Samuel Franklin Emmons 



for the formation of those types of 

 granite that pass into gneiss and crys- 

 talline schists of essentially the same 

 chemical composition, but which show 

 no evidence of having been subjected 

 to such excessive heat as would pro- 

 duce liquefaction, he called in the 

 agency of the immense pressure to 

 which such rocks would necessarily 

 have been subjected. While the 

 long years of combined field-work 

 and microscopic study of modern pe- 

 trographers, made since King's theory 

 was enunciated, have proved that the 

 structure of crystalline schists is due 

 to pressure, they do not go so far 

 as he did in assuming- that the end 

 product of such mechanical pressure 

 might be granite. 



Perhaps his most enduring theo- 

 retical discussion of that time was 

 that on hypogeal fusion, in which, 

 accepting the validity of the physical 

 arguments against the fluid interior 

 285 



