The Convertible Aces
On the ace of spades fix, with soap, a heart, and on the ace of hearts
a spade, in such a manner that they will easily slip off.
Show these two aces to the company; then, taking the ace of spades,
you desire a person to put his foot upon it, and as you place it on
the ground, draw away the spade. In like manner you place the seeming
ace of hearts under the foot of another person. You then command the
two
ards to change their places; and that they obey your command, the
two persons, on taking up their cards, will have ocular demonstration.
A deception similar to this is sometimes practised with one card,
suppose the ace of spades, over which a heart is pasted lightly. After
showing a person the card, you let him hold one end of it, and you
hold the other, and while you amuse him with discourse, you slide off
the heart. Then laying the card on the table, you bid him cover it
with his hand; you then knock under the table, and command the heart
to turn into the ace of spades.