“ By heating the coloured dimethyl ether with caustic soda, the monomethyl ether is obtained (O. Fischer and E. Hepp, Ber., 1895, 28, p. 397) ; this crystallizes in triclinic tables, and melts at 262° C. It is to be noted that the colourless monomethyl ether fluoresces strongly in alkaline solution, the dimethyl ether of melting point 208° fluoresces only in neutral solution (e.g., in alcoholic solution) , and the dimethyl ether of melting point 198° C. only in concentrated hydrochloric or sulphuric acid solution (Fischer and Hepp) . ”

“ It crystallizes from alcohol in yellowish red needles, and dyes silk, wool, and mordanted cotton a fine pink colour. When heated with caustic alkalis it yields dibromresorcin and dibrommonoresorcin-phthalein. The corresponding iodo compound is known as erythrosin. Fluorescein is readily nitrated, yielding a di- or tetra-nitro compound according to conditions. ”