1. Introduction Coumarin 1 and Sodium fluorescein are two dyes which absorb and emit light in the visible region. By using a spectrophotometer we are recording an absorption spectrum and then determining the molar decadic absorption coefficients, which will be used later to interpret and analyse the fluorescence spectra. For fluorescence spectra, there are two kinds, the excitation and the emission spectrum. The excitation spectrum is obtained by measuring the intensity of the emission as the excitation wavelength is altered by scanning a mon ....