16 Sketch of the Geology of the Arctic Regions. 
_ Von Troil, and analyzed by Dr. Bergman, resemble, with wonder- 
ful exactness, those taken from the volcanos in the south of Europe, 
by Spallanzani.  Suturbrand and limestone are found in small patch- 
es, in different parts of the island. 
The phenomena of the boiling springs, or Geysers, are obviously 
produced by subterranean heat. Columns of boiling water, several 
feet in diameter, spout up many fathoms into the air, and around the 
orifices from which they issue, deposit a portion of silex, of which 
a large amount is held in solution, but released by the cooling of the 
water in its exposure to the atmosphere, forms a mineral basin, 
through which the waters return to the caverns below. Every sub- 
stance near enough to receive a. sprinkling from the spray of the 
Geyser, obtains a flinty covering, similar to ice on the twigs of a bush 
in a winter storm. 
In this realm of fire and snow, some tracts of decomposed lava 
yieldto the arts of agriculture, and are worked into farms: and 
amidst the terrors of earthquakes, volcanic eruptions, sulphurous 
vapor, and -pestilential marshes, the inhabitants of Iceland obtain 
more of the comforts and necessaries of life, than are enjoyed in any 
other country of the arctic regions. 
VIL. Norruern Europe. 
The north of Europe presents an immense exhibition of primitive 
yocks. 
Mr. Strangways* traces this formation from the mountains of Nor- 
wegian Lapland, through Russian Lapland, Finland, the north parts 
of Carelia, Nova Zembla, and the Islands of the Icy Sea to the north- 
erm extremity of the Ural Mountains. It also comprehends the 
whole tract of Sweden ; and its southern boundary passing under the 
«entre of the gulf of Bothnia, as may be seen in the isles of Aland, 
thence by the gulf of Finland, across the northern shore of Lake 
Ladoga to the north part of Lake Onega, continues in the same di- 
co until it terminates in the White Sea. Trap rocks are said to 
3 the north part of this tract; gneiss and other schistose rocks 
aie the central, while the southern border consists exclusively 
of gramite 
* The principal facts in this geological sketch of = aps of Europe, have been 
obtained ine of the y the Hon, Wm. T. H. F. 
Strangways. Published in the Ist Vol. 2d series of in Geological Transactions. 
