Reasonably linear correlations have been obtained for spectral lines from different elements in an double-chamber hollow-cathode lamp when the spectral-line intensity-ratio fluctuations are plotted vs. the photon energies and ionization energies of these lines. When these fluctuations are plotted as a function of the upper level energies, no linear relation at all is obtained. The analyses were done by using a computerized image-dissector echelle-spectrometer system.