Correspondence — G. M. Davies. 287 



With regard to the angle of the cliff-slope, my observations 

 entirely confirm Mr. Cams Wilson's opinion that the cliffs are 

 steeper now than formerly. 



W. T. Ord, F.G.S. 

 Bramber, 



18 LiTTLEDOWN EOAD, 



Bournemouth, E. 



NOMENCLATUEE OF THE HEAVY LIQUIDS. 



Sir, — In dealing with laboratory methods for the separation of 

 minerals of different densities, some writers speak of Klein's solution, 

 Brauns' solution, Eohrbach's solution, and Sonstadt's (or Thoulet's) 

 solution. Others use the chemical names of the fluids — cadmium 

 borotungstate, methylene iodide, etc. This double nomenclature 

 is confusing and a tax on the memory, and it would be well if one 

 or other set of names were adhered to and the other abandoned. 



In the case of the double iodide solutions, the personal name has 

 the advantage of brevity over the chemical. The desire to give 

 honour where honour is due may also incline some workers to its 

 use. But in this respect we are far from consistent. Bromoform, 

 the most generally useful of all the heavy liquids, might with justice 

 be called Schroeder van der Kolk's liquid. Moreover, Professor 

 Brauns was not the discoverer of methylene iodide, he was merely 

 the first to describe its application to mineralogy ; and some of the 

 other authors have even slighter claims to the liquids with which 

 their names are associated. 



The chief objection to the personal name is that it has no intrinsic 

 relation to the fluid and suggests none of its jDroperties. The 

 chemical name, on the other hand, specifies the composition of the 

 fluid referred to, and so recalls to mind its physical properties. The 

 chemists will not be persuaded to call methylene iodide Brauns' 

 solution, though they are not free from a similar jjractice (e.g. 

 Fehling's solution, Condy's fluid, etc.). It would be a good thing if 

 mineralogists would avoid the needless duplication of names and 

 always use the chemical instead of the personal names for the 

 heavy liquids. 



G. M. Davies. 



17 Elmwood Road, Croydon. 



May d, 1920. 



OBITUARY. 



Walter R. Billings. 



Through the death of Mr. Walter R. Billings, Canada has lost a 

 citizen of unusual attainments. His death occurred at his home in 

 Ottaw^a on March 1, in his 71st year. Mr. Billings was an architect 

 by profession and a pal83ontologist by natural taste and inclination. 



