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Although the common alphabet may be varied at plcafure, 

 and any arbitrary figns may be employed to convey the powers 

 of each letter, yet by certain rules any of thefe arrangements 

 may be decyphered. Whoever fees the movements of the 

 French Telegraph (I mean of that which is commonly knoTirn 

 as fuch") may unfold the intelligence which it conveys by merely 

 marking down the changes which he fees, and putting them 

 into the hands of a decypherer. The rules for decyphering 

 depend upon the ufual arrangements of letters. In our language 

 a fingle letter muft be y/ or /. The proportions which exift 

 between words of one, two, three, and any greater number of 

 letters, are clafFed in catalogues, and from thefe the monofyl- 

 lables of any cypher arc eafily obtained ; and from the letters of 

 thefe monofyllables the letters of longer words are difcovered. 

 By fimilar rules, fome of which are very ingenious, and which 

 depend upon the general philofophy of language, any alphabe- 

 tical cypher may be eafily unfolded. But thefe rules, except a 

 very few of them, are ufelefs when we employ cyphers, which 

 denote entire words. Here the moft obvious means of difco- 

 very may be avoided, by omitting thofe common words which 

 occur fo frequently in every language, ike, and, that, to, &c. 

 But fuppofing that from its frequent recurrence any particular 

 word fliould be difcovered, no progrefs can be made from thefe 

 data. The cypher of each word is an ifolated fadl, which leads 

 to nothing farther. Suppofe the knowledge of any particular 

 vocabulary fliould fall into hands for which it was not intended, 

 a flight change in the numeration, without any adlual change 



of 



