14. TO ASCERTAIN THE NUMBER OF POINTS ON THREE UNSEEN CARDS.
In this amusement the ace counts eleven, the court cards ten each, and the others according to the number of their spots.
Ask any one to choose any three cards, and lay them on the table, with their faces downwards. On each of these he must place as many as with the number of the card will make fifteen. He gives you the remaining cards, and when you have them in your hand, you count them over on the pretence of shuffling them, and by adding sixteen, you will have the number of points on the three cards.
For example, the spectator chooses a four, an eight, and a king. On the four he places eleven cards, on the eight seven, and on the king five. There will be then six cards left. Add to these six sixteen, and the result will be twenty-two, which is the number of points on the three cards, the king counting ten, added to the eight and the four.
15. TO TELL THE NUMBERS ON TWO UNSEEN CARDS.
As in the preceding trick, the ace counts eleven, and the court cards ten each. Let the person who chooses the two cards lay them on the table with their faces downward, and place on each as many as will make their number twenty-five.
Take the remaining cards and count them, when they will be found to be just as many as the points in the two cards. For example, take an ace and a queen, i. e. eleven and ten, and lay them on the table. On the ace you must put fourteen cards, and on the queen fifteen. There will be then fifteen cards in one heap and sixteen in the other: these added together make thirty-one cards: these subtracted from the number of cards in the pack, i. e. fifty-two, leave twenty-one, the joint number of the ace and the queen.
16. THE PAIRS RE-PAIRED.
Tell out twenty cards in pairs, and ask ten people to take a pair each, and remember them. Take up the pairs in their order, and lay them on the table in order, according to the accompanying [table], which forms a memoria technica, and may be construed. Mutus gave a name to the Coci, (a people who have yet to be discovered.)
| M | U | T | U | S[14] |
| 1 | 2 | 3 | 2 | 4 |
| D | E | D | I | T |
| 5 | 6 | 5 | 7 | 3 |
| N | O | M | E | N |
| 8 | 9 | 1 | 6 | 8 |
| C | O | C | I | S |
| 10 | 9 | 10 | 7 | 4 |