Excerpt from Proceedings of the American Academy of Arts and Sciences, Vol. 39: From June, 1903, to June, 1904 The first problem to be solved was the preparation of chromic sulphate in a pure state on a scale large enough to supply plenty of material for the research. The sulphate was chosen for the research because when once converted into the green mixture, it regains its violet condition far more slowly than almost any other salt. Thus more time is available in which to study the green solution. This very fact, however, introduces a serious difficulty into the original preparation of the violet material, which is much hydrolyzed by a very moderate rise in temperature. 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.