Ahstraet-Adsorption from binary solutions of methanol in benzene has been studied on a few samples of sugar charcoal and a PVC charcoal associated with varying amounts of combined oxygen. The presence of associated oxygen enhances the preference for methanol. The thickness of the adsorbed layer is more than unimolecular in case of the oxygen containing samples and unimolecular for the sample containing no oxygen. This indicates that there is spectic adsorption of methanol at oxygen containing sites on the charcoal surface where it could be more strongly held by chemical or quasichemical forces involving hydrogen bonding. The physisorbed and chemisorbed methanol has been separated by "alkylating" the charcoal surface on treatment with the more polar component of the mixture and redetermining the composite isotherms. The pretreated samples do not chemisorb any methanol. Their linear portions have been used to calculate the specific surface areas of carbons. These surface areas agree very closely with their BET(NJ surface areas as well as with the CO, surface areas calculated from Polanyi-Dubii equation. Thus it gives a new method for measuring the surface areas of micro-crystalline carbons.