An increase in the boiling point of a liquid when a solid is dissolved in it. The elevation is proportional to the number of particles dissolved (molecules or ions) and is given by Δ‎t=k_BC, where C is the molal concentration of solute. The constant k_B is the ebullioscopic constant of the solvent and if this is known, the relative molecular mass of the solute can be calculated from the measured value of Δ‎t. The elevation is measured by a Beckmann thermometer. See also colligative properties.