12: If the original is desired, see Tyndall's "Glaciers of the Alps."
13: Schumann wrote in a letter to Ferdinand Hiller, "We should learn to refine the inner ear."
14: From the sermon entitled "The Seriousness of Life."
15: Notice sometime how many of our English words have the Latin
con.
16: See the fourth chapter of Reuben Post Halleck's "Psychology and
Psychic Culture."
17: For instance, the subject of the C minor Fugue in the first book
of "The Well-tempered Clavicord."
18: The subject of the C sharp minor Fugue.
19: The prelude in E flat minor and the subject of the G sharp minor Fugue.
20: Robert Schumann.
21: Quoted by Xenophon in the "Memorabilia," Book II, Chapter I, Bohn edition.