Frake, a tropical wood species from Cameroon, was reacted with 1% periodic acid solution at room temperature for 24 h. Untreated and treated woods were analyzed by ESCA. As expected, O1s and C2s were the predominant species in the spectra. While the O1s peak is featureless, the C1s peak can be decomposed into several components. These contributions were calculated, and it was observed that untreated and treated woods exhibit carbon atoms in classes C1 (carbon atoms bonded by a C - C or a C - H bond), C2 (carbon atoms bonded by a C - 0 bond), and C3 (carbon atoms bonded by a C=O or by a 0 - C - 0 bond). Class C4, which refers to carbon atoms bonded by 0 - C=0 bonds, is completely absent. The periodic acid treatment produces a reduction in C1, an increase in C2, with C3 remaining relatively small. Accordingly, the expected oxidation of hydroxyl groups to carbonyl groups is not observed. It can be postulated that wood-periodic acid intermediates, which are believed to be cyclic periodic esters, do not decompose to form carbonyl groups but rather remain as stable complexes.