Hooke owned a number of books on cryptography, a topic in which he had a special interest. Given the limitations of this database, you'd need to search for 'cry

Hooke owned a number of books on cryptography, a topic in which he had a special interest. Given the limitations of this database, you'd need to search for 'crypto', 'stegano', 'trithem', etc. to see which ones. In a lecture he gave in 1690, he suggested that John Dee's conversations with angels may have been steganographical messages enciphered according to the methods of Johann Trithemius ('Of Dr. Dee's Book of Spirits' in the Posthumous Works, 1705) -- always wondered whether he was right!