228 
WERNERIAN SYSTEJI. 
Denomina- 
tions of rocks 
from tli-ir ac- 
tual t>osi‘ion 
may yeiiiaps, 
be tiio most 
eligible. 
derived from theory. But such terms are injurious in propor- 
tion as the speculations with which they are connected are 
erroneous 5 and even in chemistry it will, perhaps, appear 
hereafter, that they have rather assisted in diffusing a brilliant 
system, than advanced the progress of truth. But in geology 
to form a nomenclature upon similar principles, is evidently 
premature; and, in the mean time, such terms circumscribe 
the space through which useful knowledge can be dittused. 
Observations stated in language expressing only facts, are uni- 
versally intelligible ; while the writings of Werner's pupils, 
stamped with his insignia, are restricted to circulation in their 
particular school. 
Perhaps, then, after all, the denominations primary*, secon- 
dary, tertiary, and volcanic, might still be more eligible for the 
classes of rocks. The first term to comprehend the present 
primitive class of Werner, the second his transition, Floetz, 
and newest Floetz-trap rocks ; (in which sense the term jecon- 
dary is used by D’Aubuisson, and other French mineralogists 
of the Wernerian school.) In each of these classes there 
might be a corresponding division into conformable and over- 
lying formations ; and the present Flostz might, if necessary, 
be further distinguished from the transition rocks. The ter- 
tiary class would comprehend the alluvial rocks of Werner, 
and ihev'jlcanic those to which he has given that denomination. 
And further distinctions or subdivisions might be well ex- 
pressed by terms denoting merely order of succession, or well- 
marked circumstances of character and composition. By such 
denominations nothing hypothetic would be implied ; -and if, 
as is asserted, the theory of Werner be truly grounded on the 
phenomena, the arrangement would thus be rendered more 
conformable to it, though freed from the objections involved 
by terms implying such a connection. 
• Without a familiar knowledge of German, it is hazardous to ob- 
serve on terms borrowed from that language. Hut Urgchirge, the 
original name for this class, appears to signify, not primitive, but very 
•Id, of revered antiquity ; in which sense it conics near to j>rimary. 
With 
