Abstract: A method and apparatus for producing multi-dimensional measurements of biologically related materials involves radiating samples of the materials with left and right alternating circular polarizations of selected wavelengths. Both light transmissions through the samples and fluorescent light generated by the samples are detected. D.C. components of the transmitted light is used to determine light absorbency and A.C. components and D.C. components are used to determine circular dichroism. The data is displayed in manners to correlate with one another and with time. In this respect, three dimensional plots of a spectrum over a period of time can be obtained.