Elemente of Psychophysics by Gustav Theodor Fechner, second unaltered edition, with notes on the author's later works and a chronologically ordered list of all his works. First part. Leipzig: Breitkopf & Härtel, 1889.Elemente of Psychophysics by Gustav Theodor Fechner, second unaltered edition, with notes on the author's later works and a chronologically ordered list of all his works. First part. Leipzig: Breitkopf & Härtel, 1889.