W. H. KEESOM and J. DE SMEDT : „On the diffraction of Röntgen- 

 rays in liquids." 



Fig. 2. 

 Oxygen, with Kx-rays of copper. 



Fig. 3. 

 Water, with Kx-rays of copper. 



Proceedings Royal Acad. Amsterdam. Vol. XXV, 1922. 



