Remarks on the Transition Rocks of Werner. 17 
other members of the series were composed of fragments, 
which must have existed previously in a different state: 
hence he inferred that these rocks were formed at a sub- 
sequent period, which, from their constituent parts, he 
concluded, must have been after the creation of living ani- 
mals, and nearly at the time when the earth passed from its 
chaotic to its habitable state*; and on these grounds he 
distinguished this class by the name of Transition. 
To this another class succeeded, also presenting new and 
distinct characters, one of the most remarkable of which is 
position, They are never found conformable with the 
transition rocks: while these present an uneven or serrated. 
outline, either from the natural contortions of the strata, or 
the broken edges of the highly inclined beds; the rocks 
which succeed fill up the inequalities, and assume an ho- 
rizontal position. To them he gave the naine of fleetz 
rocks. 
Thus the system is divided into three great classes—the © 
primitive, transition, and floetz. 
Although the transition has been known in this country 
as a separate class, only within a few years, yet it occupies 
a larger superficial extent in these islands than any other 
rock-formation. But before I proceed to trace its limits, 
it may be proper to explain what is understood by the 
transition series. 
In doing this, and indeed in whatever else I have stated 
with respect to the Wernerian geognosy, I beg to be un- 
derstood as having taken it from that work, which I con- 
sider as containing the most authentic account of the sy- 
stem taught at Freyberg; 1 mean the third volume of Pro- 
fessor Jameson’s Mineralogy. As Werner has published 
no account of it himself, it is only from the works of his 
pupils that we can become acquainted with his system. 
After the intense labour which has been bestowed on 
bringing it forward, it cannot be supposed to contain any 
errors, according to the strict notions of Werner; and it 
his pupils find it necessary to introduce any material altera- 
tions, and so to mould it as to suit their own subsequent 
observations, it will no longer be the system of that philo- 
sopher,—which the arguments in the present paper are 
alone intended to meet. 
The transition series is composed of limestone, grau- 
* Jameson’s Mineralogy, vol. iii. p. 146. ) 
++ Werner, “after the most ardyous and long-continued investigation, 
conducted with the most consummate address, discovered the general struc« 
ture of the crust of the globe,” &c.---Jameson’s Mineralogy, vol, iii. p. 42. 
Vol. 42. No. 183, July 1813, B wacke, 
