Excerpt from Collected Scientific Papers We wish to acknowledge most warmly the unstinted generosity with which permission to republish the several articles has been given both by joint authors and by the original publishers, including the representatives of the following: The Birmingham Natural History and Philosophical Society. The British Association. 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.