56.6
Some letters of his to the senate are also preserved, and he seems to have been the first to reduce such documents to pages and the form of a memorial volume,That is, Caesar reduced his reports to book form. If the book was a roll, the writing was arranged in columns, parallel with the edges (or long sides) of the roll. If it was a codex, several sheets were folded and fastened together and the writing was arranged on each page in one or two columns. His predecessors merely took a sheet, or sheets, and wrote from side to side and from top to bottom, without columns or margins. whereas previously consuls and generals sent their reports written right across the sheet. There are also letters of his to Cicero, as well as to his intimates on private affairs, and in the latter, if he had anything confidential to say, he wrote it in cipher, that is, by so changing the order of the letters of the alphabet, that not a word could be made out. If anyone wishes to decipher these, and get at their meaning, he must substitute the fourth letter of the alphabet, namely D, for A, and so with the others.
56.7
We also have mention of certain writings of his boyhood and early youth, such as the Praises of Hercules, a tragedy Oedipus, and a Collection of Apophthegms but Augustus forbade the publication of all these minor works in a very brief and frank letter sent to Pompeius Macer, whom he had selected to set his libraries in order.
