Note 58 — LETTERS AND PAPERS ON PHILOSOPHICAL SUBJECTS. (continued 6)
Reading edition
"It may be just remarked here, that upon comparing these proportions with those arising from the common divisions of the monochord, it happens that the first answers to unisons, and although the second is a discord, the third answers to the third minor, the fourth to the third major, the fifth to the fourth, the sixth to the fifth, and the seventh to the octave." Nutshells, page 85.