Interaction of X-rays with Bound Electrons

I. Change of wave-length of scattered x-rays. A previous analysis of scattered x-rays in this laboratory by means of the double crystal spectrometer showed fine structure in both the unmodified and modified lines. These fine structure lines were interpreted as being due to absorption of an amount of energy equal to the binding energy of the electrons in the scattering substance. Since then, other experimenters have failed to observe this phenomenon in scattered x-rays. The earlier work has been repeated using measuring apparatus having greater stability and sensitivity but with experimental conditions for producing the scattered radiation as nearly as possible like those of the earlier experiments. No fine structure was found though a line of intensity greater than 10 percent of molybdenum $\mathrm{K}{\alpha }_1$ unmodified could have been detected.