Excerpt from The British and Colonial Printer and Stationer, Vol. 86: February 19, 1920 Esparto papers, he said, if exposed to an atmosphere in which there were gas tar pro ducts, became pink at the edges. Careful storing was therefore essential. Acid paste or glue might affect colours in cases where ultra marine or some other metallic pigments were used. He mentioned a curious case of paper discolouration in which bright yellow paper held in stock a long time was found to have turned black at the edges. On a claim being made to the firm supplying the paper, an ex pert chemist was sent to investigate, and his experiments led to the discovery that dis colouration was due to the presence of a drain near the stock-room, the fumes acting chemi cally on the paper. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.