“What is that, sir?”
“That the document is not based on conventional signs, but on what is known in cryptology as a cipher, that is to say, on a number.”
“Well, sir,” answered Manoel, “cannot a document of that kind always be read?”
“Yes,” said Jarriquez, “if a letter is invariably represented by the same letter; if an a, for example, is always a p, and a p is always an x; if not, it cannot.”
“And in this document?”
“In this document the value of the letter changes with the arbitrarily selected cipher which necessitates it. So a b will in one place be represented by a k will later on become a z, later on an u or an n or an f, or any other letter.”
“And then?”
“And then, I am sorry to say, the cryptogram is indecipherable.”
“Indecipherable!” exclaimed Manoel. “No, sir; we shall end
