Papers of John Adams, volume 12
I have not yet been made certain, that you comprehend that Cypher which I used in my Letters to you, and which will yet awhile be used.
You are to form Alphabets equal in number and of the same commencement and Range, as the Letters of the first sixth part of the family Name where you and I supped last with Mrs. Adams, and you are to look alternately into those constructed Alphabets opposite to my figures, for the Elements to spell with, some figures however I may have used as Baulks.1
For Lovell’s previous efforts to explain his cipher, see Lovell to JA, 21 June, and references in note 4 (vol. 11:381–383).