Text extracted from opening pages of book: THE ELECTROLYTIC DISSOCIATION THEORY WITH SOME OF ITS APPLICATIONS AX ELEMENTARY TREATISE FOR THE USE OF STUDENTS OF CHEMISTRY CE. E51E INSTITUTE OF TEfiBKO L. IBRARY P1TTS8UB6H, 3y VOW* HENRY P. TALBOT, PH. D. PROFESSOR OF INORGANIC AND ANALYTICAL CHEMISTRY AND ARTHUR A. BLANCHARD, PH. D. ASSISTANT PROFESSOR OF INORGANIC CHEMISTRY AT THE MASSACHUSETTS INSTITUTE OF TECHNOLOGY SECOND EDITION NEW YORK THE MACMILLAN CO. LONDON: MACMILLAN & Co., Ltd. COPYRIGHT 19 3 HENRY P TALKOT AND ARTHUR A BLANCHARD THOMAS TODD CO., PRINTERS 14 BEACON STREET, BOSTON, MASS. PREFACE IN this little treatise the authors have sought to bring together, in small compass, material relating to the Electrolytic Dissociation Theory which is now somewhat widely distributed throughout many of our excellent text books. The method of presentation is that which they have found service able in enabling their students to comprehend the main facts which are today generally accepted as supporting the Theory, and to understand its application to important types of chemical change. While the book has been written primarily for the use of students, the authors have also kept in mind its probable usefulness to the teacher in preparatory school or college, who may desire to gain in a short time an acquaintance with the fundamental facts and principles in this interesting field. In this connection, however, they desire to express their firm convic tion that this Theory should be touched upon in only the most elementary way in the secondary schools; but this does not, of course, make it less necessary that the well-informed teacher should be prepared to meet the inquiries of theoccasional unusually mature and thoughtful pupil. More has been included in this manual than the authors have found it advisable for the college student who is just beginning the study of chemical science to attempt to master, and quite as much as many students who have already had a year of chemical experience in a preparatory school will be able to thoroughly understand. Our experience has shown, however, that it is easier to maintain the interest of the thoughtful pupil if answers to some of the questions suggested to him by the discussions in the main body of the text are placed at his hand, when it is possible to do this without going too far afield. Most of the material of this nature has been printed in smaller type, and may be omitted without loss of continuity; and it is believed that in the course of a year of study the college student ( even the beginner in chemistry, if he has some knowledge of physics) can be brought to under stand the essential principles included in the main text To insure this it is necessary that the instructor should lose no opportunity throughout his course to emphasize the application of a principle, after it has once been introduced. The attempt to present the subject-matter in a simple form, and at the same time to avoid inaccurate statements, has sometimes led to a conflict of ideals, as, for example, in the application of the Law of Mass Action to iv Preface strong electrolytes. Nothing is said in this connection of the unexplained fact that such electrolytes apparently do not rigidly obey this law, since to discuss this topic would seriously complicate an important statement without corresponding advantage. We believe, however, that in suchcases no vio lence has been done to the principles of physical chemistry, and that no impressions have been given which it will be difficult for the student to unlearn if he pursues the subject to its more advanced stages. The application of the ionic theory to indicators has been omitted alto gether, as the present state of our knowledge seems to indicate that compli cated rearrangements of the atoms within the molecules of organic substances are involved, with which it would be beyond the scope of this treatise to deal. In this, the second, edition inaccuracies which h