Then we went over the whole of the narrative again, I reading this time and she stopping to ask me questions. There was not much to ask; all the story was so plain that the proceeding did not take very long. Then she asked me to explain how I had come to decipher the cryptogram. I took out my pocket book and proceeded to make a key to the cipher, explaining as I went on the principle. "To me," I said, "it is very complete, and can be used in an infinity of ways. Any mode of expression can be used that has two objects with five varieties of each." Here she interrupted me. As I was explaining I was holding out my hands with the fingers spread as a natural way of expressing my meaning. She saw at once what had escaped me, and clasping her hands exclaimed impulsively: "Like your two hands! It is delightful! Two hands, and five fingers on each. We can talk a new deaf and dumb alphabet; which no one but ourselves can understand!" Her words thrilled through me. One more secret to share with her; one more secret which would be in perpetual exercise, in pursuance of a common thought. I was about to speak when she stopped me with a gesture. "Sorry!" she said. "Go on; explain to me! We can think of variety later!" So I continued: "So long as we have means that are suitable, we have only to translate into the biliteral, and we who know this can understand. Thus we have a double guard of secrecy. There are some who could translate into symbols with which they are familiar, symbols with which they are not; but in this method we have a buffer of ignorance or mystery between the known and the unknown. There is also this advantage; the cipher as it stands is sufficiently on a basis of science or at any rate of order, that its key is easily capable of reproduction. As you have seen, I can make a key without any help. Bacon's biliteral cipher is scientifically accurate. It can, therefore, be easily reproduced; the method of exclusions is also entirely rational, so that we need have no difficulty in remembering it. If two people would take the trouble to learn the symbols of the biliteral, as kept after the exclusions and which are used in this cipher, they might with very little practice be able to write or read off-hand. Indeed the suggestion, which you have just made, of a deaf-and-dumb alphabet is capital. It is as simple as the daylight! You have only to decide whether the thumb or the little finger means 1 or 2; and then reproduce by right hand or left, and using the fingers of each hand, the five symbols of the amended biliteral, and you can talk as well and as easily as do the deaf mutes!" Again she spoke out impulsively: "Let us both learn off by heart the symbols of our cipher; and then we shan't want even to make a key. We can talk to each other in a crowd, and no one be the wiser of what we are saying."