Fluorescein
C20H12O5. An important dye-stuff, occurring as dark-red crusts, almost insoluble in water, but readily soluble in alkalies and in alcohol. Its alkaline solutions are dark reddish-brown in color, and when diluted name.
FLUTE show a remarkable yellowish-green fluorescence, to which the material owes its It is prepared by heating together phthalic anhydride and resorcinol. As a dye, fluorescein has only a limited application, as the yellow color which it produces on wool and silk is not permanent. It is used largely, however, in admixture with other dyes to produ produce fluorescence in the dyed material. The important dye Eosin is made from fluorescein.