MS L 378, September 29, 1911. Houghton Library. English translation of Peirce's French. For the original French version, see http://jfsowa.com/peirce/L378.pdf .

pp. 1, 2. Letter from A. Robert to CSP, 3 September 1911.

p. 3. Letter from CSP to A. Robert, 29 September 1911.

L'état de ma santé ne me permet de répondre que brévement á votre lettre. Mes écrits sur la logique et la philosophie, sont les suivants

The state of my health only permits me to reply briefly to your letter. My writings on logic and philosophy are the following

[From here to the end of p 8, Peirce lists various publications. On the right side of pp 9 and 10, and most of the left side of p 10, he summarizes (in French) logic as semiotic: 1. Elements; 2. Critic; 3. Methods of Science.

[The following paragraph begins at the end of the left side of p. 10, and continues on the left side of p. 9.]

To dissect deductions more completely, I use a diagrammatic syntax, which I described very badly and at an intolerable length in the Monist of October 1906, even though I was in possession of this syntax since December 1896. The idea came to me while I was correcting the proofs of my article on The Logic of Relatives in the Monist of January 1897, where there was something similar. This syntax is extremely simple.

[The remainder of the letter (both sides of pp. 11 and 12) contains a brief introduction to existential graphs, written in French. Peirce used the same conventions as L231. His French word for 'shading' is 'ombre' (shadow). Unfortunately, the pencil shading was lost in the microfiche from which the PDF was copied. But the shaded areas can be inferred from his French descriptions.]