superimposed Gaussian curves to 50 percent for peaks poor in all respects. Occasionally there is present an enersy which is too small in photon intensity even for a good estimate to be made as to the quantity. in the appropriate column in Table 2 ence of such an enercy. The symboi70 is used to indicate the pres- More rarely the symbol >>O is used to indicate the presence of an energy too poorly resolved (although not necessaril:y very small in intensity) to warrant an estimated quantitative listing. In some cases there appear to be discrepancies between photon intensities from the same lines taken at nearly the same time for the two gain settings. Most of these inten- sities are not discrepant, however, by much more than the estimated error would allow. In those cases where the dif- ference is too large, the estimated errors should be increased. However, some of the differences seem predominantly one-sided. This inconsistency is especially noticeable for some of the 220 kev lines, i.e.,areas recorded at high gain are lower than comparable areas recorded at standard gain, sometimes by as much as 30 percent. the resolution curves of Fig. 4. This effect appears in For many of the 105 kev lines compared, the effect is reversed, i.e. the areas recorded at high gain are higher than comparable areas recorded at standard gain. It 1s possible to account for the latter r4