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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. &quot; 



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 omnia (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 



aaaab 

 aaaba 

 aaabb 



aabba 

 aabbb 



abaab 

 ababa 

 ababb 



abbab 

 abbba 

 abbbb 



R 



S 



T 



V 



W 



X 



Y 



Z 



baaaa 

 baaab 



baabb 



babab 

 babba 

 babbb 



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 b, 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 thus 

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

 him for non-significants. Shaw. 



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

 differences. 



