Previous investigations (1, 2) have shown that when a 1 % buffered glucose solution (pH 7.6) is irradiated with ultraviolet light (1) or X-rays (2) an oxidationreduction system closely similar to ascorbic acid in character is formed, and the irradiated reaction mixture has an ultraviolet absorption spectrum with a maximum at 290 m,j. Irradiated alkaline solutions of a number of hexoses and pentoses exhibit ultraviolet absorption maxima between 265 and 280 miA, according to Laurent and Wertheim (3). On acidification to pH 2, the maxima shift to 245 to 255 my, again indicating a similarity to ascorbic acid. The irradiation reaction has been further investigated (4, 5) for 0.1% solutions of glucose and other monosaccharides in 0.01 M sodium hydroxide. An ultraviolet absorption maximum was found at 267 m,r, with the greatest absorption occurring in those samples which had been irradiated in a nitrogen atmosphere. The amount of reducing sugar remaining after irradiation was measured, and it was also shown that an acid of pKa 4.5 was produced. One-dimensional paper chromatographic analysis of the irradiated solutions indicated the presence of five components other than glucose. On irradiating dilute aqueous solutions of glucose and other monosaccharides with X-rays, Phillips (6) reported that only one product, the corresponding uronic acid, was formed. In the present investigation, attention is centered on the irradiation of glucose solutions with X-rays and with electrons. Series of freshly prepared 0.01 M glucose solutions, both buffered and unbuffered, at initial pH values of 6 to 12, were irradiated with doses ranging from 1 to 107 rads. The irradiated solutions were investigated by means of potentiometric titration, spectrophotometry, and paper chromatography.