E-text prepared by Juliet Sutherland, Keith Edkins, and the Online Distributed Proofreading Team (http://www.pgdp.net) Note: Project Gutenberg also has an HTML version of this file which includes the original illustrations. See 34457-h.htm or 34457-h.zip: (https://www.gutenberg.org/cache/epub/34457/pg34457-images.html) or (https://www.gutenberg.org/files/34457/34457-h.zip) Transcriber's note: Page numbers enclosed by curly braces (example: {25}) have been incorporated to facilitate the use of the Table of Contents. In chemical formulas an underscore is used to indicate that the following number enclosed by curly braces is a subscript. For example, the formula of water is indicated by H_{2}O. A carat character followed by a number enclosed by curly braces indicate an exponent. For example, ten raised to the minus 7th power is indicated by 10^{-7}. A few typographical errors have been corrected and are listed at the end of the text. THE PHASE RULE AND ITS APPLICATIONS by ALEX. FINDLAY, M.A., PH.D., D.SC. * * * * * TEXT-BOOKS OF PHYSICAL CHEMISTRY. EDITED BY SIR WILLIAM RAMSAY, K.C.B., F.R.S., D.SC. * * * * * STOICHIOMETRY. By SYDNEY YOUNG, D.Sc., F.R.S., Professor of Chemistry in the University of Dublin; together with an INTRODUCTION TO THE STUDY OF PHYSICAL CHEMISTRY by Sir WILLIAM RAMSAY, K.C.B., F.R.S., Editor of the Series. Crown 8vo. 7s. 6d. AN INTRODUCTION TO THE STUDY OF PHYSICAL CHEMISTRY. Being a General Introduction to the Series by Sir WILLIAM RAMSAY, K.C.B., F.R.S., D.Sc. Crown 8vo. 1s. net. CHEMICAL STATICS AND DYNAMICS, including THE THEORIES OF CHEMICAL CHANGE, CATALYSIS AND EXPLOSIONS. BY J. W. MELLOR, D.Sc. (N.Z.), B.Sc. (Vict.) Crown 8vo. 7s. 6d. THE PHASE RULE AND ITS APPLICATIONS. By ALEX. FINDLAY, M.A., Ph.D., D.Sc., Lecturer and Demonstrator in Chemistry, University of Birmingham. With 134 Figures in the Text. Crown 8vo. 5s. SPECTROSCOPY. By E. C. C. BALY, F.I.C., Lecturer on Spectroscopy and Assistant Professor of Chemistry, University College, London. With 163 Illustrations. Crown 8vo. 10s. 6d. THERMOCHEMISTRY. By JULIUS THOMSEN, Emeritus Professor of Chemistry in the University of Copenhagen. Translated by KATHARINE A. BURKE, B.Sc. (Lond.), Assistant in the Department of Chemistry, University College, London. Crown 8vo. 9s. ELECTRO-CHEMISTRY. PART I.--GENERAL THEORY. By R. A. LEHFELDT, D.Sc., Professor of Physics at the East London Technical College. Including a Chapter on the Relation of Chemical Constitution to Conductivity, by T. S. MOORE, B.A., B.Sc., Lecturer in the University of Birmingham. Crown 8vo. 5s. PART II.--APPLICATIONS TO ELECTROLYSIS, PRIMARY AND SECONDARY BATTERIES, etc. By N. T. M. WILSMORE, D.Sc. [_In the press._