit is when they are selling governments bonds from European peripheral countries and deriding their customers for being stupid enough to buy them! The quotes could have been taken from an investment bankers email last year.
Even the public criticism of the bankers for their bonuses and huge wealth are exactly the same as today (although minus the anti-Semitism).