The Guardian has a book review on De viribus quantitatis (On the Powers of Numbers) penned by Luca Paciola, a man who was a personal friend of Leonardo da Vinci and who is considered not only the father of modern (double entry) accounting but also one of the leaders in magic tricks. The book covers mathematical puzzles, tricks, proverbs and verses and codes.
Don’t try this at home…
Take cool well water and soak your hands for a while; then shake them, you can put them in a pan full of melted lead over a flame, and it will not cook you. It is even better if you put some ground rock alum in the water … to the uneducated … it will appear to be a miracle.