IN the course of investigating the radioactivity induced by the neutron produced by the bombardment of diplogen with diplons, we observed that the yield of radio-element produced in silver increases by a factor of about ten when the sample of silver was surrounded by a layer of paraffin 3.5 cm. in thickness during the exposure, showing the Fermi proton effect. The decay curve obtained with the Geiger counter is shown in Fig. 1, which suggests the fact that it cannot be expressed by a single exponential curve. The apparent value of half-period is about 30 sec. at the beginning, becoming approximately 2 minutes at 4 minutes after the bombardment ceased.