260 T. S. Hunt on Lithology. 
or crystals; while in some 
in Spain, described by Fournet as passing from a dull rough 
grayish feldspathic mass, into a highly crystalline aggregate of 
Teneriffe as trachytes, (Comptes Rendus, xliv, 1067); sot at this 
word, like porphyry, comes to indicate nothing more than yet 
sition; and their differences in texture probably depend pa : 
fact that _ one was solidified under great peer The 
other near the surface, trachytes ing in fact into Ja’ a 
observations of Sorby on the fluid-cavities in the crystals ¥ 3 
granite and trachyte are in point. : 
