Excerpt from The Testing of Chemical Reagents for Purity The necessity of obtaining the highest degree of purity in those reagents which are most largely used in chemical analysis and research, demands a means of speedily recognizing the impurities most often encountered. This means of recognition, together with much general information regarding the various reagents, is afforded in a very comprehensive form by Dr. Krauchs' valuable work, which we present for the first time in English, the translation being that of the third German edition. We have practically adhered to the general arrangement and treatment adopted by the author. We would particularly call the attention of the reader to the fact that, in most instances, reference has been made to English abstracts from the original communications. We have also endeavoured to enhance the value of the book by substituting for the numerous references to German text books on chemical analysis the corresponding English works. We have to acknowledge the valuable aid given by the author himself in supplying us with additions and corrections, the result of his experience since the third German edition was published. The Latin titles of the reagents are those of the Pharmacop a Germanica and have been retained, as they may be of service for the recognition of certain chemicals in price lists. In conducting the various tests, the author emphasises rigid adherence to the degree of concentration, the amount of reagent used and the manner in which the test is to be carried out. Temperatures are, in all cases, given in degrees Centigrade. Finally, our thanks are due to those friends who have assisted us in revising the proofs of this translation. 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."