When the bromine residue in graphite is heated and cooled between 20" and 900Β°C there is an emission of Brz over certain relatively small temperature ranges on both heating and cooling. It is shown that two of these emissions are associated with observed decreases in X-ray diffraction spacing between carbon layers-one on heating around 175Β°C and one on cooling around 100Β°C. The intercalation isotherms of Br2 and of ICI on graphitized carbon fibers show that the threshold pressure on the residue is lower than on the original fiber. This is believed to be caused in fibers by the production of microscopic cracks in the interlocking amorphous carbon networks between the graphitized domains during the initial intercalation. Hence, when again exposed to Br2 the compresssion-tension builds to a lower value so that the threshold pressure is lower and the rate of intercalation is higher. The anomalous bromine emission behavior in fiber is attributed to differential dimensional changes of the isotropic carbon network and the anisotropic crystallites. In natural graphites the anomalous emission originates in a differential dimensional change between the polycrystalline structure of the total sample of graphite and the anisotropic single crystal components of the graphite.