15.624. Abel, C. D., [Akt.-Ges. fiir Anilin- Fabrikation]. July 13. Aryl-naphthylamine-sulphonic acids.-The acid sodium salt of 1-naphthylamine-4 : 8-disulphonic acid is heated with aniline while stirring with or without benzoic acid or aniline hydrochloride, to 180‹ C. for 30 hours. The mass is made alkaline with sodium carbonate, and the excess of aniline removed by a current of steam. The solution is cooled and filtered, and the 1 : 8-phenylnaphthylamine sulphonic acid is precipitated by the addition of acid. Instead of aniline, ptoluidine may be used, with or without benzoic acid or p-toluidine hydrochloride, the product being then 1 : 8-p-tolyl-naphthylamine-sulphonic acid. In each case, when the condensation takes place, the sulphonic acid group in the position 4 is split off.