Abstract
Interest in soft x-ray spectroscopy of solids has seen a sharp revival in the past ten years, and the many advances during that time have been both experimental and theoretical. Following the initial impetus given to the subject in the period from about 1936 to the late 1940's, chiefly by the experimental work of Farineau,1 Skinner,2 and Cauchois,3 coupled with the theoretical groundwork of Mott and Jones,4 the field remained almost static for nearly a decade. Then two largely complementary review articles, by D. H. Tomboulian5 in 1957 and L. G. Parratt6 in 1959, respectively, probably brought the renewal of interest observed in the 1960's and certainly formed a springboard for the steady development of experimental and theoretical techniques that has since occurred. Most of the material in those two surveys remains today as an important framework around which the subject has grown.