Dumas’ Cipher — Benjamin Franklin's Favorite Cipher
Franklin's letter to Dumas dated April 30, 1776
This passage is taken from the introduction Dumas wrote of a book he sent to Franklin: Emerich de Vattel’s Le droit des gens (Law of Nations). Dumas had reprinted this work with his introduction and notes that applied its principles to the situation in America and had sent three copies to Franklin in 1775 (Franklin acknowledges it in his letter of December 19, 1775).
Since Dumas’ cipher is based on a passage in French, each letter has as many homophones as proportional to its frequency in French and K and W, not used in French, are not assigned a number. While the table illustrated above shows numbers 684-694 for W, these are struck out with a note “make use of two vs”. As for K, there is an instruction “use C”.
I saw that up thread, thanks, that was a good find!