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ADVANCEMENT OF LEARNING 



the cipher, the bearer is to produce the non-significant al 

 phabet for the true, and the true for the non-significant; 

 by which means the examiner would fall upon the outward 

 writing, and finding it probable, suspect nothing of the 

 inner. 23 



But to prevent all suspicion, we shall here annex a 

 cipher of our own, that we devised at Paris in our youth, 

 and which has the highest perfection of a cipher that of 

 signifying omnia per ortmia (anything by everything),&quot; pro 

 vided only the matter included be five times less than that 

 which includes it, without any other condition or limitation. 

 The invention is this: first let all the letters of the alphabet 

 be resolved into two only, by repetition and transposition; 

 for a transposition of two letters through five places, or 

 different arrangements, will denote two-and-thirty differ 

 ences, and consequently fewer, or four-and- twenty, the 

 number of letters in our alphabet, as in the following 

 example: 



A BILITERAL ALPHABET, 



Consisting only of a and b changed through five places, so as to represent all the 

 letters of the common alphabet 



aaaaa 

 aaaab 

 aaaba 

 aaabb 

 aabaa 

 aabab 

 aabba 

 aabbb 



Thus, in order to write an A, you write five a s, or aaaaa; 

 and to write a B, you write four a s and one &, or aaaab; 

 and so of the rest. 



And here, by the way, we gain no small advantage, as 

 this contrivance shows a method of expressing and signify - 



23 The publishing of this secret frustrates its intention ; for the examiner, 

 though he should find the outward letter probable, would doubtless, when thua 

 advertised, examine the inner, notwithstanding its alphabet were delivered to 

 him for non-significants. Shaw. 



24 For this cipher is practicable in all things that are capable of two 

 differences. 



