Structured Table of Contents for John Wilkins' Mercury

In 1641, just before the outbreak of the English Civil War, John Wilkins (1614-1672) published Mercury or the Secret and Swift Messenger, the first book on cryptology written in English. As noted in the title page, the book shows "how a man may with privacy and speed communicate his thoughts to a friend at any distance."

What is commonly called cipher/code today is described in chapters 6-9 and 11. While politicians and diplomats at this tumultuous age used numerical ciphers that represent letters or words by two- or three-digit figures (see Ciphers during the Early Reign of Charles I before the Civil War for ciphers in 1630s and King Charles I's Ciphers and Codes and Ciphers of Thurloe's Agents for 1640s-1650s), Mercury is not directed to such actual ciphers then in practice. While numerical ciphers may in principle belong to substitution ciphers described in Chapter 7 or 11, Mercury does not mention them.

Besides such orthodox ciphers, known seventeenth century ciphers include "Trevanion's cipher" (whose principle is mentioned in Chapter 8; see another article) and "Argyll's cipher" (whose principle is mentioned in Chapter 6; see another article), though there is no evidence that these ciphers were taken from Mercury.

Text of Mercury:

Structured Table of Contents

1. Secrecy

2. Swiftness

3. Joining secrecy and swiftness

©2012 S.Tomokiyo
First posted on 5 October 2012. Last modified on 5 October 2012.
Articles on Historical Cryptography
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