Abstract It has been shown that glucose and xylose are oxidized completely to formic acid with ceric sulphate and require respectively 12 and 10 equivalents of oxygen per gram mole of the sugar. Under the same conditions, fructose requires 14 equivalents of oxygen per and mole and in this case, the ketonic group is furtlicr oxidixecl to carbon dioxide. The disaceharides can be estimated by the above procedure after hydrolysis.