Abstract
Measurements of emission wave-lengths in the Kβ group of Ca and S in CaS and CaSO4, of Mg and S in MgS, of S in SrS and BaS, of Ca and Cl in CaCl2 have been made from the secondary radiation from pressed blocks of the salts. An attempt is made to determine the origin of as many x-ray lines as possible by means of electronic energy band systems in the cases of CaS, MgS, and ZnS. The Kβ5 line of Zn in ZnS and the Kβ1 line of Mg in MgS are found to be due to cross transitions from the outermost filled band of the negative ion.