Inside a 1904 scrapbook related to the Girls Department at the Perkins Institution in South Boston the Archives staff was pleased to find that photographs pasted into the pages had duplicated themselves! A clear copy of the images transferred to the opposite page of the book through a damaging process called acid migration or acid transfer.
Over time as acidic lignin found in paper oxidizes, it creates yellow and embrittled pages. The transferred image is surprisingly detailed and accurate like a reflection on a still body of water.
Open book with black and white photograph of a girls' gymnastics class. Edith Thomas, who is deafblind, stands at center in front of a low bar. Several other girls climb on a gridded apparatus hanging from the ceiling. Opposite page shows a shadowy yellow-brown mirror image of the photograph.