322 ON THE ANCIENT GRAUWACKE 
has been seen and in part corrected; and the future of Scotch 
Geology bids fair to be characterized by the doing of more 
and the saying of less. 
In the same year in which Mr. Maclaren published his 
“ Geology of Fife and the Lothians,” the “Silurian System” 
of Sir Roderick Murchison appeared,—one of those great 
works which form eras in the history of science, and from 
which, as from the charts of some distinguished voyager, after 
explorers have learned to shape their course aright, and to 
recognize as familiar and easily definable, tracts previously un- 
named and unknown. In both the old world and the new, 
the great divisions first laid down in this work by Sir Rode- 
rick have been detected and identified, and an introductory 
book added to the organic history of our planet, from the rich 
and varied materials which they supply. For, however, sev- 
eral years after its publication, our Scottish Grauwacke con- 
tinued to remain a terra incognita, as before ; for though there 
appeared from time to time truthful descriptions of the de- 
posit itself, its place in the scale was still doubtful. Two 
years after (1841), Mr. James Nicol,—now Professor of Ge- 
ology in Queen’s College, Cork — produced his Prize Essay 
on the Geology of Peeblesshire ; and to an accurate descrip- 
tion of the mineralogical components of the Grauwacke of 
that county added a new locality for its fossils, in Grierston, 
near Traquair, where, in a slate quarry, there occur thin but 
continuous layers of graptolites, often in a state of the most 
exquisite keeping. Some of the finest Scottish specimens of 
this ancient organism which I have yet seen I have derived 
from this Grierston deposit. We also find Mr. Nicol refer- 
ring, in his Essay, to that limestone quarry of Wrae Hill in 
which Sir James Hall had found his fossil shells ; but its 
lime, when he wrote, had been exhausted, or so covered up 
by the rubbish of the workings, that its organisms could be 
