NUCLEAR MAGNETIC RESONANCE 99 



explained, that the line-breadth diminishes suddenly when the substance 

 melts, and may also decline at one or more temperatures where the sub- 

 stance is still a solid. Such temperatures are considered to be those at which 

 some special type of molecular motion begins. 



References and acknowledgements are to be appended to the second 

 part of this article. Two names will however be mentioned in this place, 

 those of Felix Bloch and Edward M. Purcell; for these are the names of 

 the physicists to whom, on November 6, 1952, was awarded the Nobel 

 Prize for the discovery of nuclear magnetic resonance by the techniques 

 here respectively denoted as those of "nuclear induction" and "nuclear 

 resonance absorption." 



