THE ELEMENTS OF QUALITATIVE CHEMICAL ANALYSIS WITH SPECIAL CONSIDERATION OF THE APPLICATION OF THE LAWS OF EQUILIBRIUM AND OF THE MODERN THEORIES OF SOLUTION BY JULIUS STIEGLITZ ‹Professor of Chemistry in the University of Chicago› VOLUME I PARTS I AND II FUNDAMENTAL PRINCIPLES AND THEIR APPLICATION [Illustration] NEW YORK THE CENTURY CO. 1920 COPYRIGHT, 1911, BY THE CENTURY CO. ‹Printed, October, 1911› ‹Reprinted, August, 1912› ‹Reprinted, October, 1913› ‹Reprinted, October, 1915› ‹Reprinted, August, 1917› ‹Reprinted, January, 1919› ‹Reprinted, August, 1919› ‹Reprinted, November, 1919› ‹Reprinted, July, 1920› PREFACE In venturing to add another book on Qualitative Chemical Analysis to the long list of publications on this subject, the author has been moved chiefly by the often expressed wish of students and friends to have his lectures on qualitative analysis rendered available for reference and for a wider circle of instruction. Parts I and II of the present book embody these lectures in the form to which they have developed in the course of the last sixteen years, since, in 1894, the teaching of analytical chemistry, along the lines followed, was first suggested by Ostwald's pioneer "Wissenschaftliche Grundlagen der Analytischen Chemie." The author believes that instruction in qualitative analysis, besides teaching analysis proper, should demand of the student a very distinct advance in the study of general chemistry, and should also, consciously, pave the way for work in quantitative analysis, if it is not, indeed, accompanied by work in that subject. The professional method of work, whether routine or research work of the academic or the industrial laboratory is involved, inevitably consists in first making an exhaustive study of the ‹general chemical› aspects of the subject under examination: it includes a thorough study of books of reference and of the original literature on the subject; and when the experimental work is finally undertaken, it is carried out with a critical, searching mind, which questions every observation made, every process used. The method of instruction in this book aims at developing these habits of the professional, productive chemist. For the reasons given, a rather thorough and somewhat critical study is first made (in Part I) of the fundamental general chemical principles which are most widely involved in analytical work. The applications of these principles to the subject matter of elementary qualitative analysis are then discussed (in Part II), in closest connection with the laboratory work covering the study of analytical reactions (in Part III). The material is presented, not as a finished subject, but as a growing one, with which the present generation of chemists is still busy, and which contains many important, unsolved problems of a fundamental character. Numerous references to standard works and to the current literature are given, of which those