Anomalous dispersion of dye solutions observed in a prismatic cuvette

An experimental setup is described which uses a prismatic dye cuvette and a dispersion glass prism. The two prisms are oriented so as to ensure wavelength-dependent deflection in two perpendicular planes. The dispersion of the solvent material was subtracted by using an immersion cuvette filled with the solvent liquid of the dye solution. The setup displays the contribution of the dye material to the refractive index of the solution as a function of the wavelength. The setup is simple, inexpensive, does not use toxic or hazardous materials or high temperature ovens, and thus can be a very useful means to demonstrate the effect of anomalous dispersion at different levels of education.