Note 17 — Chapter I · A SHORT HISTORY OF METAGEOMETRY.
Reading edition
On the history of this word, see Stallo, Concepts of Modern Physics, p. 258. It was used by Kant, and adapted by Herbart to almost the same meaning as it bears in Riemann. Herbart, however, also uses the word Reihenform to express a similar idea. See Psychologie als Wissenschaft, I. § 100 and II. § 139, where Riemann's analogy with colours is also suggested.