He was also appointed Ophthalmologist to the Whitney War Hospital (American Ambulance Hospital B), located on the Marne River. The Whitney Hospital was entirely financed by Gertrude Vanderbilt Whitney, wife of wealthy financier Harry Payne Whitney and Great-Grand Daughter of "Commodore" Cornelius Vanderbilt. The Whitney Hospital which was a branch of the American Ambulance Hospital on the Marne battlefield, during this time. In order to operate at the Whitney War Hospital, he was usually forced to leave Paris at sundown in an unlighted automobile. His vehicle could only be seen by a low red cross on the radiator and he had to drive between the battle's shell holes and debris. Operating was done there at night with inadequate lighting and equipment, and his return trip to Paris was made just before dawn. Dr. Scarlett was also ophthalmologist to the "Phare", a Paris branch of the New York Light House for the Blind, caring for patients blinded by the war.