Abstract
A method of preparing deaerated aqueous solutions of haematein for kinetic studies is described. By means of solutions prepared by this method, the kinetics of the fading of haematein in aqueous solution have been studied at 25·1°C. Equilibrium is approached by a first‐order reaction which is catalysed by acid. The equilibrium constant at 25·1°C is 8·0; it decreases as the temperature increases.