Produced by Elaine Walker, Josephine Paolucci and the Online Distributed Proofreading Team at http://www.pgdp.net AN ELEMENTARY STUDY OF CHEMISTRY BY WILLIAM McPHERSON, PH.D. PROFESSOR OF CHEMISTRY, OHIO STATE UNIVERSITY AND WILLIAM EDWARDS HENDERSON, PH.D. ASSOCIATE PROFESSOR OF CHEMISTRY, OHIO STATE UNIVERSITY _REVISED EDITION_ GINN & COMPANY BOSTON * NEW YORK * CHICAGO * LONDON COPYRIGHT, 1905, 1906, BY WILLIAM MCPHERSON AND WILLIAM E. HENDERSON ALL RIGHTS RESERVED The Athenaeum Press GINN & COMPANY * PROPRIETORS * BOSTON * U.S.A. Transcriber's note: For Text: A word surrounded by a cedilla such as ~this~ signifies that the word is bolded in the text. A word surrounded by underscores like _this_ signifies the word is italics in the text. The italic and bold markup for single italized letters (such as variables in equations) and "foreign" abbreviations are deleted for easier reading. For numbers and equations: Parentheses have been added to clarify fractions. Underscores before bracketed numbers in equations denote a subscript. Superscripts are designated with a caret and brackets, e.g. 11.1^{3} is 11.1 to the third power. Appendix A and B have been moved to the end of the book. Minor typos have been corrected. PREFACE In offering this book to teachers of elementary chemistry the authors lay no claim to any great originality. It has been their aim to prepare a text-book constructed along lines which have become recognized as best suited to an elementary treatment of the subject. At the same time they have made a consistent effort to make the text clear in outline, simple in style and language, conservatively modern in point of view, and thoroughly teachable.