Recent studies of electron paramagenetic resonance in γ-irradiated anthracene1–4indicate that the origin of the EPR signal is a radical in which the unpaired electron is coupled to three nearly equivalent protons. Harrah and Hughes2and Inoue3have proposed that the dibenzocyclohexadienyl radical, formed by the addition of one extra hydrogen atom to the 9 or 10 position of an anthracene molecule, gives rise to the observed spectrum. From the annealing kinetics of the EPR signal, McGhieet al.5conclude that a bimolecular reaction is the dominant mechanism for radical recombination.