Last February, while working in the Chemical Laboratory of University College, London, I had occasion to make some sulphanilic acid. This was done in the usual way by heating a mixture of 100 grammes of concentrated sulphuric acid and 30 grammes of aniline to 180°–190° C. in an oil bath for four hours. The flask containing the mixture was left in the oil bath to cool, and on examining it the next day I was surprised to find that the solid mass inside had developed a beautiful spherulitic structure. As I believe this has never been observed before, it may be worth a description.