An Account of an Ancient Jar, filled with Mercury, found in a 
Clif near the Sea Shore, at Fetlar, one of the Shetland Islands. 
By Dr Tuomas Wrieut, F.R.S., L. & E., and G.S., Lond., 
one of the Vice- Presidents of the Cotteswold Naturalists’ Club. 
_ The group of Islands comprehended under the general 
name of Shetland, Zetland, Hialtlandia, or the Thule of the 
Romans, exceeds one hundred in number, but of these only 
between thirty and forty are inhabited. These Islands are so 
far separated from the mainland that they have been described 
as the skeleton of a departed Continent, which once occupied 
this region of the North Sea. They lie 15 leagues north-west 
- of Orkney, 47 leagues north of Buchanness (Aberdeen,) 44 
leagues west of Bergen, in Norway, the nearest point of 
Continental Europe. Two of the Islands, Fair Island and 
Foula, are about 20 miles south-south-west, and 117 miles west 
by south of the most contiguous part of the mainland; all the 
others form a compact group, and lie 50° 48’ 30” and 602 52’ 
north latitude, and between 52’ and 1° 57’ longitude west from 
Greenwich. The Islands are chiefly formed of Gneissic rocks, 
associated with other azoic strata, which were disturbed by 
eruptive masses of Granite and Syenite. The Gneiss extends 
from Scalloway Bay through the centre of Mainland and Yell, 
of which it forms the whole to the north of Unst. This 
fundamental rock chiefly consists of Quartz, Felspar and Mica. 
sometimes with Hornblende added, or with Talc in place of 
Mica. It is laminar, and often distinctly stratified, and at 
Lambaness is porphyritic. The strike of the beds is west by 
south. 
The Islands which fall more immediately under our con- 
sideration are two of the most northerly of the group, Unst 
and Fetlar. In the latter Island the Jar which forms the 
subject of our memoir was discovered. Here are zones of rocks 
K 
