This little test always has a curious effect on the spectator. He is handed two playing cards to be mixed face down without his seeing either of their faces. Actually, one of these cards is any Ace except the Ace of Spades, and the other card is any ten-spot. Secretly you have pushed your thumb nail into the back of the Ace at some inconspicuous point. After the mixing the spectator lays the two cards side by side, still face down, onto the table or floor. You give him a dime and a penny, telling him to put one coin…