both fluoresceins give the same yellow colour in saturated solution and the results just reported for the ph of minimum solubility and for the dissociation constants also indicate that for each of the three prototropic forms of fluorescein present in solution , h ( 3 ) fl ( + ) , h ( 2 ) fl , and hfl ( - ) , only one structure exists .
C0016314
fluoresceins
C0060520
fluorescein