Modern Magic: A Practical Treatise on the Art of Conjuring

You then (by the slip or pass) bring the remaining knave of spades from the top to the bottom, and shuffle again as before, taking care not to displace the two bottom cards. Again ask the company to note the bottom card (which is now the knave of spades), and draw out, as before, apparently that card, but really the nine of diamonds. Place that also face downwards on the table, and request another person to cover it with his hand. The company are persuaded that the first card thus drawn was the nine of diamonds, and the second the knave of spades. You now announce that you will compel the two cards to change places, and after touching them with your wand, or performing any other mystical ceremony which may serve to account for the transformation, you request the person holding each to show his card, when they will be found to have obeyed your commands. The attention of the audience being naturally attracted to the two cards on the table, you will have little difficulty in palming and pocketing the second knave of spades, which is still at the bottom of the pack, and which, if discovered, would spoil the effect of the trick.