The optical absorption characteristics of GeC14, both with and without free germanium present in the system, have been studied for the wavelength region between 2300Å and 2μ,. Pure GeCl4 was found to have a dissociation continuum with the long wavelength edge beginning at 2700Å at a temperature of 150°C. When free germanium was added to the system, GeC14 was found to react with it to give rise to one or more species, depending on whether or not the molar quantity of free germanium was greater than that of GeCl4. It has also been observed that GeC12 has a strong absorption band witha peak at 3150Å. © 1966, The Electrochemical Society, Inc. All rights reserved.