Color-vision and color blindness, a practical manual for railroad surgeons (1920)
Jennings, John Ellis · Philadelphia F.A. Davis · leaf 87
idered a safe man for any position loherelie will he required to use colored signals. During the past year T have had four cases whopassed the Holmgren test without difficulty, but whomade so many mistakes with the reds and greens of thelantern as to show that they were unable to distinguish 74…
Color-blindness · Eye
Internet Archive · University of Toronto Libraries · Public Domain Mark 1.0. Free to use for anything.
