On the X-Ray Absorption Frequencies Characteristic of the Chemical Elements

Object.—The critical absorption wave-lengths associated with the K series of x-rays have been ${\mathrm{measured}}^2$ for all but two of the known chemical elements from manganese ($N=25\mathrm{}$) to cerium ($N=58\mathrm{}$). The object of the experiments described in this paper was to extend the measurements to chemical elements of higher atomic numbers, using the same x-ray spectrometer.