If a beam of x-rays interacts with a substance, the x-ray beam intensity is attenuated. When this process of attenuation is examined carefully, it is found that several distinct types of interaction can occur, all of which result in a decrease in the intensity of the incident beam of x-rays. The magnitudes of these subinteractions are strongly influenced by (1) the energy of the incident x-ray beam, (2) its degree of monochromatization, and (3) the average atomic number and crystalline structure of the scattering substance. Unfortunately, there is no simple, general "rule of thumb" that adequately describes these interactions if these three variables are allowed to assume their total range of typical values.