The Person who has in his hand the three of spades that is prepared, will shew the card to all the company; you will shew in your turn the ace of diamonds that you have in yours, and then tell that person to lay his card downwards on the carpet that covers the table; make him lay his hand on the card, and ask him whether he is very certain that it is a three of spades he has under his hand. On his affirmative, you may rally him on it, and tell him, at the same time that you push his hand which is over the card, that he is mistaken, and that it is an ace of diamonds he holds. The movement you will cause him to make while you push his hand, under which the card is, will make the jet powder, that formed the three of spades over the ace of diamonds, remain on the carpet, and he will be extremely astonished to find really an ace of diamonds, whilst you, who make the trick, by turning your hand where the three of spades and the ace of diamonds are, back to back, will shew, the three of spades, and make the company believe that you have conveyed it from the person who held the same without his perceiving it. This trick must be done dexterously and quickly, in order that the little deception be not discovered. Practice is the greatest master. FOOTNOTE: [1] _Method of preparing jet powder._ Pound in a copper mortar your jet, which must have been bruised a little with a hammer; when it is well pounded, it must be sifted through a sieve, and also through a piece of muslin. Keep that powder, which cannot be too fine, in a little box, to use it when occasion may require: take a pinch of it either with your fingers or with a piece of paper; then scatter it on the card, and it will stick only in those places that have been touched by the roll of pomatum, and may be taken off very easily by the rubbing against the carpet, when you will push the hand of the person who covers the card, without the card being soiled in the least by it. CHAP. XIII. _How to guess a Card that has been thought of by any body, by writing before hand on a Paper or Card a Number, which will certainly be that of the Card that has been thought of._ All the preparation of this trick consists in a mathematical combination; here follows the method of operating in order to succeed. Take a pack of piquet cards, present them to one of the company, desiring him to shuffle them well, and to get them shuffled by whoever he pleases: then make several persons cut them. After which you will propose to one of the company to take the pack, and think of a card, and remember it, as likewise of the number of its order in the pack, by counting one, two, three, four, &c. till he comes inclusively to the card thought of by him. Then offer to go in another room while he is doing what you required, or to be blind-folded, assuring the company that you will declare before-hand, if required, the number of the order in which the card is that has been thought of. EXAMPLE.