The thermodynamic behaviour and structural evolution of 13 different mixtures of a multiparaffinic wax with a molar concentration distribution of the normal logarithmic type (Prolabo 52-54 degreesC) and (C10H8)-naphthalene were investigated at temperatures ranging from 288.15 to 373.15 K. The wax and (C10H8)-naphthalene are not miscible in the solid state but show co-solubility in the liquid state. The diagram representing the isobaric pseudo-binary (T,x) cross section of the system ((C10H8)-naphthalene + multiparaffinic wax) displays a curve of crystallization which resembles that of a binary eutectic solidification with an invariant temperature T-E = 312.25 +/- 0.7 K; below this TE temperature the equilibrium state corresponds to a two-phase domain containing the solid phases of the two compounds ((C10H8)-naphtalene and multiparaffinic solid solution of wax) separately. (C) 2003 Elsevier Ltd. All rights reserved.