178 THE OLD RED SANDSTONE. 
occurs, (for we occasionally meet with wide gaps in the scale,) 
must be buried at an unapproachable depth. It led in 
Scotland —in the northern county of Sutherland —to an 
unprofitable working for many years of a sulphureous lignite 
of the inferior Oolite, far above the true Coal Measures. The 
attempt I have just been describing was made in a locality as 
far beneath them. ‘There is the scene of another and more 
modern attempt in the same district, on the shores of the 
Moray Frith, in a detached patch of Lias, where a fossilized 
wood would no doubt be found in considerable abundance, 
but no continuous vein even of lignite. And it is related by 
Dr. Anderson, of Newburgh, that a fruitless and expensive 
search after coal has lately been instituted in the Old Red 
Sandstone beds which traverse Strathearn and the Carse of 
Gowrie, in the belief that they belong not to the Old, but to 
the Mew Red Sandstone — a formation which has been suc- 
cessfully perforated in prosecuting a similar search in various 
parts of England. All these instances — and there are hun- 
dreds such — show the economic importance of the study of 
fossils. 'The Oolite has its veins of apparent coal on the 
coast of Yorkshire, and its still more amply developed veins 
—one of them nearly four feet in thickness — on the eastern 
coast of Sutherlandshire ; the Lias has its coniferous fossils in 
great abundance, some of them converted into a lignite which 
can scarce be distinguished from a true coal; and the bitu- 
minous masses of the Lower Old Red, and its carbonaceous 
markings, appear identical, to an unpractised eye, with the 
impressions on the carboniferous sandstones, and the bitumi- 
nous masses which they, too, are occasionally found to enclose. 
Nor does the mineralogical character of its middle beds dif- 
fer 1n many cases from that of the lower members of the 
New Red Sandstone. I have seen the older rock in the north 
