NATURAL HISTORY. 
With respect to the red sand stone, we conceive 
the most probable opinion to be, that its origin 1s 
mechanical, and derived from the breaking up of 
goes on to instance this in the Schists of Transition, of 
which he observes that their structure tho’ apparently so 
different from that of porphyry or granite, presents striking 
examples of insensible passages to rocks granular, porpby- 
ritic, or granitoid; at first they become greenish and 
harder, according as the amorphous paste acquires horn- 
blende, it passes to these amphibolic trap rocks formerly 
mistaken for Basalt; in other places, the mica, concealed 
at first in the mass, is developed, and seperates into plates 
distinctly crystallized, at the same time the felspar and 
quartz become visible, and the mass assumes a granular 
appearance with elongated grains, this is a true Transition 
gneiss ; the grains lose by degrees their common direction 
—the crystals are grouped round their several centres, and 
the rock becomes a granite, or transition syenite; in other 
cases the quartz alone is developed augments becomes 
formed into round nodules, and the schist passes toa 
grauwacke very distinctly characterized.” He elsewhere 
observes, “In the Long series of rocks (primitive and 
secondary, )—an assemblage of monuments of different 
Epochas—three very striking phenomena may be distin- 
guished—viz ; the first dawn of organic life on the slobe— 
the appearance of the fragmentary (transition) rocks—and 
the catastrophe which has buried the ancient monocotyle- 
donous vegetation. These phanomena mark the Epocha 
of the intermediary (transition) rocks, and that of the 
coal sand stone, the first member of the secondary recks ; 
but notwithstanding the importance of the Phenomena 
thus remarked, the rocks of one Epocha have always a 
prototype in those of a preceding Epocha, and every thing 
denotes the effect of a continued developement.” 
