Chem. [f. FLUORESCE v. + -IN.] A chemical product fluorescent in solution obtained by heating phthalic anhydride with resorcin. Hence Fluoresceic (acid).
1876. Crace-Calvert, Dyeing, viii. 251. Pure Fluoresceïn, C20H12O4, is a red crystalline powder, which is almost insoluble in water or ether, and but slightly soluble in alcohol.
1886. trans. Benedikt’s Coal-tar Colours, 161. All the colouring matters known as eosins are derived from fluoresceïn.
1894. Muir & Morley, Watts’ Dict. Chem., II. 557/1. Fluoresceic acid.
