The research reported in the third volume of Analytical Calorimetry covers a wide variety of topics. The variety indicates the sophistication which thermal analysis is reaching and addition ally the ever widening applications that are being developed, Advances in instrumentation include: microcalorimeter design, development and refinement of titration calorimetry, definition of further theory of scanning calorimetry, studies of the temperature of resolution of thermistors, and a refinement of the effluent gas analysis technique and its application to agricultural chemicals as well as organic materials. A wide variety of applications is reported. These cover the fields of polymeric materials, dental materials, inorganic proteins, biochemical materials, gels, mixed crystals, and other specialized areas. Contributions also include applications of important related techniques such as thermomechanical and thermogravimetric analysis. The contributions to this Volume represent papers presented before the Division of Analytical Chemistry at the Third Symposium on Analytical Chemistry held at the 167th National Meeting of the American Chemical Society, March 30 - April 5, 1974.

Thermal analysis cuts a broad swath through contemporary science. Within this domain, advances in instrumentation permit the application of quantitative calorimetry to the full spectrum of modern materials. This can be illustrated perhaps no better than by the set of contributions which make up this Volume II of Analytical Calorimetry. Comprehensive studies are included on an array of polymers, copolymers, and polyblends. Calorimetry is also reported on biopolymers, gels, liquid crystals, alloys, and on a variety of inorganic compounds and materials including moon rocks. Applica- tions of calorimetric techniques to chemical reaction are also detailed. These include t~e study of decompositions, catalytic reductions, kinetics of dissolution, and the measurement of poly- merization heats as well as the curing of thermosetting resins. The techniques employed are principally differential thermal analysis and differential scanning calorimetry. Several contribu- tors have also illustrated the application of important and related techniques such as thermogravimetry, thermal depolarization analysis, and thermetric titrations. The contributions to this volume represent papers presented before the American Chemical Society Symposium held in Chicago, September 14 and 15, 1970. This symposium 0n Analytical Calori- metry was sponsored by the Division of Analytical Chemistry.

This volume represents a collection of selected papers from a symposium of the Division of Colloid and Surface Chemistry held in Chicago during the national meeting of the American Chemical Society, August, 1973. The response was remarkable to this "By Invitation" symposium on Ordered Fluids and Liquid Crystals. The size alone expresses the growth of the field. The number of contributions assembled here, for example, is approximately twice that at each of the two previous American Chemical Society symposia on this subject. Contributions from eleven countries were presented and this volume contains more than this number of papers from abroad. The increased attention to liquid crystals has brought some interesting trends in the kinds of systems, the experimental methods, and the nature of the lahoratories involved. There has, for example, been an impressive increase in the number of academic studies on liquid crystals. The works herewith published also represent an im pressive variety of traditional and novel eXperimental techniques for the study of liquid crystals. These include rheology, infrared spec troscopy, dielectrics, ultrasonics, pulsed NMR, the Kerr effect, plus thermal and electrical conductivity.

Proceedings of the American Chemical Society Symposium on Analytical Calorimetry San Francisco Cali.

This volume contains papers presented at the Second Symposium on Ordered Fluids and Liquid Crystals held at the 158th National Meeting of the American Chemical Society, New York, Sep tember, 1969. The Symposium was sponsored by the Division of Colloid and Surface Chemistry. The proceedings for the first symposium on this subject were published by the American Chemical Society in the Advances in Chemistry Series. In the preface to the volume for the first meet ing held four years ago, we noted that research on liquid crystals had gone through tremendous fluctuations, with peaks of activity around 1900 and again in the early 1930's. The present period of high activity which started about 1960 has continued to exhibit acceleration. The reason for the persistent growth in the field is due to the increasing recognition of the important role played by liquid crystals in both biological systems and in items of commerce as diverse as detergents and electronic components. Addi tionally, more powerful and sophisticated instrumentation is pro viding a basis for understanding the properties of the liquid crystalline state as weIl as yielding inc~s~ve tests for the theories of mesophase structure which are only now reaching astate of maturity. Julian F. Johnson Roger S. Porter v CONTENTS Thermal Phase Transitions in Biomembranes * . * * * * * . * * 1 Joseph M. Steim Conditions of Stability for Liquid-Crystalline Phospholipid Membranes .