Volume IV/18 is divided into two subvolumes. Subvolume IV/18 A contains the viscosities of pure organometallic and organononmetallic liquids and binary liquid mixtures. Subvolume IV/18 B contains the viscosities of pure organic liquids. The author and the editor have decided to establish selected data by avoiding long lists of viscosities for one system with respect to the printed version of this volume. The electronic version provided on the CD-ROM contains the complete data.