One day while glancing over some books in a railway station bookstall the attention of one of us was attracted by a book with a shining red cover and a title printed in black and white letters. Suddenly the white letters appeared to rise from the surface of the cover and to float in a limitless red space. Some distance behind the white letters the black ones also floated in this red "mist," and they too seemed to have no contact with the surface of the book. This phenomenon appeared so interesting to us that we decided to investigate it.
Some time afterward we discovered in the literature two references to color stereoscopic phenomena, one by Angelucci and Contino and the other by Donders and Einthoven.
At the meeting of the Societa Italiana di Oftalmologica in 1925, Contino,1 citing Angelucci, described how some artists working in stained glass for
LOEWENSTEIN A, DONALD G. A COLOR STEREOSCOPIC PHENOMENON. Arch Ophthalmol. 1941;26(4):553–564. doi:10.1001/archopht.1941.00870160027002