Volume IV/7 "Liquid Crystals" is devoted to critically selected and assessed fundamental data, mainly transition temperatures, which characterize the existing liquid crystalline phases and states of a large number of compounds. Due to the technical importance of liquid crystalline materials and its unique properties an intensive interdisciplinary research has been performed during the last decades. As a result a fast growing number of liquid crystalline compounds - from 14.000 in 1982 to about 50.000 in 1992 - were detected and the corresponding physical, chemical and biochemical properties were investigated extensively. All relevant references including the very important patent literature and data (1850-1991) were collected in the data base LIQCRYST, which has been built up at the Hamburg university sponsored by Springer Verlag and Ministry of Science and Technology, Bonn. The present Volume IV/7 has been derived from LIQCRYST by an individual critical choice of compounds, references and data. It has not been designed to compete with future Online (STN) and CD-ROM database versions of LIQCRYST. On the contrary the width of individual information available there is intended to be complemented by the advantage of printed tables, which offer an overall picture of the liquid crystalline field. Furthermore the comparison of corresponding data and perhaps the elucidation of structure-function relationships is facilitated, whereas the data base allows a facile access to any substructure and property search.