The present invention relates generally to an improved method and apparatus for measurement of properties of a sample as a function of temperature. The method and apparatus are based on formation of a stable temperature gradient through the holding fixture such as a cell or a plate containing the sample under study, measurement of the property of interest as a function of position, and relating the positions of the measurements to the temperature of the studied sample at that position. In the preferred application, thermal and thermodynamic properties of solutes are obtained. Provisions are described to combine optical interrogation with Raman spectroscopy. Alternate technique of interrogation is total internal fluorescence reflection. Chemical reaction rates as function of temperature can be advantageously studied including reactions catalyzed by enzymes.