Excerpt from A Revision of the Atomic Weights of Sodium and Chlorine The investigation of the atomic weights of the extremely common elements sodium and chlorine was undertaken because of an unac countable discrepancy which appeared in the composition of a sample of very pure sodic bromide, as compared with the results of Stas. This sodic bromide had been prepared for the purpose of determining the transition temperature of its hydrated crystals and a preparation which yielded a constant transition point, therefore giving evidence of great purity, nevertheless possessed a perceptibly lower combining weight than that indicated by Stas's results. Such a discrepancy as this was not to be passed over lightly. It indicated either an unknown constant impurity in our sodic bromide - and hence a possible error in our transition temperature - or else a flaw in the classical work of Stas. When the first cause of disagree ment had been carefully sought in vain, the second was pursued. Thus a physico-chemical investigation demanding great purity of materials led to a quantitative research of unexpected magnitude and in turn this quantitative investigation depended continually upon physico-chemical methods and considerations. In confirmation of previous work at Harvard, it was found that the physico-chemical conditions of experiment were of as serious import as the purity of the materials, and of far greater significance than an increase in the scale of operations. The essential circumstances here defined must receive consideration in any other research of a similar kind. 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.