of Secret Writing. 91 



the law of the new arrangement ; for, let any one letter be 

 chosen, and tried successively with those which follow, first omit- 

 ting one place, then two places, then three, SfC, and, if the first 

 letter fail, let another be tried ; a period must come when a 

 syllable is formed, and then a word ; and, the law once ascer- 

 tained, the deciphering of the whole ensues of course. But, in 

 substitution there is no palpable clue, at least of this nature ; 

 and a system may be devised, such as can elude all the known 

 rules and methods which authors who have written upon this 

 subject have laid down for the detection of secret writing. 



Neither the one nor the other of these methods is exempt 

 from suspicion. Both may, indeed, present the ciphered sen- 

 tence under the appearance of a foreign language, but such a 

 deception could not long prevail in any of the nations now likely 

 to use a good system of ciphering. To comprise all the ends of 

 Lord Bacon in one system, seems to present insurmountable dif- 

 ficulties ; and the strongest proof that it does so, is that one of 

 the most powerful of human intellects did not accomplish what 

 it had conceived. It is probable that the sacrifice of some one 

 of these qualities is indispensable, in order to attain the others ; 

 and, in the great generality of cases, to avoid suspicion, is that 

 which may be the least attended to. In besie^d towns, in 

 camps, armies, and wherever suspicious correspondence is 

 likely to be intercepted, it is important to deceive, even as to 

 the very existence of secret communications ; and a cipher, so 

 constructed as to elude suspicion on this head, must be preferred. 

 Such a one may easily be devised on the present principles, but 

 it cannot be otherwise than laborious to the cipherer. 



In the present system substitution is the mode employed. 

 The first object in view is secrecy ; the second ease to the 

 cipherer; the last to avoid suspicion. 



The first and most important end is attained by a peculiar 

 arrangement of what is usually termed the key. In the present 

 system, the key is constructed upon principles which differ, very 

 materially, from any that have been made public ; and the effect 

 of tliis difference is to give, to a small number of symbols, a 



