The inaccurately described bi-literal cipher, which Bacon, who claims to have invented it, explained with great elaboration in his _De Augmentis Scientiarum_, has nothing whatever to do with the composition or the wording of the works in which it is said to exist. It depends not on the author, but on the printer. It is altogether a matter of typography. One condition alone is necessary--control over the printing, so as to ensure its being done from specially marked manuscripts, or altered in proof. It shall, as Bacon says, be performed thus:--“First let all the letters of the alphabet, by transposition, be resolved into two letters only--hence bi-literal--for the transposition of two letters by five placings will be sufficient for 32 differences, much more than 24, which is the number of the alphabet. The example of such an alphabet is on this wise:-- A a a a a a I or J a b a a a R b a a a a B a a a a b K a b a a b S b a a a b C a a a b a L a b a b a T b a a b a D a a a b b M a b a b b U or V b a a b b E a a b a a N a b b a a W b a b a a F a a b a b O a b b a b X b a b a b G a a b b a P a b b b a Y b a b b a H a a b b b Q a b b b b Z b a b b b For the purpose of introducing this alphabet into the book which is to contain the secret message, certain letters are taken to stand for “a’s” and others for “b’s.” In Bacon’s illustration, he employed two different founts of italic type, using the letters of fount “a” to stand for “a’s,” and the letters of fount “b” to stand for “b’s.” Bacon takes the word “fuge” to exhibit the application of the alphabet, thus:-- F U G E. a a b a b b a a b b a a b b a a a b a a The word is enfolded, as an illustration, in the sentence _Manere te volo donec venero_, as follows:-- MANERE TE VOLO DONEC VENERO. a a b a b | b a a b b | a a b b a | a a b a a F. | U. | G. | E. A more ample example of the cipher is given on the page which is here reproduced from Mrs. Gallup’s book. The work in which the “interiour” letter is enfolded is the first _Epistle of Cicero_, and the cipher letter it contains is as follows: All is lost. Mindarus is killed. The soldiers want food. We can neither get hence nor stay longer here. [Illustration: _Cicero’s First Epistle._ (NOTE)--This Translation from Spedding, Ellis & Heath Ed.]