After the discovery of X rays in 1895 it took till 1912 before the experiment by Von Laue showed these rays to be electromagnetic waves with a wave length of appr. 0.1 nm. The diffraction of X rays started with analysis of single crystals to solve their structure, first with ionization chambers, later with photographic recording. Furthermore spectroscopy was used to study the electronic structure using Moseley's law. The introduction of the electronic counters made possible the quantitative diffractometry and fluorescent spectrometry. After their introduction these methods developped very rapidly, both in instruments and applications.
