The Philosophical Review/Volume 1/Summary: Brodhun - Ueber die Empfindlichkeit des grünblinden
The earliest investigators had found that the eye was most sensitive to change of color near the D line of the spectrum (yellow). Next to this came the region near the F line (blue). Later, König and Dieterici found the maximum sensitiveness just left of the F line. Using an apparatus in which the adjacent spectra compared were produced by an equilateral flint-glass prism, the author compares his green-blind eye with A. König's normal eye. The method of mean errors was used, and for each region of the spectrum investigated fifty adjustments were made. B. found first that the greatest sensitiveness to difference for his green-blind eye was slightly to the left of the maximum for normal eyes, i.e. to the left of F; left from the maximum, the green-blind eye shows more sensitiveness than the normal, but then decreases rapidly, while the normal eye shows a second maximum in the yellow. Surmising that another small increase in the curve of sensitiveness beyond the F line was due to change in intensity rather than quality of light, B. varied the brightness of the fields of color. For both the normal and the green-blind eye the slight increase beyond F disappeared, while throughout the observed range of colors the sensitiveness became somewhat less. Similar results were found by W. Uthoff (Gräfes Archiv, 1888, Bd. 34), who used the method of minimal changes.