In the preliminary papers the author reported that the Thoron in thermal water passes throngh the skin and stimulates the subcutaneous connective tissue cells. Sotozono proved that the reduced ascorbic acid content in the blood increases after the Radonspring bath. Before and after thermal bath the author measured the time necessary for the complete decoloration of intradermally injected dichlorphenol-indophenol solution. Compared with the plain water bath at a same temperature, the Thoron spring bath seems to have a tendency to reduce the time necessary for the decoloration.