"Mr. Donnelly's Cipher: A Paper Read By R.M. Theobald To The Bacon Society" delves into the intriguing world of codes and ciphers, specifically focusing on Ignatius Donnelly's attempts to prove that Francis Bacon was the true author of Shakespeare's works. Robert Masters Theobald, a prominent figure in the Bacon Society, critically examines Donnelly's methods and conclusions in this paper.