THIS is a trick that depends on the use of a formula, or set of words,
memorized by the performer.
You deal twenty cards from the deck, laying them face upward on the table in a series of pairs, arranged vertically. You then ask any number of the persons present to choose each a pair from the ten pairs displayed on the table, and to hold the two cards in memory.
You pick up the cards from the table, taking care to keep each pair united. But you may gather up the different pairs in any order you please, so long as the two cards in every pair are not separated.
The twenty cards are next laid face upward on the table a second time. But now the arrangement of them is in four rows, with five cards in each row. And it is now that you are to make use of the secret formula on which the trick depends.
The cards in this distribution are not laid down in the ordinary way, that is from the left to the right for the five in the first row, and then again from the left to the right for the five in the second row, and so on. Instead, you must place the two cards of each pair in certain positions indicated by the formula. The formula is: Mutus dedit nomen Cocis, which is the Latin for “Change gave name to the Coci.” The sentence is made up merely for the sake of the trick.
It will be seen that in these words there is a total of twenty letters, corresponding to the number of cards, the ten pairs. Moreover, each of the words consists of five letters, corresponding to the five cards of each row for the new arrangement. Finally, it must be noted that the twenty letters contain ten pairs. Thus, for example, there are two u’s in the first word, mutus. The first letter of this word, m, occurs also. as the middle letter of the word, nomen. The third letter of mutus, t, is the last letter of the word dedit. The final letter of mutus, s, is also the final letter of Cocis. In similar fashion, the other pairs of letters are distributed through the various words.
You must have a mental picture of the formula:
Now, in laying down the pairs of cards on the table, you must distribute them so that each pair will take the place of a pair of letters in the formula. Thus, your first card will take the place of the letter, m, at the beginning of the word, mutus.
The second card of the first pair must not be laid down beside the other. Instead, you must so place it as to take the position of the other m in the formula. This m is the central letter of the word, nomen, which forms the third line. You therefore make the second card occupy the middle place in the imaginary third row on the table.
In laying down the second pair of cards, you give them the positions of the two u’s in the first word, mutus. Thus, the first card of the pair is laid in the second place in the row, and the other card of the pair in the fourth place of the same row.
The other pairs of cards are similarly distributed, making them in each instance assume the places of the repeated letters of the formula.
The method is clearly shown in the following chart, where each pair of cards is represented by repetition of the corresponding figures from one to ten in connection with the letters that serve as guides for the arrangement.
The twenty cards having been laid down on the table according to this system, you next ask those who have selected pairs to indicate in which row, or rows, the pairs are displayed. If some one states that the two cards selected by him are in the first row and the third, you instantly name those two cards. You are able to do this because according to the formula, m is the only letter that appears in the first row and in the third. Since you have arranged the cards by pairs to correspond with the pairs of letters in the formula, you know that the first card of the first row and the central card of the third row compose this pair.
If another person declares that both the cards of his pair are in the first row, you immediately name for him the second and fourth cards as his selection, since these take the place of the letter u in that row, and the u is the only letter thus repeated in the row.
In like fashion, all of the chosen pairs may be readily named. It should be noted that any number of persons may select pairs, since the result will be exact in every instance. When more than ten persons make a selection, there will, of course, be duplication of the pairs to a greater or less extent.
It is advisable to have as many persons as is convenient make their choice at the outset, when the ten pairs are first laid down on the table. It is not expedient usually to repeat the trick. The particular method of distributing the cards in the four rows when done a second time may give a clue to the method. But, if it is desired to repeat the trick, care should be taken to. follow a different order in arranging the cards. For example, instead of giving the first pair the places of the letter m in the first and the third line, you may make them the first and third cards in the second row, corresponding to the two d’s in dedit, and then make the second pair of cards stand for the two c’s of Cocis in the bottom row. This variation will tend still further to mystify the observers. In fact, the pairs may be distributed in any order preferred, so long as each two cards occupies the two places of a particular letter.