Leipzig: Breitkopf und Hartel, 1877. Hardcover. 219pp. Octavo [24 cm], bound in marbled boards over cloth spine (original wraps intact). 3" x .5" abrasion to front board, slight fading to spine, rubbing to extremities, else very light wear; bookplate on front free endpaper, light ink stamp on front wrap, else interior is unmarked. Pages uncut. Text in German. Good. Item #45940
An early work on psychophysics by the man who coined the term.