ROCKS OF SCOTLAND. 317 
1805, Professor Jameson published his “ Mineralogical De- 
scription of Dumfriesshire ;” and to him must be assigned 
the merit of first determining that these ancient schists belong, 
not to the Primary, but to what Werner has termed the 
Transition or Grauwacke Series. He states in this work, 
that he had traced these Transition rocks in Scotland “ from 
the northern extremity of the Pentland Hills, which is about 
six miles distant from the shores of the Frith of Forth, to 
Lang-robie, in Dumfriesshire, about three miles from the Sol- 
way Frith.” We find him, too, giving very correctly the other 
limits of the system as developed in our southern counties, 
and classifying with much precision the mechanical and min- 
eralogical peculiarities of the rocks which compose it. But 
when he comes to speak of its organisms, he is content to dis- 
cuss the subjects in a single sentence, founded apparently, from 
its vague generality, less on his own observations in the field 
which he describes, than on the general conclusions of his 
master, Werner. After stating that “ Transition or Grau- 
wacke slates contain petrifactions,’ whereas “ primitive clay 
slate” does not, he goes on to say that the “ petrifactions found 
in transition rocks are of animals and plants of the lower 
orders, that probably no longer exist on the face of the earth.” 
An anonymous critic, who in the succeeding year, 1806, re- 
viewed his work in a London periodical (the “ Literary Jour- 
nal,”) and who was evidently acquainted with the Grauwackes 
of Dumfriesshire, took up the subject, and regretted that the 
Professor had not been more specific. “Our author might 
have added,” we find him saying, “that vegetable petrifactions 
are very common in the Grauwacke slates of Dumfriesshire. 
The omitting of this circumstance is rather unaccountable,” 
it is added, “as he could not possibly have avoided making 
the observation. He has been very properly punished for 
the omission. The assertion that Grauwacke contains petri- 
2t* 
