Abstract
The Kβ lines of 26 Fe—30 Zn from the sulfides of those metals have been studied in fluorescence with a focusing crystal spectrograph of the Johansson type. The only lines showing a shift from their position in the spectra of the pure metals are the Kβ5 lines of Fe and Ni. Calculation of the second ionization potential of Cu by application of Pauling's theory gave a value much too high The term values of the levels in which the Kβ5 has its origin, for Fe, Co and Ni in the sulfides, were somewhat larger than in the pure metal, whereas for Cu and Zn they were about the same.