The oxidation of graphite in air in the presence of 0.1 mole per cent of transition metals and inner-transition metal oxides over the temperature range 600" to 700Β°C has been studied. For the first row transition metais, calcium through zinc, the activation energies are at a minimum for calcium, manganese and zinc. The second row transition metals, strontium through cadmium, show apparent minima in the activation energies for strontium, technetium and cadmium. These minima are typical of the "double humped" curve usually seen for the (n-l)d level in which 0,s and 10 electrons impart unusual stabilities to the divalent state. The third row transition metals, barium through mercury, expectably exhibit no such correlation between activation energy and atomic number. In the case of the first and second row transition metals, it is postulated that the divalent state of the metal enters into the oxidation mechanism of the graphite in a manner similar to that proposed by Long and Sykes. The third row transition metals enter into the oxidation mechanism via their most stable oxidation state, which may not be the divalent state. The addition of the oxides of the lanthanides results in similar trends in that the activation energies are found to be at a minimum for lanthanum, europium, gadolinium, ytterbium and lutetium. These minima are typical of elements possessing a (n -2)f level in which 0, 7 and 14 electrons impart unusual stabilities to the trivalent state for all lanthanides except europium and ytterbium where the divaient state can be stabilized. These metals are postulated to enter into the oxidation mechanism in the Long and Sykes manner via the trivalent state except in the two cases where the divalent state possesses enhanced stability.