Nhile working on the condensation of diphenic anhydride with reeoroinol R. B. French **** found that rseorcinol andergoee an autocondensvti on lhen heated with dehydrating agents. The produot obtained in thle condensation he* a prominent green fluorescence which la strikingly similar to that of fluorescein. From the method of condensation it waa assumed that the resulting compound was meta-hydroxy rhenyl ether, and that this substance had fluorescent properties